The NHESP Natural Communities datalayer consists of polygons that represent the extent of various natural communities of biodiversity conservation interest in Massachusetts. These polygons are based on records of natural communities maintained in the Natural Heritage & Endangered Species Program (NHESP) database. Program scientists classify and delineate natural community polygons by analyzing field data collected on-the-ground and available information about the landscape (particularly topographic maps and aerial photographs). All sites in the NHESP database have been visited by NHESP biologists or by other biologists who have submitted reports on community occurrences that NHESP biologists have reviewed and accepted. Aquatic community types are not included. The polygons are spatially represented at 1:25,000 or 1:24,000. The natural community types are from Swain, P.C. 2016. Classification of the Natural Communities of Massachusetts, Version 2.0. Natural Heritage & Endangered Species Program. The classification is available from NHESP. The classification names and describes 107 types of natural communities found in Massachusetts.

The datalayer is based on information on natural communities determined by NHESP to be of biodiversity conservation importance on a statewide basis. It is not intended to be part of a comprehensive vegetation map of the state. Not all the named types are actively tracked by NHESP; NHESP’s focus is on the least common types and those for which Massachusetts has a significant part of the regional or global occurrences. Additional verified natural community occurrences received during and after the preparation of this datalayer will be included in future iterations of the datalayer.

The datalayer contains 952 records of natural communities from the NHESP database. These include 97 community types, of which 73 are Priority for conservation (ranked S1 through S3S4) and 24 types are more common or Low-priority for conservation (S4 and S5), with the included examples considered to be in Exemplary condition. Please note that a very few occurrences of natural communities in the NHESP database are not included in this public datalayer due to either the sensitivity of the sites, or they are too degraded or small to be considered viable examples of the Priority types or they are non-exemplary examples of the more common, Low Priority for conservation types.

These polygons are not related to “Priority Habitat” or "Significant Habitat" as defined by the regulations of the Massachusetts Endangered Species Act (MESA). Natural Communities are not protected under the Massachusetts Endangered Species Act, but the rare species that may occur within some of these natural communities are protected by that law.

In ArcSDE the layer is named NATCOMM_POLY.