The impact of vegetation on earthworms: A comparative study of plane trees and grassland habitats in Hamedan

There are complex interactions between earthworms and the vegetation in their habitats. As the earthworm population increases, soil quality improves, which supports better plant growth and creates a positive feedback loop, enhancing biodiversity both above and below ground. Vegetation influences earthworm populations by altering soil properties as well as the quantity and quality of available food. This study investigated the effects of two types of vegetation - plane trees and grassland - on the density and species diversity of earthworms. A method involving digging and hand sorting was employed to collect earthworms in Hamedan during November 2023. The number, weight, and morphological characteristics of the earthworms were measured and recorded. Shannon’s diversity and evenness ecological indices were calculated based on the obtained data. Two species, Aporrectodea rosea and A. trapezoides, were identified in both grassland and plane tree habitats. The relative abundance of A. rosea was higher in the plane tree habitat, while A. trapezoides was more abundant in the grassland habitat. Additionally, the weight, number of body segments, and overall biomass for both species were greater in the grassland habitat than in the plane tree habitat, which can be attributed to the more favorable food conditions there.