Journal of Himalayan Earth Sciences最新文献

{"title":"Regeneration of Pinus wallichiana AB Jackson in a trans-Himalayan dry valley of north-central Nepal","authors":"B. Ghimire, Kumar P. Mainali, H. D. Lekhak, R. P. Chaudhary, Amal Kumar Ghimeray","doi":"10.3126/HJS.V6I8.1798","DOIUrl":"https://doi.org/10.3126/HJS.V6I8.1798","url":null,"abstract":"We studied the elevational pattern of forest composition and regeneration of the subalpine conifer tree species Pinus wallichiana in Manang, a trans-Himalayan dry valley in north-central Nepal. Thirty-five quadrats (10 m × 10 m) were laid between 3300 and 4000 masl on both north- and south-facing slopes. We measured diameter at breast height (DBH) of each mature individual of all tree species (DBH ≥10 cm), and recorded the number of seedlings (DBH 30 cm). We also measured soil moisture and soil pH, estimated canopy cover, and recorded slope and altitude in each quadrat. For all species together and for several species individually, tree density, seedling density, sapling density and tree basal area were found to decrease with elevation on both north and south aspects. This trend is largely explained by the progressively harsher environment at higher elevations. The north-facing slopes in our study area have denser forests than the south-facing slopes, the density of all size classes (seedling, sapling and mature plants) and basal area being greater on the northern aspects. These aspect-wide differences are attributable to the stark difference in soil moisture between northern and southern aspects, which is in turn due to the difference in insolation. Irrespective of elevation and aspect, all the forests studied are regenerating, as indicated by inverse J-shaped density-diameter curves. The elevational pattern of seedling and sapling abundance is explained only by elevation. Whereas other variables (e.g., canopy) are considered to have an important influence on seed germination and seedling establishment, they turn out not to be significant predictors of density of seedlings and saplings. This failure to identify a relationship is probably due to our use of non-parametric test (tree regression analysis) that we used to establish the relationship between density and its potential explanatory variables or due to our selection of 1 standard error rule yielding sub-optimal models for regression trees. Key words: density-diameter curve; regeneration; seedling; sapling; altitude; canopy; Manang Valley DOI: http://dx.doi.org/10.3126/hjs.v6i8.1798 Himalayan Journal of Sciences Vol.6 Issue 8 2010 pp.19-26","PeriodicalId":42873,"journal":{"name":"Journal of Himalayan Earth Sciences","volume":"23 1","pages":"19-26"},"PeriodicalIF":0.4,"publicationDate":"2011-06-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82155653","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Mancozeb: growing risk for agricultural communities?","authors":"Kishor Atreya, B. Sitaula","doi":"10.3126/HJS.V6I8.1794","DOIUrl":"https://doi.org/10.3126/HJS.V6I8.1794","url":null,"abstract":"In a country where farmers rely on conventional wisdom to make decisions on farming practices and the government lacks clear policies based on solid research, pesticide overuse is emerging as a problem. Mancozeb, the widely applied pesticide in Nepal’s vegetable farming, has both short- and long-term health consequences to people exposed to its unsafe levels. A handful of studies in the hill regions of Nepal suggest that the pesticide is being sprayed to farms at much higher level than recommended. The widespread misuse and dangerous consequences of this pesticide suggest a need for more thorough study, better instruction, and more effective control. DOI: http://dx.doi.org/10.3126/hjs.v6i8.1794 Himalayan Journal of Sciences Vol.6 Issue 8 2010 pp.9-10","PeriodicalId":42873,"journal":{"name":"Journal of Himalayan Earth Sciences","volume":"76 1","pages":"9-10"},"PeriodicalIF":0.4,"publicationDate":"2011-06-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75716006","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Simulating farm income under the current soil management regime in the mid-hills of Nepal","authors":"G. Bhatta, Nilhari