35 research outputs found

    Biomass and diversity of dry alpine plant communities along altitudinal gradients in the Himalayas

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    A non-linear relationship between phytodiversity and altitude has widely been reported, but the relationship between phytomass and altitude remains little understood.We examined the phytomass and diversity of vascular plants along altitudinal gradients on the dry alpine rangelands of Ladakh, western Himalaya. We used generalized linear and generalized additivemodels to assess the relationship between these vegetation parameters and altitude. We found a humpshaped relationship between aboveground phytomass and altitude.Wesuspect that this is engendered by low rainfall and trampling/excessive grazing at lower slopes by domestic livestock, and low temperature and low nutrient levels at higher slopes.Wealso found a unimodal relationship between plant species-richness and altitude at a singlemountain as well as at the scale of entire Ladakh. The species-richness at the single mountain peaked between 5,000 and 5,200 m, while it peaked between 3,500 and 4,000 m at entire Ladakh level

    Status, trends and future dynamics of biodiversity and ecosystems underpinning nature's contributions to people

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    Biodiversity at the species and ecosystem levels is currently under multiple threats almost everywhere in the Asia-Pacific region, and in many areas the situation is now critical (well established). Of the various ecosystems, lowland evergreen forests, alpine ecosystems, limestone karsts, inland wetlands, and estuarine and coastal habitats are most threatened (well established). Genetic diversity within species, both wild and domestic, is also decreasing in many cases as a result of decreasing ranges (established but incomplete). In several countries there has been a small increase in the forest cover which is mostly attributed to monoculture forestry plantations and enabling policies of the governments. Forest fires associated with rapid loss of forest cover is leading to enormous environmental and socio-economic loss (well established) {3.2.1; 3.2.2; 3.2.3; 3.2.4; 3.2.5; 3.3.1}. There has been a steady decline in the populations of large vertebrates due to poaching and illegal trade in wildlife parts and products in the Asia-Pacific region (well established). As a result, most of these species now survive only in the best-managed protected areas (well established). Widespread loss of large vertebrates has had a measureable impact on several forest functions and services, including seed dispersal (established but incomplete). Australia has the highest rate of mammal extinction (>10 per cent) of any continent globally. Bird extinctions on individual Pacific islands range from 15.4 per cent to 87.5 per cent for those with good fossil records, and these extinctions have resulted in the loss of many ecological functions previously performed by birds (well established). Besides wildlife, there is a massive regional trade in timber, traditional medicines and other products (well established). Without adequate protection, remediation and proper policies, the current decline in biodiversity and nature's contributions to people on land, in freshwaters, and in the sea will threaten the quality of life of future generations in the Asia-Pacific region {3.2.1.1; 3.2.1.2; 3.2.1.4; 3.2.1.7; 3.2.2.1; 3.3.1} With the current rate of human population growth, expansion of urban industrial environments, transformation of agriculture in favour of high yielding varieties, transforming forests to uniform plantations of oil palm, rubber or timber trees, the biodiversity and nature's contributions to people in the Asia-Pacific region are likely to be adversely affected in the coming decades (well established). It is predicted that most of the biodiversity in the next few decades may be confined to protected areas or in places where the local communities have taken the lead in local level conservation in lieu of economic incentives and equitable compensation by the stake-holders. Unprecedented increase in human population of the Asia-Pacific region has stressed the fragile ecosystems to their limits; while arable cropping has been extended to sites which were not entirely suitable for it, resulting in soil degradation and erosion (well established) {3.2.1.1; 3.2.1.2; 3.2.1.5; 3.2.2.2; 3.2.2.4; 3.3; 3.3.1; 3.3.6; 3.4}. Freshwater ecosystems in the Asia-Pacific region support more than 28 per cent of aquatic and semi-aquatic species but nearly 37 per cent of these species are threatened due to anthropogenic and climatic drivers (well established). Cumulative impacts of global warming and damming of rivers in some of the river basins will have significant negative impacts on fish production and environmental flows (well established). Likewise, degradation of wetlands has had severe negative impacts on migratory waterfowl, fish production and local livelihoods (well established). However, there are scientific data gaps on the current status of biodiversity and nature's contributions to people in most of the river basins, inland wetlands and peatlands of the region {3.2.2.1; 3.2.2.2; 3.2.2.3; 3.2.2.4}. Coastal and marine habitats are likewise threatened due to commercial aquaculture, overfishing, and pollution affecting biodiversity and nature's contributions to people (well established). Detailed analyses of fisheries production in the region have shown severe decline in recent decades. It is projected that if unsustainable fishing practices continue, there could be no exploitable