@article{cook_fox_allen_cohrs_ribas-costa_trlica_ricker_carter_rubilar_campoe_et al._2024, title={Forest soil classification for intensive pine plantation management: "Site Productivity Optimization for Trees" system}, volume={556}, ISSN={["1872-7042"]}, DOI={10.1016/j.foreco.2024.121732}, abstractNote={Forest productivity and response to silvicultural treatments are dependent on inherent site resource availability and limitations. Trees have deeper rooting profiles than agronomic crops, so evaluating the impacts of soils, geology, and physiographic province on forest productivity can help guide silvicultural management decisions in southern pine plantations. Here, we describe the Forest Productivity Cooperative’s “Site Productivity Optimization for Trees” (SPOT) system which includes: texture, depth to increase in clay content, drainage class, soil modifiers (i.e., surface attributes, mineralogy, and additional limitations such as root restrictions), geologic formations, and physiographic province. We quantified the total area for each SPOT code in the native range of loblolly pine (Pinus taeda L.), the region’s most commercially important species, and used a remotely-sensed layer to quantify SPOT code areas in managed southern pine (approximately 14 million ha). The most common SPOT code in the native range is also the most planted, a B2WekoGgPD (fine loamy, shallow depth to increase in clay, well-drained, eroded, kaolinitic, granitic, Piedmont soil), spanning 1.1 million ha total, but only 12% in managed southern pine. However, the SPOT code with the greatest percentage of managed southern pine (61%; a D4PoioAmAF, spodic, deep to increase in clay, siliceous, middle Atlantic Coastal Plain, Flatwoods soil) was the 20th most common in the native range with 474,662 ha. We used machine learning and data from decades of “Regionwide” trials to assess the variable importance of SPOT constituents, climate, planting year, and N rate on site index (base age 25 years) and found that planting year was the most important variable, showing an increase of 17 cm site index per year since 1970, followed by maximum vapor pressure deficit, and precipitation. Geology was the top-ranking SPOT variable to explain site index followed by physiographic province. The Regionwide trials represent 72 unique SPOT codes (out of over 10,000 possible in the pine plantations) and approximately one million ha (or about 7% of all soils identified as supporting managed pine). To extrapolate site index values outside of the unique soil and geologic conditions empirically represented, we created a predictive model with an R2 of 0.79 and an RMSE of 1.38 m from SPOT codes alone. With this extrapolation, the Regionwide data predicts 10.5 million ha, or 74%, of all soils under loblolly pine management in its native range. Overall, this system will allow managers to assess their current site productivity, and recommend silvicultural treatments, thus, providing a framework to optimize forest productivity in pine plantations in the southeastern US.}, journal={FOREST ECOLOGY AND MANAGEMENT}, author={Cook, Rachel and Fox, Thomas R. and Allen, Howard Lee and Cohrs, Chris W. and Ribas-Costa, Vicent and Trlica, Andrew and Ricker, Matthew and Carter, David R. and Rubilar, Rafael and Campoe, Otavio and et al.}, year={2024}, month={Mar} }
 @article{rubilar_bozo_albaugh_cook_campoe_carter_allen_alvarez_pincheira_zapata_2023, title={Rotation-age effects of subsoiling, fertilization, and weed control on radiata pine growth at sites with contrasting soil physical, nutrient, and water limitations}, volume={544}, ISSN={["1872-7042"]}, DOI={10.1016/j.foreco.2023.121213}, abstractNote={Although short- and medium-term responses to early silvicultural treatments have been documented, few studies show productivity gains or losses throughout a rotation across a range of soil types and resource availability. We evaluated the rotation length productivity responses of radiata pine to subsoiling, fertilization, and weed control in dry sand (DS), red clay (RC), and recent volcanic ash (RV) soils representing a gradient of physical, nutrient, and water limitations. Stands were planted in 2000 in a split-plot factorial design, with soil preparation (subsoiling vs. shovel planting) as the main plot and fertilization at planting (B only vs. NPKB) and weed control (none vs. 2-year banded application) as factorial randomized treatment plots within the main plots. Annual diameter at breast height, height, survival, and cumulative volume responses were measured. The rotation-age results for cumulative volume showed that early gains from weed control were maintained through at least 15 years of age. At rotation age, weed control increased the cumulative volume at the DS site (56 m3/ha, 20% gain), and the response over time was maintained at the RC site (28 m3/ha, 8% gain), whereas the volume was reduced at the RV site (-36 m3/ha, 7% loss). Fertilization resulted in the greatest response at the RC site (29 m3/ha, 8% gain); there were small responses at the DS site (5 m3/ha, 2% gain) and negative responses at the RV site (-18 m3/ha, 4% loss). Interestingly, subsoiling resulted in null or negative responses at all sites, and negative effects increased over time, with volume responses ranging from −4 m3/ha (1% loss) and −27 m3/ha (7% loss) at the DS and RC sites, respectively, to −116 m3/ha (21% loss) at the RV site. Carrying capacity was reached at mid-rotation at the RV site and resulted in negative treatment effects at rotation age, suggesting the need for thinning or a younger harvest age at this site. Given the negative or null effects of soil preparation, a better understanding is needed for how this silvicultural treatment is affected by soil type and soil strength.}, journal={FOREST ECOLOGY AND MANAGEMENT}, author={Rubilar, Rafael and Bozo, Daniel and Albaugh, Timothy and Cook, Rachel and Campoe, Otavio and Carter, David and Allen, H. Lee and Alvarez, Jose and Pincheira, Matias and Zapata, Alvaro}, year={2023}, month={Sep} }
 @article{scolforo_montes_cook_allen_albaugh_rubilar_campoe_2020, title={A New Approach for Modeling Volume Response from Mid-Rotation Fertilization ofPinus taedaL. Plantations}, volume={11}, ISSN={["1999-4907"]}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-85087994086&partnerID=MN8TOARS}, DOI={10.3390/f11060646}, abstractNote={Mid-rotation fertilization presents an opportunity to increase the economic return of plantation forests in the southeastern United States (SEUS). For this reason, the Forest Productivity Cooperative established a series of mid-rotation fertilization trials in Pinus taeda L. plantations across the SEUS between 1984 and 1987. These trials identified site-specific responses to nitrogen (N) and phosphorus (P) fertilizers, resulting in increased stand production for 6–10 years after fertilization. There are successful volume response models that allow users to quantify the gain in stand productivity resulting from fertilization. However, all the current models depend on empirical relationships that are not bounded by biological response, meaning that greater fertilizer additions continue to create more volume gains, regardless of physiological limits. To address this shortcoming, we developed a bounded response model that evaluates relative volume response gain to fertilizer addition. Site index and relative spacing are included as model parameters to help provide realistic estimates. The model is useful for evaluating productivity gain in Pinus taeda stands that are fertilized with N and P in mid-rotation.}, number={6}, journal={FORESTS}, author={Scolforo, Henrique F. and Montes, Cristian and Cook, Rachel L. and Allen, Howard Lee and Albaugh, Timothy J. and Rubilar, Rafael and Campoe, Otavio}, year={2020}, month={Jun} }
 @article{schulte_cook_albaugh_allen_rubilar_pezzutti_lucia caldato_campoe_carter_2020, title={Mid-rotation response of Pinus taeda to early silvicultural treatments in subtropical Argentina}, volume={473}, ISSN={["1872-7042"]}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-85086739488&partnerID=MN8TOARS}, DOI={10.1016/j.foreco.2020.118317}, abstractNote={Pinus taeda plantations in subtropical areas of South America are extremely productive and commonly established on well-drained red clay sites. In the past, land with more poorly-drained soil was avoided due to concern over the factors limiting site productivity. Establishment of intensively managed plantations on poorly-drained soils usually includes soil preparation by subsoiling and/or bedding, weed control, and fertilization. However, forest managers lack information about the efficacy of early silvicultural practices to ameliorate environmental limitations and if these intensive practices generate long-term improvements in productivity in this area. Consequently, we established studies in northeastern Argentina on two sites differing by drainage class and soil texture as a full factorial design with site preparation (S; disking and disking + subsoiling (red clay) or bedding (wet loam)), fertilization (F; none or 78 kg ha−1 elemental phosphorus at planting), and weed control (W; none or two-year banded). Seven years after planting, the red clay and wet loam sites were equally productive, with maximum treatment means of 218 m3 ha−1 and 264 m3 ha−1 respectively. At the red clay site, only weed control significantly increased volume. At the wet loam site, both weed control and site preparation significantly increased volume, mainly due to increased survival. The combination of weed control and bedding yielded a non-additive volume response as indicated by a significant W*S interaction. Our results do not support the common practice of subsoiling on red clay soils. In addition, fertilization with P alone appears counterproductive or unneeded at both sites.}, journal={FOREST ECOLOGY AND MANAGEMENT}, author={Schulte, Morgan L. and Cook, Rachel L. and Albaugh, Timothy J. and Allen, H. Lee and Rubilar, Rafael A. and Pezzutti, Raul and Lucia Caldato, Silvana and Campoe, Otavio and Carter, David R.}, year={2020}, month={Oct} }
 @article{rubilar_allen_fox_cook_albaugh_campoe_2018, title={Advances in Silviculture of Intensively Managed Plantations}, volume={4}, ISSN={["2198-6436"]}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-85050372148&partnerID=MN8TOARS}, DOI={10.1007/s40725-018-0072-9}, number={1}, journal={CURRENT FORESTRY REPORTS}, author={Rubilar, Rafael A. and Allen, H. Lee and Fox, Thomas R. and Cook, Rachel L. and Albaugh, Timothy J. and Campoe, Otavio C.}, year={2018}, month={Mar}, pages={23–34} }
 @article{zhao_kane_teskey_fox_albaugh_allen_rubilar_2016, title={Maximum response of loblolly pine plantations to silvicultural management in the southern United States}, volume={375}, ISSN={["1872-7042"]}, DOI={10.1016/j.foreco.2016.05.035}, abstractNote={Pine plantations in the southern US are among the most intensively managed forests in the world and their productivity has tripled over natural pine forests through application of intensive pine plantation establishment and management practices. As we are trying to increase carbon (C) sequestration through further enhancing pine plantation productivity by refinement of silvicultural regimes, whether a maximum productivity or the maximum potential C sequestration exists remains unclear. Our analysis of six long-term field trials indicated that a maximum productivity and a maximum response to silvicultural practices for loblolly pine (Pinus taeda L.) exist across the species geographic range in the southern US. The maximum response was inversely proportional to the base site quality, and silvicultural treatments never increased productivity above that maximum. Further analysis of loblolly pine culture and density studies demonstrated that the effects of planting density and cultural treatment intensity on biomass production strongly interacted with site quality in that lower quality sites responded more to silvicultural intensity than higher quality sites. The results highlight that we can optimize silvicultural prescriptions for specific sites by changing silvicultural intensity depending on the site quality.}, journal={FOREST ECOLOGY AND MANAGEMENT}, author={Zhao, Dehai and Kane, Michael and Teskey, Robert and Fox, Thomas R. and Albaugh, Timothy J. and Allen, H. Lee and Rubilar, Rafael}, year={2016}, month={Sep}, pages={105–111} }
 @article{ramirez_rubilar_montes_stape_fox_allen_2016, title={Nitrogen availability and mineralization in Pinus radiata stands fertilized mid-rotation at three contrasting sites}, volume={16}, DOI={10.4067/s0718-95162016005000009}, abstractNote={Fertilization of Pinus radiata plantations mid-rotation after thinning can alter soil nitrogen availability. However, the magnitudes and durations of tree and stand growth responses are not well understood across different soils with specific site conditions. Two mid-rotation fertilization trials in Pinus radiata plantations with unexpected sustained growth responses for more than 6 years and volume gains of 25 m3ha-1 and 50 m3 ha-1 in sandy and granitic soil, respectively, and one trial with no response to fertilization were selected to study the monthly dynamics of nitrogen availability and net mineralization using in situ core incubations. After 2 years, the results showed that fertilization increased nitrogen mineralization and availability until 6 years in sandy soils and until 7 years in granitic soil following fertilization. This result explained the sustained stand growth response observed at these sites. When considering the magnitude of the response, large increases in mineralization rates and soil N availability were observed in the granitic soil relative to the sandy soil. Our results suggest that stands with available N-(NH4+ + NO3-) levels less than 2 kg ha-1 during spring and fall months or with N-(NO3-) levels lower than 0.2 kg ha-1 during any month may respond to N fertilization.}, number={1}, journal={Journal of Soil Science and Plant Nutrition}, author={Ramirez, M. V. and Rubilar, R. A. and Montes, C. and Stape, J. L. and Fox, T. R. and Allen, Howard}, year={2016}, pages={118–136} }
 @article{carlson_fox_allen_albaugh_rubilar_stape_2014, title={Growth Responses of Loblolly Pine in the Southeast United States to Midrotation Applications of Nitrogen, Phosphorus, Potassium, and Micronutrients}, volume={60}, ISSN={["1938-3738"]}, DOI={10.5849/forsci.12-158}, abstractNote={Growth of midrotation pine plantations in the southeast United States tends to be limited by nitrogen (N) and phosphorus (P). Routine applications of urea and diammonium phosphate ameliorate N and P deficiencies; however, questions concerning what other nutrients are likely to be limiting growth are being raised. Consequently, a trial series with 23 study installations was established in loblolly (Pinus taeda L.) stands, aged between 9 and 25 years, with the aim of determining whether stands would respond to potassium (K) additions once the N and P deficiencies were corrected and whether the application of a full suite of macro- and micronutrients would further increase growth. On average, N plus P applications resulted in a mean growth improvement over unfertilized controls of 3.71 m3 ha−1 year−1 for 8 years after fertilization. Further growth improvements in response to the application of K, either with the N and P, or together with a range of macro- and micronutrients, were found to be dependent on location. Studies located on Pleistocene terraces, between 10 and 65 m in elevation, associated with ancient sea levels including the Talbot, Penholloway, Wicomico, Sunderland, and Coharie terraces of Georgia and the Carolinas, showed a smaller than average positive response to the addition of N and P (2.66 m3 ha−1 year−1), with further increases in growth when K was applied as well (additional 1.33 m3 ha−1 year−1) and a further increase when a complete suite of nutrients was added (additional 2.59 m3 ha−1 year−1). Studies located elsewhere in the South showed an average response to the addition of N and P (mean improvement of 4.28 m3 ha−1 year−1), with no improvement in growth when additional nutrients were added. These results can assist foresters in identifying stands that are potentially responsive to applications of nutrients other than N and P.}, number={1}, journal={FOREST SCIENCE}, author={Carlson, Colleen A. and Fox, Thomas R. and Allen, H. Lee and Albaugh, Timothy J. and Rubilar, Rafael A. and Stape, Jose L.}, year={2014}, month={Feb}, pages={157–169} }
 @article{gonzalez-benecke_gezan_albaugh_allen_burkhart_fox_jokela_maier_martin_rubilar_et al._2014, title={Local and general above-stump biomass functions for loblolly pine and slash pine trees}, volume={334}, ISSN={["1872-7042"]}, DOI={10.1016/j.foreco.2014.09.002}, abstractNote={There is an increasing interest in estimating biomass for loblolly pine (Pinus taeda L.) and slash pine (Pinus elliottii Engelm. var. elliottii), two of the most ecologically and commercially important tree species in North America. The majority of the available individual-tree allometric models are local, relying on stem diameter outside bark at breast height (dbh) and, in some cases, total tree height (H): only a few include stand age or other covariates. Using a large dataset collected from five forestry research institutions in the southeastern U.S., consisting of biomass measurements from 744 loblolly pine and 259 slash pine trees, we developed a set of individual-tree equations to predict total tree above-stump biomass, stem biomass outside bark, live branch biomass and live foliage biomass, as well as functions to determine stem bark fraction in order to calculate stem wood biomass inside bark and stem bark biomass from stem biomass outside bark determinations. Local and general models are presented for each tree attribute. Local models included dbh or dbh and H as predicting variables. General models included stand-level variables such as age, quadratic mean diameter, basal area and stand density. This paper reports the first set of local and general allometric equations reported for loblolly and slash pine trees. The models can be applied to trees growing over a large geographical area and across a wide range of ages and stand characteristics. These sets of equations provide a valuable alternative to available models and are intended as a tool to support present and future management decisions for the species, allowing for a variety of ecological, silvicultural and economic applications, as regional assessments of stand biomass or estimating ecosystem C balance.}, journal={FOREST ECOLOGY AND MANAGEMENT}, author={Gonzalez-Benecke, Carlos A. and Gezan, Salvador A. and Albaugh, Timothy J. and Allen, H. Lee and Burkhart, Harold E. and Fox, Thomas R. and Jokela, Eric J. and Maier, Chris A. and Martin, Timothy A. and Rubilar, Rafael A. and et al.}, year={2014}, month={Dec}, pages={254–276} }