Neupane","doi":"10.3126/HJS.V6I8.3243","DOIUrl":"https://doi.org/10.3126/HJS.V6I8.3243","url":null,"abstract":"Farmers in the mid-hills of Nepal follow diverse farming systems. The peri-urban area of this region, where population density is higher, faces several problems in farming. While hills suffer from erosion because they are erodible, the peri-urban areas face the problem of decline in factor productivity, particularly in intensively cultivated farmlands. The present study is concerned with simulating farm income on a regional scale based on soil management practices. Spatial explicit simulation shows that the loss of farm income due to degradation is substantially higher in hills while it is lower in valley bottoms. Strategy formulation and testing in the spatial environment indicates that Geographic Information System is an appropriate methodological tool for simulating the consequences of particular interventions. Key words: Mid hills, Nepal, spatial modeling, soil quality index, farm income DOI: http://dx.doi.org/10.3126/hjs.v6i8.3243 Himalayan Journal of Sciences Vol.6 Issue 8 2010 pp.27-34","PeriodicalId":42873,"journal":{"name":"Journal of Himalayan Earth Sciences","volume":"13 1","pages":"27-34"},"PeriodicalIF":0.4,"publicationDate":"2011-06-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89963489","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Climate change and disease risk in the Himalayas","authors":"S. Sarkar","doi":"10.3126/HJS.V6I8.4921","DOIUrl":"https://doi.org/10.3126/HJS.V6I8.4921","url":null,"abstract":"A new challenge is unfolding in the Himalayas: a significant increase in the burden of infectious disease, driven by climate change. Vectors are moving beyond their historic ranges to higher elevations; water quality is deteriorating, and the available supply is diminishing. Preventive and ameliorative measures to address these problems require robust quantitative estimates of the size and spatial distribution of disease risk. Once enough data are available, disease risk can be mapped with predictive models so that appropriate policies can be formulated and implemented. Unfortunately, there has been virtually no quantitative epidemiological attention to this region. DOI: http://dx.doi.org/10.3126/hjs.v6i8.4921 Himalayan Journal of Sciences Vol.6 Issue 8 2010 pp.7-8","PeriodicalId":42873,"journal":{"name":"Journal of Himalayan Earth Sciences","volume":"29 1","pages":"7-8"},"PeriodicalIF":0.4,"publicationDate":"2011-06-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81648677","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Central Crystallines as the Exclusive Source Terrain For The Sandstone-mudstone Suites Of Siwalik Group: Geochemical Evidence","authors":"N. Ranjan, D. Banerjee","doi":"10.3126/HJS.V5I7.1303","DOIUrl":"https://doi.org/10.3126/HJS.V5I7.1303","url":null,"abstract":"DOI = 10.3126/hjs.v5i7.1303 Himalayan Journal of Sciences Vol.5(7) (Special Issue) 2008 p.114","PeriodicalId":42873,"journal":{"name":"Journal of Himalayan Earth Sciences","volume":"32 1","pages":"114-114"},"PeriodicalIF":0.4,"publicationDate":"2008-09-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"91338141","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Neotectonic activity and its geomorphic response in the Tangtse valley, Ladakh Himalaya","authors":"Vimal Singh","doi":"10.3126/HJS.V5I7.1329","DOIUrl":"https://doi.org/10.3126/HJS.V5I7.1329","url":null,"abstract":"DOI = 10.3126/hjs.v5i7.1329 Himalayan Journal of Sciences Vol.5(7) (Special Issue) 2008 p.148","PeriodicalId":42873,"journal":{"name":"Journal of Himalayan Earth Sciences","volume":"14 1","pages":"148-148"},"PeriodicalIF":0.4,"publicationDate":"2008-09-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90543853","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Spatio - Temporal Variation of Vegetation During Holocene in the Himalayan Region","authors":"A. Bhattacharyya, Santosh K. Shah","doi":"10.3126/HJS.V5I7.1238","DOIUrl":"https://doi.org/10.3126/HJS.V5I7.1238","url":null,"abstract":"DOI = 10.3126/hjs.v5i7.1238 Himalayan Journal of Sciences Vol.5(7) (Special Issue) 2008 p.31","PeriodicalId":42873,"journal":{"name":"Journal of Himalayan