Primula himalayana sp. nov., a new species from eastern Himalaya, India

The present study generates a glacial lake inventory of Arunachal Pradesh, Eastern Himalaya, India using Landsat 8 Operational Land Imager (OLI) images (2016-2018). The study reveals that there are in total 1532 (> 0.001 km2) glacial lakes, covering an area of 93.7 km2. Glacier erosion lakes are the most dominant type with 1268 glacial lakes (82.8%) and an area of 76.8 km2 (∼82%). About 50% of the lakes are located in the four districts of eastern Arunachal Pradesh, while ∼16% in the three districts of central and ∼33% in the four districts of western Arunachal Pradesh. The western Arunachal Pradesh has mixed patterns of glacial lakes types, whereas the erosion lakes dominate the eastern and central Arunachal Pradesh. The current inventory can serve as a baseline database for understanding glacial lake-related flood hazard studies in Arunachal Pradesh.

Arunachal Pradesh is known for its rich biodiversity, including avifauna. However, some areas in Arunachal Pradesh still need to be surveyed to document its biodiversity and avian diversity. In order to document the avian diversity in high altitude areas, especially in the north-western region bordering Myanmar and southern China, I carried out surveys in Tawang district, an important eco-region selected for the proposed Biosphere Reserve, which has similarity in bird assemblages with those of neighbouring Bhutan and southern China. Studies were carried out in four phases from November 2007 to March 2012, with more than three surveys of 14 days durations covering 24 localities of Tawang district. The main aim of the surveys was to document the seasonal bird diversity of Zimmithang-Nelya, an Important Bird Area (IBA) in the Eastern Himalaya. The surveys recorded 113 species of birds, including 25 migrant species. Significant records include the Snow Partridge Lerwa lerwa, Eurasian Woodcock Scolopax rusticola, and Broad-billed Warbler Tickellia hodgsoni.

Glacial lakes (GLs) are integral components of the cryospheric environment. Due to the persistent melting of glaciers and steady rise in the annual mean temperatures, GLs are expanding across the Himalayan mountains. Since the 1980s, the eastern Himalaya have observed a steady increase (0.031°C/year) in annual mean temperature, causing rapid glacial melting, formation of new GLs and expansion of existing ones. Therefore, to assess the role of the increasing annual mean temperature on the expansion of GLs in the eastern Himalaya, we generated GL inventories for 1987, 2005 and 2018 for Dibang Valley district, Arunachal Pradesh, in the eastern Himalaya. We used Landsat multi-temporal satellite images along with the ASTER Digital Elevation Model V2 (DEM). Using the Segment Mean Shift (SMS) method, the GL inventories were generated. Our results show that there were 509 GLs in 2018, whereas only 484 in 2005 and 469 in 1987. GLs observed a growth rate of 8.52% in number and 11.13% in area between 1987 and 2018. Most of the GLs in the study area were of Moraine-dammed lakes (MDL) (~56%), whereas Ice-dammed lakes (IDL) showed the highest expansion rate between 1987 to 2018. GL hotspots show a concentration of GLs in the eastern and southern sections of Dibang Valley but new GLs are forming in the north-western and eastern sections of the study area. An increase in annual mean temperature enhanced the glacial melt water, leading to the growth of GLs connected with the glaciers.

