Indian Himalayan Region Research Articles

Anomalous rainfall trends in the North-Western Indian Himalayan Region (NW-IHR)

Anomalous rainfall trends in the North-Western Indian Himalayan Region (NW-IHR)

An improved rapid visual screening method for seismic vulnerability assessment of reinforced concrete buildings in Indian Himalayan region

An improved rapid visual screening method for seismic vulnerability assessment of reinforced concrete buildings in Indian Himalayan region

Two new species and two new records of the genus Tenuibaetis Kang & Yang, 1994 (Ephemeroptera: Baetidae) from Indian Himalaya

As part of ongoing exploration of the mayflies of streams and rivers of Indian Himalayan regions, we describe two new species of the genus Tenuibaetis based on recently collected materials from Western Himalaya viz., Tenuibaetis himani Kubendran, Vasanth & Subramanian sp. nov. and Tenuibaetis kangi Kubendran, Vasanth & Subramanian sp. nov. Additionally, two new records from Eastern Himalaya viz., T. arduus (Kang & Yang, 1994) and T. inornatus (Kang & Yang, 1994) are presented. The biological notes of the stream/rivers are appended. A key to the known Indian species of the genus Tenuibaetis and a distribution maps are provided.

Multi-species occupancy modeling suggests interspecific interaction among the three ungulate species

Species with sympatric distribution influence ecosystem dynamics and are impacted by the presence of other co-existing species. Assessing the coexistence and the role of interspecific interactions with the landscape variables is necessary to know the species co-occurrence in space. In the Indian Himalayan region, such studies are completely lacking due to limited efforts being made, mainly because of complex terrains and inaccessible landscape features. We used camera trapping and sign survey in a multi-species occupancy framework to understand the influence of environmental variables on occupancy and detection probability of species-specific and pair-wise interaction of the three ungulates in Uttarkashi. Our results concluded that individual species' occupancy probabilities were related both to the environmental variables and the presence or absence of other interacting species. Our top model showed evidence of interspecific interaction among species pairs, and the occupancy probability of species one varied in the presence or absence of another species. The overall activity patterns were similar among all the three species and were found active throughout the day. The activity overlap between sambar—barking deer (Dhat1 value = 0.85) was considerably higher than barking deer—goral (Dhat1 value = 0.78). The findings of the present study will be useful for the conservation and management of ungulates in the Indian Himalayan and adjoining regions.

Determinants of phytolith occluded carbon in bamboo stands across forest types in the eastern Indian Himalayas

Phytoliths are known to play a significant role in the global carbon cycle by sequestering atmospheric carbon dioxide as phytolith-occluded carbon (PhytOC) for a long time. Given the resistant nature of phytolith to decomposition, PhytOC can represent up to 82 % of total carbon in some soil and sediments even after 2000 years of litter decomposition. Hence, forests with high PhytOC sequestration rates could play a critical role in increasing terrestrial carbon storage. In this study, we quantified the variation in PhytOC concentrations in bamboo leaves, branches and culms with forest types in the Eastern Indian Himalayas as bamboos are efficient accumulator of phytolith and PhytOC due to their fast growth and high biomass accumulation rates. Using nine different machine learning techniques, we also investigated the determinants of PhytOC production in bamboo stands in the study area in India. The results revealed that the PhytOC concentrations in bamboo stands were in the order of leaf (3.0 g kg−1) > culm (1.0 g kg−1) > branch (0.2 g kg−1) across forest types. The highest PhytOC stock (53.8 kg ha−1) was found in bamboo stands in the subtropical pine forests (1900–3500 m elevation), while the lowest (28.0 kg ha−1) was in the tropical evergreen forests (<900 m elevation). Machine learning techniques established a positive correlation of PhytOC content in leaf and total PhytOC content with soil available phosphorus, elevation, total nitrogen, exchangeable potassium, atmospheric humidity, SOC content, CEC and pH. Numerical evaluation criteria and graphic methods identified artificial neural network (ANN) and support vector regression as the superior techniques with a root mean square error value of 0.52 kg ha−1 and 0.59 kg ha−1 respectively. The results of these two models were found to be better among all the nine machine learning algorithms used. The high PhytOC storage in the bamboo stands in the Indian Himalayan region suggests that forest management could secure a stable carbon sink on a millennial scale.

