Eastern Himalayan Region Research Articles

New record of Sapria himalayana Griff. (Rafflesiaceae) from Eaglenest Wildlife Sanctuary, Arunachal Pradesh, India

The eastern Himalayan region is renowned for its exceptional and abundant floral and faunal biodiversity, harbouring numerous endemic plant species. Among them, Sapria himalayana Griffith, an endoparasitic, rare, and endangered plant, was first discovered in the Mishmi Hills of Arunachal Pradesh in 1836. Despite its discovery nearly two centuries ago, the species remains poorly understood. While some recent studies have begun to explore the genetics and demography of this species, there is still a significant knowledge gap in the understanding of the life history patterns of this parasitic plant. Here, a new record has been added to the distribution of Sapria himalayana from Eaglenest Wildlife Sanctuary, West Kameng District, Arunachal Pradesh. Around 21 flowers were scattered on the forest floor, spanning various developmental stages from buds to flower maturation, including desiccated flowers. The bud emerges from the roots of Tetrastigma sp. (host plant). One of the primary challenges in conducting extensive research on the intriguing Himalayan Sapria is its infrequent and unpredictable flowering patterns. Therefore, understanding these aspects (flowering phenology and enigmatic traits) is crucial for further research and preserving this rare species and its hosts in the face of ongoing habitat loss. Conducting an annual plant survey in the Eaglenest Wildlife Sanctuary can help identify patterns to unravel these mysteries.

Impact of Technological Interventions on the Yield and Income of Tribal Farm Women’s in Arunachal Pradesh under Eastern Himalayan Region

The study was conducted to determine the extent of Impact, adoption of improved technologies, economics and yield gap analysis in the empowerment of tribal farm women’s cluster having 50 nos. of respondents selected among a pool of 105 farm families in the Chug village of West Kameng District Arunachal Pradesh. Various technological interventions were made by the K.V.K for the tribal farm women’s empowerment. In this reference the present study was undertaken to have an understanding of the nature and extent of the empowerment of rural women’sthrough involvement in income generational activities under the aegis of Doubling Farmers Income Programme started by Govt. of India. The study revealed that the highest income generating activity was paddy cum Fish farming and nursery raising of temperate fruit crops with >100% increase while the lowest income generating activity was SRI of local rice with 25% increase only. The extension gap recorded was highest 2000Kg/ha in the introduction of HYV of ginger and lowest 30 eggs/year in the introduction of improved poultry breed having same trend in (TG) technology gap i.e. 12000kg and 60 egg/year respectively. The technology index TI was highest 60 in ginger production and 16.66 in SRI of local paddy.

Innovative and polygonal trend analysis of temperature in agro climatic zones of India

Understanding the long-term trends in temperature is crucial for assessing the impacts of climate change on agriculture, human and animal health, and natural habitats. An in-depth analysis of long-term spatio-temporal trends of monthly maximum and minimum temperatures along with Diurnal Temperature Range (DTR) from 1951 to 2022 in various Agro-Climatic Zones (ACZs) of India was performed using newly introduced Innovative Polygonal Trend Analysis (IPTA) and Innovative Trend Analysis (ITA) along with traditional Mann-Kendall (MK) or modified Mann-Kendall (m-MK) tests. The MK/m-MK and IPTA assessments detected significant trends in 44.6% and 86% of the time series data, respectively, while the ITA method detected significant trends in every time series data. The southern, western, and central parts of India are consistently experiencing rising monthly maximum and minimum temperatures. The western dry region, Central Plateau & Hills, East Coast Plains & Hills, Gujarat Plains & Hills, West Coast Plains & Hills, Southern Plateau & Hills, Western Plateau & Hills and Eastern Himalayan Region predominantly show increasing trends in both maximum and minimum temperatures in all months. The Indo-Gangetic Plains (Middle, Trans, Upper and Lower) exhibit decreasing trends in maximum temperatures during January, February, May, and June. The DTR showed increasing trends in the northern and western parts, while it has increasing trends in the central and southern parts of the country. The results of this study provide valuable information to assist in precise and informed decision-making on agricultural resource management and socio-economic policies.

