| | Glacier National Park Biodiversity Paper #1 |
 | | An ecosystem is "any part of the universe chosen as an area of interest, with the line around that area being the ecosystem boundary and anything crossing the boundary being input or output" (Agee and Johnson 1989), or "a community of organisms and their physical environment interacting as an ecological unit" (Lincoln et al. |
 | | 1986.) The Crown of the Continent Ecosystem is particularly rich in community diversity because of the contrast in climates between the east and west sides of the Continental Divide, the large amount of topographic relief, and the presence of both calcareous (calcium-rich, derived from limestone) and non-calcareous soils (Lesica 1985, Edwards 1957, McClelland ca. |
 | | A major challenge for ecosystem researchers and managers, therefore, will be to distinguish between natural and inevitable changes (including species extinctions and immigrations see Information Papers 4 and 5) and human-caused changes that may be irreversibly diminishing biological diversity and ecosystem health. |
| www.nps.gov /glac/resources/bio1.htm (2791 words) |