The Effect Some of Physiographic Factors and Soil Physico-Chemical Features of Hornbeam Forest Ecosystem on Earthworms Biomass

To investigate the physiographic factors and related soil physico - chemical and biological characteristics, 268.7 ha of Noushahr khanikan forests were studied on May 2012. 60 soil samples were taken from 0 - 10, 10 - 20 and 20 - 30 cm depths with systematically random method. The physiographic factors including slope, aspect and altitude recorded in soil sampling location. Soil acidity, bulk density, saturation moisture, organic carbon, total nitrogen, soil texture and biomass of earthworms were measured in the laboratory. The earthworms were collected simultaneously with the soil sampling by hand sorting and classified to epigeic, anecic and endogeic ecological groups. Site slope were divided to four classes (0 - 20, 20 - 40, 40 - 60 and 60 - 80%) and altitude divided to three classes (100 -150, 150 - 200 and 200 - 260m). Analysis of variance is indicating acidity, bulk density, saturation moisture and soil texture had significant differences among aspects and slope classes. Nitrogen and carbon to nitrogen ratio values showed significant differences among aspect and slope classes, respectively. Altitude classes showed no difference in viewpoint of physico - chemical properties. Epigeics number and biomass had significant statistical differences among aspect and slope classes. Epigeics found in soil superficial layer (0 - 10 cm). The most activity of anecic and endogeic groups was visible in more beneath depths (10 - 20 and 20 - 30 cm).