Urban Expansion Drives Forest Loss In India’s Biodiversity Hotspots

An intensifying urban expansion and changes in land use and land cover in India’s two biodiversity hotspots – the Himalayas and the Western Ghats, are largely driving significant forest loss in the regions, researchers find.

New research, based on remote sensing data by the Indian Institute of Remote Sensing (IIRS), Dehradun, whose scientists mapped land use and land cover changes (LULCC) in the western Himalayas from 1975 to 2015, reports a massive upsurge in urban areas in the ecologically fragile mountain systems, alongside a parallel forest decline. The Western Himalayan Region (WHR) is under constant threat from LULCC due to urbanisation, agricultural expansion, and population growth, the IIRS study reports.

The study’s results highlight “an outrageous 184% increase in regional urbanisation,” the authors report. The expansion of urban and cropland, about 12%, led to deforestation, which reduced the area of natural habitats, specifically forests by 11%, water bodies by 8%, and scrubland by 6%. The study also found a “significant rise” in barren land by 30%, while there was a decrease of 20% in glacier/snow melt.

Based on this data, the researchers predict that the current trend could continue till 2055, with intensified urban expansion of 63% and an approximate 9% reduction in overall forest coverage.

The findings are highly significant in the context of the speedy urban growth in the Himalayas and its environmental implications, particularly forest loss, Prakash Chandra Tiwari, professor of geography at Kumaun University, Nainital, who is not associated with this study, told Mongabay India.

Urbanisation has emerged as one of the most powerful drivers of environmental change in the Himalayas, particularly in the densely-populated Lesser Himalayan ranges in Uttarakhand and Himachal Pradesh, which are part of North West Himalayas, says Tiwari. In the absence of proper land use policy and urban planning processes, the Himalayas have experienced “phenomenal urban growth,” resulting in land use intensifications in environmentally-sensitive areas, both in towns and their peri-urban catchments, over the past decades, he adds.

A separate study by Ph.D. student Manika Kweera, supervised by Tiwari, used remote sensing data to analyse the densely populated and rapidly urbanising Nainital district in Uttarakhand. “The study revealed an 11% decline in natural forest cover between 1991 and 2023, primarily due to unplanned urban growth,” Tiwari shared. The study also recorded a more than 100% increase in the urban built-up area, mostly in agricultural land, forests, spring-sheds, flood plains, and steep slopes over the past three decades. The consequences include diminished groundwater recharge by 17%, a 35% depletion of natural springs, 11% reduction in urban wetlands, and 27% loss of biodiversity.

Tiwari also cites the example of Uttarakhand, which he says is “emerging as the most rapidly urbanising Himalayan state,” with more than 30% of its population living in urban areas (in 2011) against the 26% average urban population of the Indian Himalayan Region, according to the Census of India. The sprawling cities and towns are mainly encroaching upon the prime agricultural land (11%) and forests (9%), resulting in land use intensification and disruption of ecosystem services, mainly water, biodiversity, and green spaces and increasing the vulnerability of urban zones to climate change and climate change-induced natural disasters. “This clearly indicates the loss of forests caused by urban growth has been increasing for the past ten years,” he said.

There were similar findings earlier from scientists in Kashmir, based on satellite images of the Baramulla district. They reported that since 2000, the land use and land cover in the north-western Himalayas (NWH) “changed dramatically due to economic development and the influence of human activities.”  The paper states, “From 2000 to 2010, sand mining equipment was installed in the NWH, and a large amount of silt was deposited on the riverbank, showing a dramatic reduction in the water area. Although the modified region is enormous, and the percentage is modest, the wooded area is considerable. Timber harvesting and urban growth are the primary causes of change in the wooded area.” The findings revealed that until 2030, the amount of woodland in the NWH will decline dramatically.

The Western Ghats and the role of catchments

The Western Ghats, another important biodiversity hotspot, displays a similar trend. Assessment of the LULCC dynamics, using remote sensing data, shows a decline of evergreen forests by 5% with an increase in agriculture, plantations and built-up area in the Western Ghats, shares T. V. Ramchandra, a scientist at the Centre for Ecological Sciences, Indian Institute of Science (IISc), Bengaluru. The interior or intact forests have declined by 10% and are now confined to protected areas, he says. “The simulation of likely changes depicts the region will have only 10% evergreen cover and 17% agriculture, 40% plantations and 5% built-up area,” his 2019 study states.

Another study by his team on the landscape dynamics in Uttara Kannada district in central western Ghats showed degradation of forests from 74.19% (1973) to 48.04% (2018), with loss of evergreen forests from 56.07% to 24.85% due to large-scale developmental activities such as construction of dams, power projects, forest-based industries—paper mills—expansion of roads, urbanisation, and encroachment for horticultural and agricultural practices. The forests are currently confined to the WG and protected areas.

The analysis of remote sensing data of four neighbouring riverscapes in the central Western Ghats, from 1973 to 2018, shows a 41% decline in evergreen forests, and 60% fragmentation of intact or contiguous forests (60%), says Ramchandra. Catchment areas play a decisive role in sustaining water for societal and ecological needs, and this would help in evolving strategies to adopt integrated watershed management to sustain the water demand for both human activities and environment preservation.

The assessment by the IISc team, on people’s livelihoods, soil water properties, and availability of water in catchments in the region, found that catchments with more than 60% vegetation with native species have higher soil moisture and groundwater than catchments with fewer forests and seasonal streams. The perennial availability of water facilitates farming of commercial crops with higher economic returns to the farmers, unlike the farmers in areas with seasonal streams, who face water crisis during the lean season.

The way forward

Urban growth can be steered through sustainable development and conservation, says Tiwari. To achieve this, India needs policies for urban environmental impact assessment and the ecological carrying capacity of all the towns. Additionally, it would be necessary for the Himalayan states to have comprehensive urban land use and urban environmental planning policies.

Tiwari suggests that for sustainable urban growth and conservation of forests and other critical natural resources in the Himalayas, there is a need for adaptive urban environmental planning based on comprehensive risk-zone mapping, and conservation of urban green-blue spaces, spring sheds, wetlands, biodiversity, and farmland. This, he suggests, could be integrated with socio-economic equity and environmental justice.

Meanwhile, Ramchandra stresses the importance of catchments and the need for conservation efforts to maintain native vegetation in the catchments. This could help support people’s livelihoods with water conservation at local and regional levels, he says.

Based on his team’s findings in Uttara Kannada, which showed that areas with perennial streams in sub-catchment are dominated by native vegetation compared to areas with seasonal streams which are dominated more by anthropogenic activities with monoculture plantations, Ramachandra recommends that “the premium should be towards conservation of the forests with native species in order to sustain water and biotic diversity in the water bodies, which are vital for food security.”

Understanding the inter-linkages between native vegetation, biodiversity, perennial water availability, livelihoods of indigenous people, and human demands, would help planners and decision-makers gain valuable insights for integrated river basin management “in an era dominated by indiscriminate development of river catchment areas involving enhanced deforestation, frequent instances of altering natural regime, inappropriate cropping and poor water efficiency.”

“There still exists a chance to restore the lost natural evergreen to semi-evergreen forests through appropriate conservation and management practices,” Ramachandra concludes.

(Published under Creative Commons from Mongabay-India. Read the original article here)