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Evaluation of sampling strategies to estimate crown biomass

Forest Ecosystems 2015年第1期2卷 20-30页

作者： krishna P poudel Hailemariam Temesgen Andrew N Gray Department of Forest Engineering Resources and Management College of Forestry Oregon State University USDA Forest Service PNW Research Station3200 SW Jefferson WayCorvallis OR 97331 USA

Background：Depending on tree and site characteristics crown biomass accounts for a significant portion of the total aboveground biomass in the *** biomass estimation is useful for different purposes including evaluating the economic feasibility of crown utilization for energy production or forest products,fuel load assessments and fire management strategies,and wildfire ***,crown biomass is difficult to predict because of the variability within and among species and *** the allometric equations used for predicting crown biomass should be based on data collected with precise and unbiased sampling *** this study,we evaluate the performance different sampling strategies to estimate crown biomass and to evaluate the effect of sample size in estimating crown ***：Using data collected from 20 destructively sampled trees,we evaluated 11 different sampling strategies using six evaluation statistics：bias,relative bias,root mean square error（RMSE）,relative RMSE,amount of biomass sampled,and relative biomass *** also evaluated the performance of the selected sampling strategies when different numbers of branches（3,6,9,and 12）are selected from each *** specific log linear model with branch diameter and branch length as covariates was used to obtain individual branch ***：Compared to all other methods stratified sampling with probability proportional to size estimation technique produced better results when three or six branches per tree were ***,the systematic sampling with ratio estimation technique was the best when at least nine branches per tree were *** the stratified sampling strategy,selecting unequal number of branches per stratum produced approximately similar results to simple random sampling,but it further decreased RMSE when information on branch diameter is used in the design and estimation ***：Use of auxiliary information in design or estimation phase reduc

关键词： Aboveground biomass Crown Sampling strategies Pacific Northwest

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Estimating upper stem diameters and volume of Douglas-fir and Western hemlock trees in the Pacific northwest

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Forest Ecosystems 2018年第3期5卷 199-210页

作者： krishna P.poudel Hailemariam Temesgen Andrew N.Gray Department of Forest Engineering Resources and Management College of Forestry Oregon State University USDA Forest Service PNW Research Station

Background: Volume and taper equations are essential for obtaining estimates of total and merchantable stem volume. Taper functions provide advantages to merchantable volume equations because they estimate diameter inside or outside bark at specific heights on the stem, enabling the estimation of total and merchantable stem volume, volume of individual logs, and a height at a given ***: Using data collected from 1218 trees(1093 Douglas-fir(Pseudotsuga menziesii(Mirbel) Franco) and 125 western hemlock(Tsuga heterophylla)), we evaluated the performance of one simple polynomial function and four variable-exponent taper functions in predicting upper stem diameter. Sample trees were collected from different parts of the states of Oregon, Washington, and California. We compared inside-bark volume estimates obtained from the selected taper equation with estimates obtained from a simple logarithmic volume equation for the data obtained in this study and the equations used by the Forest Inventory and Analysis program in the Pacific Northwest(FIA-PNW) in the state of California and western half of the states of Oregon and ***: Variable exponent taper equations were generally better than the simple polynomial taper *** FIA-PNW volume equations performed fairly well but volume equations with fewer parameters fitted in this study provided comparable results. The RMSE obtained from taper-based volume estimates were also comparable with the RMSE of the FIA-PNW volume equations for Douglas-fir and western hemlock trees ***: The taper equations fitted in this study provide added benefit to the users over the FIA-PNW volume equations by enabling the users to predict diameter at any height, height to a given diameter, and merchantable volume in addition to cubic volume including top and stump(CVTS) of Douglas-fir and western hemlock trees in the Pacific Northwest. The findings of this study also give more confidence to the use

关键词： Pacific northwest Biomass equations Utilization standards Diameter inside bark

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Predicting the upper stem diameters and volume of a tropical dominant tree species

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Journal of Forestry Research 2022年第6期33卷 1725-1737页

作者： Sunita Ulak Keshav Ghimire Rabindra Gautam Shes Kanta Bhandari krishna Prasad poudel Yajna Prasad Timilsina Dhirendra Pradhan Thakur Subedi Forest Research and Training Centre KathmanduNepal Institute of Forestry Tribhuvan UniversityKathmanduNepal School of Biological Sciences The University of Western AustraliaPerthAustralia Department of Forestry Mississippi State UniversityMississippi StatePO Box 9681Starkville 39762USA

