What is Biodiversity?

Biodiversity is the variety and variability of all living organisms. It includes whole organisms, their genes, the natural communities in which they live, and the complex interactions among and between organisms and their physical environment. Natural levels of biodiversity may be very high, as in tropical regions with favorable growing conditions and high species counts per unit area. Biodiversity can also be very low in places like deserts and arctic regions, where conditions are harsh and few species can survive. The biodiversity in a given area decreases when species suffer local extinctions, when invasive species form monocultures that displace native species, and when the natural habitats that support the local species are fragmented or destroyed. On a landscape scale, unique components of biodiversity, such as species or natural communities with limited distributions, are focal points for conservation efforts.

Biodiversity has important value. Direct use values include recreation, medicine, and forest products. Indirect use values derive from important ecosystem services, such as soil building, erosion control, fire prevention, water quality improvement, contaminant absorption, flood reduction, crop pollination, and pest control. Finally, biodiversity has important non-use values. People apply value to species or places simply by knowing of their existence, even if they may never see or experience these resources firsthand.

Protecting Biodiversity in New Hampshire

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).

The NH Natural Heritage Bureau facilitates protection of the state's biodiversity by providing information about 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 individual 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, by conducting surveys 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 maintaining a series of representative examples of all the state's natural community types, with their constituent species and underlying ecological processes. A good strategy for this kind of protection would be to conserve 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 the state's residents and visitors with its native biodiversity. The
Visiting NH's Biodiversity Program offers a series of interpretive trail guides and descriptive profiles for a variety of sites with exemplary natural communities and rare plant species.

a diversity of wildflower species carpets the floor of a rich mesic forest in spring (photo by Ben Kimball for the NH Natural Heritage Bureau) 

Natural Heritage Bureau