We take their effects into account when assessing natural communities, but if the community displays appropriate attributes, including minimal human influence, then we are likely to classify it as exemplary. In the following paragraphs, several other classification systems are contrasted with the natural community classification used by NH Heritage. This system is periodically updated to include new information from more specific natural community classifications developed at the state level, such as the New Hampshire natural community classification. This system cross-references classifications produced and maintained by all state Heritage programs. SAF forest cover types are primarily based on dominant tree species, while natural communities are based on all species, the structure of these species, and the specific physical environment.
Trees are often subtle indicators of their environments.
A number of natural communities can be distinguished based largely on trees, and in some cases differences in tree composition are the main difference between two community types. Differences in tree canopy composition may also primarily relate to cutting or other disturbances. These different cover types primarily relate to stand disturbance history or the successional stage rather than to major environmental differences. In fact, the differences between these two natural communities are more dramatic than the internal differences between the four SAF spruce-fir cover types. SAF cover types are, however, useful for timber management.