DROUGHT HAS RESULTED IN WIDESPREAD TREE MORTALITY ACROSS THE WESTERN UNITED STATES AND GLOBALLY. THESE MORTALITY EVENTS CAN STRONGLY AFFECT HABITAT FOR WILDLIFE, FORAGE PRODUCTION FOR LIVESTOCK, AND TIMBER HARVESTING. THIS PROJECT IS FOCUSED ON THE PINYON-JUNIPER ECOSYSTEM TYPE, A DOMINANT VEGETATION TYPE OF THE US SOUTHWEST AND A CRITICAL COMPONENT OF RANGELAND ECOSYSTEMS. PINYON PINE IS THE MOST INTENSIVELY STUDIED TREE SPECIES FOR DROUGHT-INDUCED TREE MORTALITY, PARTLY DUE TO THE WIDESPREAD AND SEVERE MORTALITY EVENT THAT OCCURRED DURING AN EXTENDED DROUGHT IN THE EARLY 2000S. DESPITE THE EXTENSIVE AND ACTIVE RESEARCH ON IMPROVING OUR PREDICTIONS OF PINYON PINE MORTALITY, THERE IS A VERY LIMITED UNDERSTANDING OF HOW REGIONAL MORTALITY EVENTS AFFECT UNDERSTORY VEGETATION DYNAMICS. YET THIS INFORMATION IS ESSENTIAL TO BE ABLE TO ASSESS THE LONG-TERM CONSEQUENCES OF RECENT AND PROJECTED FUTURE PINYON PINE DIE-OFF EVENTS ON ECOSYSTEM FUNCTION AND PRODUCTIVITY. THIS PROJECT WILL ASSESSTHE EFFECTS OF DROUGHT-INDUCED PINYON PINE MORTALITY ON UNDERSTORY VEGETATION AND TREE REGENERATION UNDER VARYING CLIMATE CONDITIONS. THIS PROJECT WILL ALSO IDENTIFY THE MANAGEMENT OPTIONS TO ENHANCE RANGELAND RECOVERY AND PRODUCTIVITY FOLLOWING TREE DIE-OFF. THIS WILL BE DONE BY USING PRE-EXISTING INVENTORY AND MONITORING DATASETS, EXPERIMENTAL MANIPULATIONS, AND MODELING. RESULTS OF THIS PROJECT WILL PROVIDE CRITICAL INFORMATION ON THE UNDERSTORY VEGETATION RESPONSE FOLLOWING TREE MORTALITY. THIS PROJECT WILL ALSO IDENTIFY THE MANAGEMENT OPTIONS TO OVERCOME KEY BOTTLENECKS TO OBTAINING NATIVE PLANT ESTABLISHMENT AND TREE RECOVERY FOLLOWING MORTALITY EVENTS. THESE FINDINGS WILL BE CRITICAL TOWARDS CONDUCTING ANTICIPATORY MANAGEMENT IN THESE ECOSYSTEMS THAT HAVE ALREADY AND ARE PREDICTED TO CONTINUE TO UNDERGO DRAMATIC LANDSCAPE CHANGE.