Changes in carabid (Coleoptera: Carabidae) diversity and community structure in age structured forests

We examined the diversity, community composition, and wing state of Carabidae as a function of forest age and identified eighteen species as potential ecological indicators for forest age. Ground beetles (Coleoptera: Carabidae) are typically ground-dwelling, generalist predators. Carabids were collected monthly through pitfall traps from March 2009 through February 2010 from 33 sites representing 5 forest classes approximately 0, 10, 50, 85, and 150 years old. A total of 2,568 individuals were collected, representing 30 genera and 63 species. Carabid species diversity, measured by six diversity indices, was significantly different between the oldest and youngest forest age classes for some but not all of six indices. For all six measures of carabid diversity the highest calculated values were for the 0 age forest class. Most species were considered forest age habitat generalists, occurring in all or most of the age classes. Carabid species composition varied significantly across classes. The result of non-metric multidimensional scaling (NMDS) shows clear separation of forest age classes in terms of beetle community composition. Most species were considered locally rare, occurring in low abundance. Seventeen carabid species were identified as potential candidates for ecological indicators of forest age. The proportion of individuals capable of flight decreased significantly with forest age.