~ by Archita Sharma
Two conservation priority landscapes in India - the Western Ghats and Central India remain major strongholds for several endemic and threatened species. However, urbanization and land conversion have resulted in wide-scale habitat fragmentation in both the landscapes. Fragmentation can alter how animals move across a landscape.
Wide-ranging mammals are particularly affected because they travel long distances to forage, breed, and find new territories. Identifying where and how have the mammalian movements been impacted at large regional scales will be critical in ensuring habitat connectivity and preventing local extinctions.
A new study published in Biological Conservation evaluated landscape-wide permeability to the movement of five endangered and vulnerable mammals - Asian Elephant, Gaur, Leopard, Sambar, and Sloth Bear in these two priority landscapes. The expansive study area covered 120,000 km2 of the Western Ghats and 729,000 km2 of the Central Indian region. For each of the five study species, the researchers modelled movement in the presence and absence of landscape features such as land-use land-cover, infrastructure and human population. They generated spatially explicit maps identifying areas where animal movement is impeded, reduced, unrestricted, increased, and channeled. These categories can be interpreted as follows – movement is impeded and reduced due to underlying high resistance landscape features, unrestricted due to underlying low resistance areas, finally increased and channeled due to high resistance surrounding landscape features.
~ 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 (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/)
The Wildlife Conservation Trust (WCT) recently launched a website and released a report titled "A Policy Framework for Connectivity Conservation and Smart Green Linear Infrastructure in the Central Indian and Eastern Ghats Tiger Landscape." According to Milind Pariwakam, a wildlife biologist at WCT, while several reports, studies, and guidelines aim to address the issue of mitigating the negative impacts of such linear infrastructure on natural landscapes and conserving the connectivity that they offer to small populations of endangered species of wildlife, there is a lack of timely information on whether a particular project is likely to affect corridor/s.
Pariwakam further states that this report primarily seeks to address this specific lacuna by leveraging on earlier work by other entities and presents a way forward for better planning of linear infrastructure without compromising on the connectivity needs of wildlife. The same framework with improvements can be adopted by the statutory agencies for the other three important tiger landscapes in India, namely, the Western Ghats, Shivalik-Gangetic Landscape and the North East Indian Landscape by incorporating information on the corridors and proposed projects in the respective landscapes. Work is in progress on the other three reports.
by Kevin Krajick
Featuring research by Amrita Neelakantan, Columbia University
It is the black before dawn at the gate to the Kanha Tiger Reserve, in the highlands of central India. The still air carries a dank, penetrating chill. But it is hardly quiet. A buzzing line of tourists is forming at the ticket booth, peddlers are pouring steaming cups of tea. Groups of green-uniformed rangers chat at the entrance. Across the street, dozens of drivers are forming up a military-type vehicle convoy, ready for the visitors to board for the daily sunrise invasion of drive-through safaris.
It was Kanha’s lushly forested hills and ravines that inspired Rudyard Kipling’s famous story collection The Jungle Book, and it is a must-do tourist stop. Unlike much of rapidly developing India, it abounds in wildlife; it is home not only to Bengal tigers, but leopards, sloth bears, unique deer species and other rare and endangered creatures. The 360-square-mile park used to be home also to at least 1,500 extended families, but not anymore. The government started moving them out in the 1970s, and nudged out the last stragglers in 2015. This, theoretically, has been good for the fauna and flora. Whether it has been good for the people is a separate question.
Read more in the original article, posted on State of the Planet, Columbia University's Earth Institute blog.
Project Spotlight highlights our members' work in Central India.
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