Long-term Outcomes of Forest Restoration in a New York City Park

Creating, restoring, and sustaining forests in urban areas are complicated by habitat fragmentation, invasive species, and degraded soils. Although there is some research on the outcomes of urban reforestation plantings during the first 5 years, there is little research on longer term outcomes. Here, the successional trajectories of restored and unrestored forest sites are compared 20 years after initiating restoration. The sites are located within the Rodman’s Neck area of Pelham Bay Park, in the northeast corner of the Bronx in New York City (NYC), U.S.A. Compared with unrestored sites, the authors saw improvements in species diversity, greater forest structure complexity, and evidence of the regeneration and retention of native tree species in restored sites. In addition, the authors found differences in restoration outcomes depending on the level of intervention: clearing exotic shrubs and vines and planting native trees and shrubs improved tree diversity and canopy closure to a greater extent than clearing exotics alone, and the mechanical removal of invasive plants after the native plantings further improved some measures of restoration, such as tree species diversity and native tree regeneration. The results of this study suggest that the goal of a sustainable forest ecosystem dominated by native trees and other plant species may not be achievable without continued human intervention on site. In addition, these results indicate that the restoration approach adopted by NYC’s reforestation practitioners is moving the site toward a more desirable vegetative community dominated by native species.

In a nutshell, this resource offers:

• Evidence that continued intervention and maintenance of urban forested natural areas is needed to ensure healthy, native-dominated forests.
• A unique long-term look at an urban forested natural area restoration project, rather than shorter-term monitoring.

How to use this resource:

• As a peer-reviewed citation to support an argument for long-term maintenance in a forested natural area.
• As a proof point that long-term maintenance can lead to enhanced natural regeneration and increased native biodiversity.
• For examples of methods to measure forest restoration outcomes over time.

Authors: Brady L. Simmons, Richard A. Hallett, Nancy Falxa Sonti, D. S. N. Auyeung, Jacqueline W. T. Lu

Date published: January 2016

Citation: Simmons, B. L.; Hallett, R. A.; Sonti, N. F.; Auyeung, D. S. N.; Lu, J. W. T. 2016. Long-term outcomes of forest restoration in an urban park. Restoration Ecology. Vol. 24, No. 1. pp 109-118.

Resource available online here.