Aquatic insects as indicators of water quality: Seasonal distribution and biomonitoring insights from a hilly river in the Eastern Himalayan region, India

This study investigated the seasonal distribution and diversity of aquatic insect communities in the Jatinga River, a small hilly river in northeast India, to assess water quality through biomonitoring. Sampling was conducted at five sites along the river from upstream to downstream over one year seasonally (2018–2019). A total of 72 species, 58 genera, and 38 families were recorded, with species such as Micronecta sp.1, Ptilomera assamensis, and Hydropsyche sparna achieving eudominant status. Biotic index values like BMWPTHAI (score: 78–105), ASPTTHAI (score: 6.2–7.5), SIGNAL2 (score: 6.1–7), and EPT% (50.89–75.35) indicated good and clean water quality with healthy habitat at upstream sites (S1 and S2), with decreasing quality in downstream. Values of all the studied environmental variables of water were found within the permissible limit of Bureau of Indian Standards and World Health Organisation except Electrical conductivity (EC) and Total dissolved solid (TDS). Principal component analysis (PCA) and canonical correspondence analysis (CCA) revealed significant relationships between insect species distribution and environmental factors such as riverbed particles and water chemistry.

Acute poisoning with Jatropha curcas in North Eastern Himalayan region – A case series and review of literature

Plant poisoning is one of the common accidental sources of poisoning amongst the villagers and the troops going on long-range patrolling. Seeds of Jatropha curcas a/k/a biodiesel pant mimicking nuts are an uncommon source of poisoning, manifesting as mainly gastrointestinal symptoms and less frequently the other systemic manifestations. Here, we report a case series of two cases of serving soldiers who presented with gastrointestinal symptoms after consumption of seeds of unknown plants mimicking nuts, which was later identified as J. curcas. Both patients had favorable outcomes with syndromic management of the unknown poisoning.

Crustal Heterogeneity of the Bhutan Himalaya: Insights from PgQ Tomography

Abstract We present the results of a seismic investigation conducted in Bhutan using data from the Geodynamics and Seismic Structure of the Eastern Himalaya Region broadband network, focusing on variations in crustal structure and seismic attenuation properties. Through analysis of seismic data from 56 events recorded between 2013 and 2014, with magnitudes exceeding 4.5 and depths shallower than 50 km, we examined 1 Hz PgQ (Q0)-values among multiple station pairs using the two-station method. Our findings reveal significant disparities in PgQ0-values across Bhutan. The western region exhibits low PgQ0 values, indicating high seismic attenuation, whereas the central region shows medium-to-high PgQ0 values, suggesting lower attenuation. Notably, these results are consistent with the geometry of the Moho, providing valuable insights into crustal geometry and rheology. This study contributes to a deeper understanding of Bhutan’s complex crustal structure, offering insights into crustal properties and seismic attenuation mechanisms in this geologically significant region.

Application of ML- based approach for co-seismic landslides susceptibility mapping and identification of important controlling factors in eastern Himalayan region

Application of ML- based approach for co-seismic landslides susceptibility mapping and identification of important controlling factors in eastern Himalayan region

Influence of bark chemistry on distribution of epiphytic mosses on basal trunk of <i>Cryptomeria japonica</i>

Epiphytic mosses are integral parts of forest community structure in the Darjeeling Hills of the Eastern Himalayan region with remarkable contributions to the ecosystem functionality. The study was framed to assess the richness and spatial distribution of epiphytic mosses growing on the basal trunk of Cryptomeria japonica (Thunb. ex. L.) D.Don, and also to evaluate the explanatory host traits for shaping the moss assemblage. Field measurements and sampling were performed near Lamahatta village within Darjeeling district on 270 microplots placed on tree trunks. A total of twelve mosses represented by the members of Dicranales and Hypnales were recorded. Low species diversity was observed with dominance and maximum cover of Syrrhopodon confertus. Canonical correspondence analysis predicted a distinct combination of chemical requirements for local colonization of each moss. The results also demonstrated influence of bark acidic inputs on abundance and co-existence of bryophytes. The outcome can be potentially helpful in depicting the community structure of non-vascular epiphytes, which may further be considered while developing forest management strategies.

