The Nature Conservancy in Maine: Remaking Forests for a Changing Climate


The Nature Conservancy is planting conifer trees on hundreds of acres of forest in northern Maine in anticipation of climate change

The Nature Conservancy is planting conifer trees on hundreds of acres of forest in northern Maine in anticipation of climate change

Project Area

The Nature Conservancy owns and manages 159,000 acres of forest land in the Upper St. John River watershed in northwestern Maine, bordering Quebec. Of this forest, 106,000 acres is sustainably-managed as timberland and the other 53,000 acres is dedicated to forest reserves that provide mature forest habitat for species such as pine marten. This property is located in the center of more than 32 million acres of relatively contiguous forest stretching from the Adirondack Mountains to the Gaspe Peninsula on the Atlantic coast—the largest expanse of uninterrupted forest in eastern North America. Timber management of the St. John River Forest is part of a much broader strategy to conserve forest habitats at a landscape scale.

Management Goals

Prior to the Conservancy’s ownership in 1999, the land was owned and managed by large timber companies. Decades of industrial timber management dramatically altered forest composition and structure, with one of the effects being that the species composition and structural diversity of the forest were greatly reduced. For example, stands that typically contained a 25%-75% softwood (spruce, fir, pine and cedar) component have often been reduced to less than 10%, with little softwood regeneration present.  Coupled with extreme levels of moose browse on hardwood species, the overall growth of young forest stands has been severely compromised across the ownership.

Current management across this large ownership includes:

  • Protecting a vast landscape of plant and animal communities, including several rare species
  • Sustainably managing forests to provide important habitats and contribute to the region’s economy
  • Providing a location for research on important species like the Canada lynx and American marten

Climate Change Impacts

Climate change is expected to have numerous effects on the St. John River Forest and the region, including: increased precipitation, more winter rain and less snow, more frequent ice storms, more intense storms, increased risk of summer drought, and a 4-6 week longer growing season. The implications of these changes will undoubtedly vary by tree species and forest type, but some of the greatest threats from climate change on the St. John River Forest include the influence of drought stress on germination, ice damage to hardwoods, and competitive advantages for certain native species due to an extended growing season. Further, the lingering effects of past management may increase forest vulnerability to climate change. Over the long-term, climate change is expected to cause the decline of more northern species, while increasing potential habitat for species that currently have more southerly distributions. While the St. John is located extremely far north in the United States and may be buffered from substantial changes for some time, managers of the forest are beginning to consider how to adapt the forest to uncertain future conditions.

Adaptation Actions

The Nature Conservancy received a grant from the Wildlife Conservation Society's Climate Adaptation Fund to improve the ability of the St. John Forest to adapt to changing conditions. The Adaptation Workbook was used to identify restoration and adaptation activities across several hundred acres (see table below).

In the spring of 2015, a 10 acre pilot planting was done to test softwood under-planting at ~100 black spruce seedlings per acre.  Seedling species availability was limited in 2015 and we intend to increase the density and diversity of species in future plantings with spruce, white pine and cedar in future plantings at a density of approximately 400 trees per acre.  Our initial interest is to evaluate how the seedlings compete against hardwood competition, which is severely browsed and suppressed by moose.

Climate-informed forest restoration
1.4. Reduce competition for moisture, nutrients, and light.
2.1. Maintain or improve the ability of forests to resist pests and pathogens.
9.1. Favor or restore native species that are expected to be adapted to future conditions.
Implement forest management practices to reestablish the full range of native tree species to the forest.
5.1. Promote diverse age classes.
5.2. Maintain and restore diversity of native species.
Retain a variety of species and age classes.
5.3. Retain biological legacies.
Retain large wildlife trees and large downed wood
1.3. Maintain or restore riparian areas.
Retain permanent retention patches and riparian buffers within harvest stands


Planted sites will be monitored to evaluate the survival and growth of planted trees. Initial monitoring will help the managers understand how the planted seedlings compete against hardwood competition, which is severely browsed and suppressed by moose.

Project Photos

Click to enlarge photos

People standing in woods next to large yellow birch.

Learn More

To learn more about this project, contact Maria


Planting, Wildlife habitat

Last Updated

Tuesday, December 13, 2016