~ by Kalyanee Paranjape
As one of the fastest growing economies in the world, India’s topography is undergoing rapid changes. Due to this expansion, ecosystems are under threat due to rapid land use changes and fragmentation. This has led to a growing interest in integrating conservation concerns in infrastructure development in India and an urgent need to illustrate the extent of their fragmentation.
A recent paper titled, “Bits and pieces: Forest fragmentation by linear intrusions in India”, aims to understand the impact of infrastructure developments on forest structural connectivity in India through analyzing forest patch characteristics. The authors have utilized patch size, amount of perforation and inter-patch distance to quantify clusters and fragmentation categories. Cluster analysis was used to identify large, intact patches that need to be preserved in future development action plans. And results were summarized at the national scale and for the existing protected area (PA) network. The results also cover two important conservation landscapes; the Western Ghats and Central India, which are rich in biodiversity and critical for survival of several threatened large mammals including tiger and Asian elephant.
The scientists found an increase in the number of forest patches and a reduction in the number of large patches due to linear infrastructure in India. High tension power-transmission lines and major roads were the most common linear intrusions within forests, and 70 % of the assessed protected areas had some amount of linear infrastructure passing through them. They also discovered that the highest fragmentation due to linear intrusions was observed in Central India, where an intact forest habitat of size 162,000 km2 was split into 5200 smaller patches with a mean patch size of 30 km2 and the largest patch being 16,850 km2 in size.
The authors recommend that infrastructure projects should not be established through the existing forests and when inevitable, proper mitigation strategies are vital to maintain connectivity. A more rational development plan would be to connect larger numbers of villages or people while safeguarding forests rather than to establish the shortest routes that would destroy forests, biodiversity, and ecosystem services. The study addresses the issue of fragmentation within forests and develops techniques that can be usefully applied to mitigate fragmentation problems in other fragile ecosystems such as tropical grasslands and savannas.
Spatial distribution of forest patches and their size: (a) Depicts the patch size distribution as influenced by infrastructure; (b) Depicts patch size distribution in absence of infrastructure intrusion.
Original Paper: Nayak, R., Karanth, K. K., Dutta, T., Defries, R., Karanth, K. U., & Vaidyanathan, S. (2020). Bits and pieces: Forest fragmentation by linear intrusions in India. Land Use Policy, (September 2018), 104619. https://doi.org/10.1016/j.landusepol.2020.104619
~ by Archita Sharma (WWF-India)
The Central Indian Landscape has been a stronghold for several long-ranging wild mammals for several thousands of years. Its dense forests and rolling grasslands provide a rich holdout for tigers and several other carnivores, big and small, prowling, hunting, and stalking in the shadows of this wild heartland. But over the last century, Central India has lost a share of its forests to growing human settlements, railways, roads and rampant mining. So, a landscape that was once a contiguous expanse of dry deciduous forests is now fragmented, remaining with 34% forest cover, out of which only 8.5% is legally protected.
Long-ranging mammals need room to roam. In many mammalian carnivores, the juveniles move out of their mother's territory to establish their own, with the males moving long distances to find new territories. When their dispersal routes to seek out prey, territory and mates are severed by roads, cities, villages, mining, and railways, natural populations can be isolated into small island populations. These small isolated populations face a higher risk of disease and extinction. Population genetic structure can help us determine the isolation or connectivity in natural populations.
To put it simply, genetic structure captures the level of genetic variation existing in a population. If mammals from different forest patches are mating with each other, they will be genetically more similar and will consequently have a lower genetic structure. Similarly, isolated populations will be genetically more distinct and will have higher genetic structure. Using DNA as a tool, estimating structure and connectivity in mammals can help us understand fine scale impacts of fragmentation. While there are several such studies on tigers, very little is known about how fragmentation impacts other mammalian species.
A new study published in Diversity and Distribution answers how the same level of habitat fragmentation has differential impacts multiple mammalian species in the threatened Central Indian Landscape. Researchers from the National Centre for Biological Sciences (NCBS), Bengaluru, investigated the genetic structure and connectivity in four long-ranging mammalian species — jungle cat, leopard, sloth bear, and tiger. The four species have varying body size, diet and dispersal abilities, and are expected to have species-specific responses to fragmentation. The two major objectives of the study were (1) to understand how the genetic structure is partitioned between these four species and (2) to find out how different landscape features like roads, built-up areas, and human density impact connectivity and dispersal in the study species.
