Convergence and Divergence of Old-Field Vegetation After 11 yr of Nitrogen Addition

摘要: Eleven years of data from experimental nitrogen gradients in three old fields and native savanna are used to test the hypothesis that similarity resource availability should influence plant species composition. Vegetation became less similar on plots received different amounts nitrogen. The difference vegetation between was a function both added absolute levels Changes same amount were influenced by initial composition, nitrogen, rate colonization not initially present plots. Replicates many treatments similar, only increase after 3-6 yr. Data generally consistent with predictions made 1988, clearly illustrate importance long- term responses manipulations.