Predicting upper stem diameters and individual tree volumes is important for product quantification and can provide important information for the sustainable management of forests of important commercial tree species(Shorea robusta)in *** aim of this study was to develop a taper equation for ***-four trees were selected and felled in the southern low land of Nepal.A mixed effect modelling approach was used to evaluate 17 different taper functions.‘Leave-one-out cross-validation'was used to validate the fitted taper *** variable exponent taper function best fitted our data and described more than 99%of the variation in upper stem *** also showed significant effects of stand density on tree *** tree volume prediction using the local volume model developed in this study was more accurate compared to the volume predicted through the taper function and existing volume *** taper function developed in this study provides the benefit of predicting upper stem diameter and can be used for predicting volume to any merchantable height of individual *** will have implications in estimates of volume,biomass,and carbon and thus may be a potential supporting tool in carbon trade and revenue generation.

关键词： Mixed-model approach Shorea robusta Taper Volume Nepal

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Pomegranate Production in Nepal;Strategies,Challenges and Way forward

Pomegranate Production in Nepal;Strategies,Challenges and Wa...

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第三届中国园艺学会石榴分会会员代表大会暨首届中国泗洪软籽石榴高峰论坛、国家石榴产业科技创新联盟筹备会

作者： krishna poudel Zhengzhou Fruit Research Institute

The topographical variation has created an ample space for the commercialization of the horticultural crops focused on the *** to the subsistence farming system,poor infra-structure,transportation facilities,linkage to the international market and technical know-how,horticulture development in Nepal could not gain momentum as *** productivity of pomegranate as compared to the neighbouring countries India and China is very *** area under the cultivation during the year 2016 is,468 ha,production 2820 ton with a productivity of 6 t/*** is cultivated in a small area and have low productivity which might be due to the lack of the improved varieties,technical know-how and crop management *** research on variety evaluation and selection in scientific way is entirely lacking in *** existing and exotic genotype needs to be characterized,evaluated,selected and promoted for commercial plantation to reduce Nepal's dependency and substitute the *** this purpose,documentation and recommendation of exiting and introduced genotype should be carried out in national *** it is very urge to select and recommend appropriate and high yielding pomegranate genotype for the particular climatic conditions to cope up market and farmers' demand in the country.

关键词： Pomegranate Diversified Productivity Prospects Strategies

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Molecular Breeding and Economic Importance of Pomegranate:A Review

Molecular Breeding and Economic Importance of Pomegranate:A ...

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第四届中国石榴博览会暨第十届全国石榴生产与科研研讨会、首届国际石榴文化数字云博览会

作者： krishna poudel CHEN Lina LI Haoxian CAO Shangyin Zhengzhou Fruit Research Institute

Pomegranate is native to central Asia,which is an important fruit contributing to poverty alleviation and rural *** strategies followed by most of the breeders for breeding new varieties are based on the controlled crosses to select those individuals with desired traits of *** is one of the successful approaches in the production of most of the crop varieties available *** the fact,this process of breeding in fruit crops is time-consuming and costly due to the time required by the fruit crop to enter into the fruiting *** development in science as sequencing and mapping techniques are the new scientific tools for breeding in fruit *** breeding strategies have mostly focused on the introduction to the high yield and/or resistance-related traits to *** traits in pomegranates are the basic criteria for the consumers in selecting quality *** of the major traits representing the quality of the products are fruit color,seed hardness,aril color,taste,*** edibility of the fruits of pomegranate depends on the fleshy outer seed coats and hard or soft inner seed *** is the key factor for the preferences by the consumers to particular *** consumers’ preference towards softseeded pomegranates has accelerated the breeding of new soft-seeded pomegranate ***,the seed coat development in pomegranate has not yet been *** hardness is an important trait in pomegranate that determines the edibility and quality of the *** is a major factor for the economic value of the fruit as soft seeded fruits fetch a higher price in the market compared to the hard seeded ones.