Geospatial Analysis of Soil Erosion and Subsequent Geomorphic Hazards in the Eastern Himalayan Region, India

Geospatial Analysis of Soil Erosion and Subsequent Geomorphic Hazards in the Eastern Himalayan Region, India

Resurgent diversity: upland agriculture, indigenous crops and foodways in Eastern Himalayas

ABSTRACT In this article, we are concerned with the cultivation of food crops – comparing trajectories of millets and buckwheat in Eastern Himalayas, and the circumstances under which farmers plant or forgo certain crops. Crop choices and how farmers cultivate their crops have far-reaching consequences for society, economy and the environment. With accelerating climate change, present global, corporate food regime based on a handful of genetically identical crops appears as a high-risk venture. For many Indigenous peoples alternatives to and negotiations with these regimes are commonly located in their traditions: the crops, foodways, and diversity-based agricultural systems of their ancestors even as a multitude of factors have conspired to their decline across the Eastern Himalayan Region. Yet, paradoxically, with climate change these crops, agriculture and knowledge systems seem to hold the future, especially for smallholder farmers.

Two new plant records, Alangium kurzii (Cornaceae) and Ficus racemosa (Moraceae), in Bhutan and corresponding distributions

Bhutan represents a biodiversity hotspot in the eastern Himalayan region, known for its unique environment and diverse plant species. This has made Bhutan a popular destination for plant enthusiasts from all over the world. Several new plant discoveries and records have been made in recent years, contributing valuable additions to scientific knowledge and the country’s botanical records. Here, we provide two new additional records of plants for the flora of Bhutan: Alangium kurzii Craib from the Cornaceae family and Ficus racemosa L. from the Moraceae family. With these additions, Bhutan now has three Alangium species and 25 Ficus species including the current records. We also present their uses and distributions in the country.

Extent of adoption and its limiting factors affecting improved vegetable cultivation practices by small farmers in the eastern Himalayan region

Extent of adoption and its limiting factors affecting improved vegetable cultivation practices by small farmers in the eastern Himalayan region

An integrated approach for managing drought risks in the eastern himalayan region of India

Climate Risk Assessment (CRA), when applied through an integrated approach, enables the evaluation of hazard, exposure, and vulnerability within a unified framework, recognizing the interconnections between climate risks and both natural and social systems. This study uses Sikkim, a small state in the Indian Eastern Himalayan Region, as a case study to conduct a climate risk assessment of agricultural drought at the sub-national level. The objective was to identify the district most at risk from agricultural drought and determine the primary contributors to drought risk to support the development of effective adaptation strategies. The findings reveal that while all districts in Sikkim are moderately drought-prone, the main factor contributing to drought risk is the high sensitivity of the agricultural sector to drought and the limited adaptive capacity of farmers. Many marginal and small farmers rely on rainfed irrigation and have poor adaptive capacity, making them highly vulnerable to even moderate drought conditions. The study highlights that while mitigating drought hazards is important, it is a complex and long-term endeavor. Therefore, strengthening farmers' resilience by reducing their sensitivity and enhancing their adaptive capacity is essential for effectively reducing drought risks in Sikkim.

Multivariate Data Analysis Assisted Mining of Nutri-rich Genotypes from North Eastern Himalayan Germplasm Collection of Perilla (Perilla frutescens L.).

Understanding the nutritional diversity in Perilla (Perilla frutescens L.) is essential for selecting and developing superior varieties with enhanced nutritional profiles in the North Eastern Himalayan (NEH) region of India. In this study, we assessed the nutritional composition of 45 diverse perilla germplasm collected from five NEH states using standard protocols and advanced analytical techniques. Significant variability was observed in moisture (0.39-11.67%), ash (2.59-7.13%), oil (28.65-74.20%), protein (11.05-23.15%), total soluble sugars (0.34-3.67%), starch (0.01-0.55%), phenols (0.03-0.87%), ferric reducing antioxidant power (0.45-1.36%), palmitic acid (7.06-10.75%), stearic acid (1.96-2.29%), oleic acid (8.11-13.31%), linoleic acid (15.18-22.74%), and linolenic acid (55.47-67.07%). Similarly, significant variability in mineral content (ppm) was also observed for aluminium, calcium, cobalt, chromium, copper, iron, potassium, magnesium, manganese, molybdenum, sodium, nickel, phosphorus, and zinc. Multivariate analyses, including hierarchical clustering analysis (HCA) and principal component analysis (PCA), revealed the enriched nutritional diversity within the germplasm. Correlation analysis indicated significant positive and negative relationships between nutritional parameters, indicating potential biochemical and metabolic interactions present in the perilla seeds. TOPSIS-based ranking identified promising genotypes for functional foods, pharmaceuticals, and nutritional applications. This study provides a first in-depth report of the nutritional composition and diversity of perilla germplasm in the NEH region, thus aiding in the identification of superior varieties for food and nutritional diversification and security.

