RANGELANDS AS WATER LIMITED ECOSYSTEMS COVER MUCH OF THE WESTERN US WHERE AN ALREADY VARIABLE CLIMATE IS EXPECTED TO BECOME MORE VARIABLE. SUCCESSFUL MANAGEMENT OF THESE AGRO-ECOSYSTEMS TO SUSTAIN PRODUCTIVITY REQUIRES AN UNDERSTANDING OF HOW ECOSYSTEM PROCESSES ARE REGULATED BY KEY ENVIRONMENTAL DRIVERS SUCH AS WATER AVAILABILITY, AND HOW THESE RELATIONSHIPS WILL CHANGE IN THE FUTURE. INCREASING CLIMATE VARIABILITY CAN CHALLENGE OUR BASIC UNDERSTANDING OF HOW RANGELANDS FUNCTION, PARTICULARLY WITH REGARD TO FORAGE PRODUCTION. TO MEET THIS CHALLENGE, OUR RESEARCH FOCUSES ON UNDERSTANDING AND QUANTIFYING SEMI-ARID RANGELAND RESPONSES TO INCREASED CLIMATIC VARIABILITY - CAUSEDBY A GREATER PROPORTION OF TOTALRAINFALL DELIVERED ASVERY LARGE PRECIPITATION EVENTS (DELUGES). GIVEN EVIDENCE THAT LARGE RAIN EVENTSHAVE ALREADY INCREASED, OUR OVERARCHING GOAL IS TO ASSESS HOW AN INCREASE IN DELUGESWILL IMPACT RANGELAND FUNCTION, AND HOW MANAGEMENT MAY MODIFY AND ADAPT TO THIS IMPACT. WE WILL CONDUCT EXPERIMENTSTOMEASURE HOWAN INCREASE IN DELUGES MAY ALTERKEY ECOSYSTEM SERVICES SUCH ASFORAGE PRODUCTION FOR LIVESTOCK ANDWATER USE. WE WILL ALSO EVALUATE HOW GRAZING MANAGEMENT PRACTICES AT THE LANDSCAPE SCALE INTERACT WITH THESE CHANGING RAINFALL PATTERNSTO MODIFY RANGELAND FUNCTIONING. BY COMMUNICATING NEWKNOWLEDGE OF THE IMPACT OF DELUGES ON RANGELAND FUNCTION TO STAKEHOLDERS, WE WILL ASSESS HOW THIS KNOWLEDGE CAN ENHANCE LIVELIHOODS. OUR RESEARCH MEETS USDA AFRI PROGRAMGOALS OF ENHANCING FUNDAMENTAL UNDERSTANDING, AND PROVIDING END USERS WITHNEW KNOWLEDGE TO MAKE DECISIONS THAT INCREASE THE OUTPUT OF RANGELAND ECOSYSTEM SERVICES.