During 2003-2005, we are investigating: 1) the effects of forest type, forest stand characteristics, beech bark disease (BBD), and mechanical thinning on the biodiversity of ground-dwelling arthropods in northern hardwood stands in Michigan, and 2) the relationship between downed woody debris (DWD) and invertebrate biodiversity within forest stands. The goal of this research is to help explain the complex relationships and interactions between ground-dwelling arthropods, forest stand characteristics, and disturbances in Michigan’s northern hardwood forests. Specific research questions being asked include: (1) What is the relationship between forest type and ground-dwelling arthropod diversity? (2) What is the effect of BBD on biodiversity of ground-dwelling arthropods? (3) What is the effect of mechanical thinning on biodiversity of ground-dwelling arthropods? (4)What is the relationship between downed wood and ground-dwelling arthropod diversity? We are collecting ground-dwelling arthropods using unbaited pitfall traps in 48 northern hardwood stands in Michigan. Ground beetles (Coleoptera: Carabidae), camel crickets (Orthoptera: Gryllacrididae) and sowbugs (Crustacea: Isopoda) are identified to species to determine any species shifts related to disturbances. Spiders, centipedes, millipedes, and ground snails and slugs are identified to the family level. A better understanding of the factors affecting diversity of ground-dwelling arthropods is important for management, conservation and the preservation of biological diversity.