Biodiversity-ecosystem function relationships change through primary succession

Ecologists traditionally use environmental parameters to predict successional shifts in compositional characteristics of local species assemblages (environmental control). Another important focus in ecology is to understand functional roles of species assemblages in determining local environmental properties (diversity control). Then, the question emerges: which is the cause, and which is the consequence? To clarify the causal relationships between species assemblages and environmental properties, we focused on seral changes in species/functional diversity of vascular plants in tundra ecosystems of the High Arctic. We found that, although species richness was influenced by soil properties in the earlier stages of primary succession, the causalities were reversed in the later stages. We also found functional differentiation among coexisting species in the later stage, suggesting that the ‘complementarity effect’ of diversity on ecosystem functions likely increased with ecosystem developm...