 @article{bergh_nilsson_allen_johansson_fahlvik_2014, title={Long-term responses of Scots pine and Norway spruce stands in Sweden to repeated fertilization and thinning}, volume={320}, ISSN={["1872-7042"]}, DOI={10.1016/j.foreco.2014.02.016}, abstractNote={Recent investigations have shown that annual wood production in Sweden can be increased by 30 million m3 per year in a long-term perspective (>50 years) by using new forest management methods such as new tree species or seedling materials. However, to meet the increased demands during the next 20 years, Sweden will have to rely on silvicultural methods available today. Growth in boreal and cold temperate forest is with only few exceptions limited by nutrients availability, primarily nitrogen, and one way to satisfy the increased demands in a short-term perspective is nitrogen fertilization. A set of thinning and fertilization experiments were started in the 1960’s in Scots pine and Norway spruce stands over the whole of Sweden representing different soil, moisture and vegetation types. We used data from these experiments to examine the long-term effects of repeated fertilization in thinned stands on growth, stand development, and yield. The 34 Scots pine sites and 13 Norway spruce sites included in our analyses had at least four treatment plots (no thinning, repeated light thinnings, repeated light thinnings with repeated N fertilization, and repeated light thinnings with repeated N + P fertilization). In northern Sweden, 100 kg N ha−1 and 150 kg N ha−1 were applied at each fertilization event for Scots pine and Norway spruce stands, respectively. In southern Sweden, 150 kg ha−1 N was applied in Scots pine stands and 200 kg ha−1 N in Norway spruce stands. Phosphorus was applied at the rate of 100 kg ha−1. Several sites also included non-thinned fertilized plots. Pine stands but not spruce stands were responsive (up to 25% more growth depending of the attribute assessed) to repeated fertilization. Surprisingly, the non-thinned pine stands showed strong continuing response to fertilization throughout the 30+ year observation period resulting in higher cumulative volume response than the thinned stands. In thinned stands incremental volume response to fertilization continued but slowly diminished with time indicating that fertilization and thinning effects were less than additive. However, thinning and fertilization effects were additive for diameter growth. Fertilization accelerated stand development with significant shifts in diameter distributions to larger and potentially more valuable trees. Conclusively, repeated nitrogen fertilization is a silvicultural practice that will result in significant and sustained increases in Scots pine production.}, journal={FOREST ECOLOGY AND MANAGEMENT}, author={Bergh, Johan and Nilsson, Urban and Allen, H. Lee and Johansson, Ulf and Fahlvik, Nils}, year={2014}, month={May}, pages={118–128} }
 @article{zerpa_allen_mclaughlin_phelan_campbell_hu_2014, title={Postharvest forest floor manipulation effects on nutrient dynamics in a loblolly pine (Pinus taeda) plantation}, volume={44}, ISSN={["1208-6037"]}, DOI={10.1139/cjfr-2013-0536}, abstractNote={ The synchronization of nutrient release and demand in early stand establishment is important to maximizing resource use in forest plantations. We explored the impacts of forest floor manipulations on the dynamics of forest floor and mineral soil nutrient pools in a Pinus taeda L. plantation in North Carolina prior to and during 2 years following harvest and replanting. We present a novel method to estimate forest floor decomposition that avoids the exclusion of large detritivores. Decomposition and nutrient release rates from the forest floor were higher than rates typically observed in older stands (averaging 81% mass loss and 75% N loss across treatments over the 2-year period), highlighting the potential importance of the forest floor nutrient pool in early stand nutrition. Doubling the forest floor increased available C, N, and P pools in the mineral soil 46%, 47%, and 49%, respectively. Incorporating the forest floor into mineral soil through mixing had only transient positive effects on nutrient pools. Across treatments, an expected postharvest flush of soil available N was observed; however, removing the forest floor caused an earlier flush of available N in comparison with the control treatment, and doubling the forest floor caused a year delay in maximum N availability, better synchronizing the site’s available N with stand demand. }, number={9}, journal={CANADIAN JOURNAL OF FOREST RESEARCH-REVUE CANADIENNE DE RECHERCHE FORESTIERE}, author={Zerpa, Jose L. and Allen, H. Lee and McLaughlin, Blair C. and Phelan, Jennifer and Campbell, Robert G. and Hu, Shuijin}, year={2014}, month={Sep}, pages={1058–1067} }
 @article{albaugh_fox_blinn_allen_rubilar_stape_2013, title={Developing a new foliar nutrient-based method to predict response to competing vegetation control in Pinus taeda}, volume={37}, number={4}, journal={Southern Journal of Applied Forestry}, author={Albaugh, T. J. and Fox, T. R. and Blinn, C. E. and Allen, H. L. and Rubilar, R. A. and Stape, J. L.}, year={2013}, pages={196–201} }
 @article{alvarez_allen_albaugh_stape_bullock_song_2013, title={Factors influencing the growth of radiata pine plantations in Chile}, volume={86}, DOI={10.1093/forestry/cps072}, abstractNote={We examined environmental factors affecting growth rates of Pinus radiata in Chile. The relationships between annual volume growth and soil, climate, canopy and stand factors were analysed using data from 48 permanent sample plots in P. radiata plantations in central Chile. Water availability (as affected by precipitation, soil water holding capacity and potential evapotranspiration) appeared to be the factor most limiting to leaf area and growth. Maximum growing season temperature also negatively affected growth. Sites with the highest productivities had the lowest annual water deficits. The most productive sites used water and light more efficiently. Growth per unit of potential evapotranspiration ranged from 0.5 to 1.6 kg of wood per m 3 of water and growth per unit of radiation ranged from 0.3 to 0.5 g of wood per MJ of photosynthetically active radiation for low and high productivity sites. The inclusion of simple climatic variables such as maximum temperature and precipitation into Chilean P. radiata growth and yield models should improve their performance.}, number={1}, journal={Forestry}, author={Alvarez, J. and Allen, Howard and Albaugh, T. J. and Stape, J. L. and Bullock, B. P. and Song, C.}, year={2013}, pages={13–26} }
 @article{campoe_stape_albaugh_allen_fox_rubilar_binkley_2013, title={Fertilization and irrigation effects on tree level aboveground net primary production, light interception and light use efficiency in a loblolly pine plantation}, volume={288}, ISSN={["1872-7042"]}, DOI={10.1016/j.foreco.2012.05.026}, abstractNote={Fertilization and irrigation may substantially increase productivity of forests by increasing stand leaf area index and the efficiency of converting intercepted light into wood biomass. This stand-level growth response is the summation of individual tree responses, and these tree-level responses are often non-linear, resulting from shifting in the intensity of competition and dominance. We examined tree-level responses of aboveground net primary production (ANPP), absorbed photosynthetically active radiation (APAR) and (light use efficiency) LUE in relation to tree size class to explore how stand-level outcomes depend on shifting patterns among trees. We evaluated the production ecology of a nine-year-old loblolly pine (Pinus taeda L.) plantation, 2 years after the initiation of treatments: control, irrigation, fertilization and irrigation + fertilization. We measured tree level ANPP, simulated APAR for individual tree crowns using the MAESTRA process-based model and calculated LUE (ANPP/APAR) in relation to tree size to explore the influence of tree dominance on both light capture and light use efficiency. Fertilization and irrigation + fertilization strongly increased both APAR and LUE, in contrast to little effect of irrigation alone. Tree size had a strong influence on APAR and LUE across all treatments; the largest 20% trees showed 3.4 times greater ANPP when compared to the smallest 20% trees, with 66% resulting from higher APAR, and 34% from higher LUE, than the smallest 20% of trees. Fertilization increased the growth of the largest 20% trees 2-fold (8.6 kg tree−1 year−1), with 29% of the increase resulting from higher APAR (13.7 GJ tree−1 year−1), and 71% from higher LUE (0.63 g MJ−1), relative to the largest trees in the control treatment (4.3 kg tree−1 year−1, 11 GJ tree−1 year−1 and 0.39 g MJ−1, respectively). Irrigation and fertilization tripled production (13.2 kg tree−1 year−1) of the largest trees with an even greater proportional contribution from increased LUE (15.1 GJ tree−1 year−1, 85% response contribution; APAR 0.87 g MJ−1, 15% response contribution). Overall, large trees grow faster than smaller trees because of greater light capture, whereas the greater response of large trees to treatments resulted more from increased efficiency of using light.}, journal={FOREST ECOLOGY AND MANAGEMENT}, author={Campoe, Otavio C. and Stape, Jose Luiz and Albaugh, Timothy J. and Allen, H. Lee and Fox, Thomas R. and Rubilar, Rafael and Binkley, Dan}, year={2013}, month={Jan}, pages={43–48} }
 @article{rubilar_albaugh_allen_alvarez_fox_stape_2013, title={Foliage development and leaf area duration in Pinus radiata}, volume={304}, ISSN={["0378-1127"]}, DOI={10.1016/j.foreco.2013.05.044}, abstractNote={Abstract Site-specific constraints on foliage development and leaf area duration were investigated in two-year-old Pinus radiata D. Don. plantations established under a factorial combination of soil tillage (shovel vs. subsoil + bedding + shovel), fertilization (B only vs. N, P, K, and B), and weed control (pre-plant vs. pre-plant + two-year banded) at three contrasting textural (sand, clay and ash) and climatic soil-site conditions in the Central Valley of Chile. We examined site effects and five treatments at each site to test hypotheses that soil tillage and nutrient and water limitations, would not influence foliage development or leaf area duration. Site effects were evident for foliage development and leaf area duration. Improved nutrient availability increased fascicle length at the sand and clay sites. Improved water availability increased fascicle length and leaf area duration at the sand site, and increased fascicle number at the sand and clay sites. Soil tillage reduced fascicle length at the ash site. Fascicle length may be influenced by factors including water and nutrient availability and soil and air temperature; however based on our data and indications in the literature that the largest effects on foliage length have been associated with resource availability we hypothesize that tillage may have induced nutrient and or water limitations at the ash site.}, journal={FOREST ECOLOGY AND MANAGEMENT}, author={Rubilar, Rafael A. and Albaugh, Timothy J. and Allen, H. Lee and Alvarez, Jose and Fox, Thomas R. and Stape, Jose L.}, year={2013}, month={Sep}, pages={455–463} }
 @article{blinn_albaugh_fox_wynne_stape_rubilar_allen_2012, title={A Method for Estimating Deciduous Competition in Pine Stands Using Landsat}, volume={36}, ISSN={["0148-4419"]}, DOI={10.5849/sjaf.10-034}, abstractNote={A method for identifying pine plantations that may require vegetation control using remotely sensed imagery is presented.Landsat satellite images are used to estimate the leaf area index (LAI) of competing deciduous vegetation by subtracting winter LAI from spring LAI.This differencing works because pine leaf area increases relatively little in comparison with deciduous vegetation between winter and early spring.Competing vegetation LAI levels were compared before and after midrotation release treatments to measure the success of the release treatments.The LAI differencing method estimates the relative abundance of competing vegetation in pine stands and was successful at measuring a reduction in competition levels after release treatments.Midrotation stands prior to release treatments were found to have levels of competing vegetation leaf area equivalent to stands that had never received vegetation control treatments and lower levels of competing vegetation after release treatments.}, number={2}, journal={SOUTHERN JOURNAL OF APPLIED FORESTRY}, author={Blinn, Christine E. and Albaugh, Timothy J. and Fox, Thomas R. and Wynne, Randolph H. and Stape, Jose L. and Rubilar, Rafael A. and Allen, H. Lee}, year={2012}, month={May}, pages={71–78} }
 @article{albaugh_bergh_lundmark_nilsson_stape_allen_linder_2012, title={Do biological expansion factors adequately estimate stand-scale aboveground component biomass for Norway spruce? (vol 258, pg 2628, 2009)}, volume={270}, ISSN={["0378-1127"]}, DOI={10.1016/j.foreco.2012.02.031}, journal={FOREST ECOLOGY AND MANAGEMENT}, author={Albaugh, Timothy J. and Bergh, Johan and Lundmark, Tomas and Nilsson, Urban and Stape, Jose Luiz and Allen, H. Lee and Linder, Sune}, year={2012}, month={Apr}, pages={314–314} }
 @article{albaugh_allen_stape_fox_rubilar_price_2012, title={Intra-annual nutrient flux in Pinus taeda}, volume={32}, ISSN={["1758-4469"]}, DOI={10.1093/treephys/tps082}, abstractNote={Intra-annual nutrient (nitrogen, phosphorus, potassium, calcium and magnesium) flux was quantified for Pinus taeda L. at a nutrient-poor, well-drained sandy site in Scotland County, NC, USA where a 2 × 2 factorial of irrigation and nutrition was applied in four replications in a 10-year-old stand with 1200 stems ha(-1). Treatments were applied with the goal of providing optimum nutrition (no nutritional deficiencies) and water availability. Component (foliage, branch, stem and root) nutrient content was estimated monthly for 2 years using nutrient concentration and phenology assessments combined with destructive harvests. Positive flux values indicated nutrient accumulation in the trees while negative values indicated nutrient loss from the trees. Fertilization significantly increased nitrogen, phosphorus, potassium, calcium and magnesium flux 140%, on average, over non-fertilized. Irrigation significantly increased calcium flux 28% while there was no significant irrigation effect on nitrogen, phosphorus, potassium or magnesium. Maximum nutrient fluxes (kg ha(-1) day(-1)) for non-fertilized and fertilized stands were 0.36 and 1.05 for nitrogen, 0.042 and 0.095 for phosphorus, 0.13 and 0.51 for potassium, 0.27 and 0.42 for calcium, and 0.04 and 0.12 for magnesium, respectively. Maximum flux was coincident with ephemeral tissue (foliage and fine root) development and likely would be higher in stands with more foliage than those observed in this study (projected leaf area indices were 1.5 and 3.0 for the non-fertilized and fertilized stands). Minimum nutrient fluxes (kg ha(-1) day(-1)) for non-fertilized and fertilized stands were -0.18 and -0.42 for nitrogen, -0.029 and -0.070 for phosphorus, -0.05 and -0.18 for potassium, -0.04 and -0.05 for calcium, and -0.02 and -0.03 for magnesium, respectively. Minimum fluxes were typically observed in the dormant season and were linked to foliage senescence and branch death. Foliage and branch component nutrient contents were out of phase for nitrogen, phosphorus, potassium and magnesium, indicating nutrient retranslocation and storage in branches prior to foliage development and after foliage senescence. In contrast to current operational fertilizer programs which often target winter application these data suggest the best application times would be during foliage development.}, number={10}, journal={TREE PHYSIOLOGY}, author={Albaugh, Timothy J. and Allen, H. Lee and Stape, Jose L. and Fox, Thomas R. and Rubilar, Rafael A. and Price, James W.}, year={2012}, month={Oct}, pages={1237–1258} }
 @article{albaugh_stape_fox_rubilar_allen_2012, title={Midrotation Vegetation Control and Fertilization Response in Pinus taeda and Pinus elliottii across the Southeastern United States}, volume={36}, ISSN={["0148-4419"]}, DOI={10.5849/sjaf.10-042}, abstractNote={We examined fertilization (224 and 56 kg ha−1 of elemental nitrogen and phosphorus, applied as urea and diammonium phosphate, respectively) and vegetation control (one-time site-specific application) in a 2 × 2 factorial design with three or four replicates at each site on 13 sites (10 in Pinus taeda and 3 in Pinus elliottii). Nitrogen and phosphorus limited pine growth on seven sites where we found significant volume growth responses to fertilization in at least one measurement period. Five sites had significant volume growth responses to vegetation control in at least one measurement period. Biologic response treatment order was fertilizer plus vegetation control > fertilizer > vegetation control. The combined treatment effects were additive, indicating that resources other than nitrogen and phosphorus were being ameliorated by the vegetation control. Vegetation control response was not related to estimates of competing vegetation basal area, and its duration was likely limited by regrowth of competing vegetation on some sites. Competing vegetation leaf area was proposed as a good metric by which to estimate the extent of interference of noncrop vegetation. We recommend that future work examining vegetation control focus on a process approach to better understand the influences of competing vegetation on crop tree growth.}, number={1}, journal={SOUTHERN JOURNAL OF APPLIED FORESTRY}, author={Albaugh, Timothy J. and Stape, Jose L. and Fox, Thomas R. and Rubilar, Rafael A. and Allen, H. Lee}, year={2012}, month={Feb}, pages={44–53} }
 @article{espinoza_allen_mckeand_dougherty_2012, title={Stem sinuosity in loblolly pine with nitrogen and calcium additions}, volume={265}, ISSN={["1872-7042"]}, DOI={10.1016/j.foreco.2011.10.026}, abstractNote={Abstract Stem sinuosity is a deformation that occurs in loblolly pine ( Pinus taeda L.), and in many other pine species, that frequently affects the quality of the wood and hence, the final products. This deformation occurs mainly on the stem and has been associated with nutritional and physiological disorders. Nitrogen (N) and calcium (Ca) are two important elements affecting the formation, growth, membrane stability and maintenance of tree cell integrity. We hypothesized that high N and low Ca availability could be a cause for sinuous growth in young loblolly pine. A trial was established in the Coastal Plain of South Carolina using different loblolly pine genotypes to evaluate sinuosity when nitrogen fertilizer was applied with and without calcium additions. Eight genotype blocks were fertilized with N (224 kg ha −1 ) as (NH 4 ) 2 SO 4 and Ca (168 kg ha −1 ) as CaSO 4 . Nutrient concentrations from flushing shoot tissue were examined and then correlated with stem sinuosity. Nitrogen additions caused significant increases in both stem sinuosity and N concentrations. Calcium additions reduced stem sinuosity and mitigated the negative effect of N addition when it was applied with N. The magnitude of the effect of nutrient additions observed in the eight genotypes used, however, suggests that long-term trials composed of more genotypes need to be established in order to confirm the effect of Ca, N and genotype on stem sinuosity found on this study. Our findings infer that the appropriate nutrient balance and selection of genetic material are important to provide good growth and acceptable stem form when managing stands of loblolly pine.}, journal={FOREST ECOLOGY AND MANAGEMENT}, author={Espinoza, J. A. and Allen, H. L. and McKeand, S. E. and Dougherty, P. M.}, year={2012}, month={Feb}, pages={55–61} }
