Heritage Programs

There are an estimated 5 to 10 million species on earth. They occur in numerous different communities and species aggregations. To ensure the survival of the greatest number of natural communities and the species comprising them, we first need to know which communities and species are in greatest danger of disappearing. But the world with all its species is too large to try to organize in one inventory. It is much easier to work within geographic and political boundaries. Thus, The Nature Conservancy (TNC) has initiated projects known as "Heritage Programs" in 26 of the United States. The California Natural Diversity Data Base (CNDDB) is one such program.

These programs manage information about "elements of natural diversity." Elements of natural diversity are plant or animal species, natural communities, both terrestrial and aquatic, or geological features which occur in the inventory area. Information documenting the status and distribution of certain species and communities is used to identify significant natural areas, to re-evaluate decisions about the relative status of various elements, and to justify claims that particular elements need additional protection. The world-wide programs undertaken by TNC and UNESCO's Biosphere Reserve System also aim to preserve some of the world's natural diversity, although neither currently inventories elements. TNC's International Heritage Program is beginning a data management system which would track the preserves already in

[1] Paper presented at the California Riparian Systems Conference. [University of California, Davis, September 17–19, 1981].

[2] Deborah B. Jensen is Plant Ecologist at the California Natural Diversity Data Base, California Department of Fish and Game, Sacramento, Calif.

existence in the world and the elements of natural diversity protected within these preserves. State heritage programs complete this task as only one part of their inventory.

The basic steps in a heritage program like the CNDDB are quite simple (fig. 1). First an element list is made. The CNDDB is inventorying three types of "elements": plants, animals, and natural communities. The plant and animal lists come from floras, faunas, or check lists. The list of community elements is a revision of the "Annotated List of California Habitat Types" (Cheatham and Haller 1975).

Some elements are more endangered than others and therefore need immediate attention. So, the element list is ranked to create a list of critical elements in each of the three categories. There are already state and federal lists of rare and endangered species as well as inventories such as Smith etal . (1980). In addition, many agencies have lists of species of concern. Criteria used to rank species include range in California, total range, total number of occurrences which are protected, uniqueness (taxonomic distinctiveness), and endangerment. Thus, a species or community endemic to California and now rare in the state, occurring only at a few locations, which is also distinctive and found in an area quickly being converted by urban development would have a very high priority rank. Priority ranks indicate in what order information will be collected. Highest priority elements are inventoried first.

Figure 1.
Flow chart showing heritage program inventory methods.
Step 1—list all elements. Step 2—rank the element
list. Step 3—collect data. Step 4—analyze the data.

Next, information on locations where these critical elements are found, and their status and condition at these sites is collected. Since work is being done on many elements simultaneously, very little original research on the locations of various elements is being conducted. Rather, all available information is being collected so an up-to-date inventory can be begun. The data are from diverse sources: state and federal agencies, private corporations, and numerous knowledgeable professionals and laypersons.

The information is then analyzed. Knowing where critical elements occur, what their conditions are at each site, and whether or not they are protected makes it possible to draw some conclusions about the status of natural diversity in California. It is possible to analyze what elements are rare and endangered, what elements are rare but protected, and what sites (protected or not) contain the highest numbers of rare and endangered elements. Potential sites for designation as "significant natural area" status and other conservation activities can be identified and the question: "Are the best examples of the highest priority critical elements protected?" can be answered—thereby evaluating the endangerment and protection status of the elements in the system. This is an iterative process. Important natural areas are identified, and some areas protected. Then over time the priority ranks of different elements of diversity can be re-evaluated as the accuracy of inventoried information increases and/or the number of places where this element is protected changes.

Programs such as these can make effective use of limited financial and human resources to objectively identify those species and communities most in need of protection. The CNDDB and other programs like it inventory elements in the belief that by looking at the various species and communities in the state, important sites can be located. This approach should guarantee that the CNDDB does not simply identify pretty places for natural areas, but rather includes representative samples of all facets of California's natural heritage.