Biogas switch aids forest recovery, claims new study

Recently released research shows that a shift to biogas in southern India helped revive some of the region’s forests.

Published in July’s edition of the journal Global Ecology and Conservation, the new study describes how forests in south India that had become degraded due to excessive fuelwood extraction recovered after villagers living nearby switched to biogas for their cooking fuel needs.

In particular, the study argues that biogas interventions are associated with higher forest biomass as well as higher sapling abundance and diversity, suggesting that plants have a higher probability of reaching sapling stage.

“These results indicate the potential for alternative energy sources that reduce dependence on fuelwood to promote regeneration of degraded forests,” states the introduction to the study. “However, forest regrowth is not uniform across treatments and is limited by soil nutrients and biased towards species that are light demanding, fire-resistant and can thrive in poor soil conditions.”

Biomass is the fourth largest source of energy in the world, with some countries taking 90% of their total energy from traditional fuels such as wood, straw and dung. Although fuelwood has the advantage of being a renewable and widely accessible energy source, it has the disadvantage of contributing to forest degradation. The study aimed to determine whether a reduction in fuelwood use would allow forests to recover.

The study focused on Chikkaballapur district in the state of Karnataka, India. In 2005, ten years prior to the start of the study, a ‘biogas intervention’ saw several villages in the region switch to biogas to heat their homes. They found that in regions where more than 20% of households had switched to biogas, there was a significantly higher amount of forest biomass.

Meghna Agarwala from Columbia University, the lead author of the study told Scidev.net: “This study shows that if you reliably provide a viable and affordable alternative, people will reduce their fuelwood use.”

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