关键词： Pomegranate Seed hardness Molecular breeding Marker Genetic diversity

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石榴SUT基因家族鉴定及其在籽粒发育过程中的表达分析

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果树学报 2020年第4期37卷 485-494页

作者：骆翔曹尚银李好先赵弟广张富红陈丽娜 krishna poudel 敬丹唐丽颖中国农业科学院郑州果树研究所郑州450009

【目的】对石榴SUT家族基因成员进行全基因组鉴定,并分析SUT家族基因成员的结构域特征、启动子序列、生化特征、进化关系和表达特性,为深入研究该基因作用及其分子调控机制提供参考。【方法】利用同源比对及HMMER模型鉴定石榴SUT基因家... 详细信息

【目的】对石榴SUT家族基因成员进行全基因组鉴定,并分析SUT家族基因成员的结构域特征、启动子序列、生化特征、进化关系和表达特性,为深入研究该基因作用及其分子调控机制提供参考。【方法】利用同源比对及HMMER模型鉴定石榴SUT基因家族成员;利用邻近法和基因结构分析解析石榴SUT基因及其启动子序列的系统发生关系。【结果】共鉴定了10个石榴SUT基因,可以分为3大类;石榴SUT基因及其启动子区的GC含量都明显低于其在拟南芥和水稻中的含量;石榴SUT家族基因GC含量远高于启动子区的GC含量;石榴SUT基因的序列长度与GC含量呈明显正相关;石榴SUT基因启动子区含有10种MYB元件;此外,4个石榴SUT基因(PgL0328370.1、PgL0099690.1、PgL0145810.1和PgL0145770.1)在籽粒发育过程中发生了差异表达。【结论】SUT基因在进化过程中其序列和基因结构相对保守,而其启动子序列在进化过程中变化较大,SUT基因的表达量变化与籽粒发育显著相关。

关键词：石榴 SUT 基因家族籽粒表达分析

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基于多源遥感数据的植被冠层高度估算

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空间科学学报 2023年第6期43卷 1176-1193页

作者：田镇朋周维袁敬毅刘小强叶粟 poudel krishna HIMES Austin RENNINGER Heidi 王家新马勤南京师范大学地理科学学院南京210023 南京师范大学虚拟地理环境教育部重点实验室南京210023 江苏省地理信息资源开发与利用协同创新中心南京210023 中国科学院植物研究所植被与环境变化国家重点实验室北京100093 浙江大学环境与资源学院杭州310058 密西西比州立大学林学系斯塔克维尔39762

为了大范围精确估计空间连续的森林冠层高度,研究使用随机森林回归方法,通过融合冰、云和陆地高程卫星二号(Ice,Cloud and land Elevation Satellite-2,ICESat-2)测量数据和Landsat-8影像,并结合地形、气温等数据来估算森林冠层高度,生... 详细信息

为了大范围精确估计空间连续的森林冠层高度,研究使用随机森林回归方法,通过融合冰、云和陆地高程卫星二号(Ice,Cloud and land Elevation Satellite-2,ICESat-2)测量数据和Landsat-8影像,并结合地形、气温等数据来估算森林冠层高度,生成2020年美国密西西比州30 m空间分辨率的森林冠层最大高度和平均高度图。结果表明,森林覆盖区域冠层最大高度的均值为24.14 m,标准差为4.24 m。森林覆盖区域冠层平均高度的均值为12.04 m,标准差为2.59 m。研究区冠层高度估计值与机载测量值吻合良好(冠层最大高度R2=0.486,HRMSE=4.532 m;冠层平均高度R2=0.467,HRMSE=2.848 m)。利用估算数据进一步对森林冠层垂直结构复杂度进行了分析。研究提出的森林冠层高度制图方案对中国长江三角洲地区的森林管理、物种多样性保护与碳中和评估等具有指导意义。

关键词：激光雷达 ICESat-2 冠层高度制图多源遥感密西西比森林

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Tribological properties of Al-GNP composites at elevated temperature

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Friction 2024年第5期12卷 1028-1041页

作者： Sunil poudel Rizwan BAJWA Yongde XIA Zakir KHAN Yi ZHANG Yanqiu ZHU College of Engineering Mathematics and Physical SciencesUniversity of ExeterExeterEX44QFUK European Technical Centre Daido Metal Co.Ltd.Iliminster SomersetTA199PHUK

Lighter and more powerful next generation vehicles and other rotary machinery demand bearings to operate in harsher conditions for higher efficiency,and the continuous development of advanced low-wear and friction materials is thus becoming even more important to meet these *** aluminium composites reinforced with high performance lubricate phases such as graphene nanoplatelets(GNPs)are very promising and have been vigorously *** maintaining a low coefficient of friction(COF)and offering great strength against wear due to their self-lubricating capability,the solid lubricant like GNPs protect the bearing surface from wear damage and prevent change in metallurgical properties during temperature *** paper first studies the high-temperature tribological performance of aluminium matrix composites reinforced with GNP,consolidated via powder metallurgy,then elucidates their tribological *** report that the best tribological performance is achieved by the composite containing 2.0 wt%GNP,with an extraordinarily low COF of 0.09 and a specific wear rate of 3.5×10^(−2)mm^(3)·N^(−1)·m^(−1),which represent 75%and 40%reduction respectively,against the plain aluminium consolidated under identical *** in-track and out-of-track Raman analysis have confirmed the role of GNPs in creating a tribofilm on the counterpart surface which contributed to the excellent performance.

