COS 40-8 - Office developments as novel ecosystems: The role of development and landscaping in determining ecosystem function and biodiversity

Wednesday, August 10, 2016: 10:10 AM
Grand Floridian Blrm A, Ft Lauderdale Convention Center
Karen L. Dyson, Interdisciplinary PhD Program in Urban Design and Planning, University of Washington, Seattle, WA

Novel ecosystems are defined not only by the novel communities of organisms found there, but by supplanted, supplemented, and amended ecosystem processes.

In commercial office developments, site development is a major disturbance event that determines legacy vegetation, habitat provision, and soil communities. Subsequent ongoing landscaping maintenance modifies ecosystem processes including decomposition, nutrient cycling, and succession. Understanding how these altered processes impact other aspects of novel ecosystems provides a basis for management actions to increase the habitat quality and conservation potential for species of concern (e.g. native and endemic species).

Here I ask: do different approaches to development and landscape maintenance influence the ecosystem function and biodiversity outcomes of office development ecosystems? To answer this question, I performed winter bird, mushroom, and vegetation surveys at twenty study sites across Redmond and Bellevue, WA, chosen via stratified random sampling. Birds were surveyed using the standardized search method while mushrooms were sampled via complete site census. I coupled this field data with information from interviews with property owners and landscapers using multivariate regression.


Over two field seasons (November-March), I documented more than 3000 bird observations and 2500 mushroom samples. Generally, more species of birds and genus of mushrooms were found at larger sites and those with greater cover of large native conifers, indicating the importance of site development decisions. One notable exception for bird diversity are the finches, who were also common at sites with deciduous seed bearing trees. The site with the greatest mushroom abundance and diversity had largely undisturbed soils, significant cover of large native conifers, and did not apply mulch--suggesting a role for landscape maintenance. These results suggest that key actions during development include not disturbing existing large native trees and the soil where possible, while planting either native trees or trees that provide winter food for birds. Post development, landscape maintenance should consider the tradeoffs for using mulch.

In the Puget Sound Region, over one million new inhabitants are expected in the next twenty years, and significant new infrastructure is needed to support this growth including office developments. Coupled with conservation, implementing practices like those above for (re)development could result in the preservation of ecosystem functions including habitat provision, decomposition, and nutrient cycling.