Soil Quality Assessment in a Landslide Chronosequence of Indian Himalayan Region

Landslides cause ecosystem degradation; they can significantly alter and deteriorate the soil quality. The analysis of deterioration in soil quality is critical as it provides baseline evidence for subsequent revegetation and management of forest. The effects of landslides on the natural environment (losses of soil resources), on the other hand, have received little consideration. Such information about the status of loss of soil resources in the landslide–disturbed areas of the Garhwal Himalayas is lacking. Therefore, the objective of the study is to assess the changes in soil quality restoration after the occurrence of landslides. A chronosequence of four landslide disturbed sites, L6–6–year–old, L16–16–year–old, L21–21–year–old and L26–26–year–old, was selected in the Alaknanda watershed of Uttarakhand. Seventy–six samples have been collected from the four landslide sites and a reference site (undisturbed site). The sites L6 and L16 are considered as recent landslide sites, whereas L21 and L26 are considered as old landslide sites. Entisols (Lithic–Udorthents) predominate in all the studied sites. The results have demonstrated that with the increasing age of landslides, the soil quality progressively improves with time, and the concentration of soil nutrients, viz., available phosphorus (AP), available potassium (AK) and mineralisable nitrogen (MN), in old landslide sites reaches to about 84%, 87% and 97%, respectively, of the reference site. Soil Quality Index (SQI) scores have been calculated using the Integrated Quality Index (IQI) equation. The disturbed sites L6, L16, L21 and L26 and the reference site have SQI scores of 0.136, 0.279, 0.447, 0.604 and 0.882, respectively. However, significant differences exist between the SQI of all the studied sites (p &lt; 0.05, Tukey’s HSD), which implies that the concentration of soil organic carbon (SOC) and available nutrients was reduced due to the occurrence of landslides. The results also suggested that SOC, AP and clay fraction can be considered important evaluation indicators to assess soil quality and development.

Investigation and performance analysis of active solar still in colder Indian Himalayan region

Traditional basin-type solar stills are not as popular due to their lower productivity, but a number of ways have been developed globally to increase their production capacity. This article demonstrates an overview of the recent studies aimed at improving the productivities and the effective functioning of conventional solar stills. In order to have a better insight of the thermal performance, the studies focused on evaluating the thermodynamic efficiencies of solar stills have also been reviewed and found that active solar distillation has strong potential in enhancing the performance characteristics of basin type systems. It was observed that, enormous efforts made by various researchers in understanding and improving the thermal characteristics of solar stills for better output have been majorly examined in hotter and arid regions, and solar stills for colder regions need an attention too. In this context, the proposed work attempts to carry out an experimental study to assess the effect of lower ambient conditions on performance characteristics of an active solar in an Indian cold hilly location. The observations from the study showed that the effective daily output of the active solar still was as high as twice the daily distillate output produced by the conventional passive still. The thermodynamic efficiencies of the active system were also evaluated. Further, during different sunny days, the variation in average exergy and energy efficiencies of the active system ranged from 14.86 to 16.18% and 1.95–2.41%, respectively. Due to the prevailing storing effect, the nocturnal productivity of solar still was increased at deeper water levels. The study also helped to conclude that the exergy destruction in solar still is highly influenced by low ambient temperatures and in future, effective design optimization studies can be carried out to gain the benefits through minimized energy/exergy losses.

Diversity, distribution and drivers of alien flora in the Indian Himalayan region

The Himalaya – a global biodiversity hotspot – harbors diverse flora and fauna, but increasingly beset with multiple threats, including biological invasion by alien species. Here, we aimed to investigate the diversity, distribution, and drivers of alien flora in the Indian Himalayan Region (IHR), a region spread across 12 states/union territories in India. We developed a comprehensive checklist on alien flora of IHR based on review of 141 studies published during the years 1934 to 2022, and further disentangled the key environmental (average annual rainfall, total area, protected area, forest area, total plant richness) and socioeconomic (total population, traffic length) drivers that better explain regional alien and naturalized plant richness. We recorded 771 alien plant species, including 375 cultivated and 396 naturalized species. We found that the species native to Southern America and those with perennial life span and herbaceous growth form were most represented in the IHR. Similarly, the annual herbs native to Southern America had a higher probability to become naturalized in the IHR. Based on the species composition of the total alien and naturalized flora distributed across different parts of the IHR, we found evidence of distance decay of floristic similarity. The total alien plant richness was best explained by the average annual rainfall, while the naturalized plant richness was best predicted by total traffic length. Our results identify the key environmental (i.e., average annual rainfall) and socioeconomic (i.e., total traffic length) drivers that determine the diversity and distribution patterns of alien and naturalized plants in the IHR. Our findings have practical applications in developing a scientifically-informed management and policy framework to mitigate the impacts of plant invasions and to predict the potential future plant invaders in the Himalaya. Overall, the checklist of alien flora of the IHR represents a step forward in filling the knowledge gaps on biological invasions from the Himalaya – a globally data-deficient region. • Diversity, distribution and drivers of alien flora in Indian Himalayan Region studied. • The alien flora comprise of 771 species, including 375 cultivated and 396 naturalized. • Annual herbs from Southern America showed higher naturalization probability. • Total alien plant richness was best explained by the average annual rainfall. • Naturalized plant richness was best predicted by total traffic length.

