Forests of various ages provide many ecological services including wildlife habitat, flood and erosion control, public health benefits, recreational opportunities, and carbon sequestration. Protecting our forests from development is a crucial first step to secure these natural benefits.
In addition to forest protection, there are various ways to steward forests to retain or at times enhance their ecological services. This includes passive management, a mostly hands-off approach, and active management to create a particular habitat type or benefit a species of conservation need.
Passive Forest Management
A passive approach to forest management lets forests continue to mature. This is the approach that Mass Audubon employs across the majority of our permanently protected forested land. Allowing forests to naturally mature has inherent values, including:
- One of the rarest habitats in Massachusetts is old growth forest, which has never been cleared or highly disturbed by humans. These forests have a unique multi-layered structure of vegetation, and provide particularly high quality habitat for some wildlife species. Old growth conditions can only develop with time, usually after 200–300 years.
- As forests grow, they remove (aka sequester) carbon dioxide from the atmosphere and store it within forest biomass and soils. Thus, forest growth plays an important role in combatting climate change. Currently, carbon sequestration in our forests offsets about 14% of annual emissions in Massachusetts. Mass Audubon recently set aside 10,000 acres of forest specifically for carbon sequestration and enrolled those acres in the California carbon offset market.
- As forest managers and scientists study the various benefits and implications of active forest management, it is important to have untouched sites for comparison. Many of our sanctuaries fill that role.
Active Forest Management
Most of Massachusetts’ forests were once cleared for agricultural purposes. These forests began to regrow about 80–120 years ago and are now considered “middle-aged." This means we have very little young forests (0-20 years) or old growth forests (200+ years).
The thoughtful application of forest management practices can help restore habitat conditions found within young and old growth forests. When appropriate, Mass Audubon takes this approach with a focus on protecting wildlife and their habitat.
Young forests occur in relatively open conditions and are dominated by dense growth of shrubs and sapling trees. This type of habitat used to occur naturally due to large-scale disturbances such as beaver activity and fires. These disturbances are now less frequent and are controlled to protect human lives and resources.
Removing older trees from small areas of the forest is an effective way to recreate this type of habitat for wildlife species that depend on young forest habitat, including several warblers and White-throated Sparrows.
Middle-aged forests often have a less complex structure than once common old growth forests and provide poorer habitat for some species. Habitat management can be used to mimic the unique features of old growth forest, and bolster wildlife species of conservation concern.
Adaptation to Climate Change
The forests of Massachusetts face several challenges which threaten their ecological integrity and the natural benefits they provide. In addition to loss to development, these include (but are not limited to) fragmentation, invasive plants, insect pests, disease, and overabundant deer. Climate change is yet another threat, interacting with and amplifying the impacts of other forest challenges.
As we look to the future, adapting our forests to overcome various challenges is a crucial consideration. Some sites may be considered especially vulnerable, and management can be geared towards creating resilient conditions. For example, managing a forest to increase tree species diversity and limit the effects of invasive plants can help ensure a forest continues to function well into the future.