 @article{alvarez_mitasova_allen_2011, title={ESTIMATING MONTHLY SOLAR RADIATION IN SOUTH-CENTRAL CHILE}, volume={71}, ISSN={["0718-5820"]}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-84255171688&partnerID=MN8TOARS}, DOI={10.4067/s0718-58392011000400016}, abstractNote={La radiacion solar es un componente clave en los modelos basados en procesos. La cantidad de esta energia depende de la ubicacion, epoca del ano, y tambien de las condiciones atmosfericas. Varias ecuaciones y modelos han sido desarrollados para diferentes condiciones, utilizando datos historicos de las redes de estaciones meteorologicas o de las mediciones por satelite. Sin embargo, las estimaciones de la radiacion solar son demasiado locales con estaciones meteorologicas, o con una resolucion muy gruesa cuando se trabaja con satelites. En el presente estudio se estimo radiacion solar global mensual para la region centro sur de Chile mediante el uso del modelo r.sun y se valido con observaciones de estaciones meteorologicas automaticas. Se analizo el desempeno de los resultados de la irradiacion global con los modelos Hargreaves-Samani (HS) y Bristol-Campbell (BC). Las estimaciones del modelo calibrado r.sun explican un 89% de la varianza (r2 = 0.89) en valores medios mensuales observados. El modelo se comporto muy bien para una amplia zona de las condiciones de Chile, comparados con los modelos HS y BC. Nuestras estimaciones de la radiacion global utilizando el modelo r.sun podrian ser mejoradas aun mas con una posterior calibracion a partir de observaciones y una mejor estimacion de la nubosidad en la medida que esten disponibles. Con procedimientos adicionales, el modelo r.sun podria ser utilizado para proporcionar estimaciones espaciales de la radiacion solar diaria, semanal, mensual, y anual.}, number={4}, journal={CHILEAN JOURNAL OF AGRICULTURAL RESEARCH}, author={Alvarez, Jose and Mitasova, Helena and Allen, H. Lee}, year={2011}, pages={601–609} }
 @article{albaugh_blevins_allen_albaugh_fox_stape_rubilar_2010, title={Characterization of foliar macro- and micronutrient concentrations and ratios in loblolly pine plantations in the southeastern United States}, volume={34}, number={2}, journal={Southern Journal of Applied Forestry}, author={Albaugh, J. M. and Blevins, L. and Allen, H. L. and Albaugh, T. J. and Fox, T. R. and Stape, J. L. and Rubilar, R. A.}, year={2010}, pages={53–64} }
 @article{zerpa_allen_campbell_phelan_duzan_2010, title={Influence of variable organic matter retention on nutrient availability in a 10-year-old loblolly pine plantation}, volume={259}, ISSN={["1872-7042"]}, DOI={10.1016/j.foreco.2010.01.024}, abstractNote={The effects of varying forest floor and slash retention at time of regeneration were evaluated 10 years after the establishment of a loblolly pine plantation near Millport, Alabama. Treatments included removing, leaving unaltered, or doubling the forest floor and slash material. Forest floor and litterfall mass and nutrient concentrations, available soil N, foliar nutrient concentrations and stand yield were all impacted by the treatments. Forest floor mass and nutrient contents in the doubled treatment were significantly greater than the other two treatments. The doubled treatment accumulated 25, 45 and 350% more forest floor mass and 56, 56, and 310% more N than the control treatment in the Oi, Oe, and Oa layers, respectively. The other nutrients followed similar patterns. Potentially mineralized NO3−-N in the mineral soil was also significantly higher in the doubled treatment. The positive effect of doubling the forest floor on soil N availability was reflected in greater foliage production, 30% more litterfall and 25% more stand yield for this treatment. This study shows that increasing the forest floor retention has resulted in increased nutrient availability and improved tree growth.}, number={8}, journal={FOREST ECOLOGY AND MANAGEMENT}, author={Zerpa, J. L. and Allen, H. L. and Campbell, R. G. and Phelan, J. and Duzan, H.}, year={2010}, month={Mar}, pages={1480–1489} }
 @article{albaugh_allen_stape_fox_rubilar_carlson_pezzutti_2010, title={Leaf area duration in natural range and exotic Pinus taeda}, volume={40}, ISSN={["0045-5067"]}, DOI={10.1139/x09-190}, abstractNote={ Exotic Pinus taeda L. plantations may be more productive than native ones. Several hypotheses may explain this difference; however, process models with a light-interception-driving variable cannot test these hypotheses without foliage display first being quantified in native and exotic trees. We quantified leaf area duration in North Carolina, USA (natural), and Gobernador Virasoro, Argentina (exotic), with no additional nutrients and optimum fertilizer treatments. More (60%–100%) foliage was displayed but for a shorter (∼86 fewer days) time per fascicle in the exotics than in the naturals. Study inference was limited, with only one native and one exotic site. However, while the sites were markedly different in soils, climate, resource availability, and genetics, and we observed significant differences in fascicle display and longevity, most fascicles at both sites survived two growing seasons: the one in which they were produced and the subsequent one. This robust finding indicates it would be reasonable to use two growing seasons for fascicle longevity in process modeling to test hypotheses explaining growth differences in native and exotic loblolly. Fertilization had no effect on any exotic tree parameter, but it increased natural tree fascicle number (24%) and length (30%). }, number={2}, journal={CANADIAN JOURNAL OF FOREST RESEARCH-REVUE CANADIENNE DE RECHERCHE FORESTIERE}, author={Albaugh, Timothy J. and Allen, H. Lee and Stape, Jose Luiz and Fox, Thomas R. and Rubilar, Rafael A. and Carlson, Colleen A. and Pezzutti, Raul}, year={2010}, month={Feb}, pages={224–234} }
 @article{peduzzi_allen_wynne_2010, title={Leaf area of overstory and understory in pine plantations in the flatwoods}, volume={34}, number={4}, journal={Southern Journal of Applied Forestry}, author={Peduzzi, A. and Allen, H. L. and Wynne, R. H.}, year={2010}, pages={154–160} }
 @article{jeffries_wentworth_allen_2010, title={Long-term effects of establishment practices on plant communities across successive rotations in a loblolly pine (Pinus taeda) plantation}, volume={260}, ISSN={["1872-7042"]}, url={https://dx.doi.org/10.1016/j.foreco.2010.08.003}, DOI={10.1016/j.foreco.2010.08.003}, abstractNote={Implementation of repeated, high-intensity short rotations in forest plantations raises concerns about the effects of such practices on herbaceous layer biodiversity and overall sustainability. To investigate these concerns, we conducted a comparative study of second and third rotation plant communities in a loblolly pine plantation in the Piedmont of North Carolina. The second rotation stand was established in 1960 using conventional practices and was harvested in 1981, leaving two plots in each of three blocks as “historical” plots representing the second rotation. The third rotation was planted in 1982, and a 2 × 2 factorial experiment was established within an area that had been complete-tree harvested, using two site preparation (drum-chop versus shear, pile, and disk) and two cultural (vegetation control versus no vegetation control) treatments in each of three blocks. Presence/absence data for vascular plant taxa were collected in the second rotation historical plots at year 22 and also in the third rotation treatment plots at year 18 and analyzed using non-metric multidimensional scaling (NMDS) ordination, indicator species analysis, analysis of species richness, and computation of species turnover. Results indicated overall similarities in the herbaceous layer from year 22 in the second rotation to year 18 in the third rotation, while revealing some key differences in species composition, including persistence of disturbance-responsive species associated with the vegetation control treatment in the third rotation plots. The addition of these species largely accounted for an increase in species richness from the second to the third rotation. Species composition in low intensity third rotation plots (chop, no vegetation control) most closely resembled that of the second rotation plots of similar age. In addition, differences in species composition due to soil and topographic differences within the study persisted through both rotations, while compositional effects of treatments implemented at the beginning of the third rotation diminished with time. We conclude that more intensive silvicultural practices, such as site preparation and vegetation control, reduce initial competition from woody species and thus permit the persistence of early successional species, increasing overall diversity. From the larger perspective of the entire study, the second and third rotation stands converged to similar species composition after approximately two decades post-planting despite early treatment-related differences in the third rotation. It remains to be seen whether additional harvests, rotations, and intensive practices will continue to support a functioning understory plant community in these short rotation plantation forests.}, number={9}, journal={FOREST ECOLOGY AND MANAGEMENT}, author={Jeffries, Stephanie B. and Wentworth, Thomas R. and Allen, H. Lee}, year={2010}, month={Sep}, pages={1548–1556} }
 @article{rubilar_allen_alvarez_albaugh_fox_stape_2010, title={Silvicultural manipulation and site effect on above and belowground biomass equations for young Pinus radiata}, volume={34}, ISSN={["1873-2909"]}, DOI={10.1016/j.biombioe.2010.07.015}, abstractNote={There is little understanding of how silvicultural treatments, during the early stages of tree development, affect allometric relationships. We developed and compared stem, branch, foliage, coarse and fine root biomass, and leaf area estimation equations, for four-year-old genetically improved radiata pine trees grown on three contrasting soil-site conditions. At each site, selected trees were destructively sampled from a control (shovel planted, no weed control, fertilized with 2 g of boron), a shovel planted + weed control (2 first years) + complete fertilization (nitrogen + phosphorus + boron 2 first years + potassium 2nd year), and a soil tillage (subsoil at 60 cm) + weed control (first 2 years) + complete fertilization treatment. Tissues were separated into foliage, branch, stem, fine and coarse roots (>2 mm). Regression equations for each tree biomass tissue versus leaf area were fit for each site and compared among treatments and sites with the same genetic material. Our results indicated that individual tree biomasses for young plantations are affected by silvicultural treatment and site growing conditions. Higher variability in estimates was found for foliage and branches due to the ephemeral nature of these components. Stem biomass equations vary less, but differences in biomass equations were found among sites and treatments. Coarse root biomass estimates were variable but less than expected, considering the gradient among sites. Similar to stem biomass, a simple positive general linear relationship between root collar diameter, or diameter at breast height with coarse roots biomass was developed across sites and treatments.}, number={12}, journal={BIOMASS & BIOENERGY}, author={Rubilar, Rafael A. and Allen, H. Lee and Alvarez, Jose S. and Albaugh, Timothy J. and Fox, Thomas R. and Stape, Jose L.}, year={2010}, month={Dec}, pages={1825–1837} }
 @article{carlson_fox_burkhart_allen_albaugh_2009, title={Accuracy of subsampling for height measurements in loblolly pine plots}, volume={33}, number={3}, journal={Southern Journal of Applied Forestry}, author={Carlson, C. A. and Fox, T. R. and Burkhart, H. E. and Allen, H. L. and Albaugh, T. J.}, year={2009}, pages={145–149} }
 @article{albaugh_bergh_lundmark_nilsson_stape_allen_linder_2009, title={Do biological expansion factors adequately estimate stand-scale aboveground component biomass for Norway spruce?}, volume={258}, ISSN={["0378-1127"]}, DOI={10.1016/j.foreco.2009.09.021}, abstractNote={We developed site specific component (stem, branch, and foliage) biomass functions for two sites in Sweden (64° and 57° North latitude) where four treatments (control, irrigated, fertilized, irrigated plus fertilized) were applied in the existing Norway spruce stands (Picea abies L. Karst.) for 17 years. We tested for site effects in the component biomass equations and compared site specific biomass estimates to those generated using published functions (Lehtonen et al., 2004, Wirth et al., 2004). Site effects were significant for all components and indicated it would be unlikely to generate equations that well estimate biomass across the Norway spruce range as implicitly indicated in our efforts to generate species biomass expansion factors. We rejected our hypothesis that the published functions would well estimate component biomass for control plots. The published functions did not compare well with site specific component biomass estimates for the other treatments; both published functions well estimated stem mass up to stem mass of 25 Mg ha−1, beyond which stem mass was overestimated, and both functions over and under estimated foliage and branch mass. Nor did the published functions compare well with each other, with stem, foliage and branch mass estimate differences of 12, 55, −8% and 11, 77, and 59% for the southern and northern sites, respectively, when averaged over all treatments and years. Adding limiting resources through fertilization increased stem, foliage and branch mass 57, 11, 18% and 120, 37, and 69% at the southern and northern sites, respectively, which would increase carbon sequestration and available stemwood and bioenergy materials. We recommend that more effort is spent in process-based modeling to better predict mass at a given site and ultimately provide better estimates of carbon sequestration and bioenergy material production changes.}, number={12}, journal={FOREST ECOLOGY AND MANAGEMENT}, author={Albaugh, Timothy J. and Bergh, Johan and Lundmark, Tomas and Nilsson, Urban and Stape, Jose Luiz and Allen, H. Lee and Linder, Sune}, year={2009}, month={Nov}, pages={2628–2637} }
 @article{liu_king_booker_giardina_allen_hu_2009, title={Enhanced litter input rather than changes in litter chemistry drive soil carbon and nitrogen cycles under elevated CO2: a microcosm study}, volume={15}, ISSN={["1365-2486"]}, DOI={10.1111/j.1365-2486.2008.01747.x}, abstractNote={Abstract}, number={2}, journal={GLOBAL CHANGE BIOLOGY}, author={Liu, Lingli and King, John S. and Booker, Fitzgerald L. and Giardina, Christian P. and Allen, H. Lee and Hu, Shuijin}, year={2009}, month={Feb}, pages={441–453} }
 @article{albaugh_allen_fox_carlson_rubilar_2009, title={Opportunities for fertilization of loblolly pine in the sandhills of the southeastern United States}, volume={33}, number={3}, journal={Southern Journal of Applied Forestry}, author={Albaugh, T. and Allen, H. L. and Fox, T. R. and Carlson, C. A. and Rubilar, R. A.}, year={2009}, pages={129–136} }
 @article{jackson_pittillo_allen_wentworth_bullock_loftis_2009, title={Species Diversity and Composition in Old Growth and Second Growth Rich Coves of the Southern Appalachian Mountains}, volume={74}, ISSN={["1938-4386"]}, DOI={10.2179/07-017.1}, abstractNote={Abstract Because of ongoing debate over the long term impacts of logging, we conducted a study to assess if second growth (70 ± 10 years) rich coves differ from old growth rich coves (> 125 years) in species diversity or composition. We sampled twenty-six 0.1 ha plots, representing these two age classes. We distributed the plots amongst three randomly selected mountain ranges in the southern Appalachians of North Carolina, and sampled each mountain range in separate years. We used nested subplots of 0.01 m2, 0.1 m2, 1 m2, 10 m2, 100 m2, and 1000 m2 to establish species-area relationships (SARs) for each age class. We found no significant differences between the SARs for the two age classes, nor did we find significant differences between age classes using the Simpson, Shannon-Wiener, or Sorensen indices of species diversity. However, we found that total cover of all plant species was greater in old growth rich coves, and that 10% of the tested species had lower abundance in second growth. No species were present in old growth and absent in second growth, but species with lower second growth abundance may warrant future study.}, number={1}, journal={CASTANEA}, author={Jackson, B. Clay and Pittillo, J. Dan and Allen, H. Lee and Wentworth, Thomas R. and Bullock, Bronson P. and Loftis, David L.}, year={2009}, month={Mar}, pages={27–38} }
 @article{carlson_burkhart_allen_fox_2008, title={Absolute and relative changes in tree growth rates and changes to the stand diameter distribution of Pinus taeda as a result of midrotation fertilizer applications}, volume={38}, ISSN={["0045-5067"]}, DOI={10.1139/X08-050}, abstractNote={ Silvicultural treatments have the potential to change the diameter distribution of a stand, which can alter the final product mix of the stand. Growth and yield models need to account for these changes in the diameter distribution to assess the economic viability of the silvicultural operations. We investigated how the diameter distribution of Pinus taeda L. stands changes as a result of midrotation fertilization. Data from 43 installations of a nitrogen and phosphorus midrotation fertilizer trial series established in the southeastern United States were used in the study. The results indicated that both the absolute growth response and the relative growth response of individual trees were greater among the larger trees. A three-parameter Weibull distribution fitted at each study site was used to investigate how the parameters of the distribution changed with time and treatment. The location and scale parameters of the Weibull distribution were both affected by fertilization. Stand variables, such as site index, age, stand density, and mean diameter at time of fertilization, also affected the location and scale parameters. The shape parameter was not affected by any of the treatments in this study. }, number={7}, journal={CANADIAN JOURNAL OF FOREST RESEARCH-REVUE CANADIENNE DE RECHERCHE FORESTIERE}, author={Carlson, Colleen A. and Burkhart, Harold E. and Allen, H. Lee and Fox, Thomas R.}, year={2008}, month={Jul}, pages={2063–2071} }
 @article{phelan_allen_2008, title={Have repeated applications of nitrogen and phosphorus to a loblolly pine plantation changed stand productivity and soil nutrient supply?}, volume={38}, ISSN={["1208-6037"]}, DOI={10.1139/X07-131}, abstractNote={To develop a nitrogen (N) and phosphorus (P) fertilization regime that produces long-term increases in stand productivity and soil nutrient supply in loblolly pine plantations, a series of N + P fertilizer studies were established in the Southeastern United States. One of these installations was examined partway through the study to determine if changes to stand productivity and soil nutrient supply had already been achieved. Stand growth and foliar nutrient concentrations were measured for 6 years, and during the third year, a seedling bioassay was conducted with soil collected from the highest fertilization and nonfertilized treatments. Annual stand growth was increased by 14%–27% in the fertilized plots suggesting that the fertilizer regime improved stand productivity. However, results from the seedling bioassay showed that only P fertilization had caused changes in soil nutrient supply. Seedling P contents in the fertilized treatments were 3.6 times larger than those in the nonfertilized treatments. In contrast, total system N contents were equivalent in the fertilized and nonfertilized systems, and extractable nitrate (NO3–), ammonium (NH4+), and biologically active N were higher in the nonfertilized soils. Future measurements and seedlings bioassay assessments should be conducted to determine when and if long-term changes in soil quality and stand productivity are achieved.}, number={3}, journal={CANADIAN JOURNAL OF FOREST RESEARCH}, author={Phelan, Jennifer Bennett and Allen, H. Lee}, year={2008}, month={Mar}, pages={637–644} }
