Vegetated Roofs as Reconciled Habitats: Rapid Assays Beyond Mere Species Counts

by Reid R. Coffman¹ and Tom Waite²

¹Division of Landscape Architecture, University of Oklahoma, 830 Van Vleet Oval, Norman, OK 73019

²Department of Evolution, Ecology, and Organismal Biology, The Ohio State University, 318 W. 12th Avenue, Columbus, OH 43210

Abstract

This study describes animal diversity on two dissimilar vegetated roofs and promotes a general methodological approach for analyzing the species found. Insect, spider, and bird data on these roofs were collected using a rapid assessment method, and species diversity was described from presence-absence and relative abundance data. Birds were assessed at the species level, and insects and spiders were assessed at higher taxonomic levels. Animal diversity beyond the species level on the two roofs was quantified using the Rényi family of diversity indices, which encompasses conventional metrics. Insects, spiders, and birds were present on both vegetated roofs, with some differences in species assembly. Bird diversity was lowest, while spider and insect diversity were higher and specific to each roof. This study promotes the methodological approach used here, speculates on factors influencing species assembly on the vegetated roofs, and discusses conservation implications of these constructed habitats.

Keywords: green roof, habitat, biodiversity, vegetated roof, vegetative roof, ecoroof, Rényi, rapid assessment.