Functional diversity of experimental annual plant assemblages drives plant responses to biological soil crusts in gypsum systems

1. Biological soil crusts (BSC) are complex biotic aggregates comprised of lichens, cyanobacteria, algae, and other microorganism that are known to differently affect plant development along life cycle by selecting plant functional traits based on species-specific effects. In addition, functional differences between interacting species should modulate their response ability to other environmental factors. Thus, it should be expected that the effects of the BSC on plants will be significantly determined by the own functional diversity in the community.
2. To understand the multiple effects of BSC and the extent to which the functional diversity of interacting plant species can modulate their effects on the development of coexisting species, we applied an experimental approach by manipulating the initial functional diversity of the entire annual plant community and BSC conditions in a common garden trial. We crossed three sorts of assemblages built on the basis of plant stature (combinati...