This 3-year interdisciplinary project will address the Joint Fire Science Program (JFSP) Task 3, Implications of changing fuels and fire regimes selected region Great Basin. The project will assess the efficacy of fuel management strategies at decadal time-scales by synthesizing existing data to develop inputs for a vegetation dynamics model, the Ecosystem Demography (ED) model. The purpose of using the process-based ED model is to provide alternative future scenarios of the sagebrush-steppe ecosystem of the Great Basin under changing climate and fire regimes. Climate forcings for ED will be developed by using the Weather Research and Forecasting model to dynamically downscale output from a unique large ensemble global climate modeling experiment based on the Community Earth System Model. This approach allows us to address not only the potential impacts of global climate change, but also internal climate variability that can lead to transient regional anomalies that significantly depart from global trends. The ED model will be run at annual time steps to simulate dynamics over the next 20 years across the Great Basin. Model simulations will explicitly parameterize fuel treatments (e.g. fuel reduction and seeding) to provide predictions of the effectiveness of treatments on future fuel amounts and distributions and fire regimes. The outputs of these simulations will be compared to existing fuel treatment studies and vegetation monitoring datasets (e.g. SageSTEP sites, Chronosequence study, NCA fuels study) to constrain uncertainty and provide interpretations between model predictions and local interactions between land management, vegetation, fire, and climate. The spatially- and temporally-explicit projections will provide 1) assessments of the efficacy of existing and proposed fuels reduction treatments (i.e., quantified future fuel loadings and continuity); 2) estimates of the sustainability of such treatments (i.e., estimated maintenance for treatment intervals and intensity); and 3) fuel treatment effects on the ecology of Great Basin (i.e., with a focus on shifting plant community dynamics, and potential effects on sage-grouse habitat). The science team, comprised of university and USGS scientists, has expertise in fire ecology, restoration, hydrology, remote sensing, and land-atmosphere and ecological modeling. Importantly, we have engaged and will continue to engage land managers through our collaboration network and the JFSP fire science exchange network. We propose bi-annual meetings with fuels and land managers to better inform our model inputs and simulations and to understand potential alternative scenarios and management practices. Our interactions will facilitate an assessment of the implications of changing fuels and fire regimes on land managers ability to meet management objectives. In addition, we anticipate that scientists and managers will jointly interpret model outputs to improve iterations of the ED model for the Great Basin. In addition to the bi-annual meetings, the model outputs including associated uncertainties and interpretations will be made widely and freely available via data repositories, presentations at regional meetings and conferences, two webinars, and publications. Whereas this project is focused on fuels management, our results as well as model inputs (e.g., downscaled climate projections), developed parameterizations (e.g., representation of specific fuel treatments) and outputs (e.g., biomass, net ecosystem productivity) can be used by a wide range of public, private, tribal, and non-governmental organizations for comprehensive, process-based, and decadal-scale planning across the Great Basin.