 @article{carlson_fox_allen_albaugh_2008, title={Modeling mid-rotation fertilizer responses using the age-shift approach}, volume={256}, ISSN={["0378-1127"]}, DOI={10.1016/j.foreco.2008.04.020}, abstractNote={Growth and yield modelers have incorporated mid-rotation fertilizer responses by: modifying site index; developing new models to include fertilizer responses directly; using multipliers or additional terms to scale existing models. We investigated the use of age-shifts to model mid-rotation fertilizer responses. Age-shift prediction models were constructed from 43 installations of a nitrogen (0, 112, 224 and 336 kg ha−1 elemental) by phosphorus (0, 28 and 56 kg ha−1 elemental) factorial experiment established in mid-rotation loblolly (Pinus taeda L.) pine stands in the southeastern US. Age-shifts for dominant height and basal area increased with time after fertilization, to a maximum and then either remained fairly constant, or declined. The initial rate of increase, maximum age-shift and decline were functions of the rate and combinations of fertilizers applied, as well as stand density and age at fertilization. Volume age-shifts increased linearly throughout the 10-year measurement period for most treatments with the rate of increase being a function of the elements applied, stocking, site index and age at fertilization. A mid-rotation fertilizer application of 224 and 28 kg ha−1 elemental N and P, respectively, resulted in age-shifts of 1.1, 1.9 and 2.4 years for dominant height, basal area and volume, respectively, 10 years after fertilization. The age-shifts were incorporated into growth and yield models.}, number={3}, journal={FOREST ECOLOGY AND MANAGEMENT}, author={Carlson, Colleen A. and Fox, Thomas R. and Allen, H. Lee and Albaugh, Timothy J.}, year={2008}, month={Jul}, pages={256–262} }
 @article{albaugh_allen_fox_2008, title={Nutrient use and uptake in Pinus taeda}, volume={28}, ISSN={["0829-318X"]}, DOI={10.1093/treephys/28.7.1083}, abstractNote={We quantified nitrogen (N), phosphorus (P), potassium (K), calcium (Ca) and magnesium (Mg) content, use (nutrient amount for one growth year), retranslocation (nutrients recycled before foliage senescence), uptake (use minus retranslocation), volume production per unit of uptake and fertilizer-uptake efficiency (percent applied taken up) in a 2 x 2 (nutrient and water) factorial experiment replicated four times in an 8-year-old loblolly pine (Pinus taeda L.) stand growing on a nutrient-poor sandy soil in Scotland County, North Carolina, USA. Over 14 years, we applied 1140, 168, 393, 168 and 146 kg ha(-1) of elemental N, P, K, Ca and Mg fertilizer, respectively, and an average of 710 mm year(-1) of irrigation. All plots received complete vegetation control. Fertilization about doubled tissue N, P, K and Mg contents at age 21, whereas irrigation resulted in smaller increases in nutrient contents. Maximum annual uptake was 101, 9.3, 44, 37 and 13 kg ha(-1) year(-1) and volume production per unit of nutrient uptake was 0.35, 3.5, 0.66, 1.1 and 3.1 m(3) kg(-1), for N, P, K, Ca and Mg, respectively. Irrigated plots had greater volume production per unit of N, P, K and Mg uptake than control plots, likely because irrigation allowed photosynthesis to continue during dry periods. Fertilized plus irrigated plots had less volume production per unit of these elements than the fertilized plots either because nutrient uptake exceeded the requirement for optimum growth or because available water (rainfall plus irrigation) was insufficient for the leaf area achieved with fertilization. At age 19, fertilizer-uptake efficiencies for N, P, K, Ca and Mg were 53, 24, 62, 57 and 39%, respectively, and increased with irrigation to 68, 36, 78, 116 and 55%, respectively. The scale of fertilizer uptake was likely a result of low native site nutrient availability, study longevity, measurement of all tissue components on site, a comprehensive assessment of coarse roots, and the 3-m rooting depth. Ecosystem nitrogen retention (applied nitrogen found in living plant material, litter fall and soil to 150-cm depth) was estimated at 79% at age 17, a value that would likely be greater when including soil nitrogen to rooting depth and calculating retention at age 21 when the study ended. The ecosystem retention value provides evidence that intensive site resource management can be accomplished with low likelihood of applied materials moving offsite.}, number={7}, journal={TREE PHYSIOLOGY}, author={Albaugh, Timothy J. and Allen, H. Lee and Fox, Thomas R.}, year={2008}, month={Jul}, pages={1083–1098} }
 @article{albaugh_allen_fox_2007, title={Historical patterns of forest fertilization in the southeastern United States from 1969 to 2004}, volume={31}, number={3}, journal={Southern Journal of Applied Forestry}, author={Albaugh, T. J. and Allen, H. L. and Fox, T. R.}, year={2007}, pages={129–137} }
 @article{johansson_nilsson_allen_2007, title={Interactions between soil scarification and Norway spruce seedling types}, volume={33}, ISSN={["0169-4286"]}, DOI={10.1007/s11056-006-9010-y}, number={1}, journal={NEW FORESTS}, author={Johansson, Karin and Nilsson, Urban and Allen, H. Lee}, year={2007}, month={Jan}, pages={13–27} }
 @article{mora_allen_daniels_clark_2007, title={Modeling corewood-outerwood transition in loblolly pine using wood specific gravity}, volume={37}, ISSN={["1208-6037"]}, DOI={10.1139/X06-250}, abstractNote={ A modified logistic function was used for modeling specific-gravity profiles obtained from X-ray densitometry analysis in 675 loblolly pine ( Pinus taeda L.) trees in four regeneration trials. Trees were 21 or 22 years old at the time of the study. The function was used for demarcating corewood, transitional, and outerwood zones. Site and silvicultural effects were incorporated into the model. Heteroscedasticity and within-group correlation were accounted for by specifying the variance and serial-correlation structure, respectively. The estimated transition zone was located between rings 5 and 15, and the outerwood demarcation point varied from rings 12 to 15. No effects of treatments on the demarcation points were observed; however, site preparation and fertilization affected the lower asymptotes of the curves in all sites. A geographical trend for the demarcation point was observed, with the northern site requiring more time to reach a plateau in specific gravity compared with the southern sites. The diameter of the juvenile core was increased as a result of the treatments. However, the amount of corewood was not statistically affected, ranging from 55% in the north to 75% in the south, except at one site where fertilization decreased the percentage of corewood. }, number={6}, journal={CANADIAN JOURNAL OF FOREST RESEARCH}, author={Mora, Christian R. and Allen, H. Lee and Daniels, Richard F. and Clark, Alexander}, year={2007}, month={Jun}, pages={999–1011} }
 @misc{fox_jokela_allen_2007, title={The development of pine plantation silviculture in the southern United States}, volume={105}, number={7}, journal={Journal of Forestry}, author={Fox, T. R. and Jokela, E. J. and Allen, H. L.}, year={2007}, pages={337–347} }
 @article{fox_allen_albaugh_rubilar_carlson_2007, title={Tree nutrition and forest fertilization of pine plantations in the southern United States}, volume={31}, number={1}, journal={Southern Journal of Applied Forestry}, author={Fox, T. R. and Allen, H. L. and Albaugh, T. J. and Rubilar, R. and Carlson, C. A.}, year={2007}, pages={5–11} }
 @article{richter_allen_li_markewitz_raikes_2006, title={Bioavailability of slowly cycling soil phosphorus: major restructuring of soil P fractions over four decades in an aggrading forest}, volume={150}, ISSN={["0029-8549"]}, DOI={10.1007/s00442-006-0510-4}, abstractNote={Although low solubility and slow cycling control P circulation in a wide range of ecosystems, most studies that evaluate bioavailability of soil P use only indices of short-term supply. The objective here is to quantify changes in P fractions in an Ultisol during the growth of an old-field pine forest from 1957 to 2005, specifically changes with organic P (Po) and with inorganic P (Pi) associated with Fe and Al oxides as well as Ca compounds. Changes in soil P were estimated from archived mineral soil samples collected in 1962 shortly after pine seedlings were planted, and on six subsequent occasions (1968, 1977, 1982, 1990, 1997, and 2005) from eight permanent plots and four mineral soil layers (0-7.5, 7.5-15, 15-35, and 35-60 cm). Despite the net transfer of 82.5 kg ha(-1) of P from mineral soil into tree biomass and O horizons, labile soil P was not diminished, as indexed by anion exchange resins, and NaHCO(3) and Mehlich III extractants. An absence of depletion in most labile P fractions masks major restructuring of soil P chemistry driven by ecosystem development. During 28 years of forest growth, decreases were significant and substantial in slowly cycling Po and Pi associated with Fe and Al oxides and Ca compounds, and these accounted for most of the P supplied to biomass and O horizons, and for buffering labile soil fractions as well. Changes in soil P are attributed to the P sink strength of the aggrading forest (at 2.9 kg ha(-1) year(-1) over 28 years); legacies of fertilization, which enriched slowly cycling fractions of Po and Pi; and the changing biogeochemistry of the soil itself.}, number={2}, journal={OECOLOGIA}, author={Richter, Daniel D. and Allen, H. Lee and Li, Jianwei and Markewitz, Daniel and Raikes, Jane}, year={2006}, month={Nov}, pages={259–271} }
 @article{fox_allen_albaugh_rubilar_carlson_2006, title={Forest fertilization in Southern pine plantations}, volume={90}, number={2}, journal={Better Crops With Plant Food}, author={Fox, T. R. and Allen, H. L. and Albaugh, T. J. and Rubilar, R. and Carlson, C. A.}, year={2006}, pages={12–15} }
 @article{carlson_fox_colbert_kelting_allen_albaugh_2006, title={Growth and survival of Pinus taeda in response to surface and subsurface tillage in the southeastern United States}, volume={234}, ISSN={["0378-1127"]}, DOI={10.1016/j.foreco.2006.07.002}, abstractNote={A trial series investigating the impact of surface and subsurface tillage on the survival and growth of planted Pinus taeda L. was established between 1994 and 1998 with the goal of identifying site types responsive to tillage. The trial series consisted of 15 studies with multiple replicates of a 2 × 2 factorial with surface (offset disking or opposed bedding) and subsurface (winged subsoiling shank) tillage. Subsurface tillage significantly improved survival at four sites and surface tillage improved survival at one site. The positive response to the subsurface tillage was associated with the Piedmont sites where survival improved from 74 to 82%. Surface tillage significantly improved height, diameter and volume growth with the response being greatest on soils with siliceous mineralogy, which showed an improvement of 5.1 m3 ha−1 at 6 years. The improvement was less for soils with kaolinitic mineralogy (4.0 m3 ha−1) or those with mixed mineralogy (3.1 m3 ha−1). Initially Piedmont sites showed a positive response due to subsurface tillage. However, the response was short lived and had dissipated by year 6. Effects of tillage on stand uniformity were negligible. In general, responses to tillage were relatively small compared to those that can be obtained from other silvicultural practices such as vegetation control and fertilization.}, number={1-3}, journal={FOREST ECOLOGY AND MANAGEMENT}, author={Carlson, Colleen A. and Fox, Thomas R. and Colbert, Steve R. and Kelting, Daniel L. and Allen, H. Lee and Albaugh, Timothy J.}, year={2006}, month={Oct}, pages={209–217} }
 @article{albaugh_allen_fox_2006, title={Individual tree crown and stand development in Pinus taeda under different fertilization and irrigation regimes}, volume={234}, ISSN={["1872-7042"]}, DOI={10.1016/j.foreco.2006.05.074}, abstractNote={We examined individual tree foliage mass and branch demography for 13 years in a Pinus taeda L. stand growing on a nutrient poor, well drained sandy soil with a 2 × 2 factorial of fertilization and irrigation treatments replicated four times. Branch level foliage mass was estimated using equations derived from 2500 destructively sampled branches with branch basal diameter, crown location, age and treatment as independent variables. Branch diameter and crown location were measured for all live branches on 80 trees (20 in each treatment) each year for 13 years. Maximum dormant season individual tree foliage mass was 5.4 and 10.7 kg tree−1 in the control and fertilized and irrigated treatments, respectively. The maximum fertilized and irrigated individual tree foliage mass was achieved 3 years after treatment initiation when apparent light and space limitations prevented additional increase in individual tree foliage mass. Individual stem volume increment was linearly related to individual tree foliage mass and individual tree foliage mass was reduced by the presence of large nearby trees. Branch diameter and number were significantly increased by fertilization (52 branches tree−1, 11% increase, 19.8 mm branch−1, 14% increase). Branch longevity was significantly reduced by fertilization; branches survived 6.6 and 5.4 years for the non-fertilized and fertilized treatments, respectively. Branch size, number and longevity in the fertilized treatments would not be likely to reduce stem quality. In stands where nutrients and water were adequate and light and space limitations developed, individual tree foliage mass development could be increased with thinning. However, individual tree foliage mass development was limited much earlier in stand development than heretofore thought. Waiting to thin until stand conditions currently used to trigger thinning (to avoid density dependent mortality) would promote overall stand growth at the expense of crop tree growth. Individual tree foliage mass was correlated with branch development and branches in the lower crown half were more likely to die, had a lower carbon balance due to low light and high respiring tissue relative to photosynthesizing tissue. This combination of factors indicated that pruning may be a likely tool to manage crown development and insure that crop trees have a high value stem. The balance between individual stem growth and stand growth may need to be reevaluated in the context of currently used intensive silvicultural regimes.}, number={1-3}, journal={FOREST ECOLOGY AND MANAGEMENT}, author={Albaugh, Timothy J. and Allen, H. Lee and Fox, Thomas R.}, year={2006}, month={Oct}, pages={10–23} }
 @article{mckeand_jokela_huber_byram_allen_li_mullin_2006, title={Performance of improved genotypes of loblolly pine across different soils, climates, and silvicultural inputs}, volume={227}, ISSN={["1872-7042"]}, DOI={10.1016/j.foreco.2006.02.016}, abstractNote={Deployment of improved loblolly pine (Pinus taeda L.) genotypes across the southern United States is a standard silvicultural practice. Most planting is conducted using open-pollinated (OP) families from first- or second-generation seed orchards, and these OP families typically display remarkable rank stability for productivity and quality traits across a range of site characteristics, climates, and silvicultural systems. With only a few exceptions, families are generally stable in performance across all sites within a climatic zone. As tree improvement and nursery programs progress towards deployment of more intensively selected genotypes and less genetically diverse full-sib families or clones, there may be a greater likelihood that genotype by environment (G × E) interactions will become important, particularly as the level of silvicultural treatment intensity increases. We present evidence from numerous trials with full-sib families and clones demonstrating that G × E for growth and other traits is no more significant than for OP families. At present and for the foreseeable future, G × E does not appear to be a major concern for the majority of deployed genetic sources under most silvicultural systems.}, number={1-2}, journal={FOREST ECOLOGY AND MANAGEMENT}, author={McKeand, Steven E. and Jokela, Eric J. and Huber, Dudley A. and Byram, Thomas D. and Allen, H. Lee and Li, Bailian and Mullin, Timothy J.}, year={2006}, month={May}, pages={178–184} }
 @article{miller_allen_maier_2006, title={Quantifying the coarse-root biomass of intensively managed loblolly pine plantations}, volume={36}, ISSN={["1208-6037"]}, DOI={10.1139/X05-229}, abstractNote={Most of the carbon accumulation during a forest rotation is in plant biomass and the forest floor. Most of the belowground biomass in older loblolly pine (Pinus taeda L.) forests is in coarse roots, and coarse roots persist longer after harvest than aboveground biomass and fine roots. The main objective was to assess the carbon accumulation in coarse roots of a loblolly pine plantation that was subjected to different levels of management intensity. Total belowground biomass ranged from 56.4 to 62.4 Mt·ha–1and was not affected by treatment. Vegetation control and disking increased pine taproot biomass and decreased hardwood taproot biomass. Pines between tree coarse roots were unaffected by treatment, but hardwoods between tree coarse roots were significantly reduced by vegetation control. Necromass was substantially lower than between-tree biomass, indicating that decomposition of coarse-root biomass from the previous stand was rapid for between-tree coarse roots. Total aboveground biomass was increased by vegetation control, with the lowest production on the least intensively managed plots (180.2 Mt·ha–1) and the highest production on the most intensively managed plots (247.3 Mt·ha–1). Coarse-root biomass ranged from 19% to 24% of total biomass. Silvicultural practices increasing aboveground pine productivity did not increase total coarse-root biomass carbon because of the difference in root/shoot allocation between pine and hardwood species.}, number={1}, journal={CANADIAN JOURNAL OF FOREST RESEARCH}, author={Miller, AT and Allen, HL and Maier, CA}, year={2006}, month={Jan}, pages={12–22} }
 @article{albaugh_allen_kress_2006, title={Root and stem partitioning of Pinus taeda}, volume={20}, ISSN={["0931-1890"]}, DOI={10.1007/s00468-005-0024-4}, number={2}, journal={TREES-STRUCTURE AND FUNCTION}, author={Albaugh, TJ and Allen, HL and Kress, LW}, year={2006}, month={Mar}, pages={176–185} }
 @article{miller_allen_zutter_zedaker_newbold_2006, title={Soil and pine foliage nutrient responses 15 years after competing-vegetation control and their correlation with growth for 13 loblolly pine plantations in the southern United States}, volume={36}, DOI={10.1139/X06-164}, abstractNote={ Influences of competition-control treatments on long-term soil and foliar nutrition were examined using a regional data set (the Competition Omission Monitoring Project) that documents loblolly pine (Pinus taeda L.) plantation development for 15 years after early intensive woody and (or) herbaceous control. Examined were trends for macro nutrients in soils sampled at years 0 and 15 and in pine foliage at years 2, 6, and 15 and their correlations with one another and with pine growth. Early control treatments resulted in distinct plantation successional patterns with contrasting herbaceous and woody components, all under pine-dominated canopies. There was an overall decrease in soil nutrient concentrations after 15 years of pine-plantation management, while C, N, and Ca decreased most after vegetation control. Early herbaceous treatments resulted in significantly less foliar N and K at year 15 as well. Foliar nutrient contents and fascicle mass at year 2 tended to be better correlated with year-15 pine volume than values at year 6 or year 15. Year-15 P concentrations had the strongest correlations between soil and foliar nutrient levels (r = 0.71–0.77). By year 15, intensive pine culture and vegetation control had placed demands on soil nutrient supplies to support enhanced growth that have not yet been replaced. }, number={10}, journal={Canadian Journal of Forest Research}, author={Miller, J. H. and Allen, Howard and Zutter, B. R. and Zedaker, S. M. and Newbold, R. A.}, year={2006}, pages={2412–2425} }
