Fig. 4: Hypothesized (dashed lines) and observed (solid lines) effects of the increasing number of global change factors (GCFs) on ecosystem functions.

An increasing number of GCFs can reduce ecosystem functions via biodiversity loss (path 1), the reduction in biodiversity effects (path 2), the changes in community composition and the reduction in abundance (path 3). The reduction in biodiversity effects could come from the changes in community composition and the reduction in population abundance induced by an increasing number of GCFs.