• Start-up
  • Planning
  • Action
  • Evaluation

Seeking to maintain quality habitat for terrestrial and aquatic wildlife, ensure healthy forest regeneration, and manage invasive plant species.

As Sudbury Valley Trustees updates their reservation’s management plan, they are taking the opportunity to consider the potential impacts of climate change on the land and resources there. They are also working to include their neighboring land managers to foster cooperative land management in the greater conservation area.

Project Area

Map of the 40 caves project area
The Forty Caves conservation area lies in a low range of hills between the Assabet River and Nashua River valleys, about a mile and a quarter east of the Wachusett Reservoir in eastern Massachusetts. This wooded property features rugged topography, with outcroppings and huge boulders, a hemlock-shaded coldwater stream (North Brook, a major tributary to the Assabet River) with a native trout population, carpets of wildflowers and ferns, and a sense of wilderness, despite a bisecting railroad track. Three state-listed wildlife species have occurrence records in the forest. The site’s primary forest type is a mature, mixed hardwoods-white pine-hemlock forest. Hemlock stands are occasional on the property—a particularly large grove covers the steep slopes east of a marsh-pond complex. Invasive species are largely limited to disturbed areas, such as along the rail line and trails.

Management Goals

Amphibians, reptiles and fish found in the project area
  • Maintain health of natural communities
  • Limit the spread of invasive species, and, where possible, reduce their amount.
  • Maintain and improve the health of North Brook, as a Coldwater Fish Resource

Climate Change Impacts

Key impacts for this area are:
Temperatures in New England are projected to increase 3.5 to 8.5 °F by the end of the century, with the greatest warming expected to occur during winter.
The growing season in New England and northern New York is generally expected to increase by 20 days or more by the end of the century, due to fewer days with minimum temperatures below 32°F.
The winter season will be shorter and milder across New England and northern New York, with less precipitation falling as snow and reduced snow cover and depth.
Many invasive plants will increase in extent or abundance in New England and northern New York.
Certain insect pests and pathogens will increase in occurrence or become more damaging in New England and northern New York.
Tree regeneration and recruitment will change in New England and northern New York.
Changes in herbivore populations may also have substantial effects on forest growth and composition.

Challenges and Opportunities

Climate change will present challenges and opportunities for accomplishing the management objectives of this project, including:


Invasive species such as buckthorn, honeysuckle, and garlic mustard are expected to become more problematic as our climate changes.
Increased disturbances and potential for new invasive species moving into our area are expected to add to the current challenge of managing invasives in our forest.
Insect pests and forest diseases may become more problematic in central hardwood-pine forests with a warmer climate.
Hemlock Woolly Adelgid threatens a key tree species in our forest, especially along the cool North Brook corridor.
Changes in herbivore populations may also have substantial effects on forest growth and composition. Shorter, milder winters will put less stress on an already growing white-tailed deer population.


Forest productivity in New England and northern New York will increase during the next several decades in the absence of significant stressors.
High levels of diversity may increase the ability of forests to adapt to climate change.

Adaptation Actions

Project participants used the Adaptation Workbook to develop several adaptation actions for this project, including:

Central hardwood-pine forest
As necessary, replace highly compromised hemlocks along wetlands and stream corridor with more adaptable canopy species. Encourage growth of mountain laurel in the shrub layer to act as evergreen cover.
Focus invasive plant removal at forested wetlands
Institute Hemlock Woolly Adelgid Volunteer survey and monitoring program.
Prioritize removal of Japanese barberry along stream corridor in Berlin's original Forty Caves parcel, west of Trail Point I.
Prioritize removal of glossy buckthorn along rail line/stream corridor.
Remove Oriental bittersweet along rail line/stream corridor east of Trail Point K.
Prioritize removal of 30' x 50' patch of Japanese barberry along unnamed tributary west of Trail Point D on Berlin Ciesluk parcel.
Increase monitoring for current invasive population and early detection species.
Establish protocol for invasives monitoring that does not rely on limited cell service in the area
Educate staff and volunteers on current invasives and early detection species identification.
Monitor for deer browse impacts.
Encourage deer hunting.
Coldwater stream & wetlands
Install bridge over stream where popular informal trail crosses, causing sedimentation, and widened, less defined stream channel. Restore stream channel.
Vegetate stream corridor by planting and encouraging natural growth of native plants along stream banks.
Plant wetland-associated plants plants near current wetland edges to prepare the areas as wetter conditions will expand wetlands.
Encourage or put in added forest debris (branches, logs, leaves) to add diversity to stream flow and habitats.


Project participants identified several monitoring items that could help inform future management, including:
Health of Mature Eastern Hemlocks: HWA will be considered for treatment when confidently identified on the property. Specific trees will be removed and replaced with another shady plant (i.e. mountain laurel) when the tree is 50% defoliated.
Deer Browse: Look for characteristics of heavy deer browse on yearly visits. These signs may include: lack of foliage up to 6ft. tall and deep visibility into the forest; evidence of browse of low preferred species.
Survival of saplings or whips of well-suited trees in future conditions: 70% survival after three years.
Stream health: This includes substrate proportions, stream anatomy, and vegetated banks; for example fine silt in substrates compared to gravels and cobble, mixture of stream anatomy (runs, riffles, and pools), presence of deep, narrow stream channels.
Cooperative management plan with towns of Berlin and Clinton: Successful planning, communication, and implementation of management actions on the plans.
Habitat health of listed species: Presence of human disturbance in the habitats of the three listed species. These habitats include vernal pools, forested wetlands, and streams.
Develop map of invasives on the property: Invasive populations will be fully mapped.
Develop and implement a management plan to control the invasive species: Isolated patches of invasives will be reduced by 90% in 3 years. Larger patches will not spread within the first 3 years and will be reduced by 70% in 6 years.

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