A baseline study of an abandoned mine site in Purnapani, Odisha: a step towards ecological restoration

The human influences on biodiversity and ecosystem functioning have deleterious impacts resulting in significant changes in land and resource sustainability. Ecological restoration is the process of overcoming damage caused by humans to the diversity and dynamics of an ecosystem. This can be done more successfully using artificial interventions if they mimic and accelerate the natural processes. A holistic approach is required to mitigate the impact of anthropogenic activities such as mining operations on the natural habitats. Purnapani, a valley situated in Sundargarh district of Odisha had an abandoned open cast limestone and dolomite quarry; without any restoration efforts for the last about 40 years. In order to initiate an effective restoration effort, community analysis was conducted to generate a base line status of the degraded abandoned site. Two sites were selected viz., a 40 years old abandoned overburden dump and a nearby stabilized area as a reference site. The analysis of community structure revealed a general decrease in species richness with an increase in disturbance. Species composition markedly varied among both the sites. Invasive plants like Chromalaena odorata (L.) R.M.King & H.Rob., Parthenium hysterophorus L. and Ludwigia octovalvis L. sp. were the dominant taxa to invade the over-burdened site. Also, it was evident that Margalef and Menhinick indices along with rank-abundance curve were the useful indicators for detecting and quantifying the extent of damage to the disturbed site.