关键词： nanocomposite graphene nanoplatelet(GNP) tribology powder metallurgy

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Assessing Financial Management Practices and Accounting Mechanisms in Agricultural Cooperatives:A Case Study From Nepal

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Management Studies 2024年第3期12卷 146-171页

作者： Chiranjeewee Khadka Ghanshyam Pandey Arbin poudel Eva Cudnilova Global Change Research Institute CAS BrnoCzech Republic University of South Bohemia ČeskéBudějoviceCzech Republic Pokhara Campus PokharaNepal Green Foundation Nepal KathmanduNepal

The study focuses on assessing the financial management practices and accounting mechanisms in agricultural cooperatives in Tulsipur Sub-Metropolitan,Dang District,Nepal with a focus on understanding their implications for financial performance and organizational *** sample size of total cooperatives(n=46)was divided into Savings and Credit Cooperatives(n=18)and Multipurpose Cooperatives(n=28),respectively,with a total number of respondents(n=138)categorized into managing directors,employees,and general *** a mixed-methods approach that combines quantitative analysis of financial data with qualitative insights gathered through interviews and surveys,the study emphasizes the importance of modern financial practices,improved reporting mechanisms,and relevant staff training for long-term *** include the integration of criteria and evaluation tools to assess cooperative performance,with Hamro Pahunch Multipurpose Cooperative identified as a high *** the need for robust financial management strategies to navigate the complexity of the agricultural sector,manage risks,and achieve sustainable development,the study notes frequent preparation of financial management reports on a monthly and annual basis,and predominantly annual accounting *** cooperatives are using computerized models to present financial positions,but face challenges such as lack of marketing infrastructure,cooperative skills,and technical ***,the study advocates for educating policy makers,cooperative leaders,practitioners and stakeholders on the role of effective financial management and accounting in enhancing the resilience,expansion and socio-economic impact of agricultural cooperatives,thereby fostering their long-term prosperity and viability as drivers of rural development and empowerment.

关键词： accounting mechanisms agricultural cooperatives financial management evaluation criteria and performance transparency

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石榴群体果实品质相关性状分析

石榴群体果实品质相关性状分析

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第三届中国园艺学会石榴分会会员代表大会暨首届中国泗洪软籽石榴高峰论坛、国家石榴产业科技创新联盟筹备会

作者：骆翔李好先赵弟广张富红陈利娜 krishna poudel 敬丹唐丽颖曹尚银中国农业科学院郑州果树研究所

以不同地理分布、不同表型变异的150份遗传多样性石榴种质为资源材料,对其果实品质相关性状进行测定,分析其在群体水平上的表型变异、相关关系及群体结构效应,以期为石榴优良品种资源的改良提供参考依据。研究结果表明群体的可溶性固形... 详细信息

以不同地理分布、不同表型变异的150份遗传多样性石榴种质为资源材料,对其果实品质相关性状进行测定,分析其在群体水平上的表型变异、相关关系及群体结构效应,以期为石榴优良品种资源的改良提供参考依据。研究结果表明群体的可溶性固形物含量在不同品种间变异相对稳定,而可滴定酸含量在不同品种间变异幅度较大。氨基酸总含量在p<0.01水平上与可溶性总糖含量显著负相关,与可滴定酸含量显著正相关。回归分析表明氨基酸总含量可以解释可滴定酸含量表型变异的21.56%。可溶性固形物含量与可溶性总糖含量在p<0.01水平上显著正相关,相关系数为0.35;回归分析表明可溶性总糖含量可以解释可溶性固形物含量表型变异的11.78%。可滴定酸含量与可溶性总糖含量在p<0.01水平上显著负相关。群体遗传多样性分析表明该群体可以分为4个亚群。可溶性固形物含量变异在各个亚群中表型变异差异不显著,而氨基酸总含量、可溶性总糖及可滴定酸含量变异在不同亚群间差异显著。

关键词：石榴果实品质群体相关分析

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