Fauna-associated changes in soil biochemical properties beneath isolated trees in a desert pastureland of India and their importance in soil restoration

摘要

Biodiversity conservation and management of natural resources are the best options to restore and increase productivity of degrading pastureland in dry areas. Hence, arthropod abundance, organic matter, respiration, and dehydrogenase activity were measured in canopy zone soil of Prosopis cineraria (PC), Acacia nilotica (AN), Zizyphus nummularia (ZN), Capparis decidua (CD), and Acacia Senegal (AS) associated with grasses with a view to establish interrelation for productivity enhancement of pastureland. Pure grass bock outside tree canopy was control plot. Acari, Myriapoda, Coleoptera, Isoptera, Col-lembola, and other soil arthropods were the major soil faunal groups. Integration of tree in pastureland enhanced population of soil arthropod by 9-65-fold in May 2001 and 8-13-fold in August/September as compared with control. The trends of changes in soil organic matter (SOM), soil respiration (SR), and dehydrogenase activity (DHA) were similar to the changes in soil arthropod population, indicating the role of soil fauna in facilitating biochemical processes and soil fertility. Two, eight, and nine times greater SOM, SR, and DHA, respectively, in silvipastoral system than the values in control suggest the beneficial effects of trees on improvement in biochemical processes and thus biodiversity in pastureland, as supported by negative values of relative tree effects (RTE). Microbial activities were highest in the ZN system, which had highest abundance of soil arthropods. In the other systems, CD and AS systems showed greater soil arthropod abundance and biological activities than with the PC and AN systems. Therefore, Z. nummularia-, C. decidua-, and A. senegal-based silvipastoral systems and related soil fauna may be promoted for enhancement of biological activity and productivity of pastureland in desert. The strategy may be adopted for developing a sustainable pedoecosystem in a region of the world where agriculture is notoriously difficult.