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Predicting the impact of climate change on the distribution of two threatened Himalayan medicinal plants of Liliaceae in Nepal

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Journal of Mountain Science 2017年第3期14卷 558-570页

作者： RANA Santosh kumar RANA Hum Kala GHIMIRE Suresh Kulllar shrestha krishna kumar RANJITKAR Sailesh Key Laboratory for Plant Diversity and Biogeography of EastAsia Kunming Institute of BotanyChinese Academy of SciencesKunming 650201China University of Chinese Academy of Sciences Beijing 100049China Central Department of Botany Tribhuvan UniversityKirtipurKathmanduNepal World Agroforestry Centre East and Central Asia 132 Lanhei RdHeilongtanKunming 650201China

Predicting the potential distribution of medicinal plants in response to climate change is essential for their conservation and management. Contributing to the management program, this study aimed to predict the distribution of two threatened medicinal plants, Fritillaria cirrhosa and Lilium nepalense. The location of focal species gathered from herbarium specimen housed in different herbaria and online databases were geo-referenced and checked for spatial autocorrelation. The predictive environmental variables were selected, and MaxEnt software was used to model the current and future distributions of focal species. Four Representative Concentration Pathway （RCP） trajectories of the BCC-CSMI.1 model were used as the future （2050） projection layer. The MaxEnt modelling delineated the potential distribution of F. cirrhosa and L. nepalense. The current suitability is projected towards Central and Eastern Hilly/Mountainous regions. Both species gain maximum suitability in RCP 4.5 which decline towards other trajectories for L. nepalense. Overall, both the focal species shift towards the north-west, losing their potential habitat in hilly and lower mountainous regions by 2050 across all trajectories. Our results highlight the impact of future climate change on two threatened and valuable species. The results can be further useful to initiate farming of these medicinally and economically important species based on climatically suitable zone and for designing a germplasm conservation strategy.

关键词： Commercial exploitation Conservation Lily Fritillaria cirrhosa Lilium nepalense MaxEntmodelling Species distribution

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Determining bioclimatic space of Himalayan alder for agroforestry systems in Nepal

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Plant Diversity 2018年第1期40卷 1-18页

作者： Santosh kumar Rana Hum Kala Rana krishna kumar shrestha Suresh Sujakhu Sailesh Ranjitkar Key Laboratory{or Plant Diversity and Biogeography of East Asia Kunming Institute of BotanyKunming 650201China University of Chinese Academy of Sciences Beijing 100049China Systematics and Biodiversity Unit Central Department of BotanyTribhuvan UniversityKirtipurKathmanduNepal jade Consult Private Limited KabilmargThapathaliKathmanduPOB 746Nepal World Agroforestry Centre East and Central Asia 132 Lanhei RdHeilongtanKunmingChina

Himalayan alder species are proven to be very useful in traditional as well as contemporary agroforestry practice. These nitrogen-fixing trees are also useful in the land restoration. Therefore, understanding the distribution of Himalayan alder and the potential zone for plantation is meaningful in the agroforestry sector. Suitable climatic zones of Alnus spp. were modelled in Max Ent software using a subset of least correlated bioclimatic variables for current conditions(1950 -2000), topographic variables(DEM derived) and Landuse Landcover(LULC) data. We generated several models and selected the best model against random models using ANOVA and t-test. The environmental variables that best explained the current distribution of the species were identified and used to project into the future. For future projections, ensemble scenarios of climate change projection derived from the results of 19 Earth System Models(ESM) were used. Our model revealed that the most favorable conditions for Alnus nepalensis are in central Nepal in the moist north-west facing slope, whereas for Alnus nitida they are in western *** major climatic factor that contributes to Alnus species distribution in Nepal appears to be precipitation during the warmest quarter for A. nepalensis and precipitation during the driest quarter for A. nitida. Future projections revealed changes in the probability distribution of these species, as well as where they need conservation and where they can be planted. Also, our model predicts that the distribution of Alnus spp. in hilly regions will remain unchanged, and therefore may represent sites that can be used to revitalize traditional agroforestry systems and extract source material for land restoration.

