Plant community assembly on restrictive gypsum soils

Previous studies have shown that plant communities on infertile soils are relatively resistant to climatic variation due to stress tolerance adaptations. However, plant communities in gypsum soil habitats require further investigation. Gypsum outcrops are widespread throughout the world but typically occur in arid and semi-arid ecosystems. The soils of these outcrops are restrictive and impose harsh abiotic conditions on the plants growing in them. Despite this making them an ideal system to analyse community assembly under harsh conditions, questions remain about this process. Specifically, (1) whether arid conditions determine the characteristics of the species in these communities? (2) if the selection of species that assemble under arid conditions is mediated by the ability to grow on gypsum soils, and (3) if this selection of species is related to evolutionarily conserved plant functional traits?

In a new study published in AoBP, Luzuriaga et al. investigated these questions by studying plant community resistance to climatic variation in gypsum soil sites across the Iberian Peninsula. They found perennial communities on gypsum soils to be relatively resistant to changes in precipitation however, temperatures in the hottest month were the main factor responsible for the selection of the species that finally established communities. It should be noted that species adapted to grow on gypsum soils (i.e. gypsophites) dominated plant communities in the hottest locations. These findings suggest that the warmer environmental conditions predicted by global change models will favour gypsum specialists over generalists.