A HERD OF 250 COWS CAN PRODUCE APPROXIMATELY 15,000 LBS OF FECES EVERY DAY. WITHOUT ADEQUATE DECOMPOSITION, FECES STAYS ON THE SOIL SURFACE FOULING FIELDS, SLOWING NITROGEN CYCLING, AND DECREASING FORAGE PRODUCTION ON THE LANDSCAPE. SUSTAINABLE LIVESTOCK PRODUCTION IS DEPENDENT ON THE ECOSYSTEM FUNCTION OF FORAGE PRODUCTION. CONSEQUENTLY, DECOMPOSITION IS ESSENTIAL FOR SUSTAINABLE RANGELAND LIVESTOCK PRODUCTION.DUNG BEETLES ARE CRUCIAL FOR EFFICIENT DECOMPOSITION OF LIVESTOCK FECES. A FECES PAT WITH DUNG BEETLES DECOMPOSES APPROXIMATELY 4X FASTER THAN A PAT WITHOUT. HOWEVER, INCREASINGLY PRODUCERS ARE MAKING DECISIONS TO APPLY PARASITICIDES TO THEIR LIVESTOCK TO CONTROL INTERNAL PARASITES. PARASITICIDES HAVE BEEN SHOWN TO HAVE OFF-TARGET EFFECTS ON DUNG BEETLES. WHEN THESE OFF-TARGET EFFECTS IMPAIR DUNG BEETLE COMMUNITIES AND ACTIVITY, THE SUSTAINABILITY OF RANGELAND LIVESTOCK PRODUCTION IS JEOPARDIZED BECAUSE OF THE SLOWER DECOMPOSITION AND NITROGEN CYCLING AND SUBSEQUENT DECREASE INFORAGE AVAILABILITY.THEREFORE, THE OVERALL GOAL OF THIS RESEARCH IS TO EXAMINE THE DECISION MAKING PROCESS OF LIVESTOCK PRODUCERS TO USE PARASITICIDES AND TO QUANTIFY THE EFFECTS OF PARASITICIDES ON ECOSYSTEM FUNCTION. SUPPORTING OBJECTIVES AND METHODS ARE TO 1) CONDUCT SOCIAL INDICATOR SURVEYS TO ASSESS THE RELATIVE IMPORTANCE OF FACTORS ON DECISIONS TO USE PARASITICIDES; 2) USE FIELD OBSERVATIONS AND MANIPULATIVE STUDIES TO ASSESS THE EFFECT OF PARASITICIDES ON DUNG BEETLES, DECOMPOSITION, NITROGEN CYCLING, AND FORAGE PRODUCTION; AND 3) USE A NETWORK MODEL TO COUPLE INFORMATION PRODUCED IN OBJECTIVES 1 AND 2 TO UNDERSTAND THE CASCADING EFFECTS OF A SINGLE DECISION (TO USE PARASITICIDES) ON HEALTHY AGROECOSYSTEMS AND SUSTAINABLE RANGELAND LIVESTOCK PRODUCTION.