Introduction This brief paper presents some preliminary results of a survey conducted among the transhumant Mon Pa pastoralists of the alpine terrain of Tawang, in Arunachal Pradesh in the eastern Indian Himalayas. The term Mon Pa is an exonym and means `the others' in Tibeto-Burmese. These primarily yak herders who are indigenous to the area also own some cattle, mules, horses and sheep and practice limited horticulture in their village lands, at around 3,000m. While Mon Pa men take their herds over long distances in search of pasture, women, children and the elderly remain throughout the year in these villages, tending some of their livestock and collecting firewood. Till quite recently, Mon Pa pastoralists, who are Mahayana Buddhists (Sarkar 1980) were polyandrous, and since herds are owned jointly by brothers, one herder can be replaced after a while by his brother. Thus, yak herds live in the forests and alpine meadows (Farooquee 1997) continuously, with the herders in charge rotating. With rapidly shrinking pastures and the breaking down of their exchange relationships with Mon Pa farmers of the Tawang region, who bartered grain for yak cheese, butter, and meat (Nanda 1981, Furer-Haimendorf 1982, Jha 1988, Duarah 1992, Farooquee 1997), the entire community is struggling against the severe impact of economic change. In order to maintain the regular barter system, Mon Pa pastoralists have had large herds of up to 145 yaks per household besides two or three heads of cattle, one or two mules and horses, and a few goats. To feed such a large stock of yaks, they have nomadised, and this environmental strategy has, in its turn, both enabled a sustainable pastoral economy and become the basis of Mon Pa pastoralist identity. The Area The Thingbu-Mukto division of Tawang district in Arunachal Pradesh where this survey was carried out, lies in the alpine zone between 3,100 and 4,000 m, well above the timberline. The mean annual temperature is below 6[degrees]C, with mean winter temperatures below -1[degrees]C (Champion and Seth 1965). The herbage of the high altitude eastern Himalaya is highly nutritious and can contain crude protein up to seventeen percent. It is very common to find the farmers here harvesting grass from the forest areas to feed their animals (Verma 1988). Some of the commonest plants found in the region are species of the genera Corydalis, Sorosis, Silens, Saussurea, Geranium, Geum, and common grasses in the alpine region are Poa, Agrostis, Calamogrostis, Yak grass, Festuca, Korbressia, Irish grass (Sundriyal 1995). Traditional Patterns of Pastoral Movement Mon Pa pastoralists rotate traditionally between a multi-pasture encampment used in mid- and late winter, spring and summer, and an encampment used in autumn and early winter. This system allows them to utilise a series of common grazing lands, while also providing an ample supply of ungrazed forage reserves for use in autumn and early winter on which the animals subsist through the long winters. They stay in each of these pastures for only as long as enough fodder is available here as calculated by them traditionally. This complex system of pasture rotation appears quite similar to that of the nomads of the Tibetan Plateau (Goldstein et al. 1990). Unlike, say, herders in non-mountainous arid zones, such as the Bedouin of Saudi Arabia who move opportunistically among very large areas of land in response to random and patchy rainfall (Perevalotsky 1987), these alpine herders have skilfully cashed-in on climatic and altitudinal variations spread across a spatio-temporal scale. They distribute their herds between different pastures in such a manner that they calve in winter when they move down closer to their villages after grazing in the alpine meadows in summer. Over the years, a certain ecological balance had been maintained and untill recently, there were no indications of overgrazing. Increasingly, however, there are indications of the degradation of these common resources. …

The Eastern Himalayas is known for its fragile mountain ecosystems and is highly sensitive towards climate change. In recent decades, rapid warming and glacial retreat caused significant changes in the number, size and distribution of lakes. These changes increased concerns over a major hazard for downstream regions called Glacial Lake Outburst Floods (GLOFs). The present study focuses on changes in the number and area of different lake classes and GLOF risks in Arunachal Pradesh, Eastern Himalaya during 1988 and 2020. Using multitemporal satellite data, results indicate a significant increase in both number and area of nonglacial lakes (NGLs) by 498 lakes and 3212.56 ha, respectively. Proglacial lakes (PGLs) decreased slightly in number but expanded in area, whereas unconnected glacial lakes (UGLs) increased in number while decreasing in area. The majority of newly formed lakes were located between 4000 and 5000 m above mean sea level (AMSL). A total of 127 lakes was selected for GLOF risk assessment using the Analytic Hierarchy Process (AHP), with lake expansion rate and proximity to glaciers as the most critical parameters. Results indicated that 2 lakes are identified as high risk, 36 as medium risk and 89 as low risk, with a consistency ratio of 0.091. The study highlights the increasing risk potential of expanding glacial and high altitude lakes under climate change. The study further emphasized the need for continuous monitoring, targeted risk mitigation strategies and early warning systems to mitigate the downstream regions in the Eastern Himalaya.

