In 1998, the NH Ecological Reserves system project concluded:

Though conservation lands comprise approximately 20% of the land area in New Hampshire, the current system of conservation lands in New Hampshire does not appear to provide comprehensive, long-term protection of biodiversity at the species, natural community, or landscape levels (NH Ecological Reserve System Project 1998a).

NH Heritage strives to facilitate protection of the state's biodiversity through the protection of key areas that support rare species, rare types of natural communities, and high quality examples of common natural community types. Exemplary natural communities are particularly important because we assume that if we protect an adequate number of viable examples of each natural community type, we can protect the majority of New Hampshire's species. This is sometimes referred to as a "coarse filter" approach to protecting biodiversity.

The "coarse filter" can miss important species, however, so it needs to be augmented with a finer filter. The "fine filter" approach generally focuses on specific rare species that are not tied to specific natural community types. For example, the rare, federally threatened small whorled pogonia (Isotria medeoloides) occurs in common forest communities in southern New Hampshire, but only in a few places. Existing populations may not be captured by the coarse filter approach, so we need to employ a fine filter approach (i.e., survey for the plant itself) to ensure that the species is protected.

Long-term protection of New Hampshire's species, natural communities, and ecological processes requires a variety of conservation approaches. The goal of NH Heritage's coarse and fine-filter approaches is to inform management decisions by identifying those sites that have a relatively greater potential for maintaining the natural diversity within the state.

The foundation for successful biodiversity protection is a series of representative, high-quality examples of all the state's natural community types, with their constituent species and their underlying ecological processes. The best option for this kind of protection would be a series of connected, high quality natural community types; this series would ensure that ecological processes that connect natural communities remain functionally intact within a broader landscape context. In short, there is a need for reserve areas with natural communities protected within a diverse landscape, not just in isolation.

NH Natural Heritage strives to connect residents of (and visitors to) the state with its native biodiversity. The Visiting NH's Biodiversity Progam offers a series of interpretive trail guides and descriptive profiles for a variety of sites with exemplary natural communities, systems, and species. The list of sites can also be viewed sorted by the NH Division of Travel & Tourism's Travel Regions.