Forecasting Dryland Ecosystem Vulnerability to Change: A Cross-System Assessment of Vegetation and Process Responses to Disturbance and Climate Variability on DoD Lands
Scott Ferrenberg | U.S. Geological Survey
The Department of Defense (DoD) manages vast installations in western U.S. drylands. The maintenance of native vegetation and ecosystem processes is key for the utility and health of these ecosystems, which face escalating pressures from climate change. At the same time, critical training activities on DoD lands cause disturbances that will interact with the changing climate to affect distributions of habitat-defining plants and ecosystem processes. An improved understanding of how these factors will interactively impact DoD lands is needed for adaptive management. This project is organized around four objectives to provide management tools and improved forecasting of ecosystem vulnerability to individual and interacting pressures from climate change and disturbance at multiple spatial and temporal scales:
- Objective 1 - assess the vulnerability of plant species and communities to climate change and disturbance on three DoD installations of distinct drylands (i.e., Great Basin, Mojave, and Chihuahuan deserts) across a latitudinal climatic gradient;
- Objective 2 - scale the findings and existing data to assess spatial and temporal variability in the drivers of species vulnerability to climate change and disturbance across this climatic gradient;
- Objective 3 - develop an improved understanding of how vegetation responses to climate change and disturbance will affect key ecosystem processes; and
- Objective 4 - deliver a robust set of tools for predicting responses of vegetation and ecological processes to climate change and disturbance to support DoD land management.
This research will help DoD managers plan for and manage ecosystems affected by climate change through a multi-disciplinary effort to understand the interactive effects of climate change and disturbance on vegetation communities and ecosystem processes of DoD lands across three large deserts of the western U.S. These deserts represent a natural, latitudinal gradient in climate and vegetation types. As a result, ecosystem vulnerability and drivers of change are expected to vary among deserts. The research team will assess the vulnerability of vegetation and ecosystem processes (productivity, habitat quality, soil fertility and stability) to drought and disturbance with a set of factorial field experiments aimed at isolating key drivers of change under drought conditions predicted by climate models. Second, researchers will combine these experimental results with existing long-term climate and vegetation data (field survey data, remote sensing archives) collected in actively managed and paired protected areas to quantitatively model and scale vegetation sensitivity to different climate drivers in relation to disturbance history. Importantly, this allows for frameworks of understanding and planning at spatiotemporal scales not possible with on-the-ground or site-specific measurements alone. Third, through a synthesis of experimental and remotely-sensed measures of processes, researchers will develop an improved understanding of climate change and disturbance impacts on key processes at the ecosystem scale. Collectively, these experimental and numerical approaches enable the delivery of tools and predictive frameworks regarding which types of habitat are most vulnerable to climate change and land use, how drivers of change vary across spatiotemporal scales, and where across the landscape these changes will be most pronounced.
Roughly 70% of DoD lands consists of installations in western U.S. drylands. These installations provide critical pre-deployment training grounds that aid in national security. As a result of interacting climate and land use pressures, DoD resource managers face significant challenges for managing core biological communities and ecosystem processes under non-stationary conditions. Scientific knowledge regarding dryland vegetation and ecosystem process responses to climate change and disturbance allow for scientifically-supported adaptive management strategies to meet DoD’s resource management challenges. These strategies, for example, could prioritize the conservation of specific plant species with stronger links to ecosystem processes, that demonstrate greater resistance or resilience to drought and disturbance, or guide managers with regard to the best conditions to make go/no-go decisions regarding management interventions in light of environmental conditions. This research would also markedly advance the scientific understanding of dryland responses to change, offering a range of scientific and social benefits.