A rich body of knowledge now links biodiversity to ecosystem functioning (BEF), but it is primarily focused on small scales. A new generation of experiments and empirical studies is tackling the question of BEF at larger scales: from coasts to landscapes, regions to entire continents. In this talk, I will review current theory focused on how BEF may change with scale and what is required for BEF to emerge at larger scales. I will highlight six expectations, two from statistical scaling theory and four from process-based theories.
Results/Conclusions
Statistical theory predicts a 1) a nonlinear change in the slope of the BEF relationship with spatial scale, and 2) a triphasic relationship between biomass fluctuations and area. Process-based theories predict: 3) scale-dependence in BEF when species coexist by partitioning environmental heterogeneity within and among assemblages; 4) autocorrelation in environmental variability mediates the rate of species turnover and thus the change in BEF slope with scale; 5) connectivity in metacommunities generates nonlinear BEF and stability relationships by mediating the (a)synchrony in dynamics at local and regional scales; 6) in food webs, spatial and temporal scale reveal vertical diversity and trophic complementarity among consumers and predators, both of which mediate the scaling of BEF. I will highlight empirical support for these expectations where available.
Human global change drivers interact with the processes at play in these expectations to alter the scaling of BEF. Tests of these expectations could combine remote sensing and a generation of networked experiments that include scale in their design. This knowledge can guide policy aligning the goals of managing biodiversity change and ecosystem services at different spatial scales.