Ecological Inventory and Monitoring

The Maine Natural Areas Program (MNAP), in cooperation with the Maine Department of Inland Fisheries and Wildlife (MDIFW), has completed landscape level natural resource assessments in a number of "biophysical regions" throughout the state of Maine. These assessments aim to identify new locations of rare plants, rare animals, and exemplary natural communities through a three stage process: 1) landscape analysis, 2) landowner identification, and 3) field inventory.

The landscape analysis process helps us identify sites with the greatest potential for supporting rare plants, rare animals, and exemplary natural communities. Landowner information is collected for each of the sites selected through landscape analysis and permission is requested to do surveys. Only after landowner permission has been obtained are field surveys conducted. After surveys are completed, landowners are provided with the results along with management suggestions when appropriate. Results from inventory efforts are added to MNAP's biodiversity database where they are used to help landowners and other conservation organizations in an effort to bring about improved management and/or protection of significant natural areas. The information is also used to determine the relative degree of rarity of species and habitat types throughout the state.

What are we looking for?

  • Animals considered rare or imperiled by MDIFW;
  • Plants and/or natural communities considered rare or imperiled by MNAP; and
  • Outstanding examples of common natural communities and ecosystems.

How are the assessments conducted?

  1. Landscape analysis "Landscape Analysis" is the process by which MNAP identifies areas likely to support rare natural communities, outstanding examples of common communities, and/or habitat for rare plants. Areas identified by MNAP typically range from 50 to 500 acres, and are assigned priorities for subsequent field verification. These methods are consistent with those developed by state natural heritage programs throughout North America. These methods have been successfully modified for Maine's landscape, and they have been recently used to identify hundreds of priority sites throughout Maine. The following information sources are used in landscape analysis, note that you can get digital data for most of these online at the Maine Office of GIS Data Catalog:
    1. USGS Topographic Maps: Traditionally hard copy maps served as a baseline for initial mapping of areas. As MNAP has integrated Geographic Information Systems (GIS) into its daily operations, digital USGS maps have been used to a greater extent. Topographic maps also indicate obvious landscape features that are correlated with certain community types, such as floodplain forests, mountain summits, ravines (for 'cove forests'), and large wetland complexes.
    2. Digital Elevation Data: GIS analysis of digital topographic information can help in the identification of areas that meet distinct topographic criteria. Analysis of this type of data serves as an efficient and systematic way to identify areas with certain slope, aspect, and elevation characteristics. It can also be used to derive general moisture characteristics across a study area.
    3. Digital Land Use/Land Cover Data: GIS analysis of digital land use and land cover data can help to identify unfragmented, undisturbed areas that should receive more focus through aerial photograph analysis. When used in conjunction with other digital data such as elevation and soils data (where available), digital land cover data becomes a powerful tool for modeling the possible location for specific community types.
    4. Digital Roads Data: This can be an important set of data used to determine fragmentation and development threats to an area. It is used in conjunction with digital land cover data to identify high quality, unfragmented or roadless areas for further analysis.
    5. Aerial photographs: Depending on the scale and time of year of photography, air photos may be instrumental in identifying certain forest or wetland types.
    6. National Wetlands Inventory maps: These maps can be useful at delineating different wetland types within a larger wetland complex.
    7. Geology Maps: Bedrock maps are particularly useful at identifying areas of circumneutral bedrock (somewhat uncommon in Maine), and surficial geology maps can pinpoint areas of outwash plains, glacial marine soils, and other noteworthy features.
    8. Soil surveys: For smaller areas mapped soil survey information can be helpful at identifying certain natural community types (e.g., oak-hickory forests), but at the larger scale MNAP typically operates, soil maps are only moderately helpful.
    9. US Forest Service Inventory and Analysis Data: These data, now available on the internet, are from ~3,000 permanent forest survey plots scattered around the state. They can yield insights on large volume/mature forests as well as uncommon forest types (e.g., pitch pine, jack pine, white oak).
    10. Miscellaneous Reports: Depending on the area of interest, natural resource studies may be available from a wide variety of sources, including land trusts, town comprehensive plans, regional planning commissions, etc.
    11. Information from Land Managers: Many owners of larger tracts hold valuable natural resource information, such as timber cruise results, management plans, soil and timber productivity maps, and land use history information. Land use history can yield valuable insights into whether land was selectively harvested or clear cut, pastured or cropped, or burned. Such history can be an important determinant of the successional trend of the forest.
    12. Knowledgeable Individuals: Contacts with local natural resource professionals, such as foresters, wildlife biologists, or wetland scientists, may yield worthwhile leads. Other knowledgeable sources may include local naturalists, members of land trusts, or hunters and anglers.
    13. Air Surveys: Once preliminary sites have been identified, a flight is instrumental in verifying that the assumptions made using information above are correct. For instance, is an area identified as a pitch pine woodland using air photos actually a pitch pine woodland, or is it a white pine-grey birch barren? Our preferred flight time is shortly after leaf-out but before the field season begins.
  2. Landowner contact - It is the policy of the Maine Natural Areas Program to acquire permission from landowners before accessing lands to conduct inventory surveys. Prior to conducting field work, landownership of priority survey areas is documented through research at town halls and landowners are contacted by mail. MNAP maintains a database to track contact with landowners. Once permission is received for a given site a survey is conducted and for all areas visited landowners are notified in writing of the results of the survey. When appropriate, landowners are encouraged to preserve rare and sensitive habitats and are provided with management suggestions.
  3. Field surveys - Field surveys are conducted to assess habitats identified through landscape analysis. Field surveys are typically conducted by a crew of two people and take from a few hours to a full day depending on the size and composition of the site. Field surveys are almost always carried out during the growing season when plant species are readily identifiable.
  4. Data processing - Field surveys generate data on the status, composition, and disturbance history of areas that are surveyed. Collected information includes details on population size, reproductive status, and habitat composition of rare plants occurrences; and species composition, ages of trees, types of disturbances, and size of natural community occurrences. This information is used to assign an overall quality ranking for each occurrence which is used to determine conservation value. All of the data is processed into the Biotics database at MNAP.

Who conducts Ecoregional inventories?

  • MNAP ecologists and botanists
  • MDIFW biologists
  • Contracted ecologists, botanists, and zoologists

How much of the state has been inventoried?

To date, landscape analysis has been conducted for all regions of the state. Inventories have been completed for all regions except for the Central and Western Mountains, where inventory effort is still on-going.

What are the results of completed inventories?

Inventory results include documented and mapped occurrences of rare and exemplary natural communities and ecosystems. Results also include documented and mapped populations of rare plants. Results of inventories are compiled into reports for individual regions. Inventory discoveries are evaluated for quality and conservation value by MNAP staff and recommendations for conservation and land management are presented to landowners whose lands include documented features.

How are the data used?

The data are used in many ways, including the following:

  • to help landowners better manage for significant natural features on their lands,
  • to identify state and local conservation priorities,
  • to perform environmental reviews of both conservation and development projects,
  • to inform the comprehensive planning process in towns
  • to determine relative rarity of species and habitat types throughout the state
  • to develop and augment the state's natural community classification.