@article{smith_brown_frampton_braham_stokes_baird_2023, title={Optimizing Select Fraser Fir (Abies fraseri) Reforestation Methods within an Artificial Bald at Mount Buckley, Great Smoky Mountains National Park}, url={http://dx.doi.org/10.1656/058.022.0305}, DOI={10.1656/058.022.0305}, abstractNote={Abies fraseri (Fraser Fir) has a range that is restricted to high-elevation stands in the southern Appalachian Mountains with few suitable locations. Adelgid piceae (Balsam Wooly Adelgid) depredation that induced high mortality and chronic losses, and other anthropogenic causes, have led to Fraser Fir being designated as an endangered species by the IUCN Red List. There is great interest in restoring Fraser Fir through managed reforestation efforts, especially in protected areas such as Great Smoky Mountains National Park. To optimize Fraser Fir reestablishment in formerly forested sites, we designed a study to examine reforestation success by comparing survival and growth using treatments including mycorrhizal seedling transplants, local seedling transplants, local soil inocula, and mulching conditions to suppress surrounding vegetation. We found that while some treatments increased seedling survival and growth, any benefit was slight compared to local seedling transplants from adjacent mature Fraser Fir stands and/or local soil inocula. Greenhouse manipulations were more costly and time intensive for very little added benefit. We conclude that transplanting local seedlings with native soil to restore damaged sites provides the maximum return on investment and is a viable option for reforestation of Fraser Fir, but a sufficient local seedling bank may not always be available.}, journal={Southeastern Naturalist}, author={Smith, Benjamin and Brown, Shawn P. and Frampton, John and Braham, AnneMargaret and Stokes, C. Elizabeth and Baird, Richard}, year={2023}, month={Aug} }
 @article{walker_bullock_smith_mckeand_2020, title={Modeling Self-Thinning Patterns in Loblolly Pine with Provenance and Family Effects}, volume={66}, ISSN={["1938-3738"]}, url={https://doi.org/10.1093/forsci/fxaa030}, DOI={10.1093/forsci/fxaa030}, abstractNote={Abstract
               
                  
                  Size-density trajectories and self-thinning boundary lines were modeled for two diverse provenances of Pinus taeda L. and five open-pollinated families within each provenance. The data used come from a single site with replicated 64-tree block plots measured through age 25 years. The effects of provenance and family were tested using linear and nonlinear mixed-effects self-thinning models. The drought-hardy Lost Pines of Texas provenance displayed a greater predicted carrying capacity (almost 200 more trees per hectare at reference diameter 25.4 cm) and had a more abrupt approach to the self-thinning line than the widely planted Atlantic Coastal Plain provenance. However, the growth rate of the Lost Pines of Texas provenance was considerably slower and stem form was unacceptable for timber production. Families from the Atlantic Coastal Plain differed in their maximum stand density index predictions (from 1,118 to 1,282 trees per hectare at the reference diameter), suggesting there is an opportunity for artificial selection to change maximum stand density index in this breeding population of loblolly pine. A novel method for predicting the self-thinning boundary line using random effects inherent to the experimental design is presented and recommended for repeated measures data. Experimental design considerations for evaluating genetic differences in self-thinning are discussed.
               
