Data from: Trait-matching and mass effect determine the functional response of herbivore communities to land use intensification

1. Trait-based approaches represent a promising way to understand how
trophic interactions shape animal communities. The approach relies on the
identification of the traits that mediate the linkages between adjacent
trophic levels, i.e. “trait-matching”. Yet, how trait-matching explains
the abundance and diversity of animal communities has been barely
explored. This question may be particularly critical in the context of
land use intensification, currently threatening biodiversity and
associated ecosystem services. 2. We collected a large dataset on plant
and grasshopper traits from communities living in 204 sampled grasslands,
in an intensively managed agricultural landscape. We used a multi-trait
approach to quantify the relative contributions of trait-matching and land
use intensification acting at both local and landscape scales on
grasshopper functional diversity. We considered two key independent
functional traits: incisor strength and body size of grasshopper species.
Incisor strength, a resource-acquisition trait, strongly matches
grasshopper feeding niche. Body size correlates with mobility traits, and
may determine grasshopper dispersal abilities. 3. Plant functional
diversity positively impacted the diversity of grasshopper
resource-acquisition trait, according to the trait-matching observed
between plants and herbivores. However, this positive effect was
significantly higher in old grasslands. In addition, the presence of
specific habitats in the landscape (i.e. wood and alfalfa) strongly
enhanced grasshopper resource-acquisition trait diversity in the focal
grassland. Finally, body size increased with landscape simplification,
although its response was modulated by local factors such as soil depth.
4. Trait-matching between plants and herbivores was an important driver
explaining the abundance and diversity of resource-acquisition traits
within grasshopper communities. Herbivore functional diversity in
grasslands, however, cannot be understood without taking into account the
presence of specific habitats in the surrounding landscape, as well as the
age of the grassland. Our study suggests mass effect and assembly time are
central mechanisms promoting higher functional diversity within animal
communities in highly disturbed anthropogenic system.