@article{sumnall_trlica_carter_cook_schulte_campoe_rubilar_wynne_thomas_2021, title={Estimating the overstory and understory vertical extents and their leaf area index in intensively managed loblolly pine (Pinus taeda L.) plantations using airborne laser scanning}, volume={254}, ISSN={["1879-0704"]}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-85097899818&partnerID=MN8TOARS}, DOI={10.1016/j.rse.2020.112250}, abstractNote={Data from four discrete-return airborne laser scanning (ALS) acquisitions and three different sensor types across seven experimentally varied loblolly pine (Pinus taeda L.) plantations were used to test published and novel methodologies in quantifying forest structural attributes within stands, including height to live crown (HTLC; i.e. the lowest vertical canopy extent) of the canopy and the contributions to total plot-level leaf area from understory and overstory canopy vegetation. These ALS data were compared to in situ field measurements to develop ALS-based predictive models of these attributes. The correlation between field- and ALS-modeled HTLC data was strong, with an R2 of 0.79 (p < 0.001). We assessed the ability of eight lidar light penetration indices to estimate effective leaf area index (eLAI) in the field. The best predictor of total (sum of understory and overstory) eLAI produced an R2 of 0.88 (p < 0.001). The independent contributions of overstory and understory components could also be accurately predicted by ALS-derived canopy-only eLAI metrics (R2 = 0.71; p < 0.001) and understory-only metrics (R2 = 0.49; p < 0.001). Two new indices, calculated as the sum of return intensity for each foliar layer and correcting for transmission losses, were developed specifically for the vertical strata related to the understory (BLunder) or overstory (BLover). The estimates from BLover were equivalent to the best-performing indices for predicting canopy-only eLAI and the corresponding BLunder was superior to other indices for understory eLAI. The broad spatial and temporal extents of the data, as well as the inclusion of pine plantations with differing stand ages, planting densities, understory control, and thinning treatments, suggest the relationships generated from these methods are robust to site and seasonal variability. The results produced from the analysis of multiple acquisitions implies that the methods presented here are transferable across location, time and sensor design, without implementation-specific calibration, at least for structurally similar loblolly pine plantations.}, journal={REMOTE SENSING OF ENVIRONMENT}, author={Sumnall, Matthew J. and Trlica, Andrew and Carter, David R. and Cook, Rachel L. and Schulte, Morgan L. and Campoe, Otavio C. and Rubilar, Rafael A. and Wynne, Randolph H. and Thomas, Valerie A.}, year={2021}, month={Mar} }
 @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{schulte_robinett_weidle_duran_flickinger_2019, title={Experiments and finite element modeling of hydrodynamics and mass transfer for continuous gas-to-liquid biocatalysis using a biocomposite falling film reactor}, volume={209}, ISSN={["1873-4405"]}, DOI={10.1016/j.ces.2019.115163}, abstractNote={We investigated the hydrodynamics and mass transfer performance of falling liquid films over a rough, hydrophilic paper surface with experiments and finite element modeling. These results are critical for designing a novel gas-to-liquid continuous bioreactor with cells immobilized on the vertical surface of a paper biocomposite. The paper substrate allows investigations at very low Reynolds numbers while maintaining an unbroken liquid film. A finite element model was developed to give 10 fold faster simulation result for designing a prototype laboratory scale bioreactor. Excellent agreement was found in both the film properties and mass transfer performance between experiments and simulations. At Re < 100, mass transfer coefficients kL and kLa were ∼1E-4 m/s and ∼1000 h−1, respectively, at ∼10 W/m3. That power input is 10–1000 fold less than most gas stripping bioreactors. This work highlights the potential of this finite element method for falling film, gas absorbing, bioreactor design and analysis.}, journal={CHEMICAL ENGINEERING SCIENCE}, author={Schulte, Mark J. and Robinett, Michael and Weidle, Nick and Duran, Christopher J. and Flickinger, Michael C.}, year={2019}, month={Dec} }
