312 



Inti'iiiir Wesi — Our Livint; Resources 



For further information: 



Thomas J, Slohlgrcn 



National Biological Service 



Rocky Mountain Field Station 



Natural Resource Ecology Laboratory 



Colorado State University 



Fort Collins. CO 80523' 



150.000 to more than 320.000 kg/ha (133.828- 

 285.500 lb/acre) in standing biomass. and annu- 

 al tree growth remains relatively high in these 

 ancient forests. We are finding that ecotones are 

 sensitive indicators of forest change: the forest- 

 tundra ecotone (transitional area between dis- 

 tinct habitats or ecosystems) in Rocky 

 Mountain National Park has been undergoing 

 substantial directional change for some time 

 (Baker et al. 1994). There is substantial evi- 

 dence of seedling and sapling invasion within 

 some previously unforested areas within the 

 ecotone, patlicularly in wet areas in the patch 

 forest zone. This filling in of the ecotone could 

 substantially alter the ecotone environment 

 (Baker et al. 1994). There is little evidence, 

 however, of upward establishment of trees into 

 tundra. To synthesize the vegetation change 

 data, we are developing predictive vegetation 

 change models by using geographic informa- 

 tion systems. Our long-term study plots and 

 tran.sects will validate future models. 



Implications 



This interdisciplinary approach can be wide- 

 ly applied to most U.S. Department of the 

 Interior land units and most ecosystems and will 

 be an essential link to large-scale inventory and 

 monitoring programs (e.g.. Gap Analysis 

 Program and EMAP). Ecosystem science is the 

 most logical approach to determine the status 

 and long-term trends of selected resources, pop- 

 ulations, and ecosystems. This approach fosters 

 discovery, standardization, linkages, and part- 

 nerships as well as coordinated inventory, mon- 



itoring, and research. New, standardized sam- 

 pling protocols are being developed to accurate- 

 ly assess vascular plant species richness, an 

 index of biodiversity (Stohlgren 1994). 



References 



Baker, W.L.. J.J. Honaker. and P.J. Weisberg. 1994. Using 

 aerial photography and CIS lo map the forest-tundra eco- 

 tone in Rocky Mountain National Park. Colorado, for 

 global change research. Photogrammetric Engineering 

 and Remote Sensing. In press. 



Baron. J.. L. Band. S.W. Runnmg. R.A. Pielke. and T.G.F 

 Kmel. 1994. Dynamic land surface/atmosphenc parame- 

 terization at different spatial scales in the Colorado 

 Rocky Mountains. In Proceedings of the Use of 

 Hydrologic Models for Evaluating Climate Change 

 Effects in Snowmelt Water Supply Basins. Agricultural 

 Research Service. In press. 



LaRoe, E.T. 1993. Implementation of an ecosystem 

 approach to endangered species conservation. 

 Endangered Species Update 10:3-6. 



Pielke. R.A., J. Baron. TChase, J. Copeland. T.G.F. Kittel. 

 T.J. Lee, R. Walko, X. Zeng. 1993. Use of mesoscale 

 models for simulation of seasonal weather and climate 

 change for the Rocky Mountain states. Proceedings, 

 Second International Conference/Workshop on 

 Integrating CIS and Environmental Modeling. 

 Breckenridge, CO. In press. 



Stohlgren. T.J. 1994, Planning long-term vegetation studies 

 at landscape scales. In T M, Powell and J. H. Steele, eds. 

 Ecological time series. Chapman and Hall. New York. In 

 press. 



Stohlgren. TJ.. J. Baron, and T. Kittel. 1993. Understanding 

 coupled climatic, hydrological. and ecosystem responses 

 to global climate change in the Colorado Rockies bio- 

 geographical area. Pages 184-200 in W,E. Brown and 

 S,D. Veirs, Jr., eds. Partners in stewardship: Proceedings 

 of the 7th Conference on Research and Resource 

 Management in Parks and on Public Lands. George 

 Wnght Society. Hancock, MI. 



Veblen, T.T.. and D.C. Lorenz. 1991. The Colorado Front 

 Range: a century of ecological change. University of 

 Utah Press, Salt Lake City, he pp. 



The Greater 



Yellowstone 



Ecosystem 



by 



Paul Schullery 



National Park Service 



Greater Yellowstone is described as the last 

 large, nearly intact ecosystem in the north- 

 em temperate zone of the earth (Reese 1984; 

 Keiter and Boyce 1991 ). Conflict over manage- 

 ment has been controversial, and the area is a 

 flagship site among conservation groups that 

 aggressively promote ecosystem management 

 (Greater Yellowstone Coalition 1992). The 

 Greater Yellow Ecosystem (GYE) is one of the 

 world's foremost natural laboratories in land- 

 scape ecology and geology and is a world- 

 renowned recreational site (Knight 1994). 



History 



Yellowstone National Park (YNP) bound- 

 aries were arbitrarily drawn in 1872 in hopes of 

 including all regional geothermal basins. No 

 other landscape considerations weie incorporat- 

 ed. By the I970's, however, the grizzly bear's 

 {Ursiis arctos) range in and near YNP became 

 the first informal minimum boundary of a theo- 

 retical Greater Yellowstone Ecosystem that 



included at least 1,600,000 ha (4,000,000 acres; 

 Schullery 1992). Since then, definitions of the 

 GYE have steadily grown larger (Fig. I ). A 

 1994 study listed the GYE size as 7,689,000 ha 

 (19,000,000 acres; Clark and Minta 1994), 

 while a 1994 speech by a Greater Yellowstone 

 Coalition leader enlarged that to 8,000,000 ha 

 (20,000,000 acres; Wifcox 1994). 



In 1985 the House Subcommittees on Public 

 Lands and National Parks and Recreation held a 

 joint subcommittee hearing on Greater 

 Yellowstone, resulting in a report by the 

 Congressional Research Service (1986) outlin- 

 ing shortcomings in interagency coordination 

 and concluding that the area's essential values 

 were at risk. 



Ecosystem Management by 

 Species 



The GYE concept has been most often 

 advanced through concerns over individual 



