Development and landscaping choices differentiate heterogenous tree and shrub communities on office developments
In urban ecosystems, woody vegetation communities and the ecosystem functions and habitat they provide are largely controlled by humans. These communities are assembled during development, landscaping, and maintenance processes according to decisions made by human actors. While vegetation communities on residential land uses are increasingly well studied, these efforts have generally not extended to other and uses, including commercial land uses; we thus know little about the vegetation communities on these land uses and how they are assembled. To fill this gap, I surveyed tree and shrub communities on office developments located in Redmond and Bellevue, Washington, USA, and explored whether aggregated and parcel scale socio-economic variables or variables describing the outcome of development and landscaping actions better explained variation in vegetation communities. I found that both tree and shrub communities are heterogenous, with distinct groups of sites characterized by native or ornamental vegetation. The outcome of actors’ decision making also explains more variation than aggregated or parcel scale socio-economic variables found significant on residential property. The observed heterogeneity in vegetation communities suggests that different ecosystem functions and habitat quantity and quality are provided on office developments; better provision of these functions is possible using currently existing developments as models. Further, the heterogeneity and observed differences in variable importance between office developments and residential land uses suggests that future urban ecology research must more carefully consider sampling design and that models of the urban ecosystem must account for different decision pathways on land uses. Going forward, research should examine other commercial land uses, commercial land use in additional ecotypes, and decision pathways followed by actors on commercial land uses.