Abstract: Research on the relationship between biodiversity and ecosystem functioning typically varies biodiversity levels by establishing communities that are subsets of the species in the high diversity community. This chapter examines what happens when biodiversity change is not limited to these subsets but instead is open to colonization from a larger species pool. The chapter first examines species traits that are responsible for successful colonization, establishment, and impact on ecosystem processes. The chapter then addresses how novel species may produce cascading and irreversible effects, drawing on known processes (selection effect or complementarity effect) that drive relationships between biodiversity and ecosystem functioning. Finally, the chapter explores how information on species traits and processes driving the relationship between biodiversity and ecosystem functioning may be used to enhance the economic evaluation of invasion risks to society.

Keywords: invasion, biodiversity, ecosystem functioning, immigration, functional traits, economic evaluation, risk analysis, management,