The housing-forest interface: Testing structural approaches for protecting suburban natural systems following development

Abstract

Natural systems play important ecological, social and economic functions within suburban environments, such as wildlife habitat, community recreation and stormwater management. However, their integrity is at risk if there is encroachment into these systems from adjacent land uses. Local governments often consider active management of natural systems too expensive, so rely on structural approaches, such as fences, to manage the physical interface between housing land uses and natural systems. Despite a reliance on this approach, it is not known whether it is effective in protecting natural systems from these impacts. Research has identified spatial extent of disturbance as a key measure of human impact on forested natural systems, and planners want to know how far adjacent land use impacts extend into the forest edge to specify protective buffer strips between these land uses. This study measured the extent of post development impacts of over 350 residences built adjacent to suburban forests in Southern Ontario. The results indicate that boundary treatments can offer some long-term protection from residential encroachment; however, commonly implemented treatments can be greatly improved based on the results of this study. Boundaries between residences and natural systems should be carefully designed to control physical access, clearly delineate private from public land uses, and where appropriate, encourage community monitoring of the housing/forest interface. However, even under the most effective boundary treatment, encroachment activities continued at significant distances from forest borders. Forested buffers of at least 50 m wide are required to segregate encroachment impacts from sensitive forested natural systems.