Data from: Contrasting trait assembly patterns in plant and bird communities along environmental and human-induced land-use gradients

Human-driven environmental changes can induce marked shifts in the
functional structure of biological communities with possible repercussion
on important ecosystem functions and services. At the same time it remains
unclear to which extent these changes may differently affect various types
of organisms. We investigated species richness and community functional
structure of species assemblages at the landscape scale (1km2 plots) for
two contrasting model taxa, i.e., plants (producers and sessile organisms)
and birds (consumers and mobile organisms), along topography, climate,
landscape heterogeneity, and land-use (agriculture and urbanization)
gradients in a densely populated region of Switzerland. Our study revealed
that agricultural and urban land uses drove marked shifts in the
functional structure of biological communities compared to changes along
climate and topography gradients, especially for plants, while for birds
these changes were comparable. Agricultural and urban land uses enhanced
divergence in traits related to resource use for birds (diet and nesting),
growth forms, dispersal, and reproductive traits for plants, while it
induced convergence in vegetative plant traits (plant height and leaf dry
matter content). These results suggest that contrasting assembly patterns
may arise within and across taxonomic groups along the same environmental
gradients as result of distinct underlying processes and
'organism-specific' environmental perceptions. Our results
further suggest a potential homogenization of biological communities, as
well as low functional diversity and redundancy levels of bird assemblages
in our human-dominated study region. This might potentially compromise the
maintenance of key ecological processes under future environmental
changes.