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چکیده
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Earthworms are very responsive to changes in soil physico-chemical properties, which also directly or indirectly influence the availability of resources for their survival. Soil properties, such as soil organic matter and moisture contents, pH, and texture, have a profound effect on the diversity and abundance of earthworm communities. In this study,soil and earthworm samples were taken from four habitats (grasslands, farmlands, mixed forests, and highlands) and35 different locations in Zagros Mountains. At each sampling site, earthworms were collected from quadrats (25 x 25 x 30 cm) and hand-sorted in the field. Thereafter, the preserved biological samples were studied morphologically and dissected for further taxonomic identification. Soil samples from the same sites were analyzed for texture, pH, electrical conductivity (EC), and moisture content. Overall, 18 species of earthworms were identified, with Simpson's diversity index reaching values of 0.067, 0.071, 0.081, and 0.091 for mixed forests, farmlands, highlands, and grasslands, respectively. In addition, the Jacquard similarity index, based on the presence and absence of species, showed the highest similarity between grassland and mixed forest habitats (0.714) and the lowest similarity between farmland and highland habitats (0.438). Finally, the results of statistical analysis showed that three abiotic factors (pH, moisture, and EC) had a significant effect on their distribution and species richness, with earthworm diversity increasing with increasing EC and moisture, but decreasing with increasing pH values.
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