@article{magee_pandit_flory_crandall_broadbent_prata_dillon_bohlman_johnson_2022, title={Life Stage and Neighborhood-Dependent Survival of Longleaf Pine after Prescribed Fire}, url={https://doi.org/10.3390/f13010117}, DOI={10.3390/f13010117}, abstractNote={Determining mechanisms of plant establishment in ecological communities can be particularly difficult in disturbance-dominated ecosystems. Longleaf pine (Pinus palustris Mill.) and its associated plant community exemplify systems that evolved with disturbances, where frequent, widespread fires alter the population dynamics of longleaf pine within distinct life stages. We identified the primary biotic and environmental conditions that influence the survival of longleaf pine in this disturbance-dominated ecosystem. We combined data from recruitment surveys, tree censuses, dense lidar point clouds, and a forest-wide prescribed fire to examine the response of longleaf pine individuals to fire and biotic neighborhoods. We found that fire temperatures increased with increasing longleaf pine neighborhood basal area and decreased with higher oak densities. There was considerable variation in longleaf pine survival across life stages, with lowest survival probabilities occurring during the bolt stage and not in the earlier, more fire-resistant grass stage. Survival of grass-stage, bolt-stage, and sapling longleaf pines was negatively associated with basal area of neighboring longleaf pine and positively related to neighboring heterospecific tree density, primarily oaks (Quercus spp.). Our findings highlight the vulnerability of longleaf pine across life stages, which suggests optimal fire management strategies for controlling longleaf pine density, and—more broadly—emphasize the importance of fire in mediating species interactions.}, journal={Forests}, author={Magee, Lukas and Pandit, Karun and Flory, Stephen Luke and Crandall, Raelene M. and Broadbent, Eben N. and Prata, Gabriel A. and Dillon, Whalen and Bohlman, Stephanie and Johnson, Daniel J.}, year={2022}, month={Jan} }
 @article{johnson_magee_pandit_bourdon_broadbent_glenn_kaddoura_machado_nieves_wilkinson_et al._2021, title={Canopy tree density and species influence tree regeneration patterns and woody species diversity in a longleaf pine forest}, url={https://doi.org/10.1016/j.foreco.2021.119082}, DOI={10.1016/j.foreco.2021.119082}, abstractNote={Longleaf pine once dominated much of the forested area of the Coastal Plain of the southeastern United States and is a focal forest type for restoration efforts. In these forests, two species dominate the canopy which may influence tree regeneration. Ultimately, the outcomes of habitat filtering, competition, and disturbance manifest in spatial patterns of tree regeneration, including in longleaf pine ecosystems. Understanding regeneration and establishment patterns can aid in restoration efforts. We ask how the dominant species in an established longleaf pine forest are spatially arranged to provide insight into the mechanisms that may be driving tree establishment in longleaf pine forests. We found that longleaf pine saplings were more likely to be found near the other dominant tree species in this forest, turkey oak trees, than in gaps or near to longleaf pine trees. Similarly, turkey oak saplings clustered around turkey oak trees but were dispersed in relation to longleaf pine trees. These findings point towards the interplay between canopy tree composition, leaf litter, and fire behavior as driving mechanisms in the successful establishment of both pines and oaks in this forest.}, journal={Forest Ecology and Management}, author={Johnson, Daniel J. and Magee, Lukas and Pandit, Karun and Bourdon, Jacqueline and Broadbent, Eben N. and Glenn, Kaylyn and Kaddoura, Youssef and Machado, Siddarth and Nieves, Joseph and Wilkinson, Benjamin E. and et al.}, year={2021}, month={Jun} }
 @article{dashti_pandit_glenn_shinneman_flerchinger_hudak_graaf_flores_ustin_ilangakoon_et al._2021, title={Performance of the ecosystem demography model (EDv2.2) in simulating gross primary production capacity and activity in a dryland study area}, volume={297}, url={https://doi.org/10.1016/j.agrformet.2020.108270}, DOI={10.1016/j.agrformet.2020.108270}, abstractNote={Dryland ecosystems play an important role in the global carbon cycle, including regulating the inter-annual global carbon sink. Dynamic global vegetation models (DGVMs) are essential tools that can help us better understand carbon cycling in different ecosystems. Currently, there is limited knowledge of the performance of these models in