~ by Amrita Neelakantan (coordinator NCCI)
Mahi Puri and colleagues have conducted extensive surveys to find out what leopards eat and how might leopard diets change in the future. The study focuses on the important corridor between Kanha and Pench national parks. Leopards live within and outside of forests, with some taking up residence in the agricultural matrix. Wildlife outside the bounds of protected areas interact much more often with humans over a range of human activities – grazing cattle, growing crops and collecting non-timber forest produce to name a few. Understanding how our human lives affect and in turn change the behavior of wild species is important for a future where humans and big cats might continue to live side by side in one of the world’s more populated places that remains vital for global wildlife conservation goals. In addition, the knowledge of benefits provided by carnivore presence can help offset the negative perceptions around these species. Mahi Puri and her team extensively surveyed forest and households across the corridor to make sense of drivers of leopard distribution, conflict, and current patterns of their diet to showcase what might change in the future.
The big takeaway from this paper is that within the surveyed sites leopards predominantly ate wild prey (langur and ungulates) – an important consideration for human-wildlife conflict in the region. Occupancy statistics also highlight that leopards are more likely to be in spots with ample wild-prey confirming that leopards still prefer wild-prey and are not preferentially moving into human dominated areas for non-wild prey (signified by cattle and dog icons in the figures).
~ by Archita Sharma (University of Delhi)
Nested in Satpura-Mikal range lies the Kanha-Pench forest landscape, spanning over an area of 10,000 square kilometers. It connects two well-known tiger reserves: Kanha and Pench. This landscape is a mosaic of dry deciduous forests, rippling grasslands, and tanned scrublands, with almost 400 villages. Although protected reserves play a crucial role in conserving wildlife, many species of wild carnivores also depend on being able to occupy human-dominated spaces. There is little understanding of human-carnivore interactions in such shared spaces.
A new study published in Royal Society Open Science revealed habitat preferences, livestock predation, and conservation requirements for five lesser-known carnivores in the Kanha-Pench forest landscape. The results offer a framework for assessing human-carnivore interactions in other regions as well.
The study focused on four wild canid species - Indian grey wolf, Dhole, Indian jackal, and Indian fox. Striped hyena, which is closely related to wild canids in terms of behavior and ecology, was also included in the assessment. The research team used a unique socio-ecological framework for assessing carnivore occupancy and livestock depredation patterns by combining field data gathered from 1600 kilometers of indirect sign survey (scats and tracks) with 700 interview surveys of local residents. 10,000 square kilometers of the landscape was divided into 128 cells of 52 square kilometers each, and this grid-network was then used for data collection. Data on the distribution of free-ranging dogs in the study area was also included in the assessment.
Photo credits as on photo and Centre for Wildlife Studies (https://cwsindia.org/)
PhD Candidate, National Centre for Biological Sciences (NCBS)
With 664 million tonnes (Mt) of coal, India was the third largest producer in 2014-15, next to China (3474 Mt) and the USA (924 Mt). The Indian government has announced an ambitious plan to produce 1500 Mt of coal by 2020, at an annual growth rate of almost 20%. In order to meet this target, massive expansion of open cast mines is envisaged. About 80% of India’s coal reserves lie in the central Indian landscape and much of it is under forests. Destruction of forests is inevitable for open-cast mining. Along with deforestation, direct and indirect mining activities change the landscape surrounding the mine. Direct activities include removal of the top soil, followed by excavation of overburden and then coal extraction. Indirect activities include tree felling for constructing roads, houses and other infrastructure, thus increasing the anthropogenic impact on the surrounding landscape.
Under the Forest Conservation Act, 1980, whenever forest land is diverted for non-forest use, compensatory afforestation (CA) needs to be carried out on an equal amount of non-forest land, or double the amount of degraded forest land. It is usually recommended that CA should be done at the point closest to where diversion is taking place. Mining companies often reclaim the overburden dumps for afforestation. But can these overburden dumps, after reclamation, support similar species of trees which were found in the forest that was cleared? How different are the physical and chemical properties of the dump soil compared to the soil found in the surrounding areas?
In order to answer these questions, Jitendra Ahirwal and Subodh Kumar Maiti from the Indian School of Mines, Dhanbad evaluated the changes in soil properties due to direct and indirect mining activities around Ananta open cast mine in Odisha. They collected soil samples from 5 different sites in 2008:
Project Spotlight highlights our members' work in Central India.
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