Abstract: The effects of variation in biodiversity on transmission and risk of infectious disease have been conspicuously absent from the biodiversity-ecosystem function (BEF) debates. This chapter addresses several key issues in the BEF literature as they pertain to infectious diseases, including: (1) the shape of the association between biodiversity and disease risk; (2) the relative importance of species richness versus species composition; (3) the relative importance of species richness versus diversity of functional groups or relevant life-history traits; (4) how natural sequences of species loss under environmental change (community disassembly) vs random sequences imposed experimentally influence disease risk; and (5) the importance of diversity at organizational levels other than (host) species in influencing disease risk. In a world where biodiversity is changing dramatically and infectious diseases are emerging and resurging, understanding the role of biodiversity in the ecology of diseases is arguably one of the most important areas in BEF research.

Keywords: biodiversity, infectious disease, conservation medicine, disease ecology, lyme disease, zoonoses,