drylands partly due to characterizing the heterogeneity of the vegetation and hydrometeorological conditions. The aim of this study is to evaluate the performance of a DGVM for drylands to facilitate improved understanding of gross primary production (GPP) as one of the important components of the carbon cycle. We performed a sensitivity analysis and calibrated the Ecosystem Demography (EDv2.2) DGVM to simulate GPP in a dryland watershed (Reynolds Creek Experimental Watershed, Idaho) in the western US for the years 2000-2017. GPP capacity and activity were investigated by comparing model simulations with GPP estimated from eddy covariance data (available from 2015-2017) and remote sensing products (2000-2017). Our results show good performance of EDv2.2 at daily timesteps (RMSE≈0.38[kgC/m2/year])between simulated and measured GPP in lower elevations of the watershed. Moreover, remote sensing analysis show that EDv2.2 captures the long-term trends in this ecosystem and performs relatively well in capturing phenometrics (start/end of the season). The performance of the model degrades in more productive sites with greater GPP (located at higher elevations in the watershed). To improve model performance, future studies will need to introduce additional plant functional types for drylands such as our study area, and modify plant processes (e.g., plant hydraulics and phenology) in the model.}, journal={Agricultural and Forest Meteorology}, publisher={Elsevier BV}, author={Dashti, Hamid and Pandit, Karun and Glenn, Nancy F. and Shinneman, Douglas J. and Flerchinger, Gerald N. and Hudak, Andrew T. and Graaf, Marie Anne and Flores, Alejandro and Ustin, Susan and Ilangakoon, Nayani and et al.}, year={2021}, month={Feb}, pages={108270} }
 @article{pandit_bevilacqua_newman_butler_2021, title={Understanding the Spatial Pattern and Driving Factors Associated with Timberland Ownership Change in the Northern United States}, volume={119}, url={https://doi.org/10.1093/jofore/fvab017}, DOI={10.1093/jofore/fvab017}, abstractNote={Abstract}, number={4}, journal={Journal of Forestry}, publisher={Oxford University Press (OUP)}, author={Pandit, Karun and Bevilacqua, Eddie and Newman, David H and Butler, Brett J}, year={2021}, month={Jul}, pages={376–392} }
 @article{pandit_smith_quesada_villari_johnson_2020, title={Association of Recent Incidence of Foliar Disease in Pine Species in the Southeastern United States with Tree and Climate Variables}, volume={11}, url={https://doi.org/10.3390/f11111155}, DOI={10.3390/f11111155}, abstractNote={Pine forests in the southern United States are a major contributor to the global economy. Through the last three decades, however, there have been concerns about the decline of pine forests attributed mostly to pests and pathogens. A combination of biotic agents and environmental factors and their interaction often influences outbreaks and the resultant damage in the forests. Southern pines experience periodic mortality from bark beetles and root rot fungi and losses from fusiform rust and pitch canker have long been important for management. In recent years, there is also growing evidence of increasing damage from foliar disease in southern pines. Early detection of diseases following changes in foliar characteristics and assessment of potential risks will help us better utilize our resources and manage these forests sustainably. In this study, we used Forest Inventory and Analysis (FIA) data to explore the intensity of foliar disease in three common pines: loblolly (Pinus taeda L.), longleaf (Pinus palustris Mill.), and slash (Pinus elliottii Engelm.) in spatial and temporal terms using tree-level and climatic variables. Results from a tree-level model suggests that crown ratio may be an important factor in pine foliar disease (p < 0.1). We applied the MaxEnt model, a presence-only species distribution model (SDM), to explore any association of foliar disease incidences with the climatic variables at a landscape level. Results indicate that mean dew point temperature, maximum vapor pressure deficit, and precipitation during cold months had more influence over disease incidences than other climatic variables. While the sample size is limited as this is an emerging disease in the region, our study provides a basis for further exploration of disease detection methods, disease etiology studies, and hazard mapping.}, number={11}, journal={Forests}, publisher={MDPI AG}, author={Pandit, Karun and Smith, Jason and Quesada, Tania and Villari, Caterina and Johnson, Daniel J.}, year={2020}, month={Oct}, pages={1155} }