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Full-Text Articles in Life Sciences
Old-Field Succession On A Minnesota Sand Plain, R S. Inouye, Nancy J. Huntly, D Tilman, J R. Tester, M Stillwell, K C. Zinnel
Old-Field Succession On A Minnesota Sand Plain, R S. Inouye, Nancy J. Huntly, D Tilman, J R. Tester, M Stillwell, K C. Zinnel
Biology Faculty Publications
Vegetation and soils were sampled in 22 old fields ranging in age from 1 to 56 yr since abandonment. Soil nitrogen concentration increased significantly with field age. Vegetation cover, total aboveground plant biomass, and litter cover increased significantly with soil nitrogen. Light penetration to the soil surface was negatively correlated with total plant biomass. Field age and soil nitrogen concentration were used as independent variables in simple regression and partial correlation analyses to determine the relative importance of such time—dependent processes as dispersals vs. the availability of a limiting resource (nitrogen) as predictors of patterns in species richness or the …
Influence Of Rufuging Consumers (Pikas: Ochotona Princeps) On Subalpine Meadow Vegetation, Nancy J. Huntly
Influence Of Rufuging Consumers (Pikas: Ochotona Princeps) On Subalpine Meadow Vegetation, Nancy J. Huntly
Biology Faculty Publications
Talus slopes in western North America frequently are bordered by vegetation that differs in biomass, cover, height, and species composition from vegetation located farther from talus. These areas are grazed by pikas (Ochotona princess, which nest in that talus. Foraging theory predicts that pikas will produce a gradient of grazing pressure, which could produce the observed vegetational zonation. In a subalpine meadow in west-central Colorado, pikas produced the predicted gradient of grazing pressure, along which plant groups varied clinally in abundance. The effects of pikas on talus-border vegetation were tested by excluding pikas from small plots at several distances from …