 @article{flores_allen_cheshire_davis_fuentes_kelting_2006, title={Using multispectral satellite imagery to estimate leaf area and response to silvicultural treatments in loblolly pine stands}, volume={36}, ISSN={["0045-5067"]}, DOI={10.1139/X06-030}, abstractNote={ The relationship between leaf area index (LAI) of loblolly pine plantations and the broadband simple ratio (SR) vegetation index calculated from Landsat 7 Enhanced Thematic Mapper Plus (ETM+) data was examined. An equation was derived to estimate LAI from readily available Landsat 7 ETM+ data. The equation developed to predict LAI with Landsat 7 ETM+ data was tested with ground LAI measurements taken in 12 plots. The root mean square error of prediction was 0.29, an error of approximately 14% in prediction. The ability of Landsat 7 ETM+ data to consistently estimate SR over time was tested using two scenes acquired on different dates during the winter (December to early March). Comparison between the two images on a pixel-by-pixel basis showed that approximately 96% of the pixels had a difference of <0.5 units of SR (approximately 0.3 units of LAI). When the comparison was made on a stand-by-stand basis (average stand SR), a maximum difference of 0.2 units of SR (approximately 0.12 units of LAI) was found. These results suggest that stand LAI of loblolly pine plantations can be accurately estimated from readily available remote sensing data and provide an opportunity to apply the findings from ecophysiological studies in field plots to forest management decisions at an operational scale. }, number={6}, journal={CANADIAN JOURNAL OF FOREST RESEARCH-REVUE CANADIENNE DE RECHERCHE FORESTIERE}, author={Flores, FJ and Allen, HL and Cheshire, HM and Davis, JM and Fuentes, M and Kelting, D}, year={2006}, month={Jun}, pages={1587–1596} }
 @article{mckeand_abt_allen_li_catts_2006, title={What are the best loblolly pine genotypes worth to landowners?}, volume={104}, number={7}, journal={Journal of Forestry}, author={McKeand, S. E. and Abt, R. C. and Allen, H. L. and Li, B. L. and Catts, G. P.}, year={2006}, pages={352–358} }
 @article{rubilar_allen_kelting_2005, title={Comparison of biomass and nutrient content equations for successive rotations of loblolly pine plantations on an Upper Coastal Plain Site}, volume={28}, ISSN={["0961-9534"]}, DOI={10.1016/j.biombioe.2004.12.001}, abstractNote={This study compared first- and second-rotation biomass and nutrient equations between successive loblolly pine plantations on an Upper Coastal Plain Site in Alabama. Nutrient concentration relationships with crown position were explored in order to evaluate their significance for biomass studies determinations. Trees were destructively sampled from across the diameter distribution of the stand for each rotation. Tissues were separated into foliage, branch, stemwood, and stembark and analyzed for nutrient concentration and dry weight. Distance from the top of the tree was recorded for all tissues of the selected second-rotation trees and plotted against nutrient concentrations. Regression equations for individual tree tissue biomass and nutrient content were fit for each rotation and compared. Analyses of nutrient concentration relationships with crown position indicated that mobile nutrient (N, P, K, Mg, S, and Zn) concentrations of stemwood, bark, and branches decreased with distance from the top of the tree and height of the live crown. Foliar nutrient concentrations and non-mobile nutrients (Ca and B) for other tissues showed no patterns with tree height. Stemwood biomass regression equations were equivalent after two rotations. However, biomass and nutrient content regression equations for foliage, branches, and bark differed between rotations. Major differences between rotations were in stemwood N and P, and foliage, branch and bark B concentrations, which suggested reduced availability of these nutrients in the second-rotation stand.}, number={6}, journal={BIOMASS & BIOENERGY}, author={Rubilar, RA and Allen, HL and Kelting, DL}, year={2005}, pages={548–564} }
 @article{li_allen_2005, title={Effects of irrigation and fertilization on soil microbial biomass and functional diversity}, volume={20}, DOI={10.1300/j091v20n04_02}, abstractNote={Abstract Optimal water and nutrient treatment effects on soil mi-crobial characteristics, including microbial functional diversity and mi-crobial biomass carbon (C) and nitrogen (N) were assessed at a loblolly pine plantation on a Sandhills site after 6 years of continuous fertilization and irrigation. Fertilization significantly increased soil C and N and microbial C and N. Irrigation significantly increased soil C and N, and microbial C. Fertilization, irrigation, and their interaction changed soil microbial selection of carbon compounds, but did not influence the numbers of carbon compounds utilized by soil microbes, as measured by the BIOLOG method suggesting that soil microbial species may have changed. The increases in soil microbial biomass and soil C and N indicate that the fertilization and irrigation treatments have had a positive effect on soil productivity on this very sandy site.}, number={4}, journal={Journal of Sustainable Forestry}, author={Li, Q. and Allen, Howard}, year={2005}, pages={17–35} }
 @article{klepzig_robison_fowler_minchin_hain_allen_2005, title={Effects of mass inoculation on induced oleoresin response in intensively managed loblolly pine}, volume={25}, ISSN={["1758-4469"]}, DOI={10.1093/treephys/25.6.681}, abstractNote={Oleoresin flow is an important factor in the resistance of pines to attack by southern pine beetle, Dendroctonus frontalis Zimm., and its associated fungi. Abiotic factors, such as nutrient supply and water relations, have the potential to modify this plant-insect-fungus interaction; however, little is known of the effects of inoculation with beetle-associated fungi on oleoresin flow. We observed that constitutive and induced resin yield in loblolly pine, Pinus taeda L., were affected by either fungal inoculation (with the southern pine beetle-associated fungus Ophiostoma minus (Hedgcock) H. & P. Sydow) or silvicultural treatment. The effects of mass wounding (400 wounds m(-2)) and mass wounding and inoculation with O. minus were assessed by comparison with untreated (control) trees. The treatments were applied to trees in a 2 x 2 factorial combination of fertilizer and irrigation treatments. Fertilization did not significantly affect constitutive resin yield. Even as long as 105 days post-treatment, however, mass-inoculated trees produced higher induced resin yields than control or wounded-only trees, indicating a localized induced response to fungal inoculation. We noted no systemic induction of host defenses against fungal colonization. Although beetles attacking previously attacked trees face a greater resinous response from their host than beetles attacking trees that had not been previously attacked, the effect of an earlier attack may not last more than one flight season. Despite mass inoculations, O. minus did not kill the host trees, suggesting that this fungus is not a virulent plant pathogen.}, number={6}, journal={TREE PHYSIOLOGY}, author={Klepzig, KD and Robison, DJ and Fowler, G and Minchin, PR and Hain, FP and Allen, HL}, year={2005}, month={Jun}, pages={681–688} }
 @article{johansson_soderbergh_nilsson_allen_2005, title={Effects of scarification and mulch on establishment and growth of six different clones of Picea abies}, volume={20}, ISSN={["0282-7581"]}, DOI={10.1080/02827580500292121}, abstractNote={Abstract The effects of mulch and scarification on the establishment and growth of six clones of Norway spruce [Picea abies (L.) Karst.] were examined in a study in southern Sweden. Mulch and scarification reduced the amount of competing vegetation and tended to improve soil moisture and soil temperature. Budbreak occurred earlier for cuttings planted in the scarification treatment in comparison with the control and mulching treatment. Scarification increased survival and the combination of scarification and mulch resulted in the best growth. Gas exchange and the number of new roots were higher in planting spots covered with mulch. Clonal differences regarding gas exchange and growth were significant. Clones with a poor height growth also had a low gas exchange and a small number of new roots. In contrast, the clone with the best height growth had high gas exchange and a large number of new roots. Clonal effects on growth were greater than site preparation effects.}, number={5}, journal={SCANDINAVIAN JOURNAL OF FOREST RESEARCH}, author={Johansson, K and Soderbergh, I and Nilsson, U and Allen, HL}, year={2005}, month={Oct}, pages={421–430} }
 @article{choi_chang_allen_kelting_ro_2005, title={Irrigation and fertilization effects on foliar and soil carbon and nitrogen isotope ratios in a loblolly pine stand}, volume={213}, ISSN={["1872-7042"]}, DOI={10.1016/j.foreco.2005.03.016}, abstractNote={We examined δ13C and δ15N in needle (current and 1-year-old) and soil samples collected on two occasions (July and September 1999) from a 15-year-old loblolly pine (Pinus taeda L.) stand in an irrigation and fertilization experiment to investigate whether these treatments leave specific isotope signals in the samples and thus to infer the effects of treatments on C and N cycling. Irrespective of foliar age or sampling date, carbon isotope discrimination (Δ) was increased by irrigation, and decreased by fertilization. The carbon isotope discrimination model suggested that increased Δ by irrigation was due to decreased water use efficiency (WUE) through increased stomatal and/or mesophyll conductance. The decreased Δ by fertilization and published gas exchange measurements at the same site suggest that water stress resulting from increased water demand in the fertilized plots improved WUE through increased stomatal control of water loss. Foliar δ15N values were not affected by irrigation, but were increased by fertilization. The δ15N value of soil NH4+ were higher than those of NO3− and were positively correlated with foliar δ15N, suggesting that tree uptake of NH4+ was one of the factors affecting foliar δ15N. We conclude that irrigation and fertilization affected δ13C and δ15N values in plant and soil samples, reflecting changed C and N cycling patterns and water use efficiency in the studied loblolly pine stand.}, number={1-3}, journal={FOREST ECOLOGY AND MANAGEMENT}, author={Choi, WJ and Chang, SX and Allen, HL and Kelting, DL and Ro, HM}, year={2005}, month={Jul}, pages={90–101} }
 @article{mckeand_allen_2005, title={Summary of IEG-40 meeting: Silviculture and genetic impacts on productivity of southern pine forests}, volume={29}, number={2}, journal={Southern Journal of Applied Forestry}, author={McKeand, S. E. and Allen, H. L.}, year={2005}, pages={61} }
 @article{blevins_prescott_allen_newsome_2005, title={The effects of nutrition and density on growth, foliage biomass, and growth efficiency of high-density fire-origin lodgepole pine in central British Columbia}, volume={35}, ISSN={["1208-6037"]}, DOI={10.1139/X05-204}, abstractNote={ A factorial thinning and fertilization experiment was established in central British Columbia in a 36-year-old high-density fire-origin lodgepole pine (Pinus contorta Dougl. ex Loud. var. latifolia Engelm.) stand to examine the effects of density, nutrition, and their interaction on tree and stand growth, foliage biomass per hectare, and growth efficiency. Volume growth was increased from 2 to 7 m3·ha–1·year–1 when fertilizer was applied without thinning and to 5 m3·ha–1·year–1 when fertilizer was applied with thinning. Thinning increased tree-level foliage biomass and growth efficiency by concentrating limited resources onto fewer trees, resulting in increased tree-level volume growth. Stand-level volume growth was reduced by thinning because of the large reduction in stocking. However, by year 4, stand-level volume growth was the same on control and thinned plots, suggesting that thinned trees have already recaptured the site potential. Fertilization increased both tree-level and stand-level productivity through increases in resource availability per tree and per hectare. This resulted in increased foliage biomass and growth efficiency at the tree and stand level. The combination of thinning and fertilization resulted in the greatest tree-level growth because of increased tree-level foliage biomass and growth efficiency. Boron appears to be the most limiting element followed by sulfur and nitrogen. }, number={12}, journal={CANADIAN JOURNAL OF FOREST RESEARCH}, author={Blevins, DP and Prescott, CE and Allen, HL and Newsome, TA}, year={2005}, month={Dec}, pages={2851–2859} }
 @article{allen_fox_campbell_2005, title={What is ahead for intensive pine plantation silviculture in the south?}, volume={29}, number={2}, journal={Southern Journal of Applied Forestry}, author={Allen, H. L. and Fox, T. R. and Campbell, R. G.}, year={2005}, pages={62–69} }
 @article{flores_allen_2004, title={Efectos del clima y capacidad de almacenamiento de agua del suelo en la productividad de rodales de pino radiata en Chile: Un analisis utilizando el modelo 3-PG}, volume={25}, DOI={10.4067/s0717-92002004000300002}, abstractNote={Resumen es: En Chile, pino radiata (Pinus radiata D. Don) ha sido plantado a lo largo de un amplio rango de suelos y climas, y las plantaciones exhiben amplias varia...}, number={3}, journal={Bosque}, author={Flores, F. J. and Allen, Howard}, year={2004}, pages={11–24} }
 @article{albaugh_allen_dougherty_johnsen_2004, title={Long term growth responses of loblolly pine to optimal nutrient and water resource availability}, volume={192}, ISSN={["1872-7042"]}, DOI={10.1016/j.foreco.2004.01.002}, abstractNote={A factorial combination of four treatments (control (CW), optimal growing season water availability (IW), optimum nutrient availability (FW), and combined optimum water and nutrient availability (FIW)) in four replications were initiated in an 8-year-old Pinus taeda stand growing on a droughty, nutrient-poor, sandy site in Scotland County, NC and maintained for 9 years. Results for the first 4 years after treatment initiation at this study were first reported by Albaugh et al. [For. Sci. 44 (1998) 317]. The site is primarily nutrient limited and all measured stand parameters (height, basal area, leaf area index, live crown length, stem mass accumulation, current annual stem mass increment) were increased with fertilization throughout the study period. Irrigation effects were also positive for these parameters but the increases were much smaller than those found with fertilization. For example, 9 years after treatment initiation, standing stem mass was increased 100 and 25% by fertilization and irrigation, respectively, while current annual increment of stem biomass production was increased 119 and 23% by fertilization and irrigation, respectively. Interestingly, stem density (stems ha−1) was not significantly affected by treatment in any year of the study. Growth efficiency (stem mass increment per unit leaf area index) was 1.9 Mg ha−1 per year per LAI for CW and influenced by treatment with IW, FW, and FIW achieving growth efficiencies of 2.4, 2.7 and 2.9 Mg ha−1 per year per LAI, respectively. Growth efficiency appeared to be relatively stable in the last 4 years of the study. Ring specific gravity was measured in the third, fourth, and fifth years after treatment initiation. An average reduction in ring specific gravity of 7.5% was observed with fertilization while irrigation had little effect on specific gravity in any year measured. The continuation of high growth rates with no observable growth decline in the treated stands throughout the 9-year study may be a function of the age of the stands when treatments were initiated (8 years), the very poor initial nutrient and moisture availability, and/or the application of an ongoing optimum nutrient regime at the site. The fertilized plots are now at or near an age and a size when a commercial harvest would be feasible. For the stand conditions at this site, then, the optimum nutrient availability plots have achieved high productivity throughout the economic life of the stand without measurable declines in stand productivity.}, number={1}, journal={FOREST ECOLOGY AND MANAGEMENT}, author={Albaugh, TJ and Allen, HL and Dougherty, PM and Johnsen, KH}, year={2004}, month={Apr}, pages={3–19} }
 @article{li_allen_wollum_2004, title={Microbial biomass and bacterial functional diversity in forest soils: effects of organic matter removal, compaction, and vegetation control}, volume={36}, DOI={10.1016/j.soilbio.12.001}, number={4}, journal={Soil Biology & Biochemistry}, author={Li, Q. C. and Allen, Howard and Wollum, A. G.}, year={2004}, pages={571–579} }
 @article{sampson_albaugh_johnson_allen_zarnoch_2004, title={Monthly leaf area index estimates from point-in-time measurements and needle phenology for Pinus taeda (vol 33, pg 2477, 2003)}, volume={34}, number={3}, journal={Canadian Journal of Forest Research}, author={Sampson, D. A. and Albaugh, T. J. and Johnson, K. H. and Allen, H. L. and Zarnoch, S. J.}, year={2004} }
 @article{gurlevik_kelting_allen_2004, title={Nitrogen mineralization following vegetation control and fertilization in a 14-year-old loblolly pine plantation}, volume={68}, DOI={10.2136/sssaj2004.2720}, abstractNote={Vegetation control (VC) and fertilization (FR) can change N availability in southern pine plantations, but the magnitude, duration, and reasons for change are not fully understood. The effects of a factorial combination of vegetation control (none vs. complete) and fertilization (none vs. 224 kg N ha−1 and 56 kg P ha−1) on net N mineralization and soil temperature and moisture were investigated in a 14‐yr‐old loblolly pine (Pinus taeda L.) plantation located on the Piedmont of North Carolina. Net N mineralization and soil temperature and moisture were measured monthly for 2 yr beginning in July 1998, four months after the treatments were applied. A companion aerobic laboratory incubation study of field‐moist soil was conducted at 28°C during the second year. Vegetation control increased soil temperature by 1.8°C during the growing season. Both vegetation control and fertilization increased field net N mineralization, and there was a strong positive interaction between the treatments. Net nitrification constituted 72% of net N mineralization for the combined treatment, and only 8% of net N mineralization for the other treatments. Seasonal patterns in net N mineralization were poorly correlated with soil temperature and moisture. The field and laboratory studies showed the same seasonal dynamics and magnitude of annual treatment effects on net N mineralization, suggesting other factors (e.g., labile C inputs) may be important in controlling net N mineralization.}, number={1}, journal={Soil Science Society of America Journal}, author={Gurlevik, N. and Kelting, D. L. and Allen, Howard}, year={2004}, pages={272–281} }
