Primary Map 3:
Undeveloped Habitat Blocks
About Map | Data Components | Background Info | Strategies for Local Action
The purpose of this map is to highlight those areas that are likely to provide the best opportunities locally to conserve large relatively undisturbed blocks of habitat. By slowing further fragmentation of these areas, towns, and land trusts, can effectively keep locally common species common and maintain traditional outdoor recreation opportunities for future generations. By buffering roads and developed areas this map highlights large areas of relatively intact habitat. Blocks ≥ 100 acres are labeled with their size in acres. Local knowledge of the condition and use of roads should be used to more accurately evaluate habitat block size and extent of disturbance. Within the undeveloped habitat blocks, the general land use/landcover is shown. Areas shown as being forested are likely to contain multiple stand types, stand ages and conditions.
Data Components: (Data Sources)
Impervious/Developed Areas- Areas of impervious surfaces including buildings and roads.
Undeveloped Habitat Block Outlines- These habitat blocks contain several different habitat types (see Landcover Categories listed below). Acreage within each block is listed on the map with red text.
Development Buffer- 250-500 foot buffer of development (based on intensity).
Landcover Categories-
- Agricultural/Grass/Shrub Lands- Landcover types where human intervention maintains an open landscape dominated by grasses, row crops, or lowbush blueberry.
- Wetlands- Wetlands as identified in the 1980’s by the National Wetland Inventory of the U.S. Fish & Wildlife Service. Wetlands delineated by aerial photo interpretation may be under represented.
- Development- Small areas that are not covered by the above “Developed” layer.
- Forest Area- < 300 feet from other (non-forested) habitat OR < 500 acres. This category is likely to contain a greater edge to interior habitat ratio.
- Forest Area- ≥ 300 feet from other (non-forested) habitat AND ≥ 500 acres. This category is likely to support the most interior habitat.
- Other- Exposed rock/talus, alpine tundra; may include industrial gravel pits.
In addition, Map 3 includes an inset map showing a regional view of undeveloped blocks sizes.
"Large blocks" are relatively unbroken areas of habitat that include forest, grassland/agricultural land, and wetlands. "Unbroken" means that the habitat is crossed by few roads, and has relatively little development and human habitation.
If we want to maintain habitat for animals that have large home ranges, such as bear, bobcat, fisher, and moose, and other animals that are sensitive to human disturbance, such as upland sandpipers and wood thrushes, we need to conserve larger blocks of forest or grassland, or wetland habitat. Blocks between 1 and 19 acres are home to generalist species typical of urban and suburban landscapes (e.g., raccoons, skunks, and squirrels). Blocks of 50 acres of grassland or 250 acres of forest begin to provide habitat for birds that are uncommon in smaller grasslands and forests. These birds may include grassland species such as the upland sandpiper and grasshopper sparrow and forest species such as the veery and scarlet tanager. Moose, bald eagles, goshawks and similar species usually require 500 to 2,500 acres, while blocks of greater than 2,500 acres may hold the full complement of species expected to occur in Maine. Refer to A Response to Sprawl: Designing Communities to Protect Wildlife Habitat and Accommodate Development and Conserving Wildlife in Maine's Developing Landscape for more detail on species specific large block requirements.
In some parts of Maine, one landowner may own an entire large habitat block but more typically, several or many landowners' properties combine to create a single large undeveloped block. Because development quickly fragments these multi-owner blocks of habitat, many towns are in danger of losing their last opportunities to conserve large blocks of habitat.
- Conserve several of the largest remaining blocks possible. In a more developed southern Maine town this may mean blocks 500 acres in size. In more rural communities blocks of several thousand acres could be conserved. In either scenario, efforts to curb fragmentation today will benefit community forestry, agriculture and outdoor recreation tomorrow.
- Update your town's comprehensive plan to include policies on protecting undeveloped habitat blocks (through easements, lease, tax incentives or open space development). After the update is completed, make sure an implementation committee is formed to make any necessary zoning ordinance changes. Comprehensive plan policies and potential ordinance changes should focus on opportunities to protect existing large blocks and corridors that may connect them as part of overall town growth strategies. See the BwH Toolbox sections on Comprehensive Planning and on Land Use Ordinance Tools for more information.
- Inventory local parcels of land that could, in combination with other private or public lands, be considered important undeveloped blocks of habitat on a local scale. Acknowledge these lands in the town's comprehensive plan. Where they are distant from local services like sewers and fire stations, include these significant blocks of habitat within designated rural areas, away from which most future development is to be directed.
- Conduct outreach to landowners who might benefit from a "current use" tax status. Suggest they examine estate and tax planning with a local land trust in order to conserve large parcels of land they own. Information on "current use" tax programs can be found in the BwH Toolbox.
- Meet cooperatively with neighboring towns, land trusts, and conservation organizations to explore the conservation of large blocks of habitat across political boundaries.
- Review your standards for the construction of private roads to create building lots. Do these roads extend into large undeveloped blocks of habitat? What are the impacts of these roads and the companion buildings on wildlife habitat? Provide incentives for development design that minimize fragmentation. Consider prohibiting or restricting the length of these private roads so new building lots do not unnecessarily fragment remaining large blocks of habitat. For more information on road standards, see the BwH Toolbox.
- Explore opportunities to protect large undeveloped habitat blocks via conservation easement or fee ownership. Funds for acquisition can be raised through public appeal, appropriation of town funds, or application to private foundations or public funds (see the Financing Habitat Protection section of the BwH Toolbox for information on funding sources).
To learn more about specific strategies for local action, visit the Beginning with Habitat (BwH) Toolbox or contact BwH.
