Search Results (7)

The species richness, distribution and community structure in cold desert regions across the world are poorly understood because of their inaccessibility and remoteness. Similarly, the structure and composition of forest resources, including other management units (i.e., agroforestry and forestry systems), have hardly been studied in the cold desert of the Lahaul valley. However, such information is a prerequisite to understanding the trends and changes in the vegetation distribution under global climate change scenarios, especially considering the sensitivity of plant species in high-altitude areas of the Himalayan region. High anthropogenic activity has exerted tremendous pressure on available forest resources, including other management units in the cold desert of the Lahaul valley. Standard ecological methods were used to obtain an ecological (i.e., status, structure, composition and vegetation patterns) understanding of the region for biodiversity conservation and environmental sustainability. The present study was aimed at understanding the trend, structure and composition of plant species in the cold desert region of the western Himalaya. A total of 64 species (27 trees and 37 shrubs) of vascular plants were recorded in the present study. Tree diversity demonstrated greater variation along the gradients and slope aspects. Salix fragilis trees, with a 102 tree ha⁻¹ density and a few trees of Populus nigra, were found to be sparsely distributed under the agroforestry system on the south-facing slopes in Khoksar. In Jahlma, Salix fragilis grew in an agroforestry system with a density of 365 tree ha⁻¹. However, in Hinsa, Juniperus polycarpos was a dominant tree species in the agroforestry system, with a density of 378 tree ha⁻¹. On the north-facing slopes in Kuthar, a higher number of trees and bushes were present due to natural regeneration maintained by farmers along the edges of terraced agricultural fields. The south-facing slopes showed a relatively lower species richness and diversity as compared to north-facing slopes at similar locations due to relatively less favourable growth conditions under sun-exposed, extremely xeric soil conditions. The highest level of species turnover was found between the altitudes of 2400 m and 3000 m. Betula utilis showed the highest adaptability at higher altitudes (>3500 m). The vegetation analysis results and information generated in the present study are useful for gaining an ecological understanding of the cold desert ecosystem in the Lahaul valley. Sustainable forest resource management, including other management units (e.g., agroforestry and forestry systems), is crucial for improving the vegetation pattern, structure and function of the cold desert ecosystem, thereby contributing to climate change mitigation, adaptation, biodiversity and ecosystem service conservation. Full article

Insufficient research has been conducted on musk deer species across their distribution range, primarily because of their elusive behaviour and the fact they occupy remote high-altitude habitats in the Himalayas above 2500 m. The available distribution records, primarily derived from ecological studies with limited photographic and indirect evidence, fail to provide comprehensive information on the species distribution. Consequently, uncertainties arise when attempting to determine the presence of specific taxonomic units of musk deer in the Western Himalayas. This lack of knowledge hampers species-oriented conservation efforts, as there need to be more species-specific initiatives focused on monitoring, protecting, and combatting the illegal poaching of musk deer for their valuable musk pods. We used transect surveys (220 trails), camera traps (255 cameras), non-invasive DNA sampling (40 samples), and geospatial modelling (279 occurrence records) to resolve the taxonomic ambiguity, and identify the suitable habitat of musk deer (Moschus spp.) in Uttarkashi District of Uttarakhand and the Lahaul–Pangi landscape of Himachal Pradesh. All the captured images and DNA-based identification results confirmed the presence of only Kashmir musk deer (KDM) (Moschus cupreus) in Uttarakhand and Himachal Pradesh. The results suggest that KMD inhabit a narrow range of suitable habitats (6.9%) of the entire Western Himalayas. Since all evidence indicates that only KMD are present in the Western Himalayas, we suggest that the presence of other species of musk deer (Alpine musk deer and Himalayan musk deer) was wrongly reported. Therefore, future conservation plans and management strategies must focus only on KMD in the Western Himalayas. Full article