 @article{albaugh_rubilar_alvarez_allen_2004, title={Radiata pine response to tillage fertilization and weed control in Chile}, volume={25}, DOI={10.4067/s0717-92002004000200002}, abstractNote={Se iniciaron en el ano 2000 ensayos para investigar la respuesta a la preparacion de suelos (pala vs. subsolado), control de malezas (sin control vs. dos anos en bandas) y fertilizacion (1,5 g de B por planta vs. 150 g de fosfato diamonico + 1,5 g de B por planta) al establecimiento de pino radiata (Pinus radiata D. Don) en Chile. Los ensayos se establecieron en sitios con suelos de cenizas volcanicas recientes, cenizas volcanicas antiguas ("rojo arcillosos volcanicos"), arenas volcanicas y sedimentos fluviales depositados sobre material granitico. El diseno experimental correspondio a parcelas divididas, donde areas con preparacion de suelos (parcelas principales) fueron divididas en parcelas con control de malezas y fertilizacion (subparcelas), considerando un area minima de tratamiento de 0,4 ha incluyendo buffers de 10 m entre parcelas. Mediciones de altura, diametro de cuello y diametro a la altura del pecho (DAP) fueron obtenidas durante tres anos, junto con muestreos foliares durante los dos primeros anos. Al tercer ano de crecimiento, todos los sitios presentaron respuestas positivas al control de malezas con un promedio de 3,1 cm en diametro y 1 m en altura. Respuestas positivas a la fertilizacion en altura (0,1 m) fueron obtenidas solo en sitios de arenas volcanicas; analisis foliares nutricionales revelaron una escasa absorcion de los nutrientes en la plantacion posiblemente dada una aplicacion tardia de los fertilizantes. El subsolado mostro respuestas positivas en suelos de arenas volcanicas y de sedimentos fluviales, sin embargo, la respuesta fue 95% y 42% menor a la obtenida para control de malezas en estos sitios respectivamente. El control de malezas y el subsolado redujeron la variabilidad en altura en todos los sitios. Nuestra hipotesis es que la temprana respuesta al control de malezas se mantendra hasta la edad de rotacion (curva tipo B) para sitios de cenizas volcanicas antiguas y en sedimentos fluviales sobre material granitico; no obstante, en sitios de cenizas volcanicas recientes y arenas volcanicas esta respuesta decrecera o desaparecera (curva tipo C) a la edad de rotacion. Indudablemente, en todos los sitios evaluados, el control de malezas es recomendable. La fertilizacion es recomendable junto con el control de malezas en sitios de arenas volcanicas. Por tanto, estudios adicionales son necesarios para determinar la epoca oportuna de fertilizacion que asegure una adecuada absorcion de los nutrientes por parte de la plantacion. El subsolado no es necesario en los sitios evaluados, sin embargo, efectos indirectos tales como: mejor accesibilidad, rendimiento y calidad de plantacion, deben ser cuantificados al evaluar los beneficios de esta actividad.}, number={2}, journal={Bosque}, author={Albaugh, T. J. and Rubilar, R. and Alvarez, J. and Allen, Howard}, year={2004}, pages={5–15} }
 @misc{maier_albaugh_allen_dougherty_2004, title={Respiratory carbon use and carbon storage in mid-rotation loblolly pine (Pinus taeda L.) plantations: the effect of site resources on the stand carbon balance}, volume={10}, ISSN={["1365-2486"]}, DOI={10.1111/j.1529-8817.2003.00809.x}, abstractNote={Abstract}, number={8}, journal={GLOBAL CHANGE BIOLOGY}, author={Maier, CA and Albaugh, TJ and Allen, HL and Dougherty, PM}, year={2004}, month={Aug}, pages={1335–1350} }
 @inproceedings{mckeand_allen_2004, title={Silviculture and genetic impacts on productivity of loblolly pine in the southern United States}, booktitle={Forest Genetics and Tree Breeding in the Age of Genomics: Progress and Future,  IUFRO Joint Conference of Division 2, Conference Proceedings}, author={McKeand, S. E. and Allen, H. L.}, editor={Li, B. and McKeand, S.Editors}, year={2004}, pages={373–374} }
 @inproceedings{mckeand_grissom_allen_bullock_2004, title={Ten-year response of diverse families of loblolly pine to fertilization}, booktitle={Forest Genetics and Tree Breeding in the Age of Genomics: Progress and Future,  IUFRO Joint Conference of Division 2, Conference Proceedings}, author={McKeand, S. E. and Grissom, J. E. and Allen, H. L. and Bullock, B. P.}, editor={Li, B. and McKeand, S.Editors}, year={2004}, pages={453–455} }
 @inbook{fox_jokela_allen_2004, title={The evolution of pine plantation silviculture in the southern United States}, booktitle={Southern forest science: Past, present, future}, publisher={Asheville, NC: Southern Research Station}, author={Fox, T. R. and Jokela, E. J. and Allen, H. L.}, editor={Rauscher, H. M. and Johnsen, K.Editors}, year={2004}, pages={63–82} }
 @inbook{schmidtling_robison_mckeand_rousseau_allen_goldfarb_2004, title={The role of genetics and tree improvement in southern forest productivity}, ISBN={60843994}, booktitle={Southern forest science: Past, present, future}, publisher={Asheville, NC: Southern Research Station}, author={Schmidtling, R. C. and Robison, T. L. and McKeand, S. E. and Rousseau, R. J. and Allen, H. L and Goldfarb, B.}, editor={Rauscher, H. M. and Johnsen, K.Editors}, year={2004}, pages={97–108} }
 @article{westfall_burkhart_allen_2004, title={Young stand growth modeling for intensively-managed loblolly pine plantations in southeastern US}, volume={50}, number={6}, journal={Forest Science}, author={Westfall, J. A. and Burkhart, H. E. and Allen, H. L.}, year={2004}, pages={823–835} }
 @inproceedings{rubilar_mckeand_allen_2003, title={Dominance and stand structure analysis in a GxE interaction trial}, booktitle={Proceedings of the 27th Southern Forest Tree Improvement Conference}, author={Rubilar, R. and McKeand, S. E. and Allen, H. L.}, year={2003}, pages={34–37} }
 @article{sampson_albaugh_johnsen_allen_zarnoch_2003, title={Monthly leaf area index estimates from point-in-time measurements and needle phenology for Pinus taeda}, volume={33}, ISSN={["0045-5067"]}, DOI={10.1139/X03-166}, abstractNote={ Leaf area index (LAI) of loblolly pine (Pinus taeda L.) trees of the southern United States varies almost twofold interannually; loblolly pine, essentially, carries two foliage cohorts at peak LAI (September) and one at minimum (March–April). Herein, we present an approach that may be site invariant to estimate monthly LAI for loblolly pine using point-in-time measurements from a LI-COR LAI-2000 plant canopy analyzer (PCA). Our analyses used needle accretion and abscission data from monthly needle counts and destructive harvest data from a replicated 2 × 2 factorial experiment of water and nutrition amendments. No significant treatment effects on relative needle accretion or abscission were observed. Cohort (interannual) differences in needle accretion were found but appeared trivial. Cohort year had variable effects on needle abscission. Abscission of current-year foliage began in July and continued through November of the third year; however, only 7%–9% remained 23 months following bud initiation. A treatment-invariable regression of PCA measurements on cohort foliage biomass (r2 [Formula: see text] 0.98) was used to estimate annual cohort LAI. We derived monthly estimates of LAI from cohort accretion and abscission and cohort LAI. Monthly estimates of LAI for loblolly pine, using point-in-time measurements from the PCA, appear possible, although further testing is required. }, number={12}, journal={CANADIAN JOURNAL OF FOREST RESEARCH-REVUE CANADIENNE DE RECHERCHE FORESTIERE}, author={Sampson, DA and Albaugh, TJ and Johnsen, KH and Allen, HL and Zarnoch, SJ}, year={2003}, month={Dec}, pages={2477–2490} }
 @article{li_allen_wilson_2003, title={Nitrogen mineralization dynamics following the establishment of a loblolly pine plantation}, volume={33}, ISSN={["0045-5067"]}, DOI={10.1139/X02-184}, abstractNote={ The USDA Forest Service initiated a national study in the early 1990s to examine the effects of organic matter removal, compaction, and vegetation control on tree growth and soil processes at several locations across the United States and Canada. Our study was undertaken on the Lower Coastal Plain of North Carolina installation during the second and the fifth growing seasons following loblolly pine (Pinus taeda L.) plantation establishment. We used the in situ soil core incubation method to assess net N mineralization, and collections were conducted monthly from March to December in 1993 and 1996. The largest differences in N mineralization resulted from soil type differences between blocks. Organic matter removal did not affect N mineralization in either year; however, compaction reduced N mineralization during both years. Vegetation control had a pronounced positive effect on N mineralization and was only slightly less important as compared with soil type. Mineralization rates in year 5 were 80% less than in year 2. We hypothesized that the high N mineralization rates in year 2 may be related to a decrease in the input of soluble organic C following harvest (reducing immobilization), a quick mineralization of microbial N, fluctuating soil temperature and water conditions, and fine roots and litter biomass input following harvest. }, number={2}, journal={CANADIAN JOURNAL OF FOREST RESEARCH-REVUE CANADIENNE DE RECHERCHE FORESTIERE}, author={Li, QC and Allen, HL and Wilson, CA}, year={2003}, month={Feb}, pages={364–374} }
 @inproceedings{mckeand_grissom_rubilar_allen_2003, title={Responsiveness of diverse families of loblolly pine to fertilization: eight-year results from SETRES-2}, booktitle={Proceedings of the 27th Southern Forest Tree Improvement Conference}, author={McKeand, S. E. and Grissom, J. E. and Rubilar, R. and Allen, H. L.}, year={2003}, pages={30–33} }
 @article{nilsson_allen_2003, title={Short- and long-term effects of site preparation, fertilization and vegetation control on growth and stand development of planted loblolly pine}, volume={175}, ISSN={["0378-1127"]}, DOI={10.1016/S0378-1127(02)00140-8}, abstractNote={Short- and long-term effects of high and low site preparation intensity, fertilization at planting and vegetation control on growth and stand development were examined in a study that was established on six sites in southeastern USA. The study was established in 1979–1980, and growth after the 18th growing season is reported. The high-intensive site preparation improved long-term stand volume growth. Evidence suggests that the main long-term effect of the intensive site preparation was a reduction in competition from hardwoods. Herbicide treatment improved seedling establishment and early growth, but growth during the last period of measurements (14–18 years after planting) were lower in the herbicide-treated plots as compared to plots without herbicide treatment when herbicides were combined with intensive site preparation. Fertilization at planting, in combination with high-intensive site preparation, improved volume growth during the first 10 years after planting, while fertilization at planting in combination with low-intensive site preparation had little effect on volume growth. The hypothesis that low variability in the seedling stage due to intensive site preparation will lead to low variability in the mature stands with a subsequent reduction in self-thinning was examined. The low site preparation intensity had higher coefficient of variations of stem volumes, and higher mortality. However, the difference in mortality was probably partly a result of differences in competition from hardwoods, and it was not possible to separate the importance of reduced variability from reduced competition from hardwoods. Fertilized plots had lower variability than non-treated control plots but there was no significant difference in mortality between the two treatments. Therefore, it was concluded that reduced variability in the seedling stands, as a result of intensive regeneration methods that reduces environmental heterogeneity, reduces the variability in the mature stands. However, it could not be inconclusively proved that lower variability in the mature stands will result in reduced or postponed self-thinning.}, number={1-3}, journal={FOREST ECOLOGY AND MANAGEMENT}, author={Nilsson, U and Allen, HL}, year={2003}, month={Mar}, pages={367–377} }
 @article{gurlevik_kelting_allen_2003, title={The effects of vegetation control and fertilization on net nutrient release from decomposing loblolly pine needles}, volume={33}, ISSN={["0045-5067"]}, DOI={10.1139/X03-182}, abstractNote={This study examined the effects of vegetation control and nitrogen + phosphorus fertilization on decomposition and nutrient release dynamics of loblolly pine (Pinus taeda L.) needle litter. Needle litter was placed in litterbags and left to decompose on the forest floor, and changes in mass loss and nutrient (N, P, K, Ca, Mg, S, Mn, Zn, B, Cu) concentrations and contents were observed at 2- to 6-month intervals for 32 months. Fertilization had no effect on mass loss, while vegetation control resulted in a warmer and drier forest floor and led to reduced mass loss (k = 0.39 and 0.28 year–1for fertilization and vegetation control, respectively). Concentrations of N, P, Ca, S, Zn, and Cu in the decomposing litter increased two- to three-fold over the 32 months, while concentrations of K, Mg, Mn, and B declined, increased, or did not change depending on time and treatment. Based on the release dynamics, the nutrient mobility series was as follows: Cu [Formula: see text] N [Formula: see text] S < P < Zn [Formula: see text] Ca < K [Formula: see text] Mn < Mg [Formula: see text] B. Fertilization had no effect on release dynamics; however, vegetation control reduced release of N, P, S, and Zn, and increased release of B. The mineral soil may be the main source of plant available N and P in midrotation southern pine stands based on the slow release of these elements from decomposing needle litter.}, number={12}, journal={CANADIAN JOURNAL OF FOREST RESEARCH-REVUE CANADIENNE DE RECHERCHE FORESTIERE}, author={Gurlevik, N and Kelting, DL and Allen, HL}, year={2003}, month={Dec}, pages={2491–2502} }
 @article{albaugh_allen_zutter_quicke_2003, title={Vegetation control and fertilization in midrotation Pinus taeda stands in the southeastern United States}, volume={60}, ISSN={["1286-4560"]}, DOI={10.1051/forest:2003054}, abstractNote={Nous avons evalue l'effet sur des plantations de Pinus taeda L. de differentes methodes de controle de la vegetation (VC) a savoir des traitements chimiques (glyphosate, imazapyr, metsulfuron, methyl et triclopyr), des interventions mecaniques et une fertilisation phosphatee, ceci sur un ensemble de stations situees en plaine et en piedmont des Etats du Sud Ouest, portant des peuplements allant de 10 a 22 ans en debut d'experience. Nous avons etudie la surface terriere des pins et des feuillus (principale vegetation concurrente) ainsi que le volume et la composition foliaire en nutrients des pins dans un dispositif en bloc complet a 2 ou 3 repetitions, avec une combinaison factorielle 2 x 2 d'une seule application de VC et de fertilisation. Le controle de la vegetation reduit l'importance des feuillus de 70 % au moins, sur toutes les stations. En moyenne, c'est le traitement combine qui a l'effet le plus important sur le volume de pin (6,1 et 11,0 m 3 ha -1 an -1 ) suivi par la fertilisation seule (5,5 et 7,9 m 3 ha -1 an -1 ) et par le VC seul (1,1 et 4,5 m 3 ha -1 an -1 ), les deux nombres entre parentheses correspondant aux annees 1 et, puis 3 et 4. L'amplitude de l'effet sur le volume des pins pour l'ensemble des traitements et des stations va de -3 a 12 m 3 ha -1 an -1 . Il est possible que certains stations, non representees ici, caracterisees par un plus grand deficit en eau, une concurrence plus importante et des disponibilites suffisantes en azote et phosphore, puissent reagir de maniere plus importante aux traitements de controle de la vegetation. La fertilisation seule n'a pas d'effet significatif sur la surface terriere des feuillus aux annees 2 et 4 ; la proportion de feuillus en surface terriere est a peu pres la meme avant et apres traitement (12 et 11 %) dans les parcelles temoins et fertilisees. Pour expliquer la superiorite du traitement combine sur la croissance des pins au bout de 4 ans, nous emettons l'hypothese suivante : l'effet fertilisation tend a diminuer, les nutrients apportes ayant ete utilises, mais l'effet VC augmente compte tenu de l'augmentation des disponibilites en nutrients et en eau au profit des pins, la vegetation concurrente ne pouvant pas se developper.}, number={7}, journal={ANNALS OF FOREST SCIENCE}, author={Albaugh, TJ and Allen, HL and Zutter, BR and Quicke, HE}, year={2003}, pages={619–624} }
 @article{king_albaugh_allen_buford_strain_dougherty_2002, title={Below-ground carbon in put to soil is control led by nutrient availability and fine root dynamics in loblolly pine}, volume={154}, ISSN={["0028-646X"]}, DOI={10.1046/j.1469-8137.2002.00393.x}, abstractNote={•  Availability of growth limiting resources may alter root dynamics in forest ecosystems, possibly affecting the land-atmosphere exchange of carbon. This was evaluated for a commercially important southern timber species by installing a factorial experiment of fertilization and irrigation treatments in an 8-yr-old loblolly pine (Pinus taeda) plantation. •  After 3 yr of growth, production and turnover of fine, coarse and mycorrhizal root length was observed using minirhizotrons, and compared with stem growth and foliage development. •  Fertilization increased net production of fine roots and mycorrhizal roots, but did not affect coarse roots. Fine roots had average lifespans of 166 d, coarse roots 294 d and mycorrhizal roots 507 d. Foliage growth rate peaked in late spring and declined over the remainder of the growing season, whereas fine roots experienced multiple growth flushes in the spring, summer and fall. •  We conclude that increased nutrient availability might increase carbon input to soils through enhanced fine root turnover. However, this will depend on the extent to which mycorrhizal root formation is affected, as these mycorrhizal roots have much longer average lifespans than fine and coarse roots.}, number={2}, journal={NEW PHYTOLOGIST}, author={King, JS and Albaugh, TJ and Allen, HL and Buford, M and Strain, BR and Dougherty, P}, year={2002}, month={May}, pages={389–398} }
 @article{nilsson_albaugh_allen_2002, title={Development of size hierarchies prior to the onset of density-dependent mortality in irrigated and fertilized loblolly pine stands}, volume={32}, ISSN={["0045-5067"]}, DOI={10.1139/X02-021}, abstractNote={ Nine years of growth and stand development were investigated in a 2 × 2 nutrient and water factorial experiment with four replications. The study was located on an infertile, excessively drained sandy site in Scotland County, North Carolina, U.S.A. The hypothesis tested was that increased growth following irrigation and fertilization would increase the rate at which size hierarchies develop. The hypothesis was investigated by comparing the coefficient of variation (CV) of stem volume over time and examining the stem volume relative growth rate (RGR) of trees of different initial size in control and irrigated + fertilized stands. Even though there were no statistically significant differences in CV among treatments, there was a tendency for increased CV over time in the control stands, whereas CV initially increased, then decreased, and became constant in the irrigated + fertilized plots. The lack of increase in CV in the irrigated + fertilized plots was explained by unusually low variation in RGR across tree size classes and negative relation of RGR and size. Therefore, the hypothesis that increased growth resulted in a more rapid development of size hierarchies was rejected. The high RGR of small trees in the irrigated + fertilized treatment could not be explained by differences in vertical distribution of needles compared with the control treatment. Small trees in the irrigated + fertilized plots were overtopped by neighboring trees to the same degree as small trees in the control plots. }, number={6}, journal={CANADIAN JOURNAL OF FOREST RESEARCH-REVUE CANADIENNE DE RECHERCHE FORESTIERE}, author={Nilsson, U and Albaugh, TJ and Allen, HL}, year={2002}, month={Jun}, pages={989–996} }
 @inproceedings{newton_robison_hansen_allen_2002, title={Fertilization and thinning in a 7-year-old natural hardwood stand in Eastern North Carolina}, volume={Rep. SRS-48}, booktitle={Proceedings of the Eleventh Biennial Southern Silvicultural Research Conference : Knoxville, Tennessee, March 20-22, 2002}, publisher={Asheville, N.C. : USDA Forest Service, Southern Research Station}, author={Newton, L. P. and Robison, D. J. and Hansen, G. and Allen, H. L.}, editor={K. W. Outcalt, P. A. Outcalt and Tucker, R. B.Editors}, year={2002}, pages={193–195} }
