Insect Communities On Green Roofs that are Close in Proximity but Vary in Age and Plant Coverage

The effects of roof age and plant coverage on insect communities were investigated between three green roofs located on the campus of Southern Illinois University Edwardsville. Insect collections were made using pitfall traps on green roofs that were established between 0.5 month and five years prior to insect collection. The green roof with the greatest insect collection rate was the oldest but intermediate in size and percent plant coverage. The oldest green roof had similar collection rates as a nearby ground-level rain garden; however measures of species diversity and evenness were greater in the rain garden.