Effect of Grazing Management on Predator Soil Mite Communities (Acari: Mesotigmata) in Some Subalpine Grasslands from the Făgăraş Mountains—Romania

SIMPLE SUMMARY: Grasslands are one of the most widely distributed ecosystems at a global scale. They provide a broad range of ecosystem services, such as provisioning, regulating, cultural and supporting. Regulating services are strongly connected with biodiversity. Grasslands have an important role in sustaining the biodiversity of Europe, being considered a model system for biodiversity analyses. One of the important components of biodiversity is soil fauna, mites especially. Grazing management has also had an impact on soil mite communities. In this context, the aim of this research was to demonstrate the influence of the management type and of environmental variables on the composition of mite communities. The study revealed that the highest species richness was found in ungrazed grasslands compared with intensively grazed ecosystems, where the overall number of these invertebrates was higher. The study demonstrated that air temperature and soil penetration resistance were significantly higher in intensively grazed grasslands, while air relative humidity and vegetation cover were significantly lower in intensively grazed grasslands. Considering the range of species, the significant differences between the two types of grassland management are due to the varied influences of environmental variables, especially of vegetation coverage and soil electrical conductivity. This study revealed that the management regime of grasslands influences the structure and the spatial dynamics of soil mites. ABSTRACT: For the first time in Romania, a complex study was conducted on soil mite communities from two types of managed grasslands: ungrazed and intensively grazed. The study was accomplished in August 2018, in the Făgăraş Mountains. Within the soil mite communities (Mesostigmata), 30 species were identified, from 80 soil samples. The following population parameters were investigated: species richness, numerical abundance, dominance, Shannon index of diversity, evenness and equitability. Eight environmental variables were also measured: soil and air humidity; soil and air temperature; soil pH; resistance of soil to penetration; soil electrical conductivity; and vegetation coverage. The results revealed that species richness, Shannon index of diversity, evenness and equitability indices had higher values in ungrazed grasslands, whereas in intensively grazed areas, the numerical abundance and dominance index had significantly higher values. The species Alliphis halleri was dominant in the ungrazed grasslands. Each type of managed grassland was characterised by specific environmental conditions, which had an important influence, even at the species level.