Anthropogenic sources and liquid water drive secondary organic aerosol formation over the eastern Himalaya

Atmospheric aerosols have a serious impact on altering the radiation balance of the vulnerable Himalayan atmosphere. Organic aerosol (OA), one of the least resolved aerosol fractions in the Himalayas, constrain our competence to assess their climate impacts on the region. Here we investigate water-soluble OA molecules in PM10 samples collected from March to May 2019 at Lachung (27.4°N and 88.4°E), a high-altitude location (2700 m a.s.l.) in the eastern Himalaya, to elucidate their origin and formation process. The dominance of oxalic acid (C2) reveals that water-soluble OA in the eastern Himalaya are atmospherically processed. Backward air mass trajectories and mass concentration ratios of organic tracers as well as relationships with inorganic species (K+, SO42−, NH4+) suggest an anthropogenic origin of water-soluble OA with significant atmospheric processing during long-range transport to the eastern Himalayan region. We used the thermodynamic prediction of aerosol liquid water (ALW) to examine the formation mechanism of secondary OA (SOA) such as oxalic acid. Correlations of ALW with SO42− and water-soluble organic matter show that ALW is sensitive to both anthropogenic sulfate and water-soluble organic compounds in Himalayan aerosols. A strong positive relationship of C2 acid with predicted ALW provides evidence of extensive SOA formation from precursors via aqueous phase photochemical processes. This inference is supported by positive correlations of C2 acid relative abundance with diagnostic mass concentration ratios of C2 acid to precursor molecules. Our findings underscore the importance of anthropogenic sources and ALW in SOA formation through aqueous phase processes in the eastern Himalaya.

Spatial distribution law of landslides and landslide susceptibility assessment in the eastern Himalayan syntaxis region

The eastern Himalayan syntaxis region is located on the eastern edge of the Qinghai–Tibet Plateau, and it is one of the regions with the most intense geological tectonic activity in the world. There have been many large-scale landslides in the eastern Himalayan syntaxis region and the distribution of these landslides is of great significance for the inversion of regional tectonic activity strength, major engineering construction and urban–rural planning. However, no researchers have systematically studied all these landslides of this area. In this study, based on Google Earth satellite imagery, landslides were identified using artificial visual interpretation. Then, we analysed 11 landslide-influencing factors were selected, comprising topographic factors (elevation, slope, aspect, curvature), geological environmental factors (strata, distance to faults, distance to water, distance to roads, normalized difference vegetation index), inducing factors (peak ground acceleration, rainfall), the relationships between the distribution law of landslides and influencing factors. Finally, we used the logistic regression model, the weight of evidence model and the weight of evidence–logistic regression coupled model to evaluate the landslide susceptibility.

Evaluation and application of satellite rainfall datasets using Google Earth Engine platform in Arunachal Pradesh, Eastern Himalayan Region of India

Evaluation and application of satellite rainfall datasets using Google Earth Engine platform in Arunachal Pradesh, Eastern Himalayan Region of India

The Effects of Climate Change on the Distribution Pattern of Species Richness of Endemic Wetland Plants in the Qinghai-Tibet Plateau.

