Functional and Phylogenetic Characteristics of Vegetation: Effects on Constructed Green Infrastructure

Constructed green infrastructure consists of artificial ecosystems designed to produce specific services. Vegetation in constructed ecosystems such as bioretention strips (rain gardens), water treatment wetlands, living roofs and walls generally results from conscious design. The choice of plants can make a large difference with regard to the ecosystem services provided by green infrastructure. We review the literature on constructed green infrastructure and vegetation characteristics, specifically addressing the role of plant functional types, traits and evolutionary relatedness among species in the vegetation in driving ecosystem services. Each type of constructed green infrastructure involves different but consistent preferences in the functional types of plants used, but studies using general plant trait approaches including manipulations of functional or phylogenetic diversity are only just beginning. Empirical studies have identified key plant traits that drive ecosystem services in each type of constructed ecosystem. Experimental studies that manipulate plant functional or phylogenetic diversity in green infrastructure are still uncommon but, in some systems, show that service provisioning can improve with more diverse vegetation. In other cases, selection of the top-performing monocultures seems to optimize provision of a single service. Future work may yet reveal a role for diverse vegetation in constructed ecosystems to provide a variety of services simultaneously.