关键词： Alder Agroforestry Species distribution modeling Climate change MaxEnt

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Changes in regeneration and leaf traits of Rhododendron campanulatum along a treeline ecotone in central Nepal

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Journal of Mountain Science 2020年第3期17卷 602-613页

作者： SHARMA Prasad krishna TIWARI Achyut shrestha Babu Bharat Central Department of Botany Tribhuvan UniversityKathmandu44613Nepal Budhanilkantha School Kathmandu44622Nepal

Changes in population structure and plant functional traits across environmental gradient in the near natural treeline is a critical determinant of environmental changes in treelines. In this study we analyzed population characteristics and leaf traits of Rhododendron campanulatum across treeline ecotone in a trans-Himalayan region of Mustang district in central Nepal. Along 4 vertical transects, a total of 72 quadrats(5 m × 5 m)-34 above Betula utilis treeline and 38 below treeline-were sampled to analyze the population structure, regeneration,specific leaf area(SLA) and leaf-stem relationship of R. campanulatum. Our results showed that the regeneration of R. campanulatum was fairly good in both habitats, as evident from density-diameter *** species showed type Ⅲ survivorship curve in both habitats with the highest mortality during early stage of life. However, the seedling density and mortality was higher below treeline than above treeline. Canopy cover and basal cover were found to be the major factors affecting regeneration, as indicated by higher number of juveniles in relatively open areas above treeline. The total leaf area increased(p <0.001) with stem cross-section area in both habitats. However, the SLA was higher below treeline(55 cm^2/g) than above(47 cm^2/g)(p < 0.001);it also increased with the canopy cover of trees(R^2 =0.59, p <0.001) below the treeline. In conclusion,high density of juvenile, low mortality of seedlings,and low SLA above treeline indicated that the species has successfully adapted in climatically stressful alpine habitat with potential to expand upward.

关键词： Rhododendron Climate change Life table Mortality Specific leaf area Mustang district

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How does the stand structure of treeline-forming species shape the treeline ecotone in different regions of the Nepal Himalayas?

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Journal of Mountain Science 2020年第10期17卷 2354-2368页

作者： Parveen K.CHHETRI Raju BISTA krishna B.shrestha Department of Earth Science and Geography California State UniversityDominguez HillsCarsonCalifornia90747USA Department of Biological Sciences University of BergenPO Box 7803N-5020BergenNorway

Stand structure dynamics are considered as major happenings in any forest as a response to environmental ***,this important topic is underrepresented in the treeline studies in the Nepal *** aimed to investigate site-as well as species-specific changes in morphometric features(basal diameter,crown cover,density,and height)along the elevational gradient across treeline ecotones in response to recent environmental *** stand structure characteristics of Abies spectabilis,Pinus wallichiana,and Betula utilis across the treeline ecotone of three study sites in Eastern(Barun),Central(Manang),and Western(Dhorpatan)Nepal were analyzed to elucidate structural ***,eight transects(20 m×(60–250 m))across the treeline ecotone were *** of all life forms,trees(>2 m),saplings(0.5–2 m),and seedlings(<0.5 m),within each transect were enumerated and sampled for the morphometric features and ***-specific and species-specific stand structure dynamics were *** rate of basal area increment was higher in Barun,but the Manang treeline,despite profound regeneration in recent years,had a low annual basal area ***,the altitudinal distribution of age and morphometry were not consistent among those ***,intra-specific competition was not *** site-specific stand structure dynamics explain why treelines do not respond uniformly to increasing *** invokes,in further studies,the incorporation of the tree’s morphometric adaptation traits,phenotypic plasticity,and interactions between species genotype and the environment.

关键词： Climate change Morphometry Nepal Himalayas Stand structure Treeline Tree-rings

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Recent treeline dynamics are similar between dry and mesic areas of Nepal, central Himalaya

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Journal of Plant Ecology 2015年第4期8卷 347-358页

作者： krishna B.shrestha Annika Hofgaard Vigdis Vandvik Department of Biology University of BergenPO Box 7803NO-5020BergenNorway UiB Global University of BergenJekteviksbakken 31PO Box 7800NO-5020BergenNorway Norwegian Institute for Nature Research PO Box 5685 SluppenNO-7485TrondheimNorway

Aims We investigated the treeline dynamics of two environmentally con-trasting areas in the Nepalese Himalaya to address the following questions:(i)Does the timing of establishment of the current tree-line differ between the two study areas,and can area-specific tree-line developments be identified?(ii)Do recruitment patterns and height growth indicate recent climate-driven treeline advance,fol-lowing the general prediction for the central Himalayan region,in the two study areas?Methods a dry-climate treeline dominated by Pinus wallichiana and a mesic-climate treeline with Abies spectabilis were selected for *** each area,we sampled the size and age structure of the study spe-cies along three elevational transects(20-m wide)from the forest line to the tree species line crossing the *** also sampled treeline trees from within and outside transects to reconstruct past treeline establishment *** Findings Despite differences in moisture regimes,tree species and recent climate trends,our two study areas showed very similar treeline dynamics over the past six *** both areas,the recruitment of treeline trees indicates stationary treelines over the past six decades with the current treelines being dominated by trees that were established around *** mesic area has experienced an overall climatic warming trend,and the stationary Abies treeline is hypothesized to be regulated by non-climatic factors,notably *** dry area has not experienced warming but increased climatic variability and some very cool summers in the recent dec-ades may explain the stationary to weakly receding Pinus treeline,which appears more climatically controlled with decreased recruit-ment over the past decades and decreased growth towards higher *** both areas,there is a potential for treeline advance,depending on future land use and climate *** results highlight the importance of conducting treeline ecotone analyses for several sites or are