Performance Evaluation of Hillside Buildings under Blast and Blast-Induced Ground Motion

The present study evaluates the performance of two hillside building configurations, i.e., split foundation (SF) and step-back (SB), commonly observed in the seismically active Indian Himalayan region, under blast and blast-induced ground motion using an uncoupled approach. Force-controlled nonlinear static analyses are carried out to probabilistically assess the critical blast location for bare- and infill-framed buildings. It is observed that the blast on the downhill side is critical for the hillside buildings having a story ratio of 0.5; whereas, the blast on the uphill side is more damaging for the buildings with a story ratio of 1 and 2. The blast fragility curves, developed herein, show that the presence of infills significantly affects the blast response of RC hillside buildings and the location of the peak response. Further, critical scaled distances corresponding to various damage states for the hillside buildings are found to be more than that for the regular buildings. Furthermore, the response of hillside buildings was investigated under blast-induced ground motions to evaluate the key engineering demand parameters pertinent to structural and non-structural damages.

Climate, Agriculture, and Migration: Exploring the Vulnerability and Outmigration Nexus in the Indian Himalayan Region

Climate change is increasingly affecting mountain communities around the world with major implications for human livelihoods and wellbeing. With its predominantly rural population and limited resources, the Indian Himalayan Region is particularly vulnerable. While previous research has highlighted the destructive potential of climate change, we focused on the socioeconomic and ecological drivers of climate vulnerabilities and their links to migration and depopulation trends, which can be observed in the area. A mixed-methods case study approach was used to explore these relationships in the state of Uttarakhand in the western Indian Himalayan Region. Combining evidence from an aggregate vulnerability index, migration data, and insights from qualitative interviews, we found a close link between local climate vulnerabilities and migration. Considering different drivers, we show that limited adaptive capacities are the decisive factor shaping vulnerabilities and migration in the region, in particular, the high dependency on rainfed agriculture together with ecological, infrastructural, human, and financial constraints. With higher vulnerability, migrants tend to become younger, engage more in short-term migration, and increasingly employ migration in response to structural vulnerabilities and livelihood risks. The outmigration of young males has major implications for their origin communities, as the population left behind becomes older and more feminized.

Detection of body shape variations in vulnerable snow trout, Schizothorax richardsonii (Gray, 1832) from rivers of the Indian Himalayan Region

Species population structure and composition are components of essential biodiversity variables (EBVs) to measure change in global freshwater diversity. Multiple stressors affect the population structure of coldwater fishes in the Indian Himalayan Region (IHR). In this study, 463 individuals of snow trout, Schizothorax richardsonii were collected from 14 locations on seven rivers of IHR (Satlej, Chenab, Beas and Ravi rivers of Indus basin, and Bhagirathi, Alaknanda and Kosi rivers of Ganges basin) to assess the inter and intra-basin population-level shape variation through landmark-based “geometric morphometrics”. Procrustes ANOVA on the superimposed shape coordinates revealed significant relationship (F = 4.51, p < 0.05) among groups. Principal component analysis (PCA) accounted for 42.37% of the total variance (22.69% for PC1, 19.68% for PC2), indicating overlapping among populations. Canonical variate analysis (CVA) accounted for 66.71% of the total variance (37.07% for CV1 and 29.64% for CV2), indicating non-overlapping between basins and within Ganges basin, and overlapping within Indus basin. Pair-wise distances extracted from PERMANOVA also found to be non-significant (p > 0.05) between Satlej, Chenab, Beas and Ravi rivers, indicating overlapping of samples within the Indus basin, and significant (p < 0.05) between rivers of Indus basin, Alaknanda, Bhagirathi and Kosi river systems, indicating non-overlapping of specimens between these rivers. Overall, results of multivariate analysis indicated four heterogeneous populations of snow trout in the selected rivers based on their shape: 1. Indus basin comprising of Satlej, Chenab, Beas and Ravi rivers, 2. Bhagirathi River, 3. Alaknanda River and 4. Kosi River. This study will be useful in stock identification, and provide a key to climate change and demographic research for developing sustainable management strategies to conserve this threatened species.

