Post-hurricane vegetation recovery in an urban forest

摘要

Urban forests are increasingly vulnerable to catastrophic disturbance, and their isolation and human use may challenge the ability of vegetation to recover spontaneously. We examined vegetation responses to recent hurricane disturbance in a temperate mixedwood urban forest: Point Pleasant Park in Halifax, Nova Scotia, which suffered over 70% canopy loss during Hurricane Juan in fall 2003. In 2005 we surveyed 30 paired plots with disturbed and intact tree canopies to assess early regeneration patterns and seed banks. Native early successional tree species dominated seed bank and seedling layers. Soil properties were similar between intact and disturbed urban plots and local reference forests, thus long-term woody debris removal, hurricane disturbance and subsequent clean-up activities have not caused substantial soil degradation. Non-native species were not abundant throughout the park but were concentrated at the park boundary adjacent to residential neighbourhoods. The results of this study suggest that urban forests can show natural successional trajectories after catastrophic disturbance, and management is probably not necessary for forest recovery in Point Pleasant Park. Conversely, intervention to speed up regeneration of shade-tolerant canopy species may be desired by local citizens, so managers will have to balance conflicting values in developing a restoration plan for the park. (c) 2007 Elsevier B.V. All rights reserved.