stocks of fish by as early as 2048. This could lead to trophic cascades and collapse of marine ecosystems (established but incomplete). Loss of seagrass beds which forms main diet of several threatened species such as dugong is a major concern (well established). There is a need to conduct systematic and region-wide assessment of fisheries stocks and coastal habitat in the region to aid conservation, management and restoration. {3.1.3.1; 3.2.3.3; 3.2.3.6; 3.2.4.6; 3.4}. Mangrove ecosystems in the Asia-Pacific region are most diverse in the world. They support a rich biodiversity and provide a range of provisioning, regulating and supporting services, which are crucial for the livelihood of local communities (well established). Both mangrove and intertidal habitats form a buffer from siltation for offshore coral reefs protection hence affecting productivity of reefs including seagrass. However, up to 75 per cent of the mangroves have been degraded or converted in recent decades (well established). The conversion of mangroves to aquaculture, rice, oil palm, and other land-use changes is leading to the loss of the buffer between sea and land which can reduce the impact of natural disasters such as cyclones and tsunamis. It is projected that rise in sea level due to global warming would pose the biggest threat to mangroves, thereby affecting nature's contributions to people especially in Bangladesh, Philippines, New Zealand, Viet Nam and China (well established) {3.2.3.1; 3.2.3.2; 3.3.4}. There has been a steady increase in the number, abundance and impacts of invasive alien species in the Asia-Pacific region, negatively affecting native biodiversity, ecosystem functioning and socio-cultural environments (well established). The total annual loss caused by invasive alien species has been estimated at US35.5billioninSEAsiaandUS35.5 billion in SE Asia and US9B in Australia. Costs to agriculture due to invasive alien species are likewise immense in the region {3.2.1.1; 3.2.1.2; 3.2.1.4; 3.2.1.5; 3.2.1.6; 3.2.1.7; 3.2.2.1; 3.2.2.2; 3.2.2.3; 3.2.3.6; 3.3.5}. There has been a nearly 30 per cent decline in biocultural diversity in the Asia-Pacific region since the 1970s (well established). Decline of linguistic diversity has been catastrophic in the indigenous Australian and Trans-New Guinean families, as a result of a shifting away from small indigenous languages towards larger, national or regional languages (well established). Linguistic and biological diversity often coincide in the Asia-Pacific region and parallel strategies need to be developed for their conservation. National conservation priorities should take into consideration the bioculturally rich areas that are facing great threats {3.2.5; 3.2.5.2; 3.2.5.4; 3.4}. Protected Area coverage in the Asia-Pacific region has increased substantially since last three decades. Despite this progress, however, at least 75 per cent of Key Biodiversity Areas remain unprotected, suggesting that the region is not on track to conserve areas of particular importance for biodiversity, as called for under Aichi Target 11 (well established). Oceania has the highest overall Protected Area coverage in the region. North-East Asia has the highest proportion of Key Biodiversity Areas covered by Protected Areas, but only 1 per cent of its marine area is protected (well established) {3.2.5.6; 3.2.6; 3.2.6.1}. The Asia-Pacific region has high levels of endemism, and some 25 per cent of the region’s endemic species are facing high extinction risks as per the IUCN Red List. Endemic species in some subregions face an extinction risk as high as 46 per cent of endemic species threatened in South Asia (well established). South-East Asia has the greatest number of threatened species and the fastest increases in extinction risk (Red List Index) in the Asia-Pacific region. North Asian endemic species extinction risk is also higher than the regional average; the high percentage of Data Deficient species (36 per cent) indicates that more research and conservation action are needed for endemic species in this subregion (well established) {3.2.1; 3.2.2; 3.2.6.2; 3.3.4}. Some aspects of biodiversity have recently started to recover in several countries in the Asia-Pacific region (established but incomplete). This recovery has resulted from various changes, including population concentration in cities, increased agricultural production per unit area, increasing conservation awareness among citizens, and the enabling policies of the governments. Future trends of biodiversity in the Asia-Pacific region will largely depend on whether other countries will follow this recovering trajectory by stabilizing land/sea use change, manage their natural resources sustainably, and cooperating with each other in meeting the Aichi Targets and the Sustainable Development Goals {3.2.1.5; 3.2.3.5; 3.3.1; 3.3.3; 3.3.6}. Given that the scientific information on the status and trends of biodiversity and nature's contributions to people is not available uniformly across all ecosystems and habitats in the region, the national governments are encouraged to initiate systematic documentation and monitoring of health of ecosystems and ecosystem flows (established but incomplete). Saving terrestrial fauna especially big mammals and other fauna that require large roaming areas such as Orangutans, proboscis monkey, hornbills, tigers, Sumatran rhinoceros, gaurs and Asian elephants can be done by connecting large tracts of forests with wildlife corridors or through rehabilitation projects; the same goes for coastal and marine, freshwater and other ecosystems in the region {3.2.1.1; 3.2.2.4; 3.3.4; 3.4}

