Species diversity and composition of Oribatida in former breeding colonies of the great cormorant (Phalacrocorax carbo) in Poland

The great cormorant (Phalacrocorax carbo) is a species that alters ecosystems significantly, mainly by depositions of guano, which changes the chemical properties of soil and can lead even to deforestation as well as have a significant impact on soil mite communities. The study was conducted on three islands: abandoned by cormorants recently (Z1), abandoned three years ago (LI) and a site without cormorants (Z2) for comparison. The species composition of island Z1 did not differ significantly from the fauna of the previously studied colonies. Many xerophilous and meadow species occurred on LI island, which was likely caused by deforestation because of cormorant activity.