Data from: Facilitation enhances ecosystem function with non-random species gains

Facilitation, an ecological interaction assembling plant communities
worldwide, has been shown to modulate both species richness and ecosystem
functions. Such a Biodiversity-Ecosystem Functioning (BEF) relationship
can be decomposed into different components not only related to species
losses and gains but also to the identity of the species and the context
in which they live. Using an extension of the classical BEF approach named
CAFE (Community Assembly and the Functioning of Ecosystems), we quantified
the contribution of these components to the BEF relationship in a Spanish
semiarid plant community shaped by facilitation. We used species richness
as a measure for biodiversity and plant cover as a proxy of multiple
ecosystem functions including plant productivity, soil protection, soil
fertility and microbial productivity. Nurse plants doubled the number of
species that live beneath them relative to open ground, but caused a
five-fold increase in plant cover. The disproportionate increase of plant
cover was a consequence of the identity of the species enhanced by nurse
plants, which were more productive than the average. We discuss these
results in terms of sampling effects (i.e., the higher probability of
richer communities to harbour hyperproductive species) and complementary
effects (i.e., richer communities enhancing productivity through resource
partitioning, abiotic facilitation, or biotic feedbacks). The enhancement
of ecosystem functions that plant facilitation produces by incorporating
species with high functional values to the community may reverberate among
other trophic levels and propagate beyond the local scale where the
ecological interaction is produced.