Why Forest Regeneration is Needed in SMR?

The Problem: Our Forest is Dying
Our forest is dying. The current forest canopy, the most distinctive characteristic of the South Mountain Reservation, is in jeopardy. New trees and shrubs — the future of our deciduous forest — are not replacing older trees that are dying off. This is primarily due to the destruction of the understory from the browsing of the overabundant white tailed deer which tend to eat native species and leave invasive plants. Walk in the Reservation and you can often see the browse line created by the deer 4 ½ feet off the forest floor. In the height of summer, look out from a trail; you can see hundreds of feet without green growth between the trees. These are the signs of a forest in peril. While there has been some improvement since the annual deer management program was begun by the County in 2008, significant forest restoration is still needed.

This is not how the Reservation was in decades past, just ask long-term residents of Essex County. Then, if you walked off a trail, you could lose your way in the dense underbrush. Now, large tracts of land look like a denuded moonscape with no or minimal understory flowers, shrubs, and saplings. If there is vegetation, it is increasingly thorny wine berry and Japanese barberry, bamboo-like Japanese knotweed, matted stilt grass, and other invasive species. These species, aided by the deer browsing, have been expanding, taking over the Reservation and crowding out all other native understory plants and the tree seedlings that are the next generation of our forest.

An example of the Reservation’s invasive stilt grass.
And the problem is not just plants. Along with the loss of this understory are the song birds, insects, and other animals that help create and sustain a balanced forest ecology. Only the woodpeckers, which thrive on aging trees, are in abundance. If we look closely, the signs are all there. Our Reservation is dying. In a few decades, if we do not persevere, the forest as we know it will be gone.

The Plan: A Multi-Year Forest Regeneration Program
To counter the immanent loss of the Reservation’s forest, the Conservancy along with Essex County unveiled a unprecedented twenty-year, $950,000 regeneration program in the spring of 2008. It was funded primarily by the County’s Open Space Trust Fund and the State’s Green Acres Program and supplemented by $50,000 in smaller grants from the NJ DEP Recreational Trails program and the USDA WHIP program.

This initiative created an enclosed 14-acre Wildflower and Forest Preserve surrounding the dog park (a deer exclosure in decades past) and in 2009 constructed 42 other smaller, fenced-in regeneration sites ranging from 5,000 to 40,000 square feet. Combined, these areas represent just over 1 million square feet of protected area, or about one percent of the Reservation. In these areas, tens of thousands of native species were planted in 2009. They serve as long-term seed distribution points to stimulate growth by eventually spreading over the next decade beyond the one percent of fenced-in area to the Reservation as a whole. Although a 2013 study has indicated that this effort has been only partially successful, the Preserve has been the exemplar for this program.

The original idea for dispersed regeneration sites originated with Dr. Emile DeVito, manager of science and stewardship at the New Jersey Conservation Foundation. The actual planning for this major initiative was undertaken by the Conservancy working with the County Parks Department under the guidance of landscape architect Dan Dowd of Barreto/Dowd and ecologists Drs. Steven Handel and Kristen Ross of the Center for Urban Restoration Ecology, a joint program of Rutgers University and the Brooklyn Botanical Garden.
The success of this effort is dependent upon three factors. One is the maintenance of the forest regeneration sites through the removal of invasive plants and installation of native species. Here, the Conservancy’s Forest Regeneration Corps in the Preserve has played a crucial role, with less success at other sites through our Adopt-a-Site and IRIS programs. The program will also only succeed if the fencing surrounding the various forest regeneration sites remains intact, a problem after toppled trees damaged several sites during the severe storms of 2011 and 2012 (Sandy). While Preserve fencing was, and is, restored quickly given the enormous investment there, many of the other sites after several years still have not been repaired by the County.

(Note: If you see damage to any of these sites, please contact the Conservancy at forestregen@somocon.org. If you see vandals damaging the fencing, please immediately call the Essex County Sheriff’s Office at 973-621-4111.)

Finally, the growth beyond the one percent fenced in areas will only occur if the deer population is significantly reduced and maintained at an ecologically sustainable level. Forest ecologists argue that 10 deer per square mile is a maximum for regeneration, or 34 for the Reservation as a whole, half of what a healthy forest can sustain. Preferably, it should be half that again for a forest that is damaged by severe deer browsing, as is the SMR. (See excerpt of 2017 recommendations for deer management.) For this reason, the County, supported by the Conservancy, has undertaken annual deer culling since 2008. Nonetheless, even with the removal of hundreds of deer over the last decade, and signs of improvement in the understory, the Reservation still has well above the level that will allow significant regeneration of the forest. Based on nighttime spotlight counts, the over-wintering density for 2017-2018 was estimated to be over 48 per square mile. Consequently, the deer management program needs to continue every year if our forest is to be restored; uncontrolled, the white-tailed deer population would double in three years.

We only have one chance to resuscitate, to regenerate, to restore our dying forest. Please help in these efforts and join the Forest Regeneration Corps and our other forest regeneration programs.

References:
Forests in Peril by Glenn Collins. New York Times, October 7, 2007 www.nytimes.com/2007/10/07/nyregion/nyregionspecial2/07rCOVER.html?_r=1&scp=1&sq=forests%20in%20peril&st=cse

The Once and Future Forest: A Guide to Forest Restoration Strategies by Leslie Jones Sauer, Island Press, 1998

On the Ground, Counting Deer by Mary Jo Patterson, New York Times, May 4, 2008www.nytimes.com/2008/05/04/nyregion/nyregionspecial2/04deernj.html?scp=1&sq=deer%20essex%20county%20nj%20ground&st=cse

Photos of the South Mountain Reservation forest courtesy of Troy Ettel, New Jersey Audubon Society