Earth Sciences","volume":"170 1","pages":"31-31"},"PeriodicalIF":0.4,"publicationDate":"2008-09-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73223971","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Anatomy, Age and Evolution of the Baltoro granite batholith, Pakistani Karakoram","authors":"M. Searle, A. Thow, R. Parrish, S. Noble, David D. Waters","doi":"10.3126/HJS.V5I7.1319","DOIUrl":"https://doi.org/10.3126/HJS.V5I7.1319","url":null,"abstract":"Geological mapping around the Baltoro granite batholith in North Pakistan has resulted in a more detailed picture of the 3-D anatomy of the batholith. U-Th-Pb geochronology on all the main intrusive phases has resulted in more detailed timing constraints on batholith evolution. The Karakoram terrane in North Pakistan, shows abundant evidence for Middle Jurassic and Cretaceous (170-90 Ma) Andean-type subduction-related granite intrusion (eg: K2, Muztagh Tower gneisses, Hunza granodiorites, Hushe gneisses). Following collision and accretion of first the Kohistan Arc, and later the Indian plate to the southern margin of Asia, crustal thickening along the Karakoram resulted in polyphase deformation, and multiple ‘phases’ of metamorphism and melting (Searle and Tirrul 1991; Fraser et al.2001). The major phase of kyanite- and sillimanite-grade metamorphism in the Baltoro region was Oligocene – Lower Miocene (28-22 Ma; UPb monazite ages). A widespread network of leucogranitic dykes that cross-cut folds and regional fabrics has been dated at 24.7 ± 0.6 Ma (U-Pb zircon) indicating that major thickening and folding was over by that time. Renewed deformation and heating in the middle-lower crust to sillimanite + K-feldspar grade with migmatisation and generation of gem-bearing leucogranite dykes occurred in the deep crustal Dassu gneiss dome in the southern Karakoram between 5.5 – 3.5 ± 0.2 Ma (U-Pb zircon, monazite). The Baltoro granite batholith, previously dated between 25-20 Ma (Parrish and Tirrul 1989, Scharer et al. 1990, Searle et al. 1992) also includes Early Miocene granites. New U-Pb monazite ages from crustal melt biotite + muscovite + garnet leucogranites from the Trango Towers, Cathedral peak and Paiyu peak span 19.8 – 17.5 ± 0.5 Ma. The youngest leucogranites from the huge sheeted sill complex that feeds the Masherbrum garnet-bearing 2 mica leucogranite are the youngest dated phases in the Baltoro batholith at 17.6 ± 1.1 Ma. The Masherbrum and K7 granites extend east to the Siachen glacier region where they are cut abruptly by the Karakoram strike-slip fault, indicating that the fault must have initiated after 17 Ma, in common with earlier U-Pb dating constraints from the Tangtse region (Phillips et al. 2004).","PeriodicalId":42873,"journal":{"name":"Journal of Himalayan Earth Sciences","volume":"9 1","pages":"137-137"},"PeriodicalIF":0.4,"publicationDate":"2008-09-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84367851","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Heterogeneous Himalayan crust using shear wave attenuation in the Pithoragarh region of Kumaon","authors":"Anand A. Joshi, M. Mohanty, A. R. Bansal, V. Dimri, R. Chadha","doi":"10.3126/HJS.V5I7.1271","DOIUrl":"https://doi.org/10.3126/HJS.V5I7.1271","url":null,"abstract":"DOI = 10.3126/hjs.v5i7.1271 Himalayan Journal of Sciences Vol.5(7) (Special Issue) 2008 p.72","PeriodicalId":42873,"journal":{"name":"Journal of Himalayan Earth Sciences","volume":"72 1","pages":"72-72"},"PeriodicalIF":0.4,"publicationDate":"2008-09-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79222519","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Unzipping Lemuria from its Himalaya suture to understand mammalian origins","authors":"M. Wit, J. Masters","doi":"10.3126/HJS.V5I7.1249","DOIUrl":"https://doi.org/10.3126/HJS.V5I7.1249","url":null,"abstract":"DOI = 10.3126/hjs.v5i7.1249 Himalayan Journal of Sciences Vol.5(7) (Special Issue) 2008 p.44","PeriodicalId":42873,"journal":{"name":"Journal of Himalayan Earth Sciences","volume":"5 1","pages":"44-44"},"PeriodicalIF":0.4,"publicationDate":"2008-09-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80888208","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}