               
                  Study Implications
                  Genetic improvement of growth rate in forest trees has resulted in large gains in plantation productivity, but the effect on carrying capacity has not been addressed. This study indicated that artificial selection on tolerance to competition in the widely planted Atlantic Coastal Plain provenance of loblolly pine can potentially increase harvest yield without sacrificing growth rate. The drought-hardy Lost Pines of Texas provenance displayed greater carrying capacity but had poor stem form and slow growth. The Lost Pines provenance may be attractive for aboveground carbon sequestration, since it sustained substantially more biomass because of greater maximum stand density and denser wood.
               }, number={6}, journal={FOREST SCIENCE}, publisher={Oxford University Press (OUP)}, author={Walker, Trevor D. and Bullock, Bronson P. and Smith, Benjamin C. and McKeand, Steven E.}, year={2020}, month={Dec}, pages={712–725} }
 @article{diversity and density of the em fungal community present in high elevation fraser fir forests of great smoky mountains national park_2014, url={http://dx.doi.org/10.2509/naf2014.009.001}, DOI={10.2509/naf2014.009.001}, abstractNote={A study of the diversity and density of ectomycorrhizal (EM) fungi in two Fraser fir stands near Clingmans Dome, Great Smoky Mountains National Park was conducted over a period of three years. Plots were established in three naturally occurring age class treatments including mature tree, sapling, and low regeneration (no trees) sites.  Lesser vegetation data were determined for nine plant species within all plots including two ferns and two grasses that impeded survival of Fraser fir seedlings. Diversity and densities of vegetation were significantly greater in low regeneration plots as compared to other treatments.  For each plot bryophyte mat forest floor percent occurrence/cover was obtained and percent root colonization/sclerotia of the EM fungus taxa were collected from the three management treatments including 11 decomposers and 33 ectomycorrhizal species. Clavulina cristata occurred in 22.5% of all plots and had a frequency of 1.7% in low regeneration treatments. Four species of Laccaria occurred in 17.3% of all plots, and Laccaria laccata and L. laccata var. pallidifolia were the most common of these species, the former having the highest frequency of occurrence (1.9%) in low regeneration treatments. Four species of Cortinarius occurred in 10.3% of the plots, and Cortinarius anomalus s.l., the most common Cortinarius , occurred in 4.4% of all plots. Seven of the 44 species had significantly greater percent frequency among the three treatments, and six of those were the most frequent in sapling plot treatments at the two locations.  Species found at the two locations were similar, although in 2009 their frequency values were greater than in 2010 and 2011 due to greater total precipitation.  Mature and sapling plot frequency values were significantly greater than those for low regeneration sites due to the low establishment of Fraser fir.  Significant results for species richness, diversity and evenness between years, locations and treatments are present below.  Based on percent frequency values, Laccaria could be used in reforestation of Fraser firs in all plots. A project is underway to evaluate seedling establishment and survival following inoculation with Laccaria spp. on a low regeneration site at Mount Buckley.}, journal={North American Fungi}, year={2014}, month={May} }
 @article{smith_bullock_isik_mckeand_2014, title={Modeling genetic effects on growth of diverse provenances and families of loblolly pine across optimum and deficient nutrient regimes}, volume={44}, ISSN={["1208-6037"]}, url={http://dx.doi.org/10.1139/cjfr-2013-0379}, DOI={10.1139/cjfr-2013-0379}, abstractNote={ Optimal deployment of improved loblolly pine (Pinus taeda L.) planting stock in the southeastern United States requires knowing how diverse seed sources and families perform over time across the wide range of sites used for plantations. This study tests if the relative growth performance of provenances and families is the same at the individual-tree and stand levels for family block plantings and determines what type of adjustment may be required to account for genetic differences when modeling growth and yield. Ten open-pollinated families from two very different provenances, Atlantic Coastal Plain and “Lost Pines” Texas, were grown in single-family block plots to test for growth differences between provenances and among families under severely deficient and optimal nutrition regimes on a nutrient-deficient, dry site. The three-parameter Chapman–Richards function was fit to plot means over time by provenance, family, and nutrition treatments. Models with provenance- or family-specific parameters of the Chapman–Richards function were tested for significant improvement over global parameters. At age 14 years, family, provenance, and nutrition treatments all significantly affected individual-tree growth traits of height, diameter, and volume. Significant nutrition by provenance interactions were found for stand-level traits of basal area per hectare and volume per hectare. Family differences were also significant for these traits. Provenance- or family-specific asymptotic parameters accounted for differences in growth over time. Several traits required the use of local asymptotic and rate parameters in the fertilized treatment only. For modeling growth, a multiplier would be sufficient to account for genetic effects on the majority of traits. }, number={11}, journal={CANADIAN JOURNAL OF FOREST RESEARCH}, publisher={Canadian Science Publishing}, author={Smith, Ben C. and Bullock, Bronson P. and Isik, Fikret and McKeand, Steven E.}, year={2014}, month={Nov}, pages={1453–1461} }
 @article{understanding and developing resistance in hemlocks to the hemlock woolly adelgid_2014, url={http://dx.doi.org/10.1656/058.013.s610}, DOI={10.1656/058.013.s610}, abstractNote={Abstract 
 In light of the increasing need for long-term, sustainable management for Adelges tsugae (Hemlock Woolly Adelgid), researchers are investigating host-plant resistance as part of an integrated approach to combat the pest. This paper reviews the progress made towards developing a resistant hemlock in the southern Appalachians and highlights the importance of investing research and development resources in this field. Along with describing inter- and intraspecific resistance in hemlocks, this paper reviews investigations into resistance mechanisms and outlines the many options for actions that could be or are being taken to increase resistance and restore hemlock forests.}, journal={Southeastern Naturalist}, year={2014} }
 @article{domec_rivera_king_peszlen_hain_smith_frampton_2013, title={Hemlock woolly adelgid (Adelges tsugae) infestation affects water and carbon relations of eastern hemlock (Tsuga canadensis) and Carolina hemlock (Tsuga caroliniana)}, volume={199}, ISSN={0028-646X 1469-8137}, url={http://dx.doi.org/10.1111/nph.12263}, DOI={10.1111/nph.12263}, abstractNote={Summary


Hemlock woolly adelgid (HWA) is an exotic insect pest causing severe decimation of native hemlock trees. Extensive research has been conducted on the ecological impacts of HWA, but the exact physiological mechanisms that cause mortality are not known.

Water relations, anatomy and gas exchange measurements were assessed on healthy and infested eastern (Tsuga canadensis) and Carolina (Tsuga caroliniana) hemlock trees. These data were then used in a mechanistic model to test whether the physiological responses to HWA infestation were sufficiently significant to induce changes in whole‐plant water use and carbon uptake.

The results indicated coordinated responses of functional traits governing water relations in infested relative to healthy trees. In response to HWA, leaf water potential, carbon isotope ratios, plant hydraulic properties and stomatal conductance were affected, inducing a reduction in tree water use by > 40% and gross primary productivity by 25%. Anatomical changes also appeared, including the activation of traumatic cells.

HWA infestation had a direct effect on plant water relations. Despite some leaf compensatory mechanisms, such as an increase in leaf hydraulic conductance and nitrogen content, tree water use and carbon assimilation were diminished significantly in infested trees, which could contribute to tree mortality.

}, number={2}, journal={New Phytologist}, publisher={Wiley}, author={Domec, Jean‐Christophe and Rivera, Laura N. and King, John S. and Peszlen, Ilona and Hain, Fred and Smith, Benjamin and Frampton, John}, year={2013}, month={Apr}, pages={452–463} }