SOIL ORGANIC CARBON STOCKS CONTAIN THREE-TIMES THE AMOUNT OF CARBON AS THE ATMOSPHERE, AND YET IT IS STILL UNCLEAR WHAT MECHANISMS CONTROL THIS CRITICAL BALANCE. AN EMERGING MECHANISM IS THE MOLECULAR DIVERSITY, OR THE RICHNESS AND EVENNESS OF COMPOUNDS THAT COMPRISE THE WHOLE ORGANIC MATTER COMPOSITION. MOLECULAR DIVERSITY IS HYPOTHESIZED TO NOT ONLY BE INFLUENCED BY MICROORGANISM ACTIVITY, BUT IT LIKELY ALSO IMPEDES THE MICROBIAL RESPIRATION OF SOIL ORGANIC CARBON. SOIL ORGANIC MATTER MOLECULAR DIVERSITY HAS THE POTENTIAL TO CONTRIBUTE TO SOIL ORGANIC CARBON SEQUESTRATION EFFORTS, CAN CONTRIBUTE TO CLIMATE CHANGE MODELS BY INTRODUCING A NOVEL VARIABLE TO THE EQUATION, AND CAN ALSO ENHANCE CARBON AND NUTRIENT RETENTION, THEREFORE INCREASE CROP YIELDS,IN AGRICULTURAL ACTIVITIES.TO FULLY INVESTIGATE THE IMPACT THAT MOLECULAR DIVERSITY HAS ON SOIL ORGANIC CARBON PERSISTENCE, WE WILL FIRST IDENTIFY HOW MICROBIAL TRANSFORMATIONS OF PLANT LITTER OVER TIME IMPACT THE MOLECULAR DIVERSITY OF THE RESULTING SOIL ORGANIC MATTER.USING THIS INFORMATION, WE WILL GENERATE A MOLECULAR DIVERSITY GRADIENT TO USE AS A SUBSTRATE IN MINERALIZATION TRIALS, WHERE WE WILL DETERMINE IF SOIL MICROBIAL COMMUNITIES RESPIRE ORGANIC MATTER WITH LOWER MOLECULAR DIVERSITIES AT FASTER RATES. ADDITIONALLY, WE WILL TEST MICROBIAL COMMUNITIES FROM VASTLY DIFFERENT ECOSYSTEMS (I.E., DESERTS, CONIFEROUS FORESTS)ACROSS THE US TO IDENTIFY IF MICROBIAL DIVERSITY CAN OVERCOME MOLECULAR DIVERSITY. FINALLY, WE WILL IDENTIFY IF MINERAL COMPONENTS OF SOIL HAVE AN EFFECT ON THE RELATIONSHIPS BETWEEN MOLECULAR DIVERSITY AND MICROBIAL RESPIRATION RATES.THROUGH THIS EXPERIMENTAL APPROACH, WE ULTIMATELY AIM TO DETERMINE HOW MOLECULAR DIVERSITY CONTRIBUTES TO THE RETENTION OF SOIL ORGANIC CARBON. INCREASED UNDERSTANDING OF THE MOLECULAR COMPOSITION AND DIVERSITY OF SOIL ORGANIC MATTER CAN IMPROVE OUR SOCIETIES OVERALL EFFORTS OF OFFSETTING THE EFFECTS OF CLIMATE CHANGE THROUGH INCREASED SOIL ORGANIC CARBON SEQUESTRATION.