@article{robbins_loudermilk_mozelewski_jones_scheller_2024, title={Fire regimes of the Southern Appalachians may radically shift under climate change}, volume={20}, ISSN={["1933-9747"]}, url={https://doi.org/10.1186/s42408-023-00231-1}, DOI={10.1186/s42408-023-00231-1}, abstractNote={Abstract}, number={1}, journal={FIRE ECOLOGY}, author={Robbins, Zachary J. and Loudermilk, E. Louise and Mozelewski, Tina G. and Jones, Kate and Scheller, Robert M.}, year={2024}, month={Jan} }
 @article{robbins_xu_jonko_chitra-tarak_fettig_costanza_mortenson_aukema_kueppers_scheller_2023, title={Carbon stored in live ponderosa pines in the Sierra Nevada will not return to pre-drought (2012) levels during the 21st century due to bark beetle outbreaks}, volume={11}, ISSN={["2296-665X"]}, DOI={10.3389/fenvs.2023.1112756}, abstractNote={Outbreaks of several bark beetle species can develop rapidly in response to drought and may result in large transfers of carbon (C) stored in live trees to C stored in dead trees (10s of Tg C yr-1 in the western U.S. alone), which over time will be released back to the atmosphere. The western pine beetle (WPB) outbreak incited by the 2012–2015 mega-drought in the Sierra Nevada, California, U.S., could portend more frequent and/or severe bark beetle outbreaks as the temperature warms and drought frequency and intensity increase in the future. However, changes in the frequency and/or severity (resultant levels of host tree mortality) of beetle outbreaks are difficult to predict as outbreaks are complex with non-linear and eruptive processes primarily driven by interactions among beetle populations, the demography of hosts and other tree species, and climate and weather. Using an insect phenology and tree defense model, we projected the future likelihood of WPB outbreaks in the Sierra Nevada with climate drivers from different Earth System Models. Our goal was to understand how host (ponderosa pine, PIPO) recovery and future warming and drought affect the frequency and severity of WPB outbreaks and their C consequences. Our projections suggested that by 2100 the C stored in live PIPO (mean: 1.98 kg C m-2, 95% CI: 1.74–2.21 kg C m-2) will not return to levels that occurred before the 2012–2015 drought (2012: ∼2.30 kg C m-2) due to future WPB outbreaks. However, differences in climate models indicate a wide range of possible WPB outbreak frequencies and severities. Our results suggest that total plot basal area is the most significant factor in the mortality rate of PIPO by WPB in any given year, followed by drought severity and temperature. High levels of host basal area, higher temperature, and extreme drought all contribute to the frequency and severity of future WPB outbreaks. While PIPO basal area may decline under increased drought and warming, limiting high-stand basal area (>60 m2 ha-1) may reduce the severity of future WPB outbreaks in the Sierra Nevada.}, journal={FRONTIERS IN ENVIRONMENTAL SCIENCE}, author={Robbins, Zachary J. and Xu, Chonggang and Jonko, Alex and Chitra-Tarak, Rutuja and Fettig, Christopher J. and Costanza, Jennifer and Mortenson, Leif A. and Aukema, Brian H. and Kueppers, Lara M. and Scheller, Robert M.}, year={2023}, month={Mar} }
 @article{robbins_loudermilk_reilly_o'brien_jones_gerstle_scheller_2022, title={Delayed fire mortality has long-term ecological effects across the Southern Appalachian landscape}, volume={13}, ISSN={["2150-8925"]}, url={https://doi.org/10.1002/ecs2.4153}, DOI={10.1002/ecs2.4153}, abstractNote={Abstract}, number={6}, journal={ECOSPHERE}, publisher={Wiley}, author={Robbins, Zachary J. and Loudermilk, E. Louise and Reilly, Matthew J. and O'Brien, Joseph J. and Jones, Kate and Gerstle, Christopher T. and Scheller, Robert M.}, year={2022}, month={Jun} }
 @article{mozelewski_robbins_scheller_2022, title={Forecasting the influence of conservation strategies on landscape connectivity}, volume={6}, ISSN={["1523-1739"]}, DOI={10.1111/cobi.13904}, abstractNote={Abstract}, journal={CONSERVATION BIOLOGY}, author={Mozelewski, Tina G. and Robbins, Zachary J. and Scheller, Robert M.}, year={2022}, month={Jun} }
 @article{buotte_koven_xu_shuman_goulden_levis_katz_ding_ma_robbins_et al._2021, title={Capturing functional strategies and compositional dynamics in vegetation demographic models}, volume={18}, ISSN={["1726-4189"]}, DOI={10.5194/bg-18-4473-2021}, abstractNote={Abstract. Plant community composition influences carbon, water, and
energy fluxes at regional to global scales. Vegetation demographic models
(VDMs) allow investigation of the effects of changing climate and
