**AWARDS ISSUED PRIOR TO JANUARY 20, 2025, WERE FUNDED UNDER PREVIOUS ADMINISTRATIONS AND MAY NOT REFLECT THE PRIORITIES AND POLICIES OF THE CURRENT ADMINISTRATION.** INVASIVE SPECIES CAN THREATEN THE BENEFITS PROVIDED BY SEMIARID RANGELANDS, INCLUDING SOIL HEATH, WATER CYCLING, AND FORAGE FOR NATIVE AND MANAGED HERBIVORES. OFTEN, STUDIES OF EXOTIC SPECIES FOCUS ON A PARTICULAR INVADER; HOWEVER, PLANT COMMUNITIES ARE OFTEN AFFECTED BY A DIVERSE ARRAY OF EXOTIC PLANTS THAT MAY DIFFER IN THE WAYS THAT THEY ALTER BOTH PLANT COMMUNITIES AND SOIL CHARACTERISTICS. WHEN RESTORATION TREATMENTS ARE APPLIED IN INVADED AREAS, THESE NONNATIVE SPECIES MAY LEAVE BEHIND LONG-LASTING LEGACIES IN SOILS, WHICH CAN REPRESENT A BARRIER TO THE RECOVERY OF NATIVE PLANT COMMUNITIES. WE HYPOTHESIZE THAT DIVERSELY INVADED SITES (I.E., CONTAINING HIGH DIVERSITY OF EXOTIC SPECIES) MAY BE IMPACTED BY A GREATER NUMBER OF POSSIBLE CHANGES TO SOIL CONDITIONS THAT ENCOURAGE THESE COMMUNITIES TO RETURN TO A DEGRADED, INVADED STATE, INHIBITING RESTORATION OF NATIVE PLANT COMMUNITIES.TO EXPLORE HOW INVADER DIVERSITY INFLUENCES HOW EASILY SITES MAY BE RESTORED, WE WILL MEASURE WHICH LEGACIES INVADERS LEAVE BEHIND IN THE SOILS OF RESTORED AREAS, FOCUSING ON THEIR IMPACTS ON NITROGEN AND WATER CYCLING, FOCUSING ON SAGEBRUSH STEPPE ECOSYSTEMS IN THE GREAT BASIN REGION. WE WILL ASSESS HOW THESE CHANGES IN SOIL PROCESSES ARE ALTERED BY THE COMPOSITION OF INVASIVE SPECIES PRESENT IN AN AREA BEFORE RESTORATION, AND WE WILL QUANTIFY HOW THESE LEGACIES INFLUENCE THE SUCCESS OF RESTORATION TREATMENTS. THEN, WE WILL APPLY SEVERAL EXPERIMENTAL SOIL TREATMENTS TO TEST WHETHER NEW STRATEGIES MAY BE EFFECTIVE IN MINIMIZING THE NEGATIVE IMPACTS OF PAST INVASIVE SPECIES IN RESTORED SAGEBRUSH STEPPE ECOSYSTEMS. LASTLY, WE WILL COMMUNICATE THE RESULTS OF THIS WORK THROUGH NRCS PARTNERS AND A VARIETY OF OTHER MANAGEMENT COMMUNITIES (E.G. THE GREAT BASIN SOCIETY FOR ECOLOGICAL RESTORATION). AS RESTORATION FREQUENTLY FAILS IN SAGEBRUSH STEPPE RANGELANDS ACROSS THE WESTERN U.S., THIS PROPOSAL WILL BOTH ENHANCE OUR UNDERSTANDING OF THE IMPACTS OF INVASIVE SPECIES, AS WELL AS EVALUATE NEW AND PROMISING MANAGEMENT STRATEGIES IN THIS WIDESPREAD ECOSYSTEM.?