Alpine Nodal Ecology and Ecosystem Evolution in the North-Central Rockies(Mount Washburn; Yellowstone National Park, Wyoming)
Aho K and Weaver T. 2010. Alpine Nodal Ecology and Ecosystem Evolution in the North-Central Rockies(Mount Washburn; Yellowstone National Park, Wyoming). Arctic, Antarctic, and Alpine Research. 42(2):139-151
We studied Mount Washburn (Yellowstone National Park, Wyoming) to describealpine ecosystem function and evolution at an important site in the North-CentralRockies. To describe the alpine environment we sampled major environmental nodes(north-faces, south-faces, snowbanks, ridges, talus, and ledges). Our analysis wasbolstered by the measurement, over five years, of seasonal soil water andtemperature. Clusters representing nodal plant communities explained 86% ofscatterplot variability, after accounting for spatial location, in a strong (non-metricr2 5 0.98) NMDS ordination. Water inputs and nutrient storage (also significantpredictors of community structure) increased while soil temperature fell fromsouthern to northern nodes. Seasonal soil water availability was strongly influencedby transpiration. As a result soils dried earlier than expected under dense northfacingturf and later than expected under talus and ledges. We propose that abioticand biotic processes have combined to increase resources for northern nodes at theexpense of southern nodes since the last glaciation. This is because soils havecontinually blown with snow from south slopes to north-facing lee slopes, improvingtheir water and nutrient status. Increases in vegetation have further increased waterand nutrient capture and decreased water and nutrient losses in a biologically drivenpositive feedback loop.
- Type
- Journal Article
- Authors
- Aho, Ken; Weaver, T
- Units
- GRYN
- Keywords
- abiotic, biotic, Glaciation, soil water, Temperature, Transpiration