The cold desert ecosystem of the north-western Himalaya in India’s is considered to be the most vulnerable region to climate change. In this region, Juniperus macropoda Boisser grows across an altitudinal gradient and is highly sensitive to biotic, physiographic, and climatic factors. Keeping this in view, the present study aimed at ascertaining the response of Juniperus macropoda to changing climatic conditions. To achieve the target of the study, the area (elevation ranges from 3525 to 4150 m asl) was divided into thirteen elevation ranges in the cold desert of Lahaul valley (Himachal Pradesh). The NDVI change detection map from 1994–2017 revealed an increase in the area under the vegetation in the NDVI range of 0–0.15 (240%) and 0.15–0.30 (32%), which indicated the emergence of grasses and new recruits in the area. An increase in the minimum and maximum temperature during monsoon and post-monsoon season correlated positively with the emergence of the recruits in a significant manner. Furthermore, a decline in rainfall during the monsoon period was also recorded which bears a significant positive correlation with the establishment of recruits. However, the increase in the precipitation during winter resulted in a positive effect on the emergence of recruits. The biophysical parameters, like average height, diameter as well as the average age of the dominant trees showed a declining trend with the elevation. However, the age histogram revealed that the majority of the establishment occurred around 1900 and between 1975–2010. The tree ring analysis of J. macropoda revealed that the species is shifting upward at a rate of 3.91 m year⁻¹. Besides this, the area is experiencing the impact of climate change resulting in an increase in the area under vegetation and migration towards the higher elevation, and many species of lichens were also found to invade the bare rock. Full article

Vegetation patterns in the high-altitude Himalayas are influenced by a complex set of biotic and abiotic factors. Anthropogenic disturbances are one of the primary factors influencing the community patterns and diversity, which are largely determined by the level of accessibility in the Himalayas. However, with advancing urbanization and accessibility, limited efforts have been made to quantify the impact of road constructions on the alpine flora of the Himalayas. To overcome this data gap, this study aimed to quantify the impact of anthropogenic disturbance on the alpine vegetation community pattern along the altitudinal gradient, i.e., 3264–4340 m in Kullu district and 3148–4634 m in Lahaul and Spiti district of Himachal Pradesh, Northwestern Himalayas. The impact of anthropogenic disturbance was assessed by comparing species diversity and richness between selected disturbed and undisturbed sites. The diversity profiles of disturbed sites (2.45), near roads and highways (within 25–50 m), were indicative of a higher level of anthropogenic disturbances than undisturbed sites (2.56), which were located at a farther distance (more than 25–50 m) from roads and highways. The variation in diversity profiles of disturbed and undisturbed sites was further favored by lower values of soil moisture, potassium, phosphorous, and nitrogen content in disturbed sites. In addition, the disturbed sites have lower numbers of threatened and endemic species (15 and 29, respectively) than undisturbed sites (30 and 15, respectively). Linear modelling between soil properties and density indicated a perfect linear relationship for both disturbed and undisturbed sites. Canonical correspondence analysis for disturbed sites indicated sand, silt, clay and bulk density as major controlling factors. The present study indicated a significant impact of anthropogenic disturbances on the alpine floristic diversity and soil properties which needs urgent mitigation actions to conserve the unique and threatened alpine floristic diversity of the Himalayas. Full article

In Himalaya, the temperature plays a key role in the process of snow and ice melting and, importantly, the precipitation phase changes (i.e., snow or rain). Consequently, in longer period, the melting and temperature gradient determine the state of the Himalayan glaciers. This necessitates the continuous monitoring of glacier surface melting and a well-established meteorological network in the Himalaya. An attempt has been made to study the seasonal and annual (October 2015 to September 2017) characteristics of air temperature, near-surface temperature lapse rate (tlr), in-situ glacier surface melting, and surface melt simulation by temperature-index (T-index) models for Sutri Dhaka Glacier catchment, Lahaul-Spiti region in Western Himalaya. The tlr of the catchment ranges from 0.3 to 6.5 °C km⁻¹, varying on a monthly and seasonal timescale, which suggests the need for avoiding the use of standard environmental lapse rate (SELR ~6.5 °C km⁻¹). The measured and extrapolated average air temperature (tavg) was found to be positive on glacier surface (4500 to 5500 m asl) between June and September (summer). Ablation data calculated for the balance years 2015–16 and 2016–17 shows an average melting of −4.20 ± 0.84 and −3.09 ± 0.62 m w.e., respectively. In compliance with positive air temperature in summer, ablation was also found to be maximum ~88% of total yearly ice melt. When comparing the observed and modelled ablation data with air temperature, we show that the high summer glacier melt was caused by warmer summer air temperature and minimum spells of summer precipitation in the catchment. Full article