The genus Calypogeia Raddi is represented in India by six species (Singh, 2001). All the six species are found in Eastern Himalaya with three species, C. aeruginosa Mitt., C. fissa (L.) Raddi and C. marginella Mitt., restricted to this region alone in Indian bryoflora. Of the remaining three, C. arguta Nees & Mont. is common to Eastern Himalaya, Central India, South India and the Andaman and Nicobar Islands; C. azurea Stotler & Crotz occurs in both Eastern and Western Himalaya and South India and C. lunata Mitt. is common to Eastern as well as Western Himalaya (Mitten, 1861; Chopra, 1943; Sharma & Srivastava, 1993; Singh & al., 2008). During the course of study on the liverworts and hornworts of Mehao Wildlife Sanctuary in Arunachal Pradesh, Eastern Himalaya, the authors came across an interesting species of the genus Calypogeia Raddi. Detailed morphotaxonomic study of the species and study of relevant literature (Bischler, 1962a, 1962b; Srivastava & Sharma, 1986; Sharma & Srivastava, 1993; Paton, 1999) revealed it to be a hitherto undescribed species of the genus. The same has been described and illustrated as C. udarii in the present communication.

The vertically integrated horizontal vapour transport (IVT) accompanied by westerlies and southwesterlies mainly contributes as a distant source of moisture to the seasonal precipitation (PR). The moisture transport and PR patterns across the eastern Himalayas (Sikkim, northern Sub‐Himalayan West Bengal and Arunachal Pradesh) are strongly modulated by the orographic setup, local land‐atmospheric factors and teleconnection with climate indices of the Indian and Pacific oceans. This study elaborates on the changing patterns of PR and IVT, changes in IVT contribution to the seasonal PR under the nonstationary framework and evaluates the nonlinear dependency on local and distant drivers with piecewise regression model. Asymmetries in significant seasonal trends are conspicuous due to multi‐altitude interactions. Strong declining trend over Assam and Arunachal Pradesh is evident for PR with concurrent rising trend over the Meghalaya plateau. The IVT signals show a significant decline in post‐monsoon (October and November) and winter (December to February) across Assam Plain. The increase in mean IVT contributes significantly to seasonal PR. Significant decline in the contribution of heavy IVT to winter PR is observed over Manipur, Mizoram, Tripura and part of Assam. Surface 2 m temperature and net thermal radiation exhibit contrasting influence on seasonal PR. IVT shows mainly positive association with surface 2 m dew point temperature and latent heat flux across the eastern Himalayas. NINO3.4 index exhibits strong negative influence on post‐monsoon PR. The Pacific Decadal Oscillation is strongly associated with summer (March to May) PR. Monsoon (June to September) IVT is negatively influenced by the Pacific Decadal Oscillation over the Sub‐Himalayan West Bengal, Gangetic West Bengal, Bihar and Jharkhand. The Southern Oscillation Index is negatively linked with summer IVT. The combination of local driving forces mainly controls the seasonal PR and IVT across all seasons. Besides, distant drivers are prominent in monsoon and post‐monsoon. This study reveals insights into recent changes of PR and IVT, their contribution to seasonal water resources in the eastern Himalayas and the controlling strength of local land‐atmosphere feedback mechanism and distant land‐ocean coupling drivers under nonstationary climate.

BackgroundPastoralists comprising different ethnic groups of people dominate the Eastern Himalayas. Traditional knowledge in the Eastern Himalayas reflects the common linkage of origin and settlement of the ethnic groups in the regions. The practice of milk fermentation along the Eastern Himalayan regions shows similar types of ethnic naturally fermented milk (NFM) products that are regularly prepared by different ethnic groups of people. MethodsA survey of various types of NFM products of Eastern Nepal, Darjeeling Hills, Sikkim, and Arunachal Pradesh in India, and Bhutan and their methods of preparation, mode of consumption, and ethnic values was documented as per the standard method. ResultsSikkim and Nepal have several varieties of NFM products, which include dahi, mohi, gheu, soft chhurpi, hard chhurpi, dudh-chhurpi, chhu, somar, maa, philu, and shyow. The main products, which are daily prepared in Arunachal Pradesh, are mar, chhurpi/churapi, churkam, and churtang/chhurpupu. NFM products of Bhutan are dahi, datshi, mohi, gheu, chugo, and hitpa. ConclusionUnique types of NFM products have been reported from the Eastern Himalayas. Although these are minor products, they are of high biological importance.

