- Three studies published over the past seven months show that forest cover in India is declining, contrary to findings from the latest Forest Survey of India report.
- One study found 16 to 30 percent forest loss in the eastern Himalayan state of Sikkim, while another study found that the Eastern Ghats lost nearly 16 percent of their forest area between 1920 and 2015.
- The third study, which analyzed patterns of forest cover across India from 2001 to 2014, found “significant negative changes” in the seasonal green cover, with the highest decline recorded in tropical moist deciduous forests.
Natural forests across India are slowly disappearing, a set of new studies shows, contradicting recent government claims about increasing forest cover.
The three studies, published over the past seven months, use a mix of satellite data, ground vegetation observations and historical maps. They show the Eastern Ghats, a series of mountains running along India’s eastern coast, have lost 15.83 percent of its forest area over a span of almost 100 years. Tropical montane forests are also disappearing in the eastern Himalayas in the state of Sikkim, particularly at lower elevations, the reports note, and there is a noticeable decline across all forest types in India.
These findings are at odds with the latest Forest Survey of India report that assesses the country’s forest cover. The FSI estimates India’s forest cover at 708,273 square kilometers (273,466 square miles) in 2017, an increase of just 0.9 percent from 2015. This apparent rise in forest cover has been debated, with some experts pointing out that the government estimates include plantation cover, which are different from natural forests.
The three recent studies add weight to the critics’ arguments.
These studies “very rigorously and unambiguously establish that there is significant reduction in green cover in many natural forest and habitat types of India,” said Vishwesha Guttal, an assistant professor of ecology at the Indian Institute of Science (IISc) in Bengaluru (formerly Bangalore).
“Of course, many have long suspected this is the case but these studies put any such doubts to rest,” Guttal told Mongabay-India.
“It is important to note that these studies are measuring green cover in natural forest areas,” he said. “The government often keeps claiming that the green cover is increasing, but it is often due to plantations and not due to expansion of forest [cover]. Natural forest cover is an important determinant of biodiversity, ecosystem services and stability of ecosystems and the same cannot be said of plantations. That such natural forests are declining substantially, is not very surprising to many of us working in this area. Yet, it is quite alarming.”
The latest study, published in the March 2018 issue of Applied Geography, analyzed forest transitions in a 2,206-square-kilometer (852-square-mile) area of the Teesta River basin in the Eastern Himalayas.
Although a biodiversity hotspot, there is inadequate knowledge of factors driving loss of biodiversity and ecosystem functions in the area. By using a combination of satellite data to analyze change in land cover over 23 years, and an extensive set of ground measurements of vegetation types and land-use patterns, the scientists found 16 percent primary forest loss at elevations of 2,200 to 2,800 meters (7,200 to 9,200 feet), mostly comprising oaks and beeches.
At lower elevations, of 800 to 2,200 meters (2,600 to 7,200 feet), the team found 30 percent forest loss, mostly of warm broadleaf forest. The study notes that “forest transition from primary to secondary forest was largely driven by land use for agroforestry and development.”
“Our research highlights that in a landscape like Sikkim with highly complex terrain, factors such as elevation and slope influence people’s decision about land use,” said lead author Radhika Kanade, of the Bengaluru-based Ashoka Trust for Research in Ecology and the Environment (ATREE). “We found that natural forest in the lower elevations and more accessible areas of Sikkim are being modified and converted to other land use systems since the past two and a half decades.”
The research adds to the findings from two previous studies published in Ecological Indicators — one on extensive forest loss across all forest types in India, and the second on forest loss in the Eastern Ghats, including rare, endangered and threatened species.
In the former, published in November 2017, scientists at the National Remote Sensing Agency (NRSA) in Hyderabad used satellite data to analyze the patterns of declining green cover across India from 2001 to 2014. They also measured decline in the core forest areas and identified hotspots of forest loss in large protected forest areas.
The researchers found “significant negative changes” in the seasonal green cover, with the highest decline recorded in tropical moist deciduous forests, followed by tropical dry deciduous, tropical wet evergreen, tropical semi-evergreen, subtropical broad-leaved, and Himalayan moist temperate forests. Most of the declines occurred in core areas of the different forest types, as well as over large protected areas such as Simlipal National Park in Odisha state, Rajaji National Park in Uttarakhand, Achanakmar Wildlife Sanctuary in Chhattisgarh, and the Sundarbans of West Bengal. The study also found a 15.6 percent decrease in the total area of mangrove forests.
The other study published in Ecological Indicators, in October 2017, studied land-use changes and forest fragmentation in the Eastern Ghats over a period of 95 years, using historical maps and satellite data from 1920 to 2015.
The study found that the Eastern Ghats lost 15.83 percent of their forest area during the study period, with an estimated 7.92 percent of forest area converted to farmland and nearly 4 percent to scrubland and grassland. The researchers also found that agricultural land was being converted into scrubland, largely driven by mining, agricultural practices and urbanization.
The study’s lead author, Reshma M. Ramachandran from the University of Hyderabad, said the scrubland area was increasing, mostly because of left-out croplands or long fallows.
The study also found that the habitats of rare, endangered and threatened (RET) species as well as endemic species were either reduced or degraded due to human activities, with the habitats of RET species being “fragmented alarmingly.”
Fragmentation of the natural forests splits the habitats of species into several patches. This makes the habitat vulnerable, particularly for endemic species, which have restricted distribution, Ramachandran said.
The team did not analyze specific species or develop inventories for RET species. But, Ramachandran cautioned, “if the degradation continues in this manner in the near future, many species are likely to disappear from the Eastern Ghats forests.”
Many people depend on forests for livestock grazing, collection of firewood, and farming, she added.
“Since the Eastern Ghats forests are highly accessible to human beings, community-based conservation activities would make a great impact towards regeneration of forests,” Ramachandran said.
Measures to improve the forest cover include planting indigenous trees in the large fallow areas left behind after cropping, implementing programs to regenerate forests in the mining areas, and sustainable use of forests, she added.
“These studies provide a strong case that we should investigate if there is a potential for large-scale irreversible changes in these ecosystems,” Guttal from the IISc said. “To do so, we need to calculate metrics such as spatial variability in green cover and estimate how it is changing over time.”
Any increase in the variability with a reduction in average green cover could indicate “possibility of irreversible transitions in the near future,” he said.
“[T]here is a strong case that we should measure indicators of potential irreversible transitions in Indian forest ecosystems, which can help provide policy recommendations on how to protect them,” Guttal added.
And because the studies have identified some of the causes for the shrinking green cover, such as changes in land-use patterns driven by mining, roads, expansion of agriculture and agroforestry, “obviously, we need policies that protect natural areas and substantially limit their exploitation,” he said.
“This is a socio-ecological problem and there are many who have worked on how to achieve the seemingly conflicting goals of development and protection of natural forests,” he added.
Kanade, R., & John, R. (2018). Topographical influence on recent deforestation and degradation in the Sikkim Himalaya in India; Implications for conservation of East Himalayan broadleaf forest. Applied Geography, 92, 85-93.
Chakraborty, A., Seshasai, M. V. R., Reddy, C. S., & Dadhwal, V. K. (2018). Persistent negative changes in seasonal greenness over different forest types of India using MODIS time series NDVI data (2001–2014). Ecological Indicators, 85, 887-903.
Ramachandran, R. M., Roy, P. S., Chakravarthi, V., Sanjay, J., & Joshi, P. K. (2018). Long-term land use and land cover changes (1920–2015) in Eastern Ghats, India: Pattern of dynamics and challenges in plant species conservation. Ecological Indicators, 85, 21-36.
This story was first published on May 15, 2018, by Mongabay-India.