Indian forest health wilting despite greening effort

While India is experiencing significant greening and contributing to global terrestrial carbon sequestration, its forest health is steadily declining due to reduced photosynthetic efficiency. Highlighting this paradox, an Indian Press Information bureau (PIB) report presents this analysis from a recent study by researchers at the Indian Institute of Technology (IIT) Kharagpur.

India may be gaining tree cover, but its forests are growing weaker. Forests across the country are showing signs of declining health under the stress of a warming climate, reducing their ability to absorb carbon dioxide according to this new study, says a Down to Earth (DTE) report. The analysis, the first of its kind, found that despite an apparent increase in India’s green cover, there is a mismatch between forest growth and the carbon being sequestered.

Published in the journal ‘Resources, Conservation and Recycling’, the study is titled ‘Weakening of forest carbon stocks due to declining Ecosystem Photosynthetic Efficiency under the current and future climate change scenarios in India’. It is the first to link increases in forest “greenness” with changes in carbon sequestration. The authors analysed the climate’s influence on the forests’ efficiency in using carbon for growth and water for photosynthesis. It showed a decline in photosynthetic efficiency, carbon absorption and water-use efficiency in forests across India, both under present and projected climate conditions.

The key findings of the study are listed by the PIB release. Photosynthetic efficiency of Indian forests has declined by five per cent between 2010–2019 compared to the previous decade (2000–2009). The decline is most pronounced in pristine forests of the Eastern Himalaya, Western Ghats, and Indo-Gangetic Plain. Forests show low resilience to warming, drying, land and atmospheric aridity, and wildfires, with only 16% exhibiting high integrity. This degradation therefore poses serious risks to biodiversity, timber production, livelihoods of forest dwellers, and long-term climate resilience. Indian forests are non-resilient to the extremes of warming, drying, land and atmospheric aridity and wildfires. Climate projections suggest the weakening of the forest carbon sinks and declining forest health and is likely to be stronger in the future due to climate change and anthropogenic interventions. The degradation of forest resources is a concern for the economy, and it would impact its timber production, market, planting intensity and lives of forest dwellers in India. weakening of forest carbon sinks will become more severe under future climate change and anthropogenic pressures. Forests have a limited carbon storage capacity, already insufficient to offset the rise in atmospheric CO₂. The study emphasises the urgent need for preservation of indigenous forests, sustainable forest management practices, scientific afforestation programmes, substantial reduction in carbon emissions, and advanced carbon capture technologies. These measures are crucial to achieve sustainability and India’s target of net zero emissions by 2070.

The research estimated how greenness translates into carbon sequestration, measured through carbon-use efficiency and water-use efficiency, the DTE report points out. It found that reduced soil moisture and rising temperatures are adding stress to forest ecosystems, conditions likely to worsen in the future. Although India accounts for just two per cent of the world’s forest cover, it contributes about seven per cent to global carbon sinks. The country also contains four of the planet’s 36 biodiversity hotspots, including two of the eight most critical.

The study analysed forests in six categories: Western Himalaya, Eastern Himalaya, North-east, Indo-Gangetic Plain, Central India, and Western Ghats and Peninsula. While carbon uptake increased in some regions, such as the Western Himalayas, Central India and the North-east, there were sharp declines in the Eastern Himalayas, Western Ghats, parts of Central India and the Indo-Gangetic Plain. Declines were most pronounced in pristine forests of the Eastern Himalayas and the Western Ghats, areas also experiencing high soil moisture stress significant warming, and greater climatic water deficit, vapour pressure deficit and atmospheric aridity. The researchers linked the decline in forest health to reduced rainfall, declining soil moisture, and rising aridity. These stresses are compounded by more frequent wildfires, which increased by 8.7% between 2010 and 2019 compared to the previous decade, and recurring landslides in the Himalayan region. Forests in many areas were found to be especially non-resilient to precipitation deficits, soil drying and wildfire outbreaks.