Forest plantations, water availability, and regional climate change: controversies surrounding Acacia mearnsii plantations in the upper Palnis Hills, southern India

Plantation forests not only impact carbon and water cycles, but also affect biodiversity, livelihoods, and shape regional economies. Each of these impacts differs across varying scales of analysis. This paper illustrates how forest, climate change and hydrology debates play out in the context of the forest plantations of Australian black wattle (Acacia mearnsii) in the upper Palni hills of southern India. We outline the contradictory perspectives of different local groups regarding the impact of plantations on catchment hydrology and water availability, and examine these in relation to changes in the regional economy and rainfall patterns. Our analysis indicates that changes in these two factors have played a more significant role than existing wattle plantations in affecting local and regional water availability. We suggest that ongoing debates regarding forest plantation–hydrology–climate change relationships need to broaden their scope to include changes in regional rainfall patterns and shifts in regional economic activity. This approach is likely to provide a more realistic assessment of plantation forests in a dynamic regional context, and offer more resilient strategies for regional landscape and catchment management under conditions of high variability in rainfall patterns.     

A Framework for Assessing Carbon Flow in Indian Wood Products

This paper uses a lifecycle analysis to trace the fate of carbon bound in wood products until most of the carbon is released back into the atmosphere. A sensitivity analysis has been carried out to find the effect of change in terminal use (recycling, land filling and burning of discarded products), half-life of wood products and decay rate of carbon in landfills. Of the total carbon harvested from forests in India, about 90% is released into the atmosphere in the first year, due to burning of fuelwood; at the end of 100 years, about 0.8% still remains in the wood products. The sensitivity analysis shows that the length of the lifespan of wood products has only a marginal effect on the amount of carbon sequestered but has significant effect on the amount of carbon in products in use. Thus an important conclusion from this scenario is that by increasing the durability of the wood products, carbon can be locked over a period equal to the time needed to grow the timber for these products. Further, the carbon storage is affected more significantly by the decay rate of carbon in landfills than the proportion of products recycled. The study also shows that wood products can be important stores of carbon, but only if they can substitute for a unit of carbon emitted by burning fossil fuels. Such a lifecycle analysis has the potential to account completely for carbon stock changes in the wood products, where and when they are occurring, and explain how they are occurring.