Experimental Evidence of High-Dimensional Elementome Shifts Due to Coexistence and Its Effects on Growth Rates.

Elementomes (i.e., the concentration of bioelements of an organism) have been shown to be related to organism traits and function, and to change across space and time mostly due to changes in environmental conditions, but also due to coexistence amongst species. While there is vast observational evidence for that, experimental evidence remains elusive. Here we set up a diversity experiment, based on 20 aquatic microcosms where we grew one, two, three or four moss species together, to test whether coexistence amongst species is an important driver of high-dimensional elementome shifts in mixed communities. Our results provide experimental evidence showing that species tend to shift their elemental composition in response to coexistence, and that the magnitude of this shift increases with the elemental diversity of the community. Overall, our results provide the first experimental evidence of high-dimensional shifts in elementomes due to coexistence, supporting the biogeochemical niche hypothesis.