Temperate orthopterans as efficient bioindicators: Detailed ecological requirements and a novel Xerothermophilicity Index for 62 species
Description
Temperate grasslands are crucial ecosystems that support species-rich communities across diverse taxa, yet they are increasingly endangered by anthropogenic pressures, such as agricultural intensification, abandonment of traditional management, and climate change. Thus, there is a need to develop precise bioindicators to monitor their conservation status and restoration initiatives. Here, we propose use of orthopterans as optimal bioindicators through significantly enhancing knowledge on their ecological requirements. In addition, we introduce a novel concept applicable to diverse ecological and ecophysiological studies: the 'Xerothermophilicity Index' (XI) and its range (XIr), which indicate species thermal specialization. To compute quantitative ecological niches and Xerothermophilicity Indices for 62 species, we analyzed their presence across 1,044 sites. The Xerothermophilicity Index showed very weak phylogenetic signal, indicating that species’ xerothermophilicities are evolutionarily highly plastic. In general, species occurrences were strongly predicted by local moisture, vegetation cover and average seasonal temperature, and to a lesser degree by other variables like shading, management intensity, vegetation height, and shrub presence. However, particular species were sensitive to different environmental drivers. The combination of the developed quantitative ecological niches with the rapidly expanding knowledge of orthopteran distribution through citizen science and acoustic monitoring platforms makes orthopterans ideal bioindicators of grassland ecosystems.