关键词： Abies spectabilis Himalaya Pinus wallichiana slope aspect treeline ecotone dynamics

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Modification of B3 Model for Sealed Concrete with Additives Based on Experimental Observations

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Journal of Donghua University(English Edition) 2011年第1期28卷 79-84页

作者：陈宝春 shrestha krishna Man 李生勇 College of Civil Engineering Fuzhou University

Thirteen specimens were tested out of which nine were for creep of sealed concrete and four for shrinkage test,for a period of 700 d under controlled temperature *** experimental results for creep and shrinkage were compared with creep and shrinkage computation model B3 and distinct discrepancies between observed and calculated creep and shrinkage strains were *** on regression analysis,modification on B3 model has been formulated which will be applicable at least for concrete of characteristics strength of C40 and C50 with ***,on the basis of observation on identical specimens with varied stress strength ratio,a function is generated which accounts effect of stress strength ratio on ***,Civil Engineering community is suggested not to follow the creep prediction models without correction at least for modern concrete,as they do not account the effect of additives on its compliance function.

关键词： stress strength ratio creep test experimental study B3 model regression analysis

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Karyotypes of three shrew species(Soriculus nigrescens,Episoriculus caudatus and Episoriculus sacratus)from Nepal

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Integrative Zoology 2008年第3期3卷 180-185页

作者： Masaharu MOTOKAWA Masashi HARADA Kazuyuki MEKADA krishna C.shrestha The Kyoto University Museum KyotoJapan Laboratory Animal Center Graduate School of MedicineOsaka City UniversityOsakaJapan Experimental Animal Division RIKEN BioResource CenterTsukubaIbarakiJapan Department of Zoology Pri-Chandra CampusKatmanduNepal

The karyotypes of three shrew species(Mammalia,Soricomorpha,Soricidae)from Nepal were examined for the first *** on the karyotypes and overall differences in skull size,the current Episoriculus caudatus appeared to include two distinct species:the larger *** and the smaller Episoriculus *** sacratus has three subspecies,*** in Nepal and Sikkim,*** in Assam,Myanmar and the Yunnan Province of China,and *** in the Sichuan Province of *** nigrescens had a diploid chromosome number(2n)and fundamental number(FN),including two X chromosomes,of 64 and 92,respectively,consisting of 11 metacentric or submetacentric,two subtelocentric and 18 acrocentric pairs of autosomes,a metacentric X and an acrocentric Y *** sacratus soluensis had 2n=74 and FN=126,consisting of 12 metacentric or submetacentric,13 subtelocentric and 11 acrocentric pairs of autosomes,a submetacentric X and an acrocentric Y *** caudatus had 2n=60 and FN=118,consisting of 19 metacentric or submetacentric,nine subtelocentric and one acrocentric pair of autosomes,a subtelocentric X and an acrocentric Y *** karyotypes of these three species are characterized by their large 2n and FN values compared with other Soricidae.

关键词： karyotype mammals polymorphism shrew speciation taxonomy

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Topography and human disturbances are major controlling factors in treeline pattern at Barun and Manang area in the Nepal Himalaya

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Journal of Mountain Science 2017年第1期14卷 119-127页

作者： Parveen K.CHHETRI krishna B.shrestha David M.CAIRNS Department of Geography Texas A&M University College Station TX 77840 USA UiB Global Jekteviksbakken 31 PO Box 7800 5020 Bergen Norway

