Density dependent processes
Incorporating density-dependent shifts in competitive interactions more fully explained the directional changes in species group cover over time (Fig 3, Table S2, S3). Broadly, global change treatments shifted intraspecific and interspecific competition in ways that reduced net competition for the dominant species but increased net competition for subdominant and to a lesser extent, moderate and rare species (Fig 3, S8). The major exception to this pattern was in the W plots, where we observed an increase in net competition for the dominant species. In addition, density-dependent species interactions shifted along environmental gradients, primarily N, leading to non-linear abundance distributions for subdominant species.