The Greater Himalayas hold the largest mass of ice outside polar regions and are the source of the 10 largest rivers in Asia. Rapid reduction in the volume of Himalayan glaciers due to climate change is occurring. The cascading effects of rising temperatures and loss of ice and snow in the region are affecting, for example, water availability (amounts, seasonality), biodiversity (endemic species, predator-prey relations), ecosystem boundary shifts (tree-line movements, high-elevation ecosystem changes), and global feedbacks (monsoonal shifts, loss of soil carbon). Climate change will also have environmental and social impacts that will likely increase uncertainty in water supplies and agricultural production for human populations across Asia. A common understanding of climate change needs to be developed through regional and local-scale research so that mitigation and adaptation strategies can be identified and implemented. The challenges brought about by climate change in the Greater Himalayas can only be addressed through increased regional collaboration in scientific research and policy making.

The Himalayas are well known for high diversity and ethnobotanical uses of the region’s medicinal plants. However, not all areas of the Himalayan regions are well studied. Studies on ethnobotanical uses of plants from the Eastern Himalayas are still lacking for many tribes. Past studies have primarily focused on listing plants’ vernacular names and their traditional medicinal uses. However, studies on traditional ethnopharmacological practices on medicine preparation by mixing multiple plant products of different species has not yet been reported in published literature from the state of Arunachal Pradesh, India, Eastern Himalayas. In this study, we are reporting for the first time the ethnopharmacological uses of 24 medicines and their procedures of preparation, as well as listing 53 plant species used for these medicines by the Monpa tribe. Such documentations are done first time in Arunachal Pradesh region of India as per our knowledge. Our research emphasizes the urgent need to document traditional medicine preparation procedures from local healers before traditional knowledge of tribal people living in remote locations are forgotten in a rapidly transforming country like India.

<div> <p>One of the first order questions regarding a cross-section representation through a fold-thrust belt (FTB) is usually “how unique is this geometrical interpretation of the subsurface?”  The proposed geometry influences perceptions of inherited structures, decollement horizons, and both rheological and kinematic behavior.  Balanced cross sections were developed as a tool to produce more accurate and thus more predictive geological cross sections.  While balanced cross sections provide models of subsurface geometry that can reproduce the mapped surface geology, they are non-unique, opening the possibility that different geometries and kinematics may be able to satisfy the same set of observations. The most non-unique aspects of cross sections are: (1) the geometry of structures that is not seen at the surface, and (2) the sequence of thrust faulting.  We posit that integrating sequentially restored cross sections with thermokinematic models that calculate the resulting subsurface thermal field and predicted cooling ages of rocks at the surface provides a valuable means to assess the viability of proposed geometry and kinematics.  Mineral cooling ages in compressional settings are the outcome of surface uplift and the resulting focused erosion.  As such they are most sensitive to the vertical component of the kinematic field imparted by ramps and surface breaking faults in sequential reconstructions of FTB.  Because balanced cross sections require that the lengths and locations of hanging-wall and footwall ramps match, they provide a template of the ways in which the location and magnitude of ramps in the basal décollement have evolved with time.  Arunachal Pradesh in the eastern Himalayas is an ideal place to look at the sensitivity of cooling ages to different cross section geometries and kinematic models. Recent studies from this portion of the Himalayan FTB include both a suite of different cross section geometries and a robust bedrock thermochronology dataset. The multiple published cross-sections differ in the details of geometry, implied amounts of shortening, kinematic history, and thus exhumation pathways. Published cooling ages data show older ages (6-10 Ma AFT, 12-14 Ma ZFT) in the frontal portions of the FTB and significantly younger ages (2-5 Ma AFT, 6-8 Ma ZFT) in the hinterland. These ages are best reproduced with kinematic sequence that involves early forward propagation of the FTB from 14-10 Ma.  The early propagation combined with young hinterland cooling ages require several periods of out-of-sequence faulting. Out-of-sequence faults are concentrated in two windows of time (10-8 Ma and 7-5 Ma) that show systematic northward reactivation of faults.  Quantitative integration of cross section geometry, kinematics and cooling ages require notably more complicated kinematic and exhumation pathways than are typically assumed with a simple in-sequence model of cross section deformation.  While also non-unique, the updated cross section geometry and kinematics highlight components of geometry, deformation and exhumation that must be included in any valid cross section model for this portion of the eastern Himalaya.</p> </div>

Three East and South-east Asian species of the genus Radula Dumort., viz. R. chinensis Steph., R. kojana Steph. and R. sumatrana Steph. are newly reported for the Indian bryoflora, from Arunachal Pradesh in Eastern Himalaya. Asexual reproduction through caducous leaves is described for the first time in R. sumatrana. Descriptions and illustrations of the three species based on Indian material are presented. A key to the Indian species of Radula is provided.

