An image of a tall tree in a forest.
A Himalayan cedar grows in the Manali Wildlife Sanctuary in Himachal Pradesh, India. Credit: Paul Evans/Wikimedia, CC BY 2.0

India’s National Forest Policy of 1988 set an ambitions target: to bring two thirds of the Indian Himalayas under tree and forest cover. In a blow to that plan, new research showed that less than half of that percentage is feasible in the Himalayan state of Himachal Pradesh. The findings suggested that the situation is similar in other mountainous states.

The study emphasizes balancing forest protection with societal needs: sustainable development. In Himachal Pradesh, as across India, “many livelihoods are still directly dependent on agriculture, and livestock economies are also dominant,” said Pushpendra Rana, an officer in the Indian Forest Service and lead author of the study, which was published in the Journal of Cleaner Production. Having a fuller understanding of agricultural land use would help scientists plan forestry projects to meet the country’s afforestation and carbon sequestration goals.

Ground truthing therefore needs to be incorporated into policymaking.

In pursuing sustainable development goals, ground truthing needs to be incorporated into policymaking, Rana said. Otherwise, there is a risk of “unrealistic targets creating massive top-down pressures.” To conduct their ground surveys, Rana and his colleagues looked to land that had been previously planted by the Himachal Pradesh Forest Department. With data from these government plots, including elevation, slope, soil depth, soil carbon, and prior tree cover, they trained a machine learning model to analyze site suitability.

Ground truthing can document that in some areas, climate conditions do not allow trees to thrive. For instance, “trees don’t grow in high-altitude areas above timberline, and hence, these high-altitude areas can’t be taken up for [tree] planting at all,” explained Satya Prakash Negi, regional director of Forest Survey of India, who was not involved with the research. More than 20,000 hectares in Himachal Pradesh lie at or above the timberline, at an elevation of 4,000 meters (13,000 feet). Large areas in the state are also cold deserts, which are similarly ill-suited for tree-planting projects, Negi added. At lower elevations, existing agriculture and grazing activities restrict how much can be brought under forest cover.

In their analysis, the researchers therefore excluded areas covered with grasslands, snow, agriculture, and infrastructure, as well as those at high elevation. The model showed that only one third of the state can feasibly be brought under forest cover. This suggests that afforestation policy reconsider the assumption that all land without forest cover is apt for carrying out planting activities, said Meenakshi Kapoor, an environmental policy researcher based in Himachal Pradesh.

Perils of Ill-Advised Tree Plantations

The study highlighted “very relevant and practical issues” about tree-planting activities in not only Himachal Pradesh but also other parts of the country, Negi said. Currently, India has two major state-led tree plantation initiatives, Green India Mission and Compensatory Afforestation Fund Management and Planning Authority. There are also community, regional, and state afforestation projects.

Earlier research has shown that decades of tree planting in Himachal Pradesh have had only a limited effect on forest canopy cover and have instead shifted forest composition away from species that are valuable to local communities.

When evaluating sites for afforestation, rangers should also consider factors such as land ownership, land use patterns, linked economic activities, and ecological factors such as suitable tree species.

The authors developed a recommendation system, e-Plantation Site Assistant (ePSA), to assist forest rangers in site selection for future afforestation activities. The tool was developed with the same machine learning approach the authors used to analyze site suitability throughout the state. Kapoor suggested that when using ePSA, rangers should also consider factors such as land ownership, land use patterns, linked economic activities, and ecological factors such as suitable tree species. Rana acknowledged that there is a need to promote solutions aimed at “community-designed, site-specific interventions.”

More broadly, the researchers said they seek to realign “overambitious national and international tree planting targets” with the realities in the region “to avoid massive wastage of funds and to obtain feasible carbon mitigation outcomes.”

—Rishika Pardikar (@rishpardikar), Science Writer

6 March 2023: This article has been updated to clarify policy goals.

Citation: Pardikar, R. (2023), The limits to tree planting in the Indian Himalayas, Eos, 104, Published on 6 March 2023.
Text © 2023. The authors. CC BY-NC-ND 3.0
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