The interplay of facilitation and competition drives the emergence of multistability in dryland plant communities

Species are wrapped in a set of feedbacks within communities and with their abiotic environment, which can can generate alternative stable states. So far, research on alternative stable states has mostly focused on systems with a small number of species and a limited diversity of interaction types. Here, we analyze a spatial model of plant community dynamics in drylands, where each species is characterized by a strategy, and interact through facilitation and competition. Our work identifies three different types of multistability emerging from the interplay of competition and facilitation. Under low-stress levels, the community organizes in small groups of coexisting species maintained by space and facilitation, while under higher stress levels, positive feedbacks from competition and facilitation lead to the dominance of a single species before desertification happens. Our study paves the way for bridging community ecology and alternative states theory in a common framework.