Detailed field mapping of glacial and paraglacial landforms and optical dating from these landforms are used to reconstruct the early Holocene glaciation in the semi-arid region of Miyar basin, Lahaul Himalaya. The study identifies three stages of glaciation, of decreasing magnitude and termed, from oldest to youngest, the Miyar stage (MR-I), Khanjar stage (KH-II), and Menthosa advance (M-III). The oldest glacial stage (MR-I) has been established on the basis of detailed geomorphological evidence such as U-shaped valley morphology, trimlines, and truncated spurs. It is speculated to be older than the global Last Glacial Maximum (gLGM) based on the magnitude of ΔELA (Equilibrium-Line Altitude, 606m). No evidence of glacier expansion recorded from the basin correlates with the period of the gLGM. The second stage (KH-II) is well represented by extensive depositional features such as lateral and terminal moraines, drumlins, and lacustrine fills that have been constrained within 10 ± 1 to 6.6 ± 1.0 ka (Optically stimulated luminescence—OSL—ages), dating it to the early Holocene advance following the Younger Dryas cooling event. Exceptionally young glacial records of expansion are limited within a few hundred meters of the present termini of tributary glaciers and correlates with the 18th-century cooling event. Records of this glacial advance, termed the Menthosa advance, are clearly noticed in some tributary valleys. Full article

Previous studies have shown contrasting glacier elevation and mass changes in the sub-regions of high-mountain Asia. However, the elevation changes on an individual catchment scale can be potentially influenced by supraglacial debris, ponds, lakes and ice cliffs besides regionally driven factors. Here, we present a detailed study on elevation changes of glaciers in the Lahaul-Spiti region derived from TanDEM-X and SRTM C-/X-band DEMs during 2000–2012 and 2012–2013. We observe three elevation change patterns during 2000–2012 among glaciers with different extent of supraglacial debris. The first pattern (<10% debris cover, type-1) indicates maximum thinning rates at the glacier terminus and is observed for glaciers with no or very low debris cover. In the second pattern (>10% debris cover, type-2), maximum thinning is observed up-glacier instead of glacier terminus. This is interpreted as the insulating effect of a thick debris cover. A third pattern, high elevation change rates near the terminus despite high debris cover (>10% debris cover, type-3) is most likely associated with either thinner debris thickness or enhanced melting at supraglacial ponds and lakes as well as ice cliffs. We empirically determined the SRTM C- and X-band penetration differences for debris-covered ice, clean ice/firn/snow and correct for this bias in our elevation change measurements. We show that this penetration bias, if uncorrected, underestimates the region-wide elevation change and geodetic mass balance by 20%. After correction, the region-wide elevation change (1712 km ${}^2$ ) was estimated to be −0.65 ± 0.43 m yr ${}^{-1}$ during 2000–2012. Due to the short observation period, elevation change measurements from TanDEM-X for selected glaciers in the period 2012–2013 are subject to large uncertainties. However, similar spatial patterns were observed during 2000–2012 and 2012–2013, but at different magnitudes. This study reveals that the thinning patterns of debris-covered glaciers cannot be generalized and spatially detailed mapping of glacier elevation change is required to better understand the impact of different surface types under changing climatic conditions. Full article