Case Study - Sparta Mountain Wildlife Management Area, Terrestrial Wildlife Adaptation Menu

Contributed by Sharon Petzinger, New Jersey Department of Environmental Protection

Main Take Aways

Strategic forest management is necessary not just for wildlife conservation, but for long-term climate resilience. Combining wildlife and carbon objectives in the climate adaptation planning allows managers to determine actions that will benefit both and find compromise where actions/goals did not agree.

Climate Impact

Forests are already shifting in response to changing climate conditions, and these changes are expected to accelerate in the future. Effective forest management must integrate climate resilience strategies while balancing priorities for wildlife conservation and long-term carbon storage.

Adaption Planning / Actions 

The Endangered and Nongame Species Program (ENSP) within NJ Fish and Wildlife participated in the Northern Institute of Applied Climate Science (NIACS) course on Terrestrial Wildlife and Forest Carbon Adaptation. This training supported ENSP in evaluating and updating the current forest management plan for the Sparta Mountain Wildlife Management Area (SMWMA) to better account for the anticipated impacts of climate change.

Background

Sparta Mountain Wildlife Management Area (SMWMA), managed by the New Jersey Division of Fish and Wildlife, encompasses 3,461 acres of primarily forest land in the Highlands Regions of Sussex County. The area has a complex history of use and disturbance. In the late 1800s - early 1900s the area was mined for iron ore and limestone. The area was deforested, and large quantities of soil were excavated and transported to other parts of the property, which drastically altered stream flow, wetlands, and topography. 

Plaque with a historic photo of factory workers at Ogden, New Jersey, now Edison; includes a credit to the U.S. Department of the Interior and National Park Service.
Photo showing the buildings and workers of the mining operations at that location in 1895, located on the monument on Sparta Mountain WMA. (https://dep.nj.gov/njfw/sparta/stewardship-plan/)

The forests on SMWMA today consist mostly of middle-aged (70-100 years old) closed canopy oak-hickory forests undergoing mesophication, the change in environment that occurs when fire is removed or suppressed in an ecosystem, with an increase in understory vegetation comprised of northern hardwood species such as sugar maple, red maple, black birch, and American beech. Regeneration harvests have been implemented on about 92 acres in this forest type so far, resulting in the regeneration of tree species such as tulip poplar, black cherry, and sometimes aspen (bigtooth and quaking) and gray birch, in addition to oaks and hickories. There are wetland and vernal pool habitats on the site. About 6% of the property contains mixed upland forests dominated by eastern hemlock (Tsuga canadensis). Many of the hemlocks are infected/dying from the Hemlock Woolly Adelgid (Adelges tsugae), and much of this forest type is rated as an extreme fuel hazard for wildfires.

 

Dense green foliage and tall trees fill a sunlit forest under a clear blue sky.
Actively managed area on Sparta Mountain WMA 3 years and 2 months after management was completed. (https://dep.nj.gov/njfw/sparta/stewardship-plan/)
Close-up view of a wire fence with wooden posts surrounded by dense green foliage and shrubs in an outdoor setting
Deer fence within an actively managed young forest site on Sparta Mountain WMA. Note the similarities of plants inside (right) and outside (left) the fence. (https://dep.nj.gov/njfw/sparta/stewardship-plan/)

SMWMA was purchased with a US Forest Service Forest Legacy grant which requires a natural resource plan. Management of this area is guided by a Forest Stewardship Plan, which was first approved in 2009 and revised in 2017 and expires in March of 2027. Some local organizations and members of the public expressed concerns about forest activities so an addendum was created  in 2021 to help address those concerns. The current plan balances ecological management with public trust. 

Climate Impact

The most important climate impact to SMWMA include increased temperatures, changes in precipitation patterns (more rain in winter, less rain in summer), and drier soil conditions during growing season (Whitehead et al.m 2023). These changes translate into;

  • Increased stress on northern hardwood tree species,
  • Increases in tree pests,
  • Prolonged flooding followed by rapid drying of vernal pools and wetlands,
  • Increased wildfire hazard (especially in areas where there is excessive hemlock die-off).

