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This study compared the oribatid mites in two natural and four industrially exploited bogs. One natural bog (Zakręt, Z) was located in northeastern Poland and the other one (Toporowy Staw Niżni, TSN), in southern Poland. The four exploited bogs were also located in southern Poland and can be ranked from least to most degraded as follows: Łysa Puścizna (LP), Baligówka (B), Puścizna Mała (PM) and Kaczmarka (K). In the natural bogs, the water pH was higher than in the degraded ones, but other parameters were lower (conductivity, colour value, oxygen demand, and concentration of chlorides). In the natural bogs, the Oribatida were highly abundant (average density was 169,100 ind./m(2)), but with low species diversity and one dominating species. In bog Z the most abundant was Limnozetes foveolatus that had dominance of 75 % and in bog TSN, located at higher altitude, Trimalaconothrus maior dominated (73 %). In two degraded bogs that had still good water conditions (LP and B) the oribatid communities resembled those from the natural bogs; in LP the most abundant species was Hydrozetes lacustris and in bog B, L. foveolatus. In contrast, in two more degraded bogs (PM and K) the abundance of mites was lower (average density was 17,850 ind./m(2)), species diversity of the Oribatida was higher, and no species achieved a high dominance like in the natural bogs. Additionally, in more degraded bogs the abundance of parthenogenetic species was lower than in the natural bogs.

Effects of liquid pig manure fertilization on the density and species structure of Oribatida (Acari) and green forage yield in a lowland meadow in PolandThe effect of liquid pig manure fertilization, with or without the disinfectant VIT-TRA, on oribatid communities was investigated in a lowland meadow in Poland. The disinfectant was tested at 3 concentrations: 0.50% (fungicidal), 0.75% (bactericidal), and 3.00% (viricidal). Liquid pig manure without the disinfectant increased the green forage yield along with increasing doses of this fertilizer, while addition of disinfectants affected the yield in different ways. Low and medium doses of fertilizer (20 and 40 m3·ha-1) with fungicide slightly decreased the yield, while the high dose (60 m3·ha-1) usually increased it, as compared to the control. Low and medium doses of liquid pig manure, treated or not with disinfectants, decreased the abundance of oribatid mites. In contrast, the high dose increased their abundance, except for the plot with a high dose of viricide, where they were slightly less abundant than in the control. In the investigated meadow,Liebstadia humerata, Parachipteria bellaandScheloribates laevigatuswere abundant, but reacted negatively to low and medium doses of liquid pig manure treated or not with disinfectants, and positively only to the high dose of fertilizer treated with fungicide and bactericide, as compared to the control plot.