 @article{ludovici_allen_albaugh_dougherty_2002, title={The influence of nutrient and water availability on carbohydrate storage in loblolly pine}, volume={159}, ISSN={["0378-1127"]}, DOI={10.1016/S0378-1127(01)00439-X}, abstractNote={We quantified the effects of nutrient and water availability on monthly whole-tree carbohydrate budgets and determined allocation patterns of storage carbohydrates in loblolly pine (Pinus taeda) to test site resource impacts on internal carbon (C) storage. A factorial combination of two nutrient and two irrigation treatments were imposed on a 7-year-old loblolly pine stand in the Sandhills of North Carolina. Monthly collections of foliage, branch, stem, bark, and root tissues were made and total non-structural carbohydrate analyses were performed on samples collected in years 3 and 4 after treatment initiation. Seasonal fluxes of carbohydrates reflected the hypothesized use and storage patterns. Starch concentrations peaked in the spring in all tissues measured; however, minimum concentrations in aboveground tissue occurred in late winter while minimum concentrations in below ground tissue occurred in late fall. Increased nutrient availability generally decreased starch concentrations in current year tissue, while increasing starch in 1-year-old woody tissue. Irrigation treatments did not significantly impact carbohydrate flux. The greatest capacity for starch storage was in below ground tissue, accounting for as much as 400 kg C/ha per year, and more than 65% of the total stored starch C pool. The absolute amount of C stored as starch was significantly increased with increased nutrient availability, however, its relative contribution to the total annual C budget was not changed.}, number={3}, journal={FOREST ECOLOGY AND MANAGEMENT}, author={Ludovici, KH and Allen, HL and Albaugh, TJ and Dougherty, PM}, year={2002}, month={Apr}, pages={261–270} }
 @article{landsberg_johnsen_albaugh_allen_mckeand_2001, title={Applying 3-PG, a simple process-based model designed to produce practical results, to data from loblolly pine experiments}, volume={47}, number={1}, journal={Forest Science}, author={Landsberg, J. J. and Johnsen, K. H. and Albaugh, T. J. and Allen, H. L. and McKeand, S. E.}, year={2001}, pages={43–51} }
 @article{piatek_allen_2001, title={Are forest floors in mid-rotation stands of loblolly pine (Pinus taeda) a sink for nitrogen and phosphorus?}, volume={31}, ISSN={["0045-5067"]}, DOI={10.1139/cjfr-31-7-1164}, abstractNote={We examined decomposition and nutrient dynamics in fresh litter and net N mineralization in old litter to determine (i) if forest floor is a source of available nutrients in mid-rotation loblolly pine (Pinus taeda L.) stands and (ii) the effect of site preparation and vegetation control on forest floor nutrient dynamics. Four types of fresh litter were decomposed in situ in mesh bags: two containing only pine (differing by history of stand management) and two pine–hardwood mixes (ratios 1:5 and 5:1). Litter bags were recovered every May and October for 26 months. Litter type, in particular the presence and amount of leaves, affected decomposition and nutrient dynamics in fresh litter. After 26 months, all fresh litters lost 55% of mass; decay rate constants were 0.43 (needles) to 0.60 year–1 (leaves). Pine (1) and pine (2) and needles in mix 1:5 immobilized N. Almost all fresh litters also immobilized P. After 26 months of decay, N and P pools suggested an accumulation in the needles of 0.7–2.7 kg N·ha–1 and 0.2–0.5 kg P·ha–1 and mineralization of 1.1–3.7 kg N·ha–1 in mix 5:1 needles and mix 1:5 leaves. All fresh litters mineralized K, Ca, and Mg. Old litter was incubated in situ in capped polyvinyl chloride containers from May to November. Monthly rates of net N mineralization in old litter were determined in KCl extracts of NH4+ and NO3–. Net N mineralization in old litter was 0.75–1.5 kg N·ha–1 per 6 months and was attributed to mineralization in mineral soil. We conclude that forest floors in these stands are not a source of available N or P. Instead, forest floors appear to be sinks for N and probably P.}, number={7}, journal={CANADIAN JOURNAL OF FOREST RESEARCH-REVUE CANADIENNE DE RECHERCHE FORESTIERE}, author={Piatek, KB and Allen, HL}, year={2001}, month={Jul}, pages={1164–1174} }
 @article{johnsen_wear_oren_teskey_sanchez_will_butnor_markewitz_richter_rials_et al._2001, title={Carbon sequestration and southern pine forests}, volume={99}, number={4}, journal={Journal of Forestry}, author={Johnsen, K. H. and Wear, D. and Oren, R. and Teskey, R. O. and Sanchez, F. and Will, R. and Butnor, J. and Markewitz, D. and Richter, D. and Rials, T. and et al.}, year={2001}, pages={14–21} }
 @article{ducey_allen_2001, title={Nutrient supply and fertilization efficiency in midrotation loblolly pine plantations: A modeling analysis}, volume={47}, number={1}, journal={Forest Science}, author={Ducey, M. and Allen, H. L.}, year={2001}, pages={96–102} }
 @inbook{allen_2001, title={Silvicultural treatments to enhance productivity}, ISBN={0632048239}, DOI={10.1002/9780470757079.ch6}, abstractNote={This chapter contains section titled: Introduction Ecophysiological Basis for Forest Production Silvicultural Treatments Interactions Among Treatments Future Opportunities References}, publisher={Oxford: Blackwell Science}, author={Allen, Howard}, year={2001}, pages={129–139} }
 @inproceedings{mckeand_allen_goldfarb_2001, title={Tree improvement and intensive silviculture - productivity increases from modern plantation methods}, booktitle={Proceedings of the 14th CAETS Convocation. World Forests and Technology}, author={McKeand, S. E. and Allen, H. L. and Goldfarb, B.}, year={2001}, pages={99–112} }
 @article{amateis_liu_ducey_allen_2000, title={Modeling response to midrotation nitrogen and phosphorus fertilization in loblolly pine plantations}, volume={24}, journal={Southern Journal of Applied Forestry}, author={Amateis, R. L. and Liu, J. and Ducey, M. J. and Allen, H. L.}, year={2000}, pages={207–212} }
 @article{mckeand_grissom_handest_o'malley_allen_2000, title={Responsiveness of diverse provenances of loblolly pine to fertilization - age 4 results}, volume={10}, DOI={10.1300/j091v10n01_10}, journal={Journal of Sustainable Forestry}, author={McKeand, Steven and Grissom, J. E. and Handest, J. A. and O'Malley, D. M. and Allen, Howard}, year={2000}, pages={87–94} }
 @article{piatek_allen_2000, title={Site preparation effects on foliar N and P use, retranslocation, and transfer to litter in 15-years old Pinus taeda}, volume={129}, ISSN={["0378-1127"]}, DOI={10.1016/S0378-1127(99)00150-4}, abstractNote={Intensive site preparation in loblolly pine (Pinus taeda L.) plantations may remove nutrients and lower site productivity. We evaluated the effects of nutrient removal in site preparation on mid-rotation pine foliar production, and foliar N- and P-use, retranslocation, and transfer to litter for two years. We also investigated changes in foliar nutrients one year after fertilization. Site preparation treatments were: shear–pile–disk and chop–burn, used with or without vegetation control. Mid-rotation pines were fertilized with 200 kg ha−1 N and 50 kg ha−1 P, or with 200 kg ha−1 N and 50 kg ha−1 P and micronutrients. Foliar production was estimated from litter mass. N- and P-use was estimated from N and P concentrations in green foliage and foliar production. Retranslocation was the difference in N and P between green foliage and litter, in percent. N and P transfer to litter was estimated from litter N and P concentration and litter mass. Nutrient removal in site preparation at plantation establishment did not affect mid-rotation pine foliar production, foliar N- and P-use, retranslocation, or nutrient transfer to litter. The lack of site preparation effects may be related to the length of time after treatment; the stage of decomposition of organic matter that may be removed in site preparation may determine when nutrient supply will be affected. Competition with hardwoods decreased pine foliar production by 56%, and N- and P-use by 55% and 52%, but not percent retranslocation. On shear–pile–disk/herbicide, shear–pile–disk/no-herbicide, and chop–burn/herbicide plots (none or small hardwood component), average pine foliar production was 4365 kg ha−1 year−1, N- and P-use was 53.2 and 4.5 kg ha−1 year−1, N and P retranslocation was 63.7% and 69.8%, N and P transfer to litter was 18.9 and 1.3 kg ha−1 year−1. Based on a hypothetical N budget for the total stand, an N limitation may develop on those treatments that lost more nutrients in site preparation. Fertilization increased foliage production by 26%, and N- and P-use both by 49%, indicating some luxury consumption.}, number={1-3}, journal={FOREST ECOLOGY AND MANAGEMENT}, author={Piatek, KB and Allen, HL}, year={2000}, month={Apr}, pages={143–152} }
 @inbook{moore_allen_2000, title={Vegetative composition and height growth of a 4-year old Atlantic white-cedar (Chamaecyparis Thyoides) stand under varying combinations of above- and below-ground competition}, booktitle={The natural history of the Great Dismal Swamp}, publisher={Madison, WI: Omni Press}, author={Moore, S. E. and Allen, H. L.}, year={2000} }
 @inproceedings{moore_allen_2000, title={Vegetative composition and height growth of a 4-year old Atlantic white-cedar (Chamaecyparis thyoides) stand under varying combinations of above- and below-ground competition}, volume={3}, booktitle={Proceedings of the Third Great Dismal Swamp Symposium}, publisher={Norfolk, VA: Old Dominion University}, author={Moore, S. E. and Allen, H. L.}, year={2000}, pages={85–91} }
 @article{allen_albaugh_1999, title={Ecophysiological basis for plantation production: a loblolly pine case study}, volume={20}, journal={Bosque}, author={Allen, H. L. and Albaugh, T. J.}, year={1999}, pages={3–8} }
 @article{zutter_miller_allen_zedaker_edwards_newbold_1999, title={Fascicle nutrient and biomass responses of young loblolly pine to control of woody and herbaceous competitors}, volume={29}, ISSN={["1208-6037"]}, DOI={10.1139/cjfr-29-7-917}, abstractNote={Individual fascicle mass and foliar nutrient content and concentration of young loblolly pine (Pinus taeda L.) were evaluated on 13 locations of a regionwide competition study in the southeastern United States. The study included a factorial combination of two levels of herbaceous weed control treatment (none, treated) and two levels of woody treatment (none, treated) following site preparation. At pine age 2 years, herbaceous treatment (HT) and woody treatment (WT) had a positive effect on individual fascicle biomass and content of N, P, and K at nearly all and at least half of the locations, respectively. In general, these effects mirrored responses noted for seedling diameter and height. N concentration increased and P concentration decreased at about half of the locations, while Ca and Mg concentrations decreased on nearly all locations with HT. By age 6 years, effects of HT and WT on fascicle mass and nutrient concentrations and contents became neutral or more neutral across the locations. This is attributed in part to the greater nutrient demand of larger crop pines and associated competition components. A notable exception from neutral effects at age 6, typically occurring on sites with high levels of woody vegetation, was the positive response in K concentration or content and negative response in Ca and Mg concentrations with WT.}, number={7}, journal={CANADIAN JOURNAL OF FOREST RESEARCH}, author={Zutter, BR and Miller, JH and Allen, HL and Zedaker, SM and Edwards, MB and Newbold, RA}, year={1999}, month={Jul}, pages={917–925} }
 @article{svensson_mckeand_allen_campbell_1999, title={Genetic variation in height and volume of loblolly pine open-pollinated families during canopy closure}, volume={48}, number={3-4}, journal={Silvae Genetica}, author={Svensson, J. C. and McKeand, S. E. and Allen, H. L. and Campbell, R. G.}, year={1999}, pages={204–208} }
 @inproceedings{handest_allen_mckeand_1999, title={Genotype and nutrition effects on stand-level leaf area in loblolly pine}, booktitle={Proceedings of the 25th Southern Forest Tree Improvement Conference}, author={Handest, J. A. and Allen, H. L. and McKeand, S. E.}, year={1999}, pages={70–72} }
 @article{warren_allen_booker_1999, title={Mineral nutrition, resin flow and phloem phytochemistry in loblolly pine}, volume={19}, DOI={10.1093/treephys/19.10.655}, abstractNote={Southern pine beetles and associated pathogenic fungi represent the largest biotic threat to pine forests in the southeastern USA. The two primary defensive mechanisms of the tree to the beetle-fungal complex are the primary oleoresin flow and the concentrations of preformed and induced secondary compounds. We compared oleoresin flow and concentrations of phloem nutrients, soluble sugars, starch, total phenolics and proanthocyanidins in Pinus taeda L. trees in fertilized and control plots in the Sandhills region of North Carolina. Four blocks of 10 trees per treatment were sampled on five dates from May to November 1995. Phloem nitrogen and potassium concentrations were elevated in trees on fertilized plots, whereas phloem calcium concentrations were decreased. Fertilization significantly enhanced (10-20%) concentrations of phloem phenolics and proanthocyanidins. In contrast, phloem soluble sugars and starch concentrations were up to 30% lower in fertilized trees than in control trees. Increased phenolic concentrations and lower nonstructural carbohydrates should correlate with reduced tissue palatability and decreased pathogen susceptibility in fertilized trees; however, resin flows were significantly lower (30-100%) in fertilized trees compared with control trees, which may facilitate pine bark beetle establishment. Furthermore, fertilization-induced increases in phloem nitrogen concentration may be more important than tissue carbohydrate or phenolic content in determining tissue palatability.}, number={10}, journal={Tree Physiology}, author={Warren, J. M. and Allen, Howard and Booker, F. L.}, year={1999}, pages={655–663} }
 @article{piatek_allen_1999, title={Nitrogen mineralization in a pine plantation fifteen years after harvesting and site preparation}, volume={63}, ISSN={["0361-5995"]}, DOI={10.2136/sssaj1999.634990x}, abstractNote={Intensive site preparation for forest tree planting may result in a mid‐rotation decline in soil N availability. Such decline has not been fully documented. This study was conducted in a loblolly pine (Pinus taeda L.) plantation in the Piedmont of North Carolina to evaluate the effects of nutrient removal during harvest and site preparation on N availability at mid‐rotation. Treatments, installed in 1981, consisted of a combination of harvest (stem‐only vs. whole‐tree) and site preparation (chop and burn vs. shear, pile, and disk), with a split‐plot of vegetation control (no herbicide vs. herbicide). In 1995 net N mineralization was examined by monthly in situ soil incubations from May through November (7 mo). Net N mineralization was approximately 3 times lower at mid‐rotation than shortly after treatment. A 5°C drop in soil temperature at 10‐cm depth helped explain ≈50% of this decline. At mid‐rotation, harvest intensity, but not site preparation intensity, affected N mineralization, with stem‐only harvest plots mineralizing 11 kg N ha−1 more than whole‐tree harvest plots during the seven months. Chop–burn–no herbicide plots mineralized 34(±3) kg N ha−1, chop–burn–herbicide: 30(±3) kg N ha−1, shear–pile–disk–herbicide: 28(±3) kg N ha−1, and shear–pile–disk–no herbicide: 19(±3) kg N ha−1 in the seven months. Mid‐rotation mineralization was positively correlated with soil temperature and negatively correlated with soil P and soil C:N ratio. The effect of harvest on N mineralization was probably exerted through P nutrition, whereas the lack of site preparation effects suggested that large nutrient removals that occurred with shearing and piling did not have lasting and negative effects on N availability in this plantation.}, number={4}, journal={SOIL SCIENCE SOCIETY OF AMERICA JOURNAL}, author={Piatek, KB and Allen, HL}, year={1999}, pages={990–998} }
 @inbook{moore_allen_1999, title={Plantation forestry (Plantation silviculture)}, ISBN={0521637686}, DOI={10.1017/cbo9780511613029.014}, abstractNote={With worldwide population growth, there are increasing demands on forests to provide an array of benefits. Growing demand for wood for energy, fiber, and wood products requires that more forests be intensively managed. As silvicultural activities are intensified to meet these demands, all forest organisms will be increasingly aected. The key question is: is intensive forest management compatible with maintenance of biodiversity? In this chapter we will cover how intensive silvicultural activities such as harvesting, site preparation, vegetation control, and fertilization may impact biodiversity. Plantation management is a dominant and growing form of intensive management. Because pine plantations of the southern United States are currently one of the most studied intensively managed forest systems, many of the examples and references cited refer to these systems. Implications, however, are more globally applicable as plantation forestry continues to expand throughout the world (Shepherd 1993, Cubbage et al. 1996).}, booktitle={Maintaining biodiversity in forested ecosystems}, publisher={Cambridge: Cambridge University Press}, author={Moore, S. E. and Allen, Howard}, year={1999} }
 @article{sampson_allen_1999, title={Regional influences of soil available water-holding capacity and climate, and leaf area index on simulated loblolly pine productivity}, volume={124}, ISSN={["0378-1127"]}, DOI={10.1016/s0378-1127(99)00054-7}, abstractNote={We simulated loblolly pine (Pinus taeda L.) net canopy assimilation, using BIOMASS version 13.0, for the southeastern United States (1° latitude by 1° longitude grid cells) using a 44-year historical climate record, estimates of available water-holding capacity from a natural resource conservation soils database, and two contrasting leaf area indices (LAI) (low; peak LAI of 1.5 m2 m−2 projected, and high; 3.5 m2 m−2). Median (50th percentile) available water-holding capacity varied from 100 to 250 mm across the forest type for a normalized 1.25 m soil profile. Climate also varied considerably (growing season precipitation ranged from 200 to 1600 mm while mean growing season temperature ranged from 13° to 26°C). Net canopy assimilation ranged from 9.3 to 19.2 Mg C ha−1 a−1 for high LAI and the 95th percentile of available water-holding capacity simulations. We examined the influence of soil available water-holding capacity, and annual variation in temperature and precipitation, on net canopy assimilation for three cells of similar latitude. An asymptotic, hyperbolic relationship was found between the 44-year average net canopy assimilation and soil available water-holding capacity. Shallow soils had, naturally, low water-holding capacity (<100 mm) and, subsequently, low productivity. However, median available water-holding capacity (125–150 mm) was sufficient to maintain near maximum production potential in these cells. Simulations were also conduced to examine the direct affects of soil available water on photosynthesis (PN) and stomatal conductance (gS) on net canopy assimilation. In the absence of water limitations on PN and gS, net canopy assimilation increased by only 10% or less over most of the loblolly pine region (when compared to simulations for median available water-holding capacity with water influences in place). However, the production differences between high and low LAI, at the median soil available water-holding capacity, ranged from 30% to 60% across the loblolly pine range. Vapor pressure deficit was found to dramatically reduce productivity for stands of similar LAI, incident radiation, rainfall, and available water-holding capacity. Thus, these simulations suggest that, regionally, loblolly pine productivity may be more limited by low LAI than by soil available water-holding capacity (for soils of median available water-holding capacity or greater). In addition, high atmospheric forcing for water vapor will reduce net assimilation for regions of otherwise favorable available water and LAI.}, number={1}, journal={FOREST ECOLOGY AND MANAGEMENT}, author={Sampson, DA and Allen, HL}, year={1999}, month={Nov}, pages={1–12} }
