Conservation of Sikkim biodiversity needs re-strategising: study

by T. V. Padma on 6 May 2019
• Protected areas in the Himalayan region in India need to be expanded to conserve endemic Himalayan species and minimise the impact of climate change, a new study has shown.
• Creating new protected areas and extending boundaries of existing ones, in addition to expanding the protected area network, are suggested to ensure meaningful conservation goals in Sikkim, the study area.
• Scientists have earlier observed breeding failure among birds, early breeding in amphibians and skewed sex ratios in snakes due to changing temperatures.
A new study has attempted to work out conservation priorities for plant species in Sikkim, in the face of climate change projections.
The existing network of ‘protected areas’ in the region is inadequate in conserving the endemic plant diversity in Sikkim, now, or in future climate scenarios. Protected areas would need to be expanded to conserve endemic Himalayan species, the research shows.
Using a combination of species distribution modelling (SDM) and systematic conservation planning techniques, the scientists delineated and prioritised areas for endemic plant species conservation under current and future (the 2050s to 2070s) climate conditions. They have proposed the addition of 896 square kilometres to the protected area network in the study area to ensure meaningful conservation goals. They have also suggested creating three new protected areas (Yumsedong, Lachen and Chungthang) and expanding the boundaries of existing ones (Maenam, Fambong Lho and Barsey) in the study area.
According to the researchers, analyses show that a single large protected area (PA), with wide geographic area and altitude reach, instead of several smaller PAs would be a more prudent strategy to mitigate the effects of climate change and conserve plant diversity.
“The consequences of warming and altered distribution of plant species entails redefining the existing boundaries of protected areas,” said lead author Maharaj Krishan Pandit, director, Centre for Inter-disciplinary Studies of Mountain and Hill Environment (CISMHE), University of Delhi and Ngee Anne Kongsi, distinguished professor, National University of Singapore, adding that the application of this research, would be helpful to the decision-makers in redrawing PA boundaries in the light of climate change.
Clear and present dangers for Sikkim’s biodiversity treasure trove
According to Pandit, “there are limited genuine empirical studies on the Himalayas that can shed light on the quantum of impact on biodiversity patterns due to global change, of which climate change is a part.”
But scientists have, for long, been cautioning that global warming is causing a shift in the location of several species in the Himalayas and many unknown ones could be lost. Sikkim is no exception and continues to still show up new or rarely-seen species.
For example, researchers at the Sikkim University in Gangtok in 2018 reported sighting the ‘small woodbrown butterfly’ species, Lethe nicetella, from Bakhim in Khanchendzonga National Park, which was last seen 120 years ago. The finding of the butterfly, reported in the Journal of Threatened Taxa “indicates a possibility of the existence of many cryptic taxa that should be explored using morphological and molecular approaches,” the Sikkim University scientists report.
Zoologist Bhoj Kumar Acharya, whose team found the small woodbrown butterfly, had reported as early as 2014 that there was some evidence of climate change effect on four important groups of animals — birds, reptiles, amphibians and butterflies — many of which have either extended or shifted their range along the slope of Sikkim, in response to climate change. The scientists also started observing late breeding or breeding failure among birds and early breeding in amphibians; and skewed sex ratios, with higher temperatures favouring females, in snakes. Higher temperatures have also led to drying springs and erratic rainfall patterns, which have, in turn, affected breeding activity of amphibians, and a decline in their population. Long dry spells have even caused the near disappearance of turtles from Sikkim.
Conservation strategy needs radical rethink
The findings of the new study, coupled with earlier observations, warrant a major rethink on India’s protected areas strategy. Said Pandit: “We have to redesign our biodiversity conservation plans to keep pace with the changing distribution patterns of species. Moreover, biodiversity and livelihoods in India are closely linked. This demands that we sit up and take note and not consider these warnings a mere academic exercise.”
According to Meghna Krishnadas, an ecologist at the School of Forestry and Environmental Studies, Yale University, the findings from this study are in line with general opinion among conservationists that current protected areas network may not suffice to conserve biodiversity in the face of climate change. “This could happen either because the protected area network is not sufficiently representative of the new climate conditions that may prevail or does not provide corridors for species to move into more favorable climate zones,” said Krishnadas, who has worked on conservation ecology, ecosystem function and forest dynamics.
Another important aspect, said Krishnadas, is that the study used plant biodiversity to assess the efficacy of protected area network. “Most conservation efforts in India, particularly in declaring protected areas, often focus on the more charismatic species — usually large mammals. This study suggests that assessing the needs of a diversity of taxa — plants, birds, insects, amphibians — could provide insights to improve the efficacy of conservation planning.”
While data gathered so far suggests that large areas are crucial for large-bodied species, for example, tiger, dhole or elephant, studies from the Amazon rain forests and South East Asia show that several small PA, interspersed across a landscape, can provide a variety of habitat conditions that support a greater diversity of some taxa (such as butterflies, plants). “We need more such studies on different taxa in India to better inform our conservation policies,” adds Krishnadas.
Whether having one large protected area is better than having several small ones to conserve species also depends on the extent and kind of biodiversity to conserved, said Krishnadas. “The largest spectrum of biodiversity will require a combination of large areas that serve as population sources and smaller areas that serve as links or repositories for habitat-sensitive species for whom habitat conditions, and not area, is the main consideration,” she points out.
According to the researchers, the severe effect of climate change on Sikkim fauna might even lead to serious consequences like the extinction of some species. “We recommend long-term monitoring and detailed studies to understand such effects and consequences so that mitigation measures can be undertaken,” they conclude.