disturbance regimes on vegetation composition and fluxes. Such investigation
requires that the models can accurately resolve these feedbacks to simulate
realistic composition. Vegetation in VDMs is composed of plant functional
types (PFTs), which are specified according to plant traits. Defining PFTs
is challenging due to large variability in trait observations within and
between plant types and a lack of understanding of model sensitivity to
these traits. Here we present an approach for developing PFT
parameterizations that are connected to the underlying ecological processes
determining forest composition in the mixed-conifer forest of the Sierra
Nevada of California, USA. We constrain multiple relative trait
values between PFTs, as opposed to randomly sampling within the range of
observations. An ensemble of PFT parameterizations are then filtered based
on emergent forest properties meeting observation-based ecological criteria
under alternate disturbance scenarios. A small ensemble of alternate PFT
parameterizations is identified that produces plausible forest composition
and demonstrates variability in response to disturbance frequency and
regional environmental variation. Retaining multiple PFT parameterizations
allows us to quantify the uncertainty in forest responses due to variability
in trait observations. Vegetation composition is a key emergent outcome from
VDMs and our methodology provides a foundation for robust PFT
parameterization across ecosystems.
                    }, number={14}, journal={BIOGEOSCIENCES}, author={Buotte, Polly C. and Koven, Charles D. and Xu, Chonggang and Shuman, Jacquelyn K. and Goulden, Michael L. and Levis, Samuel and Katz, Jessica and Ding, Junyan and Ma, Wu and Robbins, Zachary and et al.}, year={2021}, month={Jul}, pages={4473–4490} }
 @article{vakili_shakeri_motahari_farahani_robbins_scheller_2021, title={Resistance and Resilience of Hyrcanian Mixed Forests Under Natural and Anthropogenic Disturbances}, volume={4}, ISSN={["2624-893X"]}, DOI={10.3389/ffgc.2021.640451}, abstractNote={Biological disturbances are integral to forest ecosystems and have pronounced effects on forest resistance, resilience, and diversity. The Hyrcanian mixed forest, in northern Iran, is at risk of declining resistance, resilience, and diversity due to ongoing pressure from land use change, harvesting, and biological disturbances. We analyzed the resistance and resilience of this area under two biological disturbances (i.e., oak charcoal fungus, Biscogniauxia mediterranea, and alder leaf beetle, Galerucella lineola) and in concert with proposed harvesting. We used a simulation modeling approach whereby we simulated 12 combinations of biological disturbances and harvesting scenarios using the LANDIS-II landscape change model. We estimated the correlation between forest resistance and resilience and tree species diversity to harvesting and biological disturbance. We analyzed the full species composition and age class for 30 and 100 years after disturbances in order to assess resistance as the change in species composition over time. We considered resilience as the ability to recover from a disturbance back to a similar initial state. Results indicate a positive effect of biological disturbances and harvesting on diversity. Our simulations resulted in a negative relationship between diversity-resistance and diversity-resilience within high diversity areas. Our simulation of the Hyrcanian forest reveals that harvesting and biological disturbances, as tested, fulfill the goal of maintaining forest diversity. However, increasing diversity does not always follow by increasing forest resistance and resilience. Scenarios with oak charcoal fungus, both with and without harvesting indicate the lowest decrease in resilient and resistant.}, journal={FRONTIERS IN FORESTS AND GLOBAL CHANGE}, author={Vakili, Mehdi and Shakeri, Zahed and Motahari, Saeed and Farahani, Maryam and Robbins, Zachary James and Scheller, Robert M.}, year={2021}, month={Jul} }
 @article{robbins_xu_aukema_buotte_chitra-tarak_fettig_goulden_goodsman_hall_koven_et al._2021, title={Warming increased bark beetle-induced tree mortality by 30% during an extreme drought in California}, volume={10}, ISSN={["1365-2486"]}, DOI={10.1111/gcb.15927}, abstractNote={Abstract}, journal={GLOBAL CHANGE BIOLOGY}, author={Robbins, Zachary J. and Xu, Chonggang and Aukema, Brian H. and Buotte, Polly C. and Chitra-Tarak, Rutuja and Fettig, Christopher J. and Goulden, Michael L. and Goodsman, Devin W. and Hall, Alexander D. and Koven, Charles D. and et al.}, year={2021}, month={Oct} }