| Popis: |
If one stands on a peak on the eastern side of the Northern Rocky Mountains on a clear day and gazes across the surrounding landscape, striking patterns of vegetation are apparent. From valley bottoms to ridgetops, vegetation grades from grassland and shrublands to open savannas, from dense tall forest to scattered clumps of krumholtz trees in the alpine above the pronounced treeline (fig. 9-1). These recurrent patterns of climatically zoned vegetation suggest that plants are a logical starting point for understanding biodiversity response to climate change. Plants, once established, are sessile and unable to move to more favorable locations and thus are strongly limited by the local climate. The predictable variation in climate with elevation explains this striking pattern of vegetation in the Rockies. To the extent that climate changes in the future, vegetation is expected to change in establishment, growth, and death rates, in canopy structure, and in the distributions of species and thus to show major shifts upward in elevational distribution. |
