A contextualized ecological theory

The field of ecology is increasingly occupied with reconciling the structure of ecosystems with their functions: for example, trying to accurately predict the rate at which nutrients cycle through (or accumulate within) an ecosystem from the number of species in it, or from the number of traits, niche diversity or some other metric of its structure, or vice versa. A complete understanding of the structure–function relationship could provide a crucial link in a unified theory of ecology. Something that keeps me up at night is questioning whether such a unified theory is achievable.

One complication of the pursuit of unity is that the effects of biodiversity on productivity are scale-dependent, and different relationships are found at varying spatial extents. These relationships also depend on which specific metrics of biodiversity and productivity are considered, which often creates inconsistencies between theory and observation. For example, niche theory predicts a positive relationship between functional trait diversity and primary productivity, due to increased niche differentiation, but empirical evidence from observational studies only moderately supports a positive association.