The influence of some environmental factors on the species diversity of the predator mites (Acari: Mesostigmata) from natural forest ecosystems of Bucegi Massif (Romania)

The influence of some environmental factors on the species diversity of the predator mites (Acari: Mesostigmata) from natural forest ecosystems of Bucegi Massif (Romania) The ecological research was made in 2001-2003, in Bucegi Massif, in three natural forest ecosystems with Picea abies, Abies alba and Fagus sylvatica . In order to show the influence of some environmental factors on the species diversity of the investigated soil mites, the following abiotic parameters at soil level were analysed: temperature, humidity and pH. The species diversity (with Shannon-Wiener index) and the equitability were calculated. Taking account of the bio-edaphical conditions, the studied soil mite diversity had a various evolution. In spatial dynamics, the ecosystem with Abies alba offered better conditions for a species diversity (78 identified species), in comparison with ecosystem with Picea abies (67 identified species), where, due to a high altitude and to the big slope, this parameter had the most decreased values. In the ecosystem with Fagus sylvatica , the diversity showed the presence of 71 species. At the soil level, the litter and fermentation layer was a favorable habitat for development of the soil mite populations. In temporal dynamics, these parameters had recorded seasonal fluctuations. All these aspects are due to the different bioedaphical conditions, specific to each studied natural ecosystem.