Ambient
We can contrast these two broad types of shifts in community structure under global change manipulations to the patterns observed under ambient conditions (CTL), which showed little directional change over time. The cover of dominant and subdominant species did not change, while the abundance of moderate species decreased and rare species slightly increased (marginally significant) (Fig 1, Table 1). Given that different global change treatments resulted in distinct shifts in community structure, we then ask whether density-independent responses to the environment or density-dependent species interactions best explain these shifts.