检索结果-南通市图书馆

生物数学学报 1997年第4期12卷 300-307页

作者： ZhangFeng MiXiangcheng,ShangguanTieliang ZhengFengying AndersTelenius,DepartmentofLifeScience,ShanxiUniversity,Taiyuan030006．P.R．ChianandDepartmentofBotany,tockholmUniversity,S-10691Stockholm,Sweden 山西大学生命科学系山西太原 Stockholm University 瑞典

Abstract:Inthispaper,anon-hierarchicalagglomerativealgorithm,stepwiseclustering（SWC）analysisisintroducedinvegetationanalysisbyapplicationtotheE-laeagnusmolliscommunityofshanxi,NorthChina.ByusingSWCanalysis,classifica-tionisreachedbysuccessivelyadjustingthemembersofplotgroupssothatthesum-of-Squares,similartothecoefficientofdistance,isminimizedwithineachplotgroup.Thedesiredsignificantcharacteristicofmaximalhomogeneitywithineachplotgroup,butmaximalheterogeneityamongplotgroupsisthusachieved.TheresultsofanalysisbySWCiscomparedwiththoseoffuzzyc-meansalgorithmclustering（FCAC）,andtwinspan.TheuseofSWCispreferabletotwinspanduetotherelaxationofthepreconditionofthe1atterofahierarchicalre1ationshipamongplotgroups．ComparingSWCwithFCAC,theformerissuperiorsincetheresultoftheanalysisismoreinaccordancewiththeactualvegetationdistribution,asshownbyx2testofindependence．

关键词： Keywords:Non-hierarchicalclassification stepwiseclustering fuzzyc-meansalgorithmclustering twinspan Elaeagnusmolliscomm

科尔沁沙丘植物群落的twinspan数量分析

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

中国沙漠 1995年第3期15卷 233-236页

作者：徐斌中国科学院兰州沙漠研究所

本文采用国际通用软件ＴＷＩＮＳＰＡＮ把科尔沁沙丘４１个植物样方按盖度分成５组，每组代表１种沙丘植物群落类型。同时把１７个植物种也分为５组，各组植物种从流动沙丘到固定沙丘出现的顺序为：Ⅴ→Ⅳ＋Ⅰ→Ⅲ→Ⅱ。

关键词：科尔沁沙地沙丘植物群落数量分析 twinspan

牡丹江干流春季浮游植物双向指示种(twinspan)分类及水质评价研究

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

淡水渔业 2008年第3期38卷 58-62页

作者：马成学于洪贤张新刚东北林业大学水生生物学科哈尔滨150040

应用双向指示种(twinspan)分析技术,以9个采样点的数据分析为基础,对牡丹江干流春季浮游植物种群结构和水质状况进行了研究。结果显示:牡丹江干流水域可以划分为4个类型,境泊湖入水口1#点和海浪河口7#点水质最好,其次为干流的5#、6#、8#... 详细信息

应用双向指示种(twinspan)分析技术,以9个采样点的数据分析为基础,对牡丹江干流春季浮游植物种群结构和水质状况进行了研究。结果显示:牡丹江干流水域可以划分为4个类型,境泊湖入水口1#点和海浪河口7#点水质最好,其次为干流的5#、6#、8#、9#采样点,镜泊湖区域敞水区2#、3#点水质较差,镜泊湖出水口4#采样点水质最差,但根据污生指数评价标准来看,水质都属于中污染。

关键词：牡丹江浮游植物 twinspan 污生指数

高黎贡山北段植物群落twinspan数量分类研究

在线全文

学校读者我要写书评

暂无评论

云南植物研究 2008年第6期30卷 679-687页

作者：欧光龙彭明春和兆荣王崇云王浩波向伶云南大学生态学与地植物学研究所云南昆明650091 西南林学院国家林业局西南地区生物多样性保育重点实验室云南昆明650224

采用twinspan数量分类方法对高黎贡山北段植物群落进行研究,将研究区68个样地归并为18个聚组,并参照《云南植被》和《中国植被》的分类原则和系统将研究区植物群落划归为6个植被型、7个植被亚型、7个群系组、10个群系和18个群落;TWINSPA... 详细信息

采用twinspan数量分类方法对高黎贡山北段植物群落进行研究,将研究区68个样地归并为18个聚组,并参照《云南植被》和《中国植被》的分类原则和系统将研究区植物群落划归为6个植被型、7个植被亚型、7个群系组、10个群系和18个群落;twinspan数量分类反映了群落分布随海拔和干扰变化的规律。

关键词：高黎贡山植物群落 twinspan 数量分类

西藏拉孜县草地植物群落的twinspan分类及其物种多样性研究

在线全文

学校读者我要写书评

暂无评论

江西农业大学学报 2004年第1期26卷 31-36页

作者：李海涛贺金生倪志诚周榜第李乾振沈文清中国科学院地理科学与资源研究所北京100101 中国科学院植物研究所北京100044 西藏自治区生物研究所西藏拉萨850000 北京林业大学森林资源与环境学院北京100083

