Impact of habitat type and landscape structure on biomass, species richness and functional diversity of ground beetles

This study investigated how local habitat type and landscape structure affects the biomass, species richness and functional diversity of ground beetles sampled from a 1000 ha UK arable farm. At a local scale habitat type was either crop (winter wheat and oilseed rape) or one of five field margin habitats. Surrounding each of these sampling areas, landscape structure was defined using remote sensed data from Specim AISA Eagle (400–970 nm) and Hawk (970–2450 nm) hyperspectral sensors. Ground beetles were divided into predatory and phytophagous trophic levels. Local habitat type only affected phytophagous ground beetle biomass, which was lowest within crops. Total biomass of predatory beetles was negatively correlated, and species richness positively correlated, with landscape habitat diversity. Only the functional diversity of predatory ground beetles responded to landscape structure, showing positive correlations with the proportion of Tussock Grass field margins. Predatory ground beetles show a greater dependence on landscape structure than phytophagous species, a response that is attributed to their high mobility needed for movement between dynamically variable food resources.

Research highlights▶ Biomass and species richness of predatory ground beetles in UK arable landscapes respond principally to landscape structure, while phytophagous species respond to local habitat type only. ▶ The functional diversity of predatory ground beetles is positively correlated with the proportion of Tussock Grass field margins in the surrounding landscape. ▶ The functional traits that describe predatory ground beetle dispersal and movement are less diverse in landscapes containing high proportions of the crop Oilseed Rape.