A study on the effect of grazing to microarthropod composition on an alpine pasture

The effect of grazing in qualitative and quantitative composition of acari-fauna was studied on an alpine pasture in County Ioannina, Epirus, Greece for the period April 1997-November 1999. The number of species was found to be similar and comprised approximately 114 and 119 taxa for the grazed and ungrazed pasture respectively. The dominant species were: a) for the grazed pasture: Scheloribates spp., Lorryia sp. and immatures stages of Cryptostigmata which was found dominant and contant, Oribatella sp. dominant and accesory, Tarsonemus lacustris, Peloptulus sp. and Microtydeus bellus influent and accesory; b) for the ungrazed pasture: Scheloribates spp., Tarsonemus lacustris and immatures stages of Cryptostigmata which was found dominant and constant, Oribatella sp., Lorryia sp. and Steneotarsonemus konoi dominant and accesory, Tarsonemus spp. influent and constant, Mycobatidae, Siteroptes avenae, Siteroptes cerealium, Tydeus kochi influent and accesoty. The total acari population densities on ungrazed pasture was significantly higher. Significantly higher was the population densities of Prostigmata and Mesostigmata on ungrazed pasture while there was no significant difference between the populations of Astigmata and Cryptostigmata.