应用双向指示种(twinspan)分类技术对西藏拉孜县草地植物群落的71个样方进行分类和生物多样性研究;根据丰富度、均匀度和多样性指数,对分类后得到的群落类型进行排序,并探讨环境因子和草地植物群落多样性指标之间的关系。twinspan分类... 详细信息

应用双向指示种(twinspan)分类技术对西藏拉孜县草地植物群落的71个样方进行分类和生物多样性研究;根据丰富度、均匀度和多样性指数,对分类后得到的群落类型进行排序,并探讨环境因子和草地植物群落多样性指标之间的关系。twinspan分类的结果表明,上述草地植物群落可以划分为22个群落类型。通过海拔高度、经度、纬度、坡向和坡度与3个多样性指标的相关分析,只有海拔高度与均匀度之间呈显著的负相关关系,即随着海拔的升高均匀度降低,而其它的环境因子与多样性指标之间无显著相关关系存在。

关键词：西藏拉孜县草地植物群落双向指示种 twinspan 物种多样性

洮河国家湿地公园主要植物群落多样性对土壤环境因子的响应

在线全文

学校读者我要写书评

暂无评论

生态学报 2022年第7期42卷 2674-2684页

作者：李群赵辉赵成章马敏唐玉瑞赵婷婷西北师范大学地理与环境科学学院甘肃省湿地资源保护与产业发展工程研究中心兰州730070

内陆河湿地原生植被群落多样性对土壤环境因子的响应分析,有助于深入理解河岸带原生植物群落的生态适应策略。采用双向指示种分析(two-way indicator species analysis, twinspan)和典范对应分析(canonical correspondence analysis, C... 详细信息

内陆河湿地原生植被群落多样性对土壤环境因子的响应分析,有助于深入理解河岸带原生植物群落的生态适应策略。采用双向指示种分析(two-way indicator species analysis, twinspan)和典范对应分析(canonical correspondence analysis, CCA)方法对研究区27个样方的原生植物群落进行分析,研究河岸带植物群落多样性与土壤因子之间的关系。结果表明:研究区主要原生植物有8种生活型,群落类型可分为女贞(Ligustrum lucidum)+野蔷薇(Rosa multiflora)群落、杠柳(Periploca sepium)群落、艾蒿(Artemisia argyi)+狗娃花(Heteropappus hispidus)群落、旋覆花(Inula japonica)+败酱(Patrinia scabiosaefolia)群落、沙棘(Hippophae rhamnoides)+小檗(Berberis thunbergii)群落和沙棘+红花岩黄耆(Hedysarum multijugum)群落6类。群落的Shannon-Wiener多样性指数(H′)整体呈下降趋势,Pielou均匀度指数(J)呈现增减交替的趋势,Simpson优势度指数(C)整体呈增加趋势,土壤粉粒含量与Simpson优势度指数(C)呈显著正相关关系(P0.05),表明土壤中粉粒含量是影响河流湿地原生植物群落分布和多样性的关键因子之一。内陆河流湿地土壤质地类型的差异性一定程度上决定河岸带湿地生态系统原生植物群落的种类组成和分布格局。

关键词：物种多样性内陆河湿地植物群落土壤因子 twinspan

Relationship between vegetation types, soil and topography in southern forests of Iran

在线全文

学校读者我要写书评

暂无评论

Journal of Forestry Research 2018年第6期29卷 1635-1644页

作者： Gholamhosein Moradi Harald Vacik School of Natural Resources and Desert Studies Yazd University Department of Forest and Soil Sciences Institute of SilvicultureUniversity of Natural Resources and Life Science

For sustainable forest management, understanding the ecological factors that determine vegetation composition are important. Here, the relation between the vegetation composition and environmental factors(elevation, aspect, slope, CaCO3, K, P, C, N, C/N, bulk density,soil porosity, saturation moisture content, EC, pH, sand, silt and clay) was investigated in the Khonj forests, Fars Province, Iran. Characteristic land units, each 200 m2, were chosen for sampling to analyze species composition, soil characteristics and topographic factors. The floristic data were classified using a two-way indicator species analysis(twinspan). Means were then compared using an ANOVA and Duncan multiple range test to detect any variations between groups. Also, the Kaiser–Meyer–Olkin index and Bartlett test were used to measure sampling adequacy. The four vegetation groups identified comprised the species Achillea wilhelmsii, Tanacetum parthenium,Convolvulus spinosus, Capparis spinosa. A detrended canonical correspondence analysis(DCCA) ordination diagram clearly illustrated the relationship between vegetation and environmental factors. According to the results,group 1 with A. wilhelmsii as the indicator species has a positive relation with slope and elevation. T. parthenium was the indicator species of group 2, that appears in areas with high silt and low bulk density and sand. The results showed that group 3 with Convolvulus spinosus as the indicator species was distributed in soils with high bulk density, low silt and pH as well. Group 4 with C. spinosa as the indicator species occurs in sandy soils and low slopes.Using DCCA, we determined the relationship between species and environmental factors more accurately. Results of this study can be used to restore vegetation or maintain species composition in ecological sensitive areas.

