AS SOIL ECOSYSTEM ENGINEERS, ANTS CONTRIBUTE TO THE MAINTENANCE OF SOIL FERTILITY, ENRICHING AND AERATING SOIL THROUGH FORAGING AND NEST EXCAVATION. THROUGH THIS ECOSYSTEM SERVICE, ANTS FACILITATE THE DEVELOPMENT OF VEGETATION AND MICROORGANISM COMMUNITIES, A VITAL ASPECT OF AGRICULTURAL PRODUCTION. HOWEVER, THE IMPACT OF ANTS AS SOIL ENGINEERS IS LIKELY TO DIFFER ACROSS CLIMATES, AND THEIR ECOSYSTEM SERVICES MAY BE VULNERABLE UNDER CLIMATE CHANGE. THE GOAL OF THIS PREDOCTORAL RESEARCH PROJECT IS TO REVEAL HOW LANDSCAPES AND ENVIRONMENTS AFFECT SOIL MOVEMENT BY ANTS AND PREDICT THE VULNERABILITY OF THIS ECOSYSTEM SERVICE UNDER CLIMATE CHANGE. SPECIFICALLY, I SEEK TO UNDERSTAND THE EFFECTS OF TEMPERATURE, SOIL TYPE, AND VEGETATION ON NEST STRUCTURE AND SOIL MOVEMENT BY ANTS, AND UTILIZE GENOMIC DATA TO PREDICT DISTRIBUTIONAL SHIFTS UNDER CLIMATE PROJECTIONS, OF TWO SPECIES: FORMICA AERATA, PROMINENT THROUGHOUT CALIFORNIA'S AGRICULTURAL LAND, AND FORMICA PODZOLICA, COMMON IN NORTH AMERICAN FORESTS. FIRST, I WILL DETERMINE HOW ANT-SOIL INTERACTIONS CHANGE WITH ENVIRONMENTAL FACTORS BY MEASURING THEIR NEST SHAPE AND SOIL MOVEMENT IN THE LAB UNDER VARIOUS TEMPERATURES AND USING MULTIPLE SOIL TYPES AND PLANTS. SECOND, I WILL REVEAL HOW THESE SPECIES ARE ADAPTED TO CLIMATIC HETEROGENEITY THROUGH GENOMIC SEQUENCING. THIRD, I WILL PREDICT GEOGRAPHIC SHIFTS IN THE ANTS' SOIL SERVICES BY MODELING THE ENVIRONMENTAL CONDITIONS THAT WILL BEST ALLOW THESE ANT SPECIES TO SURVIVE UNDER FUTURE CLIMATE CHANGE SCENARIOS. THROUGH THESE METHODS, THIS PROJECT HOPES TO ACHIEVE THE ULTIMATE GOAL OF BETTER-INFORMING SCIENTISTS AND GROWERS ABOUT HOW ANTS CONTRIBUTE TO SOIL ECOSYSTEM MAINTENANCE AND HOW TO MANAGE THEM BEST TO OPTIMIZE SOIL FERTILITY.