Fig. 2. Diagrams expressing the idea that the number of global change factors alone might predict general trends in changes of biodiversity and ecosystem processes.

A. We hypothesize that biodiversity and ecosystem processes display a consistent directional change (this could be either an increase or decline, concave or convex; in the panel we only show a decline and only one possible curve shape) along the number of environmental factors. B. The rationale behind this prediction is that with an increasing number of factors there is an increased chance of including an influential factor (selection effect), that factors may increasingly affect different components (complementarity effect), and that factors may interact with each other, so strengthening their effect (factor interaction effect).