Mitochondrial cytochrome b indicates the presence of two paraphyletic diverged lineages of the blue sheep Pseudois nayaur across the Indian Himalaya: conservation implications.

Populations exhibit signatures of local adaptive traits due to spatial and environmental heterogeneity resulting in microevolution. The blue sheep is widely distributed across the high Asian mountains and are the snow leopard's principal prey species. These mountains differ in their evolutionary history due to differential glaciation and deglaciation periods, orography, and rainfall patterns, and such factors causes diversification in species. Therefore, we assess the phylogeographic status of blue sheep using the mitochondrial cytochrome b gene (220bp) across the Indian Himalayan region (IHR) and its relationship with other populations. Of the observed five haplotypes, two and three were from the western Himalayas (WH) and eastern Himalayas (EH) respectively. One of the haplotypes from WH was shared with the population of Pamir plateau, suggesting historical maternal connectivity between these areas. The phylogenetic analyses split the blue sheep into two paraphyletic clades, and western and eastern populations of IHR were within the Pamir and Tibetan plateau clades, respectively. We observed a relatively higher mean sequence divergence in the EH population than in the WH. We propose five 'Evolutionary Significant Units' across the blue sheep distribution range based on observed variation in the species' ecological requirements, orography, climatic conditions, and maternal lineages, viz.; Western Himalaya-Pamir plateau (WHPP); Eastern Himalaya-Tibetan plateau (EHTP); Qilian mountains; Helan mountains and Hengduan mountains population. Despite the small sample size, population divergence was observed across the IHR, therefore, we suggest a transboundary, collaborative study on comparative morphology, anatomy, ecology, behaviour, and population genetics using harmonized different genetic markers for identifying the overall taxonomic status of the blue sheep across its range for planning effective conservation strategies.

From poops to planning: A broad non-invasive genetic survey of large mammals from the Indian Himalayan Region

Large forested landscapes often harbour significant amount of biodiversity and support mankind by rendering various livelihood opportunities and ecosystem services. Their periodic assessment for health and ecological integrity is essential for timely mitigation of any negative impact of human use due to over harvesting of natural resources or unsustainable developmental activities. In this context, monitoring of mega fauna may provide reasonable insights about the connectivity and quality of forested habitats. In the present study, we conducted a largest non-invasive genetic survey to explore mammalian diversity and genetically characterized 13 mammals from the Indian Himalayan Region (IHR). We analyzed 4806 faecal samples using 103 autosomal microsatellites and with three mitochondrial genes, we identified 37 species of mammal. We observed low to moderate level of genetic variability and most species exhibited stable demographic history. We estimated an unbiased population genetic account (PGAunbias) for 13 species that may be monitored after a fixed time interval to understand species performance in response to the landscape changes. The present study has been evident to show pragmatic permeability with the representative sampling in the IHR in order to facilitate the development of species-oriented conservation and management programmes.

Can farm mechanization enhance small farmers’ income? Lessons from Lower Shivalik Hills of the Indian Himalayan Region

Can farm mechanization enhance small farmers’ income? Lessons from Lower Shivalik Hills of the Indian Himalayan Region

Response of Freshwater Macroinvertebrate Communities to Various Anthropogenic Stressors in Lolab Streams- A Lotic System of the Indian Himalayan Region