 @article{edwards_gregory_allen_1999, title={Seasonal sulfate deposition and export patterns for a small Appalachian watershed}, volume={110}, ISSN={["0049-6979"]}, DOI={10.1023/A:1005087421791}, number={1-2}, journal={WATER AIR AND SOIL POLLUTION}, author={Edwards, PJ and Gregory, JD and Allen, HL}, year={1999}, month={Feb}, pages={137–155} }
 @article{king_albaugh_allen_kress_1999, title={Stand-level allometry in Pinus taeda as affected by irrigation and fertilization}, volume={19}, DOI={10.1093/treephys/19.12.769}, abstractNote={Changing environmental conditions have the potential to alter allometric relationships between plant parts, possibly leading to ecosystem-level feedbacks. We quantified allometric shifts in field-grown loblolly pine (Pinus taeda L.) in response to altered resource availability based on data from multiple harvests to correct for size-related changes in biomass partitioning. A replicated factorial arrangement of irrigation and fertilization treatments was applied for 4 years to an 8-year-old loblolly pine plantation on a well-drained, low fertility site in North Carolina. Destructive and nondestructive growth measurements were used to develop treatment-specific regressions to estimate stand-level biomass for ephemeral and perennial plant parts, both above- and belowground. Stand-level allometric analysis indicated that irrigation increased biomass partitioning to fine roots and decreased partitioning to foliage, relative to other plant parts. Fertilization increased partitioning to perennial tissues (coarse roots, taproots, and branches) and decreased partitioning to ephemeral tissues (foliage and fine roots). Changes in allometry were small (< 6 %) but statistically significant, indicating that biomass partitioning in loblolly pine changes with altered resource availability, but is probably under strong ontogenetic control.}, number={12}, journal={Tree Physiology}, author={King, J. S. and Albaugh, T. J. and Allen, Howard and Kress, L. W.}, year={1999}, pages={769–778} }
 @article{binkley_burnham_allen_1999, title={Water quality impacts of forest fertilization with nitrogen and phosphorus}, volume={121}, ISSN={["0378-1127"]}, DOI={10.1016/S0378-1127(98)00549-0}, abstractNote={The drinking-water quality of streamwater in forests is typically very good, exceeding the quality of water in areas with other types of land use. Streams draining agricultural lands in the United States average about nine times greater concentrations of nitrate and phosphate than streams draining forested areas. Forest fertilization commonly increases nutrient concentrations in streamwater, and large increases could lead to unacceptable degradation of water quality. This review summarizes information from studies of forest fertilization around the world, and evaluates the responses of streamwater chemistry. In general, peak concentrations of nitrate-N in streamwater increase after forest fertilization, with a few studies reporting concentrations as high as 10–25 (mg N)/l as nitrate. Increases in average concentrations of nitrate are much lower than the peak values, and the highest annual average nitrate-N concentration ever reported was 4 (mg N)/l. Relatively high concentrations of streamwater nitrate-N tend to occur with repeated fertilization, use of ammonium nitrate (rather than urea), and fertilization of N-saturated hardwood forests. Ammonium-N concentrations may also show large peaks following fertilization (up to 15 (mg N)/l), but annual averages remain <0.5 (mg N)/l. Fertilization with phosphate can lead to increased peak concentrations of >1 (mg P)/l, but annual averages remain <0.25 (mg P)/l. No evidence has been reported of detectable effects of forest fertilization on the composition or productivity of stream communities, but more detailed studies may be warranted (especially in relation to P fertilization). Major limitations in current knowledge include the effects of repeated fertilization in short-rotation plantations, fertilization of large landscapes rather than small stands, and the effects of fertilization on streamwater chemistry in tropical plantations.}, number={3}, journal={FOREST ECOLOGY AND MANAGEMENT}, author={Binkley, D and Burnham, H and Allen, HL}, year={1999}, month={Aug}, pages={191–213} }
 @inbook{sampson_dougherty_allen_1998, title={An index for assessing climate change and elevated carbon dioxide effects on loblolly pine productivity}, ISBN={0387948511}, DOI={10.1007/978-1-4612-2178-4_21}, abstractNote={Loblolly pine (Pinus taeda L.) forests represent the major forest type in the southern United States. The loblolly pine region extends from Delaware and centraI Maryland south to central Florida and west to eastern Oklahoma and Texas (Fowells, 1965). The wide range of loblolly pine largely results from its rapid growth and its successful adaptation to many varieties of soil types and environmental conditions. These and other factors have made loblolly pine an important commercial species in the region. However, although loblolly pine occurs on a many types of sites, its commercial value, as measured by net primary productivity (NPP), varies tremendously and is strongly determined by variability in the local climate and stand and site conditions (McNulty et al., 1997). Uncertainty regarding potential changes in climate as a result of increasing atmospheric carbon dioxide (CO2) concentration has caused concern for the future commercial viability of loblolly pine forests.}, booktitle={The productivity and sustainability of Southern forest ecosystems in a changing environment.  (Ecological studies; 128)}, publisher={New York: Springer}, author={Sampson, D. A. and Dougherty, P. M. and Allen, Howard}, editor={Mickler, R. A. and Fox, S.Editors}, year={1998}, pages={367–389} }
 @inbook{dougherty_allen_kress_murthy_maier_albaugh_sampson_1998, title={An investigation of the impacts of elevated CO2, irrigation, and fertilization on the physiology and growth of loblolly pine}, ISBN={0387948511}, DOI={10.1007/978-1-4612-2178-4_9}, abstractNote={Southern pine forests that are dominated by loblolly pine (Pinus taeda L.) are the most intensively managed forests in the United States. They provide more than 50% of the total softwood being harvested annually in the United States and represent the first or second most economically important agricultural crops in nine of the twelve southeastern states (U.S. Department Agriculture Forest Service, 1988). Thus, any changes in environmental conditions that will alter productivity of these forests will have important ecological, economical, and sociological consequences. Over the past several decades, the environment of southeastern forests has been changing. Increases in acidic deposition (SO4 and NOx), nitrogen inputs (Husar, 1986), atmospheric CO2 concentration (Conway et al., 1988; Keeling et al., 1989), and tropospheric ozone have all been documented to parallel the increase in population since the beginning of the industrial revolution. Climate change has also been predicted for the southeastern United States for the future. Each of these atmospheric and climatic elements that are being altered by human activities has the potential to affect productivity of southern pine forests. Nutrient availability, water availability, atmospheric CO2 concentration, and temperature are presently the principal factors that are limiting the productivity of southern pine forests. Thus, it is extremely important that we understand how changes in these factors will interact to affect physiological processes of forest stands.}, booktitle={The productivity and sustainability of Southern forest ecosystems in a changing environment.  (Ecological studies; 128)}, publisher={New York: Springer}, author={Dougherty, P. M. and Allen, Howard and Kress, L. W. and Murthy, R. and Maier, C. and Albaugh, T. J. and Sampson, D. A.}, editor={Mickler, R. A. and Fox, S.Editors}, year={1998}, pages={149–168} }
 @article{allen_lein_1998, title={Effects of site preparation, early fertilization, and weed control on 14-year old loblolly pine}, volume={51}, number={1998}, journal={Proceedings, Southern Weed Science Society}, author={Allen, H. L. and Lein, S.}, year={1998}, pages={104–110} }
 @article{allen_weir_goldfarb_1998, title={Investing in wood production in southern pine plantations}, number={Apr.}, journal={Paper Age}, author={Allen, H. L and Weir, R. J. and Goldfarb, B.}, year={1998}, pages={20–21} }
 @article{albaugh_allen_dougherty_kress_king_1998, title={Leaf area and above- and belowground growth responses of loblolly pine to nutrient and water additions}, volume={44}, number={2}, journal={Forest Science}, author={Albaugh, T. J. and Allen, H. L. and Dougherty, P. M. and Kress, L. W. and King, J. S.}, year={1998}, pages={317–328} }
 @article{sampson_allen_1998, title={Light attenuation in a 14-year-old loblolly pine stand as influenced by fertilization and irrigation}, volume={13}, ISSN={["0931-1890"]}, DOI={10.1007/s004680050190}, number={2}, journal={TREES-STRUCTURE AND FUNCTION}, author={Sampson, DA and Allen, HL}, year={1998}, month={Nov}, pages={80–87} }
 @article{hynynen_burkhart_allen_1998, title={Modeling tree growth in fertilized midrotation loblolly pine plantations}, volume={107}, ISSN={["0378-1127"]}, DOI={10.1016/S0378-1127(97)00334-4}, abstractNote={Diameter and height growth models for fertilized loblolly pine stands were developed using data from midrotation loblolly pine plantations across the southeastern United States. Tree growth in fertilized stands was predicted with a reference growth model multiplied by an equation predicting the relative growth response following fertilization. The temporal distribution of the growth response was modeled by the Weibull function. These equations for fertilizer growth response were developed to be compatible with individual-tree simulation models. Information about dose, nutrient elements, and time elapsed since fertilization are needed to predict the relative growth response following fertilization.}, number={1-3}, journal={FOREST ECOLOGY AND MANAGEMENT}, author={Hynynen, J and Burkhart, HE and Allen, HL}, year={1998}, month={Aug}, pages={213–229} }
 @article{markewitz_richter_allen_urrego_1998, title={Three decades of observed soil acidification in the calhoun experimental forest: Has acid rain made a difference?}, volume={62}, ISSN={["1435-0661"]}, DOI={10.2136/sssaj1998.03615995006200050040x}, abstractNote={Abstract}, number={5}, journal={SOIL SCIENCE SOCIETY OF AMERICA JOURNAL}, author={Markewitz, D and Richter, DD and Allen, HL and Urrego, JB}, year={1998}, pages={1428–1439} }
 @article{king_allen_dougherty_strain_1997, title={Decomposition of roots in loblolly pine: Effects of nutrient and water availability and root size class on mass loss and nutrient dynamics}, volume={195}, ISSN={["0032-079X"]}, DOI={10.1023/A:1004248232450}, number={1}, journal={PLANT AND SOIL}, author={King, JS and Allen, HL and Dougherty, P and Strain, BR}, year={1997}, month={Aug}, pages={171–184} }
 @inproceedings{mckeand_grissom_o'malley_allen_1997, title={Early growth response of diverse families of loblolly pine to nutrient amendments on a poor site}, booktitle={Proceedings of the 24th Southern Forest Tree Improvement Conference}, author={McKeand, S. E. and Grissom, J. E. and O'Malley, D. M. and Allen, H. L.}, year={1997}, pages={267–274} }
 @article{mckeand_crook_allen_1997, title={Genotypic stability effects on predicted family responses to silvicultural treatments in loblolly pine}, volume={21}, number={2}, journal={Southern Journal of Applied Forestry}, author={McKeand, S. E. and Crook, R. P. and Allen, H. L.}, year={1997}, pages={84–89} }
 @article{zhang_allen_dougherty_1997, title={Shoot and foliage growth phenology of loblolly pine trees as affected by nitrogen fertilization}, volume={27}, ISSN={["1208-6037"]}, DOI={10.1139/cjfr-27-9-1420}, number={9}, journal={CANADIAN JOURNAL OF FOREST RESEARCH}, author={Zhang, SS and Allen, HL and Dougherty, PM}, year={1997}, month={Sep}, pages={1420–1426} }
 @article{allen_wentworth_1993, title={VEGETATION CONTROL AND SITE PREPARATION AFFECT PATTERNS OF SHOOT ELONGATION FOR 3-YEAR-OLD LOBLOLLY-PINE}, volume={23}, ISSN={["0045-5067"]}, DOI={10.1139/x93-263}, abstractNote={ Effects of vegetation control and site preparation on the magnitude, morphology, and phenology of loblolly pine (Pinustaeda L.) height growth were investigated duing the third growing season following planting in the Piedmont of North Carolina. Biweekly measurements were made of shoot elongation (by flush) throughout the growing season on a subsample of trees within three replicated plots receiving a factorial combination of site preparation (chop versus shear, pile, disk) and weed control (none, partial control with herbicide, and complete control by hand weeding) treatments. Cumulative height growth on the most intensively treated plots was twice that found on the chopped-only plots, with weed control having a more pronounced positive effect than intensive site preparation. Superior height growth resulted principally from greater length per flush but also from an increased number of flushes. Trees on plots where vegetation was controlled averaged between four and five flushes compared with trees on chopped-only plots, which averaged three flushes. As growth rate of one flush slowed, growth rate of the subsequent flush accelerated, resulting in a rather uniform elongation rate for the shoot apex throughout most of the growing season. Treatment effects on the seasonal distribution of growth and on growing season length were minimal. Thus, intensive culture influenced shoot growth rates and morphology, but not phenology. Apparently the effect of intensive culture was to improve the availability of limited environmental resources and, consequently, to increase growth rate throughout the growing season. }, number={10}, journal={CANADIAN JOURNAL OF FOREST RESEARCH-REVUE CANADIENNE DE RECHERCHE FORESTIERE}, author={ALLEN, HL and WENTWORTH, TR}, year={1993}, month={Oct}, pages={2110–2115} }
 @article{li_allen_mckeand_1991, title={Nitrogen and family effects on biomass allocation of loblolly pine seedlings}, volume={37}, number={1}, journal={Forest Science}, author={Li, B. and Allen, H. L. and McKeand, S. E.}, year={1991}, pages={271–283} }
 @article{allen_morris_wentworth_1991, title={Productivity comparisons between successive loblolly pine rotations in the North Carolina Piedmont}, number={161}, journal={FRI Bulletin}, author={Allen, H. L. and Morris, L. A. and Wentworth, T. R.}, year={1991}, pages={125} }
 @article{li_mckeand_allen_1991, title={SEEDLING SHOOT GROWTH OF LOBLOLLY-PINE FAMILIES UNDER 2 NITROGEN LEVELS AS RELATED TO 12-YEAR HEIGHT}, volume={21}, ISSN={["0045-5067"]}, DOI={10.1139/x91-118}, abstractNote={ Seedling shoot elongation and biomass were examined for 23 open-pollinated loblolly pine (Pinustaeda L.) families grown in a greenhouse under two nitrogen regimes. Significant genetic variation was detected among families for the number of growth cycles, total seedling height, cyclic-growth elongation, the number of stem units, and biomass of stem free growth, cyclic growth, total stem, needles, and total shoot. Heritability estimates were generally high for shoot characteristics except for mean stem-unit length. Shoot biomass measures were weakly or negatively correlated with 12-year-height performance. Elongation of cyclic growth, number of growth cycles, and number of stem units showed stronger correlations with field performance than did seedling height. Juvenile–mature correlations were higher for the low nitrogen treatment, suggesting that 12-year height of loblolly pine families can be more accurately predicted when the seedlings are grown under greenhouse conditions that mimic field nitrogen levels. }, number={6}, journal={CANADIAN JOURNAL OF FOREST RESEARCH-REVUE CANADIENNE DE RECHERCHE FORESTIERE}, author={LI, BL and MCKEAND, SE and ALLEN, HL}, year={1991}, month={Jun}, pages={842–847} }
 @article{allen_dougherty_campbell_1990, title={MANIPULATION OF WATER AND NUTRIENTS - PRACTICE AND OPPORTUNITY IN SOUTHERN UNITED-STATES PINE FORESTS}, volume={30}, ISSN={["1872-7042"]}, DOI={10.1016/0378-1127(90)90153-3}, abstractNote={The magnitude and duration of response of southern pine forests to operations silvicultural treatments including site preparation, drainage, bedding, weed control, thinning, and fertilization are reviewed. The current information for making silvicultural prescriptions in the southeastern U.S. has been developed largely from empirical trials. Silvicultural research has provided only a rudimentary understanding of how water and nutrient availability is altered through silviculture and how they influence stand productivity. Research indicates that many southern pine stands have leaf areas that are below what is theoretically considered to be optimal for maximum productivity. Leaf-area development appears to be limited by both nutrient and water availability. Few data are available to assess the role of changes in resource availability on leaf-area development, photosynthetic efficiency, carbon allocation, and growth attributable to silvicultural treatments. A conceptual model outlining the expected influence of silvicultural treatments on nutrient and water availability and thus on leaf-area development, carbon fixation, carbon allocation and stemwood production is proposed. Blending empirical information with a conceptual understanding of forest productivity should aid in developing silvicultural prescriptions that will help to ameliorate water and/or nutrient limitations, resulting in increased productivity. Major challenges impeding rapid application of existing technology are (1) lack of awareness of opportunities to increase productivity, (2) inadequate capital for silvicultural investments due to uncertainty of the long-term supply and value of wood, and (3) infrastructure barriers that slow the acceptance and implementation of new silvicultural techniques. Future research needs to focus on testing and quantifying the conceptual relationships described, as well as developing practical techniques to assess water and nutrient availability in forest stands.}, number={1-4}, journal={FOREST ECOLOGY AND MANAGEMENT}, author={ALLEN, HL and DOUGHERTY, PM and CAMPBELL, RG}, year={1990}, month={Feb}, pages={437–453} }
 @inproceedings{li_mckeand_allen_1989, title={Early selection of loblolly pine families based on seedling shoot elongation characters}, booktitle={Proceedings of the 20th Southern Forest Tree Improvement Conference}, author={Li, B. and McKeand, S. E. and Allen, H. L.}, year={1989}, pages={228–234} }
 @article{mckeand_allen_1984, title={NUTRITIONAL AND ROOT DEVELOPMENT FACTORS AFFECTING GROWTH OF TISSUE-CULTURE PLANTLETS OF LOBLOLLY-PINE}, volume={61}, ISSN={["1399-3054"]}, DOI={10.1111/j.1399-3054.1984.tb06367.x}, abstractNote={Tissue culture plantlets of loblolly pine (Pinus taeda L.) were compared to seedlings to quantify growth and developmental differences. The two plant types were grown in containers in a greenhouse and sampled periodically for twenty weeks. Dry weights and nitrogen and phosphorus concentrations of the shoots and roots were determined every two weeks.}, number={3}, journal={PHYSIOLOGIA PLANTARUM}, author={MCKEAND, SE and ALLEN, HL}, year={1984}, pages={523–528} }