This week we welcome our own Qian Gu.
Living in an (elementally) imbalanced world: Is stoichiometry useful in understanding the structure and functioning of an arctic tundra ecosystem?
Humans are causing major perturbations in global biogeochemical cycles, especially carbon, nitrogen and phosphorus. These changes put ecosystems under considerable stress, making it critical to understand the mechanisms that underpin ecosystem structure and functioning. Ecological stoichiometry (elemental ratios) is a recent theoretical approach that is based on the realization that all organisms are made of the same essential elements, and therefore provides a mechanistic link from the cellular level all way up to the biosphere. In particular, plant stoichiometric homeostasis – the ability of a species to maintain a certain elemental composition despite variation in the elemental composition in the soil – may represent a useful complementary trait to other plant traits in understanding and predicting community structure. I investigated its applicability in arctic tundra ecosystems by determining homeostasis indices for seven common tundra vascular species. I then analyzed how these homeostatic values were related to key aspects of ecological performance, such as plant dominance. Overall, these results will evaluate the potential contribution of ecological stoichiometry to predicting the impacts of environmental changes on arctic tundra vegetation.