This study evaluated the response of freshwater macroinvertebrate communities to several human-induced stresses in a characteristic temperate region with amassed population and population-related pollution. With the help of macroinvertebrate species associated with physicochemical parameters and contaminants in dissolved fractions, we aimed to establish an efficient bioassay approach for evaluating the water quality in the lotic ecosystems of Lolab streams. From the mouth of streams, a rapid scanning method was utilized and physicochemical analysis was done by utilizing APHA,2005. The standard method was used for macroinvertebrate collection and various indices were calculated using software like PAST, and Pearson correlation, CCA ,PCA were also calculated using PAST software. We discovered considerable differences in physicochemical parameters along a longitudinal gradient, with average mean values like air temperature (17.69℃), water temperature (13.2℃), pH (8.09) dissolved oxygen (7.38mg/L), free CO2(131.96mg/L), total hardness (159.46 mg/L), Ammonical nitrogen(175.6 µg/L), Total phosphorus(62.85 µg/L) with the highest values recorded in populated and largely agriculturally developed areas in the catchment. A total number of 27 taxa were recorded belonging to 8 families. Trichoptera accounted for 36% of the total abundance studied, while Diptera accounted for 26%. Ephemeroptera accounts for 16% of all species. The macroinvertebrates displayed preferences for particular abiotic parameters, highlighting their potential utility in future research as dependable ecological indicators, molded by a synergistic mix of anthropogenic influences and land use intensity.

Alien flora of Uttarakhand, western Himalaya: a comprehensive review

Alien plant species have captured attention of the scientific community, ecologists, and environmentalists throughout the world. Like other regions, the Himalayan region is also grappling with the disrupting impacts of plant invasions. Based on an extensive review of studies conducted on alien plant species in the Indian Himalayan region, we report 728 alien plant species belonging to 450 genera under 108 families in the state of Uttarakhand, which represents 15% of the state’s flora. Fabaceae (89 species under 49 genera) followed by Asteraceae (63 species under 43 genera) and Poaceae (50 species under 35 genera) were the most diverse families amid alien species. Eucalyptus (15 species) followed by Ipomoea and Euphorbia (12 species each) and Pinus (11 species) were the most diverse genera. The maximum numbers of aliens (mostly herbs) in the state were introduced from America, followed by Europe. Owing to relatively high number of alien plant species in Uttarakhand, it is submitted that serious ecological and socio-economic consequences are likely to escalate in the future.

Land restoration in the Himalayan Region: Steps towards biosphere integrity

The recent declaration of 'UN Decade on Ecosystem Restoration' recognizes the need to massively accelerate global restoration of degraded and human altered ecosystems to provide multiple environmental benefits, including mitigation of climate change impacts. Commitment to various global obligations like UNCCD and SDG-15 to achieve land degradation neutrality, sustainable land management and enhanced resilience of vulnerable populations and ecosystems requires concerted efforts at national, regional and local levels. In view of strengthening the efforts towards achieving the land neutrality the present study attempts to provide the status of 8 restoration sites located across sub-tropical to temperate region of Pithoragarh and Champawat districts in west Himalaya, which now contributes to ex-situ and in-situ biodiversity conservation, carbon sequestration, soil conservation and sustenance of local inhabitants, etc. The results of survival percentage revealed that most of the species planted at Jajut site showed better survival with an average of 69% as compared to Digtoli (59%) and Naikina (62%) after 3 years of plantation. Quercus leucotrichophora showed maximum survival percentage (72%) at all the sites followed by Q. glauca (63%), whereas minimum survival (49%) was observed in Zanthoxylum armatum at Naikina site. At Champawat site, height of all planted species increased significantly (p < 0.05) in 2021 as compared to 2011. The carbon stock value increased from 40.02 Mg ha−1 in 2011–65.53 Mg ha−1 in 2021. Increase in carbon stock and carbon sequestration in restoration areas over past 10 years shows higher potential of native species for carbon storage and prospective role of restoration sites in long term carbon sink. The study also attempts to bring the results of restoration activities, implications and benefits to draw some prescription to support the policy and practice interface. The mentioned case studies would be helpful to understand the good practices of restoration for ecological & socio-economic connect, and furtherance of efforts towards land restoration and biosphere integrity across Indian Himalayan Region (IHR).

