Challenges of Orthoptera conservation in grasslands with land use-determined sizes and structural heterogeneity

Abstract

Human activities affect all ecosystems, within that the grasslands have often been subject to intensive modification due to agricultural use and fragmentation. The result is a biodiversity crisis, on which detailed agri-environment schemes can help. For the compilation of perspective schemes, it is crucial to know the minimal area that can provide habitats for stable, species-rich insect assemblages in optimal land use.

This research aimed to collect detailed data for phrasing patch-size centric conservation strategies on orthopteran assemblages, being an umbrella taxon, in two areas of the Pannonian Ecoregion. In narrow (radius = 25 m) and broader (r = 50, 75, 100 m) environments of the assemblages, we have searched for that habitat patch size, where the primary vegetation characteristics (cover, height, composition) affect the main features of the orthopteran assemblages and relative abundances of the species to the highest degree.

According to our results, ecotype diversity of orthopteran assemblages showed the strongest correlations with average maximum grassland height and density at the finest studied scale (r = 25 m). Still, the vegetation heterogeneity significantly determines the life-form diversity of the assemblages in the larger habitat patches. Consequently, a minimum of one hectare-sized well-managed habitat patches are needed to conserve diverse, species-rich orthopteran assemblages. Specific conservation implications are adequate for preserving the main characteristics of the minimal-sized grassland patches under global warming are simulate the traditional low-intensity land use (dominated by mowing diversified both spatially and temporally).