Wetland ecosystems in the Qinghai-Tibet Plateau (QTP), the region with the richest biodiversity and the most important ecological barrier function at high altitudes, are highly sensitive to global change, and wetland plants, which are important indicators of wetland ecosystem structure and function, are also threatened by wetland degradation. Therefore, a comprehensive study of changes in the geographical distribution pattern of plant diversity, as well as species loss and turnover of wetlands in the QTP in the context of global climate change is of great importance for the conservation and restoration of wetland ecosystems in the QTP. In this study, species turnover and loss of 395 endemic wetland plants of the QTP were predicted based on the SSP2-4.5 climate change scenarios. The results showed that there were interspecific differences in the effects of climate change on the potential distribution of species, and that most endemic wetland plants would experience range contraction. Under the climate change scenarios, the loss of suitable wetland plant habitat is expected to occur mainly in parts of the southern, north-central and north-western parts of the plateau, while the gain is mainly concentrated in parts of the western Sichuan Plateau, the Qilian Mountains, the Three Rivers Source Region and the northern Tibetan Plateau. Overlaying the analysis of priority protected areas with the established protected areas in the QTP has resulted in the following conservation gaps: the eastern Himalayan region, midstream of the Yarlung Zangbo River, the transition zone between the northern Tibetan Plateau and the Hengduan Mountains, Minshan-Qionglai mountain, Anyemaqen Mountains (southeast) to Bayankala (southeast) mountains, the southern foothills of the Qilian Mountains and the northern Tibetan Plateau region. In the future, the study of wetland plant diversity in the QTP and the optimisation of protected areas should focus on the conservation gaps. This study is of great importance for the study and conservation of wetland plant diversity in the QTP, and also provides a scientific basis for predicting the response of wetland plants to climate change in the QTP.

ETHNIC STUDY OF ADUWA KO JAANR, A LESSER-KNOWN FERMENTED GINGER MILD ALCOHOLIC BEVERAGE OF EASTERN HIMALAYAS

Consumption of fermented foods and beverages is a part of the dietary cultures of the Himalayan community and is prevalent amongst various ethnic groups in this region. Native of the Himalayan range ferment food and beverages using 'ethno-microbiological' knowledge acquired and practiced since ages, which lacks documentation. This knowledge is transmitted through practice and verbally to new generations. Women folk are engaged in this traditional fermentation culture with cultural and ethnic significance. In addition to its distinctive tastes, fermented foods and beverages provide health advantages to indigenous people. It becomes essential to highlight their scientific value due to their health benefits and ethnic relevance. The diverse nature of fermented foods and beverages, the fermentation process, and the traditional knowledge behind fermentation are a heritage of the eastern Himalayas. Traditional fermentation, in which raw materials are organic and natural starter culture is used, is part of the people's socio-economic lifestyle. Their preservation highlights organic and conventional practices as an excellent alternative to a healthy lifestyle. The present study documents a lesser-known mild-alcoholic fermented beverage, 'Aduwa ko Jaanr,' from the Eastern Himalayan region. A steady decline in traditional fermentation practices has recently been observed due to changes in food habits and culinary practices.

Metabolic insights into high-altitude adaptation of Himalayan ‘Horsetails’ [Equisetum diffusum D. Don] with special reference to the fatty acid dynamicity

Equisetum diffusum D. Don, a perennial herb of Equisetaceae, is considered as native to the Himalayan mountain range. This plant has prolific distribution along different altitudes of Eastern Himalayan region. Generally, mountain flora, like E. diffusum, experience a combination of contrasting abiotic stresses and may represent a unique natural model for investigating physiological resilience to address climate change. So, the present study has been framed to compare the metabolic responses in E. diffusum growing at different elevation belts with an aim to understand the underlying basis for their high-altitude adjustment ability. The biochemical profiles of this plant, collected from three different altitudinal transects of Darjeeling hills, were compared. The fatty acid profiles of neutral lipids, membrane phospholipids and glycolipids demonstrated palmitic acid and oleic acid as the predominant fatty acids. The major outcome was the substantial increase of polyunsaturated fatty acids (PUFAs) and unsaturation index in glycolipids of the samples collected from higher altitudes. Major proportion of changes in PUFA content was contributed by arachidonic acid. Therefore, the plants homeostatically control the membrane fluidity by enhancing the unsaturation of glycolipid fatty acids. Moreover, significantly higher antioxidant enzyme activities in higher altitude samples reflect the involvement of these enzymes in coping with the oxidative stress condition and membrane damage. The stress responsive effects may be further augmented by enhanced content of secondary metabolites. Therefore, a combination of biochemical responses along with the changes in membrane plasticity can be predicted as the metabolic adjustment strategies for high-altitude adaptation of E. diffusum.