Perception and knowledge of community people on invasive Alien Plant species in Chandak-Aunla Ghat and Hat-Kalika watersheds of Kailash sacred landscape - India: A case study

Invasive alien plant species (IAPS) are considered the second most important agent after habitat destruction for species endangerment and extinction. Though dozens of alien invasive plant species (IAPS) occur in the Indian Himalayan region, information on distribution and perceived impact is lacking in the western Himalaya. In the present study, 701 randomly selected households in 45 villages were surveyed through questionnaire surveys in Chandak-Aunla Ghat (329) and Hat-Kalika (372) watersheds in Kailash Sacred Landscape (KSL-India) to know their view on the issues associated with the IAPS and attitudes towards their management. The knowledge, perception, use and management strategies of different IAPS were analyzed. Only 39% of females and 27% of males had knowledge of IAPS. The highlights of the study are: i) Ageratina adenophora had the highest Relative Frequency of Citation value among 14 major IAPS in the study area, ii) informants of Hat-Kalika showed a low richness of knowledge and sharing with their family members as compared to Chandak-Aunla Ghat, iii) respondents perceived IAPS negatively and rated biological invasion and habitat loss as major environmental problem, iv) the major management strategies identified were restoration, eradication, community education and information, and v) perception and level of knowledge sharing on invasive species among age classes and gender have implications for stakeholders and policymakers in management of IAPS.

Bacterial diversity in 110 thermal hot springs of Indian Himalayan Region (IHR).

Thermal hot springs are present throughout the world and constitute a unique habitat for microbial diversity. The current investigation is conducted to study the bacterial diversity of thermophilic microorganisms in thermal hot springs of the Indian Himalayan Region (IHR). As of today, 110 geothermal hot springs have been explored for microbial diversity. In this study, we observed that the growth of thermophilic bacteria isolated from thermal hot springs of IHR ranges between 40 and 100°C, and pH of 3.5-8 have been reported in the literature. The major bacterial species reported from the thermal hot springs of IHR are Bacillus spp., Geobacillus spp., Paenibacillus spp., Pseudomonas spp., Anoxybacillus, Paenibacillus, Brevibacillus, Aneurinibacillus, Thermus aquaticus, Aquimonas, Flavobacterium, etc. Furthermore, bacterial isolates from thermal hot springs of IHR have been reported to produce various enzymes and metabolites such as amylase, β-galactosidase, cellulase, nitrate reductase, acetoin, caffeine degradation enzymes, lipase, urease, and laccase. Metagenomic study and the entire genomic shotgun project have established the impact of physicochemical parameters (temperature and pH) on developing the microbiome. We have discussed the discoveries of microbiological data on the hot springs of IHR until the end of year 2021. As a whole, the microbiome adapts themselves as successful inhabitants to extreme environmental conditions and also serves as a diverse resource for potential applications in health, food, and environment.

Geography vs. past climate: the drivers of population genetic structure of the Himalayan langur

BackgroundContemporary species distribution, genetic diversity and evolutionary history in many taxa are shaped by both historical and current climate as well as topography. The Himalayas show a huge variation in topography and climatic conditions across its entire range, and have experienced major climatic fluctuations in the past. However, very little is known regarding how this heterogenous landscape has moulded the distribution of Himalayan fauna. A recent study examined the effect of these historical events on the genetic diversity of the Himalayan langurs in Nepal Himalaya. However, this study did not include the samples from the Indian Himalayan region (IHR). Therefore, here we revisit the questions addressed in the previous study with a near complete sampling from the IHR, along with the samples from the Nepal Himalaya. We used the mitochondrial Cytochrome-b (Cyt-b, 746 bp) region combined with multiple phylogeographic analyses and palaeodistribution modelling.ResultsOur dataset contained 144 sequences from the IHR as well as the Nepal Himalaya. Phylogenetic analysis showed a low divergent western clade nested within high divergent group of eastern lineages and in the network analysis we identified 22 haplotypes over the entire distribution range of the Himalayan langurs. Samples from the Nepal Himalaya showed geographically structured haplotypes corresponding to different river barriers, whereas samples from IHR showed star-like topology with no structure. Our statistical phylogeography analysis using diyABC supported the model of east to west colonisation of these langurs with founder event during colonisation. Analysis of demographic history showed that the effective population size of the Himalayan langurs decreased at the onset of last glacial maximum (LGM) and started increasing post LGM. The palaeodistribution modelling showed that the extent of suitable habitat shifted from low elevation central Nepal, and adjoining parts of north India, during LGM to the western Himalaya at present.ConclusionThe current genetic diversity and distribution of Himalayan langurs in the Nepal Himalaya has been shaped by river barriers, whereas the rivers in the IHR had relatively less time to act as a strong genetic barrier after the recent colonisation event. Further, the post LGM expansion could have had confounding effect on Himalayan langur population structure in both Nepal Himalaya and IHR.