The limbless, primarily soil-dwelling and tropical caecilian amphibians (Gymnophiona) comprise the least known order of tetrapods. On the basis of unprecedented extensive fieldwork, we report the discovery of a previously overlooked, ancient lineage and radiation of caecilians from threatened habitats in the underexplored states of northeast India. Molecular phylogenetic analyses of mitogenomic and nuclear DNA sequences, and comparative cranial anatomy indicate an unexpected sister-group relationship with the exclusively African family Herpelidae. Relaxed molecular clock analyses indicate that these lineages diverged in the Early Cretaceous, about 140 Ma. The discovery adds a major branch to the amphibian tree of life and sheds light on both the evolution and biogeography of caecilians and the biotic history of northeast India—an area generally interpreted as a gateway between biodiversity hotspots rather than a distinct biogeographic unit with its own ancient endemics. Because of its distinctive morphology, inferred age and phylogenetic relationships, we recognize the newly discovered caecilian radiation as a new family of modern amphibians.

Lantana (Lantana camara), one of the world's most troublesome invasive weeds, has become a menace in most of the protected areas located in tropical and subtropical belt of India. The lantana-infested landscapes not only are impoverished as habitats of wildlife but also contribute to human-wildlife conflicts owing to diminished ecosystem services. This paper is a case study of successful eradication and restoration of two lantana-invaded sites in Corbett Tiger Reserve, India. A method for eradicating lantana was developed using knowledge about its ecology, and, subsequently, weed-free landscapes were restored to productive grasslands and mixed woodlands using native species. The restoration of these areas to grassland communities has successfully prevented secondary invasions by lantana and other weeds and has enhanced the habitat quality for herbivores whose populations are vital for the survival of top carnivores such as tiger (Panthera tigris corbetti).

Pastoral systems are known to be prone to social, political and ecological uncertainties. Traditional ecological knowledge that the pastoral communities hold around their bio-physical environment has been a key to cope with stressors and adapt to the rapid socio-economic changes. We examined traditional ecological knowledge (TEK) on livestock and resource management, factors influencing livestock production and concurrent changes in an agro-pastoral system. We used mixed methods by conducting 44 semi-structured interviews, 10 key informants’ interviews and resource mapping in five villages of Upper Spiti Landscape, western Himalaya. Our specific objectives were to (i) document TEK on livestock diet and management and (ii) understand the drivers and consequences of the change in the agro-pastoral society and associated traditional knowledge system. The herders of the study area possessed extensive knowledge of livestock diet and fodder species preference. They used this knowledge to optimize livestock grazing in pastures during summers and to fulfil the nutrient requirements of livestock species during stall feeding in winters. Seasonally, the aspect, altitude and accessibility of the pasture influenced the rotational use of pastures. In contrast, the quality of forage and water availability, distance of the pasture from village and threats from predators influenced the selection of grazing areas daily. There are evident changes in the livestock production system and signs that TEK is eroding in the region. Primary contributing factors to loss of TEK include changing aspirations of local people. These aspirations were related to employment in lucrative alternative options like cash crops and tourism, out-migration of the young generation for higher education and the arrival of immigrant labourers as new actors in livestock management. Livestock numbers in the study site remained dynamic between the year 2003-2016 owing to the substantive social and ecological changes. Our results suggest that while the traditional knowledge persists, the signs of erosion in traditional knowledge and associated changes in current herding practices are evident. We argue that recent changes in the pastoral social-ecological system, especially loss of TEK and non-traditional rearing practices, due to increasing dependence on immigrant labourers, may have negative implications for livestock production, rangeland health and wildlife conservation goals in the long run. Long term site-specific studies on livestock production and associated knowledge would be critical for adaptive rangeland management and policies.

Forest fragments are characteristic features of many megacities that have survived the urbanisation process and are often represented by unique assemblages of flora and fauna. Such woodlands are representations of nature in the city—often dominated by non-native and invasive species that coexist with resilient native congeners and purposefully introduced flora. These forest fragments also provide significant ecosystem services to urban society and therefore, understanding their compositional patterns is of considerable importance for conservation and management. In this work, we use a complex network approach to investigate species assemblages across six distinct urban forest fragments in the South Delhi Ridge area of the National Capital Territory, India. We generate bipartite ecological networks using conventional vegetation sampling datasets, followed by network partitioning to identify multiple cliques across the six forest fragments. Our results show that urban woodlands primarily form invasive–native associations, and that major invasive species, such as Prosopis juliflora and Lantana camara exclude each other while forming cliques. Our findings have implications for the conservation of these urban forests and highlight the importance of using network approaches in vegetation analysis.

Recent advances in network theory have led to considerable progress in our understanding of complex real world systems and their behavior in response to external threats or fluctuations. Much of this research has been invigorated by demonstration of the ‘robust, yet fragile’ nature of cellular and large-scale systems transcending biology, sociology, and ecology, through application of the network theory to diverse interactions observed in nature such as plant-pollinator, seed-dispersal agent and host-parasite relationships. In this work, we report the development of NEXCADE, an automated and interactive program for inducing disturbances into complex systems defined by networks, focusing on the changes in global network topology and connectivity as a function of the perturbation. NEXCADE uses a graph theoretical approach to simulate perturbations in a user-defined manner, singly, in clusters, or sequentially. To demonstrate the promise it holds for broader adoption by the research community, we provide pre-simulated examples from diverse real-world networks including eukaryotic protein-protein interaction networks, fungal biochemical networks, a variety of ecological food webs in nature as well as social networks. NEXCADE not only enables network visualization at every step of the targeted attacks, but also allows risk assessment, i.e. identification of nodes critical for the robustness of the system of interest, in order to devise and implement context-based strategies for restructuring a network, or to achieve resilience against link or node failures. Source code and license for the software, designed to work on a Linux-based operating system (OS) can be downloaded at http://www.nipgr.res.in/nexcade_download.html. In addition, we have developed NEXCADE as an OS-independent online web server freely available to the scientific community without any login requirement at http://www.nipgr.res.in/nexcade.html.