Functional traits of nurse plants impact recruitment based on life form of beneficiary plants

Abstract

Arid and semi-arid ecosystems are widely distributed around the world, covering about 60% of the earth’s land area. This type of ecosystem has low resilience and high fragmentation caused by human activities related to land use changes to agricultural uses. It has been seen that one of the mechanisms that can help recover the structure and functioning of this type of ecosystem is facilitative interaction. It has been documented that in these environments, the greatest recruitment and establishment of seedlings occur under the cover of a nurse plant. This has led us to investigate whether the life forms of the benefited plants have any relationship with this type of interaction, since the presence and distribution of beneficiaries of particular life forms may result from the evolution of the facilitating interaction. In total, we registered 16 nurse species in the sampling sites, and underneath the canopies of these species, we recorded approximately 250 individuals benefiting from these plants. The majority (51%) were succulent plants, followed by shrubs comprising 27.5%. The functional attributes of the nurse plants that were most strongly associated with the succulent life form were height (H) and canopy density (CD) (Axis 1 of the PCA), as well as leaf area (LA) and specific leaf area (SLA) (Axis 2). These relationships may be due to the fact that succulents seek out nurse plants that have ample canopy cover for the best protection. These findings may help in the selection of effective nurse species for restoring functional diversity in degraded drylands.