Community structure and recolonization by earthworms in rehabilitated ecosystems in garhwal himalayas, India

Himalaya is a vast and diverse mountain system. Agro forestry land use covering (20%) of geographical area of Indian Himalayas is distributed as patches in the matrix of forest covering (52%) area. Forest based treecrop livestock integrated farming is the predominant traditional land use in central Himalayas.1 Hill agriculture appears to be key threat to soil biodiversity and ecosystem service due to huge amount of biomass extraction to sustain live stock and produce manure for managing soil fertility and also in terms of direct loss of forest cover due to agriculture land use.2 This problem has been further accentuated by extensive deforestation and unsustainable land use causing extensive degradation of the mountains. A pilot project was carried out to restore and rehabilitate the abandoned agriculture land site and degraded forest land site through agro forestry and forestry plantations.3 Land degradation implies a decline in the useable natural resource base and therefore loss of biodiversity and ecosystem functions. The interacting functions of soil organisms and the effects of human activities in managing land for agriculture and forestry affect soil health and quality.4 Soil faunal biodiversity is an important resource for environmental monitoring and natural resource management, changes in the variety and abundance of organisms in response to ecosystem disturbance, degradation and rehabilitation provide important management information.5 Soil management options can have dramatic effects upon soil invertebrate communities.6,7 Earthworm communities are the result of both interactions between species8 and sensitivity to ecological factors9 presence or absence of ground vegetation and changes in its composition are known to affect the composition of earthworm communities.10 This is the first systematic study where work is focused primarily on the ecological impact, the extent, causes and consequences of varying land degradation and subsequent rehabilitation strategies on earthworm fauna in Central Himalayas. Micro scale variability in earthworm community in traditional agro ecosystem will also be focused by comparing two types of micro sites viz below tree canopy from (13m) the bole and outside tree canopy (1-3m) from canopy margin. Changes in the vegetation cover (forest clearance, tree plantation) change the soil microclimate condition therefore present study also aims to analyze how these changes affected the functional guild of the earthworms.