 @article{schulte_mclaughlin_wurster_balentine_speiran_aust_stewart_varner_jones_2019, title={Linking ecosystem function and hydrologic regime to inform restoration of a forested peatland}, volume={233}, ISSN={["1095-8630"]}, DOI={10.1016/j.jenvman.2018.12.042}, abstractNote={Drainage is a globally common disturbance in forested peatlands that impacts peat soils, forest communities, and associated ecosystem functions, calling for informed hydrologic restoration strategies. The Great Dismal Swamp (GDS), located in Virginia and North Carolina, U.S.A., has been altered since colonial times, particularly by extensive ditch networks installed to lower water levels and facilitate timber harvests. Consequently, peat decomposition rates have accelerated, and red maple has become the dominant tree species, reducing the historical mosaic of bald cypress, Atlantic white-cedar, and pocosin stands. Recent repair and installation of water control structures aim to control drainage and, in doing so, enhance forest community composition and preserve peat depths. To help inform these actions, we established five transects of 15 plots each (75 plots total) along a hydrologic gradient where we measured continuous water levels and ecosystem attributes, including peat depths, microtopography, and forest composition and structure. We found significant differences among transects, with wetter sites having thicker peat, lower red maple importance, greater tree density, and higher overall stand richness. Plot-level analyses comported with these trends, clearly grouping plots by transects (via nonmetric multidimensional scaling) and resulting in significant correlations between specific hydrologic metrics and ecosystem attributes. Our findings highlight hydrologic controls on soil carbon storage, forest structure, and maple dominance, with implications for large-scale hydrologic restoration at GDS and in other degraded forested peatlands more broadly.}, journal={JOURNAL OF ENVIRONMENTAL MANAGEMENT}, author={Schulte, Morgan L. and McLaughlin, Daniel L. and Wurster, Frederic C. and Balentine, Karen and Speiran, Gary K. and Aust, W. Mike and Stewart, Ryan D. and Varner, J. Morgan and Jones, C. Nathan}, year={2019}, month={Mar}, pages={342–351} }
 @article{schulte_mclaughlin_wurster_varner_stewart_aust_jones_gile_2019, title={Short- and long-term hydrologic controls on smouldering fire in wetland soils}, volume={28}, ISSN={["1448-5516"]}, DOI={10.1071/WF18086}, abstractNote={
Smouldering fire vulnerability in organic-rich, wetland soils is regulated by hydrologic regimes over short (by antecedent wetness) and long (through influences on soil properties) timescales. An integrative understanding of these controls is needed to inform fire predictions and hydrologic management to reduce fire vulnerability. The Great Dismal Swamp, a drained peatland (Virginia and North Carolina, USA), recently experienced large wildfires, motivating hydrologic restoration efforts. To inform those efforts, we combined continuous water levels, soil properties, moisture holding capacity and smouldering probability at four sites along a hydrologic gradient. For each site, we estimated gravimetric soil moisture content associated with a 50% smouldering probability (soil moisture smoulder threshold) and the water tension required to create this moisture threshold (tension smoulder threshold). Soil properties influenced both thresholds. Soils with lower bulk density smouldered at higher moisture content but also had higher moisture holding capacity, indicating that higher tensions (e.g. deeper water tables) are required to reach smouldering thresholds. By combining thresholds with water level data, we assessed smouldering vulnerability over time, providing a framework to guide fire prediction and hydrologic restoration. This work is among the first to integrate soil moisture thresholds, moisture holding capacities and water level dynamics to explore spatiotemporal variation in smouldering fire vulnerability.
}, number={3}, journal={INTERNATIONAL JOURNAL OF WILDLAND FIRE}, author={Schulte, Morgan L. and McLaughlin, Daniel L. and Wurster, Frederic C. and Varner, J. Morgan and Stewart, Ryan D. and Aust, W. Mike and Jones, C. Nathan and Gile, Bridget}, year={2019}, pages={177–186} }