Seeing the Forest and the Trees: Outcomes of Forest Restoration in The Bronx
Friday, August 26, 2016
NYC Urban Field Station
Planting native trees can revive an ailing forest, but trees alone cannot fight the spread of invasive species. According to a study by the NYC Department of Parks & Recreation (NYC Parks) and the USDA Forest Service, continued maintenance is also necessary to meet restoration goals.
In a study recently published by the journal Restoration Ecology, continued research into the outcomes of multiple forest restoration techniques will provide a basis for managers to make informed decisions about the preservation and restoration of our urban landscapes. The study is based on research at Pelham Bay Park in The Bronx. Better known as the home of tough guys and Yankee Stadium, The Bronx is actually the greenest of New York’s five boroughs, and Pelham Bay Park is more than three times the size of Central Park. In the late 80s, however, you couldn’t see the forest for the vandalism and illegal dumping. Invasive vine species covered the existing canopy and was smothering the mature trees and preventing any growth in the understory. Additionally, the uplands were deforested, and the saltmarsh filled in by highway construction and development.
“Even in a highly urbanized environment like New York City there is room for a forest,” notes Ecologist Brady Simmons, part of the NYC Parks team responsible for the long-term restoration project. “In the late 80s, forest restoration crews began removing the invasive vegetation and planting native saplings to help the ailing forest fight back. We knew we could make this park the urban oasis it was meant to be.”
Very little research has been done to assess these early attempts at forest restoration in an urban environment (Oldfield et al. 2013). Researchers at the NYC Urban Field Station, a partnership between NYC Parks and the USDA Forest Service, began to reconstruct the land use history and restoration practices as part of the Urban Long-Term Research Area Exploratory Awards grant program in 2010. The study is on Rodman’s Neck in Pelham Bay Park, which has a long and complex land use history like most urban green spaces. In 1917, this was the site of a campsite for summer recreational use, which contained 500,000 campers at its peak. In 1937, Orchard Beach was created and during the process Rodman’s Neck was deforested. Today we see that the area is mostly forested.
Three distinct treatment areas were identified in the study area using management records from the restoration process. One area had been cleared of exotic vegetation, planted with native trees, and maintained through additional work by forest restoration crews in the early 2000’s. A different section of the forest had been cleared and planted with native trees but did not receive any maintenance in the 2000’s due to funding constraints. One section north of these areas had been cleared during the initial site preparation but did not receive any planting or maintenance. Forested areas adjacent to the restoration site, which remained degraded, were used for reference plots to measure restoration success. Co-authors Brady Simmons and Richard Hallett, a USDA Forest Service Research Ecologist, established vegetation plots throughout the different treatment areas to measure the canopy, midstory and understory vegetation to measure the outcomes of the restoration goals.
After 20 years of growth the newly planted trees fostered a morestructurally diverse and closed canopy forest than the control area. Not only did the native trees planted in the restoration site survive but they started reproducing. There were larger numbers of small native saplings present in the restored areas compared to the control sites. Maintenance facilitated more regeneration than the other treatment areas. There is a lingering component of exotic vegetation in the understory that has propagated from an existing seed bank. In addition, new shade tolerant exotics, such as Amur honeysuckle, have appeared likely via friendly avian species enjoying the newly restored forest (Hutchinson & Vankat 1998).
“Urban environmental conditions are complex and typically very different from the conditions found in our national forests,” according to Rich Hallett, a Forest Service research ecologist at the New York City Urban Field Station. “Forest restoration projects in the city will likely require continued human intervention in order to create healthy and vibrant green spaces, which will maximize the benefit to our urban populations.”
Hutchinson TF, Vankat JL (1998) Landscape structure and spread of the exotic shrub Lonicera maacki (Amur honeysuckle) in Southwestern Ohio forests. The American Midland Naturalist 139:383–390
Oldfield EE, Warren RJ, Felson AJ, Bradford MA (2013) FORUM: challenges and future directions in urban afforestation. Journal of Applied Ecology 50:1169–1177
Restoration Ecology, 24: 109-118 Long-term outcomes of forest restoration in an urban park Brady L. Simmons, Richard A. Hallett, Nancy Falxa Sonti, D. S. N. Auyeung and Jacqueline W. T. Lu http://onlinelibrary.wiley.com/doi/10.1111/rec.12281/abstract
About Restoration Ecology
Restoration Ecology is the Society’s bi-monthly scientific and technical peer-reviewed journal published Edited by a distinguished international panel, the journal addresses global concerns and communicates them to researchers and practitioners throughout the world
The Society for Ecological Restoration is an international non-profit organization dedicated to promoting ecological restoration as a means of sustaining the diversity of life on Earth and re-establishing an ecologically healthy relationship between nature and culture.
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Society for Ecological Restoration
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