Seasonal dynamics of mites (Acari) in pastures and meadows in Poland, with species analysis of Oribatida

Abstract

The study involved three pastures, grazed by geese, goats and fallow deer, and three nearby meadows (control plots) situated in north-central Poland. Samples of 150 cm3 each (6 cm of soil and 3 cm of lower parts of plants) were collected in spring, summer and autumn 2016 and 2017 in 10 replications, 360 samples in total. This material included 22.561 mites, among which Oribatida accounted for 69%, Mesostigmata for 21%, and other mites for 10%. At most study sites, both pastures and meadows, no significant seasonal differences in the abundance of Oribatida and Mesostigmata were seen. Such differences were only observed for the third category of other mites that were the most abundant in spring and usually the least abundant in autumn. Also species diversity of Oribatida differed between the seasons – in all pastures it was the highest in summer and the lowest in spring, while in all meadows it was the highest in spring and decreased towards autumn. Oribatid species were more affected by the habitats than by seasons, as some species were strongly associated with pastures (Platynothrus peltifer), other with meadows (Achipteria coleoptrata, Liebstadia similis, Metabelba pulverosa, Scheloribates laevigatus and Sellnickochthonius immaculatus), and some (Eupelops occultus and Tectocepheus velatus) were abundant in both habitats. Although the effect of seasonality was weaker than that of the habitat, it was still perceptible. Platynothrus peltifer was most associated with autumn, T. velatus with spring, E. occultus with spring and summer and L. similis with summer.