^~^.s^ 







Habitat Assessments 



Overview 



Articles in tiiis section 

 address the development, 

 interpretation, and analysis of ecological infor- 

 mation over very large geographic regions and 

 are characterized by the huge undertaking to 

 assemble and manipulate the data required. 

 These articles illuminate the imperative need 

 for infonnation at multiple levels of both geo- 

 graphic scale (site, small watershed, state, 

 regional, national) and biotic organization (pop- 

 ulation, species, natural community, landscape, 

 and biome). 



A systematic approach toward the develop- 

 ment of science-based ecological information at 

 multiple scales and across large areas has been 

 lacking from our management of natural 

 resources. Significant gains in achieving an 

 environmentally sustainable society with an 

 acceptable standard of living can be had by 

 addressing this issue, and the articles in this sec- 

 tion point the way. 



Edwards and Stoms and Davis present some 

 early results of the National Gap Analysis 

 Project (see box by Scott et al.. this section). 

 Edwards shows that less than 10% of the vege- 

 tation cover types in Utah are represented with- 

 in conservation lands. There is no assurance 

 that the 90% of vegetation types (or habitat 

 types) not represented in conservation lands 



will not be eliminated by changes in land use. 

 In a world where the demand for raw materials 

 is increasing and the rate of land-use change is 

 rapid, adequate representation of habitat types 

 in conservation lands is important if we are to 

 prevent extinctions. The lack of adequate rep- 

 resentation of habitat types in conservation 

 lands is also the situation described by Stoms 

 and Davis in the next article. They show that 

 while almost 10% of the total surface area of 

 southwestern California is managed to protect 

 native biological diversity, most of this land is at 

 high elevations. Natural coinmunities at low 

 elevations, such as coastal sage scrub and 

 California walnut woodlands, are in consider- 

 able danger of extinction. 



Shaw and Jennings describe the Multi- 

 Resolution Land Characteristics Database, 

 which is the first effort to provide consistent, 

 direct, and integrated observations of large-area 

 ecosystems, producing basic as well as inter- 

 preted information for a range of purposes. 

 This effort includes the land-cover types of agri- 

 cultural and urban areas as well as natural areas. 

 With access to these data sets, policy decisions 

 as well as daily management choices may, for 

 the first time, be regularly examined in a bio- 

 geographic context covering the entire distribu- 

 tion of a natural feature of concern (such as a 



Michael D. Jennings 



National Biological 



Service 



Idaho Cooperative Fish 



and Wildlife Research Unit 



University of Idaho 



Moscow, ID 83843 



