INVASIVE PLANTS LEAD TO SIGNIFICANT LOSSES IN BIODIVERSITY AND ASSOCIATED ECOSYSTEM SERVICES ACROSS THE GLOBE. UNFORTUNATELY, ONGOING NATURAL AND ANTHROPOGENIC DISTURBANCES CONTINUE TO ACCELERATE THE SPREAD OF INVASIVE PLANT SPECIES AND EXACERBATE THEIR IMPACTS. EVEN THOUGH RESEARCHERS HAVE BEEN STUDYING INVASIONS FOR DECADES, ECOLOGISTS STILL LACK A COMPREHENSIVE FRAMEWORK FOR PREDICTING WHEN AND WHERE A GIVEN ORGANISM IS LIKELY TO ESTABLISH, PROLIFERATE, AND DISRUPT ECOSYSTEM PROCESSES. NOVEL AND GENERALIZABLE INSIGHTS INTO INVASION DYNAMICS MAY BE GAINED BY CONSIDERING TWO INTERACTING COMPONENTS OF THE INVASION PROCESS SIMULTANEOUSLY: (1) THE TRAITS OF THE INVADER AND (2) HOW TRAITS OF RESIDENT SPECIES INFLUENCE SPECIES, COMMUNITY, AND ECOSYSTEM RESPONSES TO INVASION.UNLIKE SPECIES-BASED APPROACHES THAT FOCUS ON SPECIES IDENTITIES TO UNDERSTAND COMPETITION AND INVASION DYNAMICS, TRAIT-BASED APPROACHES AIM TO LINK SPECIES FUNCTIONAL TRAITS (I.E., PHYSIOLOGICAL, MORPHOLOGICAL, OR PHENOLOGICAL CHARACTERISTICS THAT INFLUENCE FITNESS) WITH COMPETITIVE OUTCOMES, INVADER PERFORMANCE, AND RESIDENT SPECIES RESPONSES TO INVASION. BY FOCUSING ON TRAITS RATHER THAN SPECIES, TRAIT-BASED APPROACHES MAY PROVIDE A UNIVERSAL FRAMEWORK FOR STUDYING THE MECHANISMS AND IMPACTS OF INVASION AT DIVERSE SITES AND SCALES. WE WILL USE A TRAIT-BASED APPROACH TO QUANTIFY HOW DIFFERENCES IN TRAITS BETWEEN INVADERS AND RESIDENT SPECIES DETERMINE SPECIES, COMMUNITY, AND ECOSYSTEM RESPONSES TO INVASION. SPECIFICALLY, WE WILL WORK WITH THE INVASIVE ANNUAL GRASS BROMUS TECTORUM (I.E., CHEATGRASS OR DOWNY BROME) AND COMBINE AN EXPERIMENTAL STUDY WITH AN OBSERVATIONAL DATASET TO ADDRESS THE FOLLOWING OBJECTIVES:DETERMINE THE EXTENT TO WHICH RESIDENT SPECIES PERFORMANCEIS INFLUENCED BY DIFFERENCES IN TRAITS BETWEEN BROMUS TECTORUM AND RESIDENT SPECIESQUANTIFY CHANGES IN FUNCTIONAL COMPONENTS OF COMMUNITIESAND ECOSYSTEM SERVICES RESULTING FROM INVASIONEVALUATE WHETHER PATTERNS VARY BY ENVIRONMENTAL CONTEXT OR SCALEIDENTIFYING GENERALIZABLE PATTERNS DRIVING PLANT INVASIONS IS IMPERATIVE FOR CURBING THE IMPACTS OF INVASIVE PLANTS ON ECOSYSTEMS WORLDWIDE. BY DETERMINING HOW TRAIT-BASED INTERACTIONS BETWEEN INVADERS AND RESIDENT SPECIES INFLUENCE INVADER SUCCESS AND ASSOCIATED IMPACTS, THIS RESEARCH WILL PROVIDE NOVEL INSIGHT TO FUNCTIONAL UNDERPINNINGS OF INVASION. OUR FINDINGS WILL HELP LAND MANAGERS PREDICT WHICH SPECIES AND COMMUNITIES ARE MOST VULNERABLE TO INVADER IMPACTS TO PRIORITIZE AREAS FOR MANAGEMENT AND WILL ENABLE RESTORATION PRACTITIONERS TO SELECT NATIVE PLANT MATERIALS WITH APPROPRIATE TRAITS FOR RESTORATION OF INVADED AREAS.