Abstract. Glacial lake outburst flood (GLOF) is one of the major unexpected hazards in the high mountain regions susceptible to climate change. The Tawang river basin in Arunachal Pradesh is an unexplored region in the Eastern Himalayas, which is impending to produce several upcoming hydro-electric projects (HEP). The main source of the river system is the snow melt in the Eastern Himalayas, which is composed of several lakes located at the snout of the glacier dammed by the lateral or end moraine. These lakes might prove as potential threat to the future scenario as they have a tendency to produce flash flood with large quantity of sediment load during outbursts. This study provides a methodology to detect the potential lakes as a danger to the HEP sites in the basin, followed by quantification of volume of discharge from the potential lake and prediction of hydrograph at the lake site. The remote location of present lakes induced the use of remote sensing data, which was fulfilled by Landsat-8 satellite imagery with least cloud coverage. Suitable reflectance bands on the basis of spectral responses were used to produce informational layers (NDWI, Potential snow cover map, supervised classification map) in GIS environment for discriminating different land features. The product obtained from vector overlay operation of these layers; representing possible water area, was further utilized in combination with Google earth to identify the lakes within the watershed. Finally those identified lakes were detected as potentially dangerous lakes based on the criteria of elevation, area, proximity from streamline, slope and volume of water held. HEC-RAS simulation model was used with cross sections from Google Earth and field survey as input to simulate dam break like situation; hydrodynamic channel routing of the outburst hydrograph along river reach was carried out to get the GLOF hydrograph at the project sites. It was concluded from the results that, the assessed GLOF would be a lead for the qualitative approximation of the amount of bed load transported along the river reach and thus hydropower project sites.

It is crucial to understand lateral differences in paleoclimate and weathering in order to fully understand the evolution of the Himalayan mountain belt. While many studies have focused on the western and central Himalaya, the eastern Himalaya remains poorly studied with regard to paleoclimate and past weathering history. Here, we present a multi‐proxy study on the Mio‐Pliocene sedimentary foreland‐basin section along the Kameng River in Arunachal Pradesh, northeast India, in order to obtain better insight in the weathering history of the eastern Himalaya. We analysed a continuous sedimentary record over the last 13 Ma. Heavy‐mineral and petrography data give insight into diagenesis and provenance, showing that the older part of the section is influenced by diagenesis and that sediments were not only deposited by a large Trans‐Himalayan river and the palaeo‐Kameng river, but also by smaller local tributaries. By taking into account changes in diagenesis and provenance, results of clay mineralogy and major element analysis show an overall increase in weathering intensity over time, with a remarkable change between ca. 10 and ca. 8 Ma.

Silkmoths are both ecologically significant and economically valuable insects, with larval host plant associations playing a crucial role in shaping their development, survival, and silk yield. Arunachal Pradesh, a biodiversity hotspot in the Eastern Himalayas, harbours diverse silk moth species. However, comprehensive documentation of their host plants remains limited. Through extensive field surveys conducted in various parts of Arunachal Pradesh, we recorded 14 species of wild silkworms, and documented seven species of new host plant associations for three wild silkmoth species in addition to the previous records. The new records include Gunda ochracea Walker (Bombycidae) on Ficus rumphii Blume (Moraceae), Antheraea frithi Moore on Terminalia chebula Retz, Terminalia myriocarpa Van Heurck and Müll. Arg, Combretum pilosum Roxb. ex G.Don (Combretaceae), Lagerstroemia speciosa (L.) Martyn (Lythraceae), Castanopsis lanceifolia (Oerst.) Hickel and A.Camus (Fagaceae) and Samia canningii (Hutton, 1859) on Litsea monopetala (Roxb.) Pers. (Lauraceae). These results fill a major gap in the ecological knowledge of wild silkmoths in the Eastern Himalayas. Additionally, it supports sericultural applications of the documented larval host plants.