During 2003-2005 we are investigating 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. This study is also examining the relationship between downed woody debris and invertebrate biodiversity within a forest stand. 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 downed woody debris and ground- dwelling arthropod diversity?, (2) What is the relationship between forest type and ground-dwelling arthropod diversity? and (3) What is the effect of BBD and thinning on biodiversity of ground-dwelling arthropods? We are collecting ground-dwelling arthropods using unbaited pitfall traps in 48 northern hardwood stands in Michigan based on forest type, presence/ absence of mechanical thinning, and presence/ absence of BBD. Ground beetles (Coleoptera: Carabidae), camel crickets (Orthoptera: Gryllacrididae) and sowbugs (Crustacea: Isopoda) are identified to the species level and are the focal groups of this study. All other ground-dwelling arthropods are grouped and quantified by taxonomic group. A better understanding of the factors affecting diversity of ground-dwelling arthropods is important for management, conservation and the preservation of biological diversity.