Other impacts unrelated or indirectly related to climate change are;

  • Mesophication,
  • Pests already impacting the forest (Hemlock Wooly Adelgid, Emerald Ash Borer, Spongy Moth),
  • Limits on funding and capacity,
  • the politicization of forest management, including a push to limit forest management in favor of carbon storage.

Adaptation Planning

To address these challenges, combining wildlife conservation with climate adaptation became the focus of SMWMA’s forest stewardship plan. NJ Fish and Wildlife’s Endangered and Nongame Species Program (ENSP) manages the implementation of the SMWMA’s forest plan. Biologists attended the Northern Institute of Applied Climate Science (NIACS) course for Terrestrial Wildlife and Forest Carbon Adaptation to assess the current forest plan.

The main actions and findings resulting from the climate adaptation planning process include;

  • Silviculture and prescribed burns to favor oak and hickory tree species    
  • Determining ways to address forest pests, especially in hemlock forests.    

Interestingly, biologists found that many of these actions were similar for both wildlife and carbon management, and actions to open the canopy in favor of oak-hickory forests are already incorporated into the existing forest stewardship plan. These actions include;

  • Silviculture and prescribed burns open the forest canopy to favor oak and hickory regeneration, which are species that are projected to be better adapted and more resilient to future climate impacts. This results in;
    • Increasing carbon sequestration rate and the amount of carbon stored over the long term,
    • Increased vegetation diversity,
    • Increased wildlife diversity,
    • Increased water availability for vernal pools and wetlands

Monitoring the responses of these actions, or treatments, was done by monitoring the response of bird species in the treatment areas. Monitoring bird diversity can be used as an indicator of forest habitat and diversity. 

To monitor the impacts of actions and treatments on carbon sequestration, carbon estimates have been calculated and projected into the future based on proposed treatments and no treatment. Results of both indicate an increase in wildlife diversity, especially bird species of greater conservation need (Figure 1), and a long-term increase in carbon sequestration rates post-treatment (Figure 2).

 

Stacked bar chart showing average number of bird species before and after treatment, divided into "Bird Species of Concern" and "All Other Bird Species" over 10 years.
Figure 1. Average number of bird species of concern (orange bar) and all other bird species (blue bar) observed during breeding bird surveys on Sparta Mountain WMA. Pre-treatment surveys were conducted on site prior to treatment or conducted in 2008 and selected based on proximity to treatment sites within the same forest stand.
Line graph comparing carbon sequestered over 50 years. Orange line shows higher peak with post-seed tree treatment, blue line remains steady.
Figure 2. Projected carbon sequestration rates in 10-year increments under the proposed forestry activity (seed tree harvests) and no activity (no management). Projections were made based on inventories of Stand 18 on the SMWMA using the Forest Vegetation Simulator.

Example

Retaining hemlock using biocontrol methods would be beneficial for wildlife species dependent on hemlock forests, such as the Black-throated Green Warbler (Setophaga virens), but that action is not recommended to defend existing carbon sinks. And, focusing solely on maximizing carbon storage for climate change mitigation by eliminating active management from New Jersey forests may compromise important wildlife habitats and reduce opportunities for increasing long-term resilience of carbon sequestration and storage (Littlefield and D'Amato 2022). A compromise, therefore, could be to replace hemlock trees with surrogate coniferous tree species that will be better adapted to future climate conditions and not susceptible to Hemlock Woolly Adelgid; these surrogate trees could provide habitat for some, but not all, of the wildlife species currently supported by hemlocks.

References:

Adapted from

Staudinger, M.D., A.V. Karmalkar, K. Terwilliger, K. Burgio, A. Lubeck, H. Higgins, T. Rice, T.L. Morelli, A. D'Amato. 2024. A regional synthesis of climate data to inform the 2025 State Wildlife Action Plans in the Northeast U.S. DOI Northeast Climate Adaptation Science Center Cooperator Report. 406 p. https://doi.org/10.21429/t352-9q86

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