Data from: Land-use history alters contemporary insect herbivore community composition and decouples plant-herbivore relationships

1. Past land use can create altered soil conditions and plant communities
that persist for decades, although the effects of these altered conditions
on consumers are rarely investigated. 2. Using a large-scale field study
at 36 sites in longleaf pine (Pinus palustris) woodlands, we examined
whether historic agricultural land use leads to differences in the
abundance and community composition of insect herbivores (grasshoppers,
families Acrididae and Tettigoniidae). 3. We measured the cover of six
plant functional groups and several environmental variables to determine
whether historic agricultural land use affects the relationships between
plant cover or environmental conditions and grasshopper assemblages. 4.
Land-use history had taxa-specific effects and interacted with herbaceous
plant cover to alter grasshopper abundances, leading to significant
changes in community composition. Abundance of most grasshopper taxa
increased with herbaceous cover in woodlands with no history of
agriculture, but there was no relationship in post-agricultural woodlands.
We also found that grasshopper abundance was negatively correlated with
leaf litter cover. Soil hardness was greater in post-agricultural sites
(i.e. more compacted) and was associated with grasshopper community
composition. Both herbaceous cover and leaf litter cover are influenced by
fire frequency, suggesting a potential indirect role of fire on
grasshopper assemblages. 5. Our results demonstrate that historic land use
may create persistent differences in the composition of grasshopper
assemblages, while contemporary disturbances (e.g. prescribed fire) may be
important for determining the abundance of grasshoppers, largely through
the effect of fire on plants and leaf litter. Therefore, our results
suggest that changes in the contemporary management regimes (e.g.
increasing prescribed fire) may not be sufficient to shift the structure
of grasshopper communities in post-agricultural sites towards communities
in non-agricultural habitats. Rather, repairing degraded soil conditions
and restoring plant communities are likely necessary for restoring
grasshopper assemblages in post-agricultural woodlands.