- Climate and land use/land cover change will enhance plant species loss and loss of ecosystem services in the heavily fragmented Eastern Ghats, studies have said.
- Water-energy dynamics broadly regulates plant richness in the Eastern Ghats, with average annual rainfall and temperature having a considerable impact on plants species richness.
- Researchers have demanded more conservation attention on the Eastern Ghats to counter the loss of biodiversity.
Climate and land use change are likely to alter plant species richness in the Eastern Ghats in the future, scientists have said, pressing for urgent conservation attention on the region that has lost 16 percent of forest cover in a span of 100 years.
“Conservation action and protection is mostly focused on hotspots such as the Himalayas and the Western Ghats. But we are losing species that are not included in the hotspots,” said IIT Kharagpur scientist Rajendra Mohan Panda, referring to the 1600-km stretch of rich, biodiverse forests on discontinuous hills lying parallel to the Bay of Bengal.
The Eastern Ghats are spread across Odisha, Andhra Pradesh, Karnataka and Tamil Nadu along the east coast of India. Only 3.53 percent of their total area is protected. Recently there has been a call by environmentalists to get UNESCO cultural heritage tag. While 40 percent of the Eastern Ghats is in Andhra Pradesh, Tamil Nadu and Odisha share 25 percent each, and Karnataka and Telangana share 5 percent each.
[Read more Mapping forest loss in the northern Eastern Ghats]
Panda and colleagues at the University of Hyderabad tapped into a national database, the Biodiversity Information System, to gauge the role of climate, physiography and disturbance on species richness in the Eastern Ghats in a study.
A total of 1670 species from 2274 sampling locations of 22564 records were examined using predictive modeling tools such as canonical correspondence analysis (CCA) and decision trees.
Water-energy dynamics broadly regulates plant richness in the Eastern Ghats, with average annual rainfall and temperature having a considerable impact on plants, said study lead author Panda.
“Plants need optimum supply of water and conducive temperature ranges to thrive and the disruption in this balance due to global warming can put species at risk,” said Panda of Centre for Oceans, Rivers, Atmosphere and Land Sciences at Indian Institute of Technology Kharagpur.
The study finds herb species (771 herb species followed by 451 tree species) dominating in the Eastern Ghats landscape, suggesting how climate and human actions are changing the course of plant species richness.
“The seasonal dryness and moderate to low rainfall favour their (herbs) growth. Additionally, because of the dense population and anthropogenic disturbance, the number of tree species has reduced,” said Panda
Explaining how changes in rainfall and temperature impact plant species, co-author Reshma M. Ramachandran said rainfall primarily controls the species richness, so the changes in rainfall disturb the species richness.
“Also, changing climate accelerates the spread of invasive species even in the core areas of the forests. We have witnessed many such invasives in different parts of Eastern Ghats during our field surveys,” said Ramachandran at University Centre for Earth, Ocean and Atmospheric Sciences (CEOAS), University of Hyderabad, Hyderabad. Invasive species are those that are typically not found in a particular area but are able to establish themselves and end up competing with native species.
Panda observed that the fluctuation in temperature is more likely to have a lasting influence on the species richness in the driest quarter of the year when there is a scarcity of water supply.
“A number of plant species are becoming more vulnerable to increasing temperatures and in the driest quarter, this vulnerability is high. This indicates that the rise in temperatures due to global warming is likely to affect plant richness in the future and that effect will be magnified with an increase in seasonal temperature fluctuations,” he said.
Land use and land cover changes
Based on a simulation study on the population, land use/land cover and species distribution in the Eastern Ghats, Ramachandran said changes in land use and land cover will also negatively shape the distribution and the habitat of the plants.
The researchers used a species distribution model to simulate the potential habitats of a group of endemic (28 species found in this region) and rare, endangered and threatened (RET) (22 species found in this region) plant species on the basis of IPCC AR5 scenarios developed for 2050 and 2070.
“Especially plants under conservation categories. The endemic and rare, endangered and threatened (RET) group of species are in the top list due to their special habitats. In addition to land use land cover change, the changing climate also accelerates habitat degradation. So changing land use/land cover and climate will affect the distribution of plant species in the Eastern Ghats,” Ramachandran added.
Climate change and the prevailing rate of land use/land cover change will reduce the extents of the habitats of endemic and RET species by around 60 percent and 40 percent, respectively, said Ramachandran of the 2050 projections.
The authors underscore the telling human impacts on biodiversity in the region. “The protection that is given to biodiversity in the Eastern Ghats is not sufficient,” stressed Panda.
Timber logging, dam construction, road-rail network and other developmental activities were the major drivers of forest cover change before the 1960s, according to a 2018 study, co-authored by Ramachandran. After 1960, the anthropogenic pressure on land increased due to mining, urban development, and agricultural practices.
[Read more on forest cover loss in the Eastern Ghats]
These demands resulted in deforestation and fragmentation. Ramachandran’s 2018 study estimated that about 7.92 percent of the forest area in the Eastern Ghats was converted into agriculture and up to 3.80 percent into scrub/grassland respectively from 1920 to 2015.
As recently as December 2019, over a span of few days, thousands of trees from the forests around Talabira area in Odisha’s Sambalpur region were cut down for a coal mining project. The Tamil Nadu State Action Plan on Climate Change acknowledges the negative impacts of projects that have come up in forestlands as also pressures of mining and population on the Gulf of Mannar ecosystem and Nilgiri Biosphere Reserve.
[Read more: Dark times await Odisha’s Talabira]
SK Palita of the department of biodiversity and conservation of natural resources at Koraput University, Odisha, who was not involved in the studies, said the diversity of species is slowly coming to light because of the recent research attention on the Eastern Ghats.
“For example, our group is documenting bat diversity and species in hill streams in Koraput. Documenting diversity and threats is key. But this attention must also expand to the environment ministry so that conservation action specific for the Eastern Ghats can be planned and initiated,” Palita told Mongabay-India.
“Simultaneously community awareness is needed because the tribal population in the Eastern Ghats have their own understanding of biodiversity through their system of traditional knowledge,” Palita said.
And as governments gear up to hash out a new framework for biodiversity, replacing the 2020 Aichi targets, researchers are hopeful of the Eastern Ghats mountain ecosystem garnering more attention.
“It should get good attention from ministry and researchers like other mountain ecosystems in the country as the Eastern Ghats is often ignored on account of other ecosystems. Plantation programmes must be conducted in many parts of the Eastern Ghats to equip with changing land use and climate. For plantation, local species should get more preference than easy growing outside plants. More awareness programmes must be conducted to secure biodiversity,” added Ramachandran.
Banner image: An axed tree in the forest area in Talabira. Photo by Manish Kumar.