    ROLE OF SOLVENT DEASPHALTING IN PROCESSING PETROLEUM RESIDUES IN REFINERIES

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    Solvent Oeasphalting (SOA) is basically a liquid-liquid extraction process. The conventional applications are in producing extra heavy viscosity grade lube oils called bright stock/cylinder oils and in upgrading bottom of barrel by recovering incremental/ additional feedstocks from vacuum residues for secondary conversion units like Fluid CatalyticCracking/Hydrocracking. Some newer applicationsinclude making of quality bitumen from waxy crudes, low sulpher fuel oils etc. Industrially,propane, butane and pentane (C3-CJ solvents, either alone or there combinationsfor greater flexibility,are being used widely. To improve the process economics, novel features like supercritical solvent recovery, better counter current columns, etc. are being incorporatedin existing and new grass-root deasphalting plants. The SOA process in combination with thermal cracking processes etc. is further contributing in reducing the availabilityof short/vacuum residues in refinerie

    A unique patch of timberline ecotone with three species of Lady’s slipper orchids in Garhwal Himalaya, India

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    The timberline ecotone experiences a large number of micro-habitats manifested by the action of snow, wind, topography, aspect and anthropogenic pressures and exhibits a sharp ecological gradient of biotic and abiotic components. These changes in micro-habitat, such as compaction of soil, replacement of herbs with grasses and consequent increase in root growth, impede the growth of tree species and affected the sensitive taxa at timberline. During baseline information collection on the structure and composition of timberline vegetation at a timberline ecotone in outer fringes of Kedarnath Wildlife Sanctuary, we came across all three species of Cypripedium at a single site, i.e. birch (Betula utilis) forest. This is the first report of these three species (C. cordigerum, C. elegans and C. himalaicum) occurring at a single locality

    Comparative study of fuelwood consumption by villagers and seasonal "Dhaba owners" in the tourist affected regions of Garhwal Himalaya, India

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    The rural inhabitants of the Himalayan region have been exploiting forest resources for their livelihood for generations. The excessive and uncontrolled use of firewood for domestic purposes has ended up with severe deforestation. Therefore, quantification, assessment and restoration of such valuable but exhaustible resources and is imperative their scientific management. The estimates reflect that a total of 88 species are consumed as fuelwood (54 trees and 34 shrubs) by the local people. Fuelwood consumption by 'dhaba' (roadside refreshment establishments) owners (90-120 kg/household/day) was much higher over the common villagers (20-22 kg/household/day). The fuelwood is mainly burnt for cooking, water heating, space heating and lighting, etc. Among these, cooking consumes the fuelwood most. In addition, fuelwood demand increases due to influx of tourists. In the near future, this may also affect the status of the undisturbed forests at the middle elevation. The information in this communication could be utilized for developing various conservation and sustainable strategies in the region to mitigate the impact of forest resource for fodder and fuelwood.Western Himalaya Fuelwood consumption

    Pattern of invasion by Adhatoda vasica in savannas of Sariska Tiger Reserve, Rajasthan, Western India

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    As part of global experiments on Savanna vegetation, we examined the ecological characteristics of an importantsemiarid savanna in the Indian sub-continent i.e Sariska Tiger Reserve, Rajasthan, Western India during April 2009 toMay 2011. 149 plots across five line transects were sampled for phyto-sociological interpretation in the Sariska-Kalighativalley which is the largest savanna valley habitat in the study area. Plots were segregated on the presence/absence ofnative invasive species Adhatoda vasica and community analysis revealed a total of eleven communities (five frominfested plots and six from non-infested plots) and communities having similar composition were compared. Treedensity, seedling density, species richness of shrubs and herbs and diversity and evenness of herbs was higher in noninfestedplots. Sapling density did not follow a trend. Evenness of shrubs was lower in non-infested plots. Furthermore,2 mapping of Adhatoda vasica in the study area revealed that 5.22 km (26.1%) of the Sariska-Kalighati valley was underinfestation and three sites were compared following removal of this species which resulted in increased sapling density,shrub density and grass cover and decreased seedling density and herb density

    COMPARATIVE STUDY OF VARIOUS TECHNIQUES FOR ENVIRONMENTAL RADON, THORON AND PROGENY MEASUREMENTS

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    Long-term average concentrations of radon, thoron and progeny were measured in normal and high background radiation areas in India using different techniques. Radon, thoron and progeny concentrations were measured using Raduet, Pin-Hole dosimeter, deposition-based CR-39 and deposition-based direct radon/thoron progeny sensor (DRPS/DTPS) detector system. All these techniques were used at a same time inside an individual dwelling. Radon concentration was recorded higher than thoron concen- tration in Garhwal Homes (NBRA) while thoron concentration was found relatively higher in the houses of Chhatarpur area (HBRA) in Odisha, India. The values measured with the CR-39 detector-based technique were found comparable with the values measured with the LR-115 detector-based technique. The comparisons of results using various techniques and their usefulness in radiation measurements are discussed in detail
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