The alpine treeline ecotone is an important component of mountain ecosystems of the Nepal Himalaya; it plays a vital role in the livelihood of indigenous people,and provides ecosystem services. However,the region faces a problem of paucity of data on treeline characteristics at the regional and landscape scales. Therefore,we used Remote Sensing(RS),and Geographic Information Science(GIS) approaches to investigate cross-scale interactions in the treeline ecotone. Additionally,European Space Agency land cover map,International Center for Integrated Mountain Development(ICIMOD) land cover map,ecological map of Nepal,and United States Geological Survey Shuttle Radar Topography Mission-Digital Elevation Model were used to analyze treeline pattern at the regional scale. Digital Globe high-resolution satellite imagery of Barun(eastern Nepal) and Manang(central Nepal) were used to study treeline patterns at the landscape scale. Treeline elevation ranges from 3300-4300 m above sea level. Abies spectabilis,Betula utilis,and Pinus wallichiana are the main treeline-forming species in the Nepal Himalaya. There is an east to west treeline elevationgradient at the regional scale. No slope exposure is observed at the regional scale; however,at the landscape scale,slope exposure is present only in a disturbed area(Manang). Topography and human disturbance are the main treeline controlling factor in Barun and Manang respectively.

关键词： Alpine Treeline Mountain ecosystem Himalaya Remote Sensing(RS) Geographic Information Science(GIS)

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Pavement performance model for road maintenance and repair planning: a review of predictive techniques

Digital Transportation and Safety

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Digital Transportation and Safety 2023年第4期2卷 253-267页

作者： krishna Singh Basnet Jagat kumar shrestha Rabindra Nath shrestha Department of Civil Engineering Pulchowk CampusInstitute of EngineeringTribhuvan UniversityKathmanduP.O.Box 1915Nepal

This paper provides a review of predictive analytics for roads,identifying gaps and limitations in current *** explores the implications of these limitations on accuracy and application,while also discussing how advanced predictive analytics can address these *** article acknowledges the transformative shift brought about by technological advancements and increased computational *** degradation of pavement surfaces due to increased road users has resulted in safety and comfort *** have conducted studies to assess pavement condition and predict future changes in pavement *** Management Systems are crucial in developing prediction performance models that estimate pavement condition and degradation severity over *** learning algorithms,artificial neural networks,and regression models have been used,with strengths and *** generally agree on their accuracy in estimating pavement condition considering factors like traffic,pavement age,and weather ***,it is important to carefully select an appropriate prediction model to achieve a high-quality prediction performance *** the strengths and weaknesses of each model enables informed decisions for implementing prediction models that suit specific *** advancement of prediction models,coupled with innovative technologies,will contribute to improved pavement management and the overall safety and comfort of road users.

关键词： Road Maintenance Prediction Model Deterministic Model Probabilistic Model Machine Learning Model

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Variation in Plant Functional Traits along Altitudinal Gradient and Land Use Types in Sagarmatha National Park and Buffer Zone, Nepal

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American Journal of Plant Sciences 2019年第4期10卷 595-614页

作者： Srijana Shah krishna kumar shrestha Christoph Scheidegger Department of Plant Resources National Botanical Garden Kathmandu Nepal Central Department of Botany Tribhuvan University Kathmandu Nepal Ethnobotanical Society of Nepal (ESON) Kathmandu Nepal Swiss Federal Institute of Forest Snow and Landscape Research (WSL) Birmensdorf Switzerland

Functional traits are predictors of plants in response to environmental stimuli. They represent specific functional adaptations to various environmental stresses. This study deals with the variation in plant functional traits along elevation gradient and land-use types in Sagarmatha National Park and Buffer Zone, Nepal. Two field investigations in April and September, 2011 were made to collect samples. Sampling was done from 2200 - 3800 m asl varying approx. 400 m. East and west facing aspects of each valley were chosen. In each aspect four land-use type categories including disturbed (cultivated land, exploited forest and meadow) and less disturbed natural forest were selected. A transect of 25 m long and 2.5 m wide was laid. Different eight traits of plants including lifeform, plant height, clonality, spinescence, leaf dry matter content, stem specific density, twig dry matter content and twig drying time were examined for 60 plant species belonging to 31 families, collected from 40 sampled plots. Nine different types of growth forms were recorded. Plant height of the investigated species ranged from 0.03 - 15 m. The stolon consisting species were dominant in exploited forests. Diversity of clonal species was more in meadow and non-clonal species were dominant in all the altitudes. Only eight species consisted of spines. In the disturbed land-use categories, we found high variation in a particular trait. Correlation analyses revealed the significant relationship (p < 0.01) among different traits. Herbs and shrubs were dominant at higher elevation and in disturbed land-use categories. Species from high altitude were mostly short basal herbs, while spinescence and tall trees were observed at lower altitudes. Species recorded in meadows and exploited forests showed high variation in traits due to disturbance mainly grazing, fire, litter collection and trampling. Altitudinal variation, climatic conditions and disturbance most strongly influence trait expression in the

关键词： Functional Traits Altitudinal Gradient Land-Use Types Disturbances

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