Researchers recently completed a project to compare maps and classification systems from various producers to identify opportunities for consolidating the strongest qualities in each mapping system to produce a ‘best map’ for the Northeastern and Midwestern U.S. This project, Critical Evaluation of Methods and Outcomes for Habitats/Ecological Systems Classification and Mapping in the Northeast and Midwest U.S., was funded by the Northeast Climate Science Center.

Investigators compared maps produced by LANDFIRE (LF), Southeast GAP Analysis (SEGAP), The Nature Conservancy (TNC), and NatureServe (NS) for the eastern USA. All the efforts use the NS Ecological Systems Classification with modifications as their legend. The LF and NS maps cover the whole U.S., whereas the area of coverage for other maps is limited. The NS map is a compilation and modification of the LF and SEGAP maps. In areas of overlap, the four maps are quite different at their finest thematic resolution (when more vegetation types are mapped) but more similar when fewer vegetation types are mapped. Differences are in part due to the nature of the vegetation continuum itself (e.g. inexact differences separating mapped types). Investigators concluded that it was not possible to determine which map was more accurate, and they could not be mixed and matched to create a ‘best map.’

As described in the project's final report, each map exhibits qualities and challenges unique to end users’ needs. The TNC map is most cartographically appealing. The LF effort adheres to set national methods and standards and producers are most often unable to respond to the individual concerns of regional, state, or local users. Depending on their needs, end users must create customized maps at their own cost (e.g. the TNC map), modify national maps, or simply use national maps as they are delivered. The LF map is due for a refresh within the next few years, but other maps may not be refreshed. The National Landcover Dataset, which was not assessed as part of this effort, has the longest history of being refreshed at regular intervals but maps the fewest vegetation types. It is easy to interpret, and would be the most straightforward for a local user to modify by using map overlays.

Find out more about the work conducted in this project and the findings and products that resulted from it in the final report on the project page.