关键词： DCCA Environmental factors Khalij-Omani sub-region twinspan

海浪河春季底栖动物twinspan分类及水质初步评价

在线全文

学校读者我要写书评

暂无评论

水产学杂志 2010年第4期23卷 41-46页

作者：费滕于洪贤东北林业大学野生动物资源学院黑龙江哈尔滨150040

应用双向指示种(twinspan)技术对海浪河春季的7个采样点进行分类和水质评价研究;共采集到环节动物、软体动物和节肢动物3大类,包括4纲7目9科14属共18种;结合污染指数,twinspan分析结果表明海浪河春季采样点划分为四个类型,海浪河大桥6#... 详细信息

应用双向指示种(twinspan)技术对海浪河春季的7个采样点进行分类和水质评价研究;共采集到环节动物、软体动物和节肢动物3大类,包括4纲7目9科14属共18种;结合污染指数,twinspan分析结果表明海浪河春季采样点划分为四个类型,海浪河大桥6#点水质最好,其次为海南桥7#采样点,河夹大坝1#、2#点水质较差,3#、4#、5#采样点水质最差,但根据污染指数评价标准来看,水质都处于不同程度的污染状态。

关键词：海浪河底栖动物水质评价 twinspan

Desert vegetation distribution and species-environment relationships in an oasis-desert ecotone of northwestern China

在线全文

学校读者我要写书评

暂无评论

Journal of Arid Land 2019年第3期11卷 461-476页

作者： ZHAO Peng QU Jianjun XU Xianying YU Qiushi JIANG Shengxiu ZHAO Heran Key Laboratory of Desert and Desertification Northwest Institute of Eco-environment and ResourcesChinese Academy of SciencesLanzhou 730000China State Key Laboratory Breeding Base of Desertification and Aeolian Sand Disaster Combating Gansu Desert Control Research InstituteLanzhou 730070China Gansu Minqin National Field Observation and Research Station on Ecosystem of Desertification Rangeland Minqin 733000China University of Chinese Academy of Sciences Beijing 100049China

Environmental heterogeneity significantly affects the structure of ecological communities.Exploring vegetation distribution and its relationship with environmental factors is essential to understanding the abiotic mechanism(s)driving vegetation succession,especially in the ecologically fragile areas.In this study,based on the quantitative analysis of plant community and environmental factors in 68 plots at 10 different transects in the Minqin oasis-desert ecotone(ODE)of northwestern China,we investigated desert vegetation distribution and species-environment relationships using multivariate analysis.Two-way indicator species analysis(twinspan),detrended correspondence analysis(DCA),and canonical correspondence analysis(CCA)methods were used.A total of 28 species,belonging to 27 genera in 8 families,were identified.Chenopodiaceae,Zygophyllaceae,Gramineae,and Leguminosae were the largest families.Annual and perennial herbs accounted for 28.60%of the total number of plants,while shrubs(42.90%)were the most dominant.Nitraria tangutorum was the constructive species of the desert plant community.We divided the 68 plots surveyed in this study into 7 community types,according to the results of twinspan.The distribution of these 7 communities in the DCA ordination graph showed that species with a similar ecotype were clustered together.Results of CCA indicated that groundwater was the dominant factor influencing vegetation distribution,while distance between plot and oasis(Dis)and soil electrical conductivity(EC)were the local second-order factors.Our study suggests that optimizing the utilization of groundwater in oases is key to controlling the degradation of desert vegetation.The favorable topographic conditions of sand dunes should be fully utilized for vegetal dune stabilization,and the influence of soil salinity on the selection of afforestation tree species should be considered.

关键词： twinspan classification ordination desert plant groundwater oasis-desert ecotone species-environment relationship Minqin

Community Characteristics of Wild Fruit Forests Along Elevation Gradients and the Relationships Between the Wild Fruit Forests and Environments in the Keguqin Mountain Region ofⅠii

在线全文

学校读者我要写书评

暂无评论

Journal of Mountain Science 2012年第1期9卷 115-126页

作者： ZHUANG Li TIAN Zhonping CHEN Yaning LI Weihong LI Jiangui LU Shuang Xinjiang Shihezi University ShiheziXinjiang 832000China Xinjiang Institute of Ecology and Geography ChineseAeademy of ScienceUrumqi 830011China Xinjiang agricultural university Urumqi 830021China

In this paper,the quantitative relationship between the wild fruit communities and direct environmental factors is discussed on the basis of detailed data on landscape scale habitats obtained through field vegetation investigation.The results from twinspan and DCCA showed that:1) In the distribution sections of the wild fruit forest in the Keguqin Mountain region,the basic patterns characteristic of the different habitats are due to topographic factors,nutrients and moisture conditions;2) The elevation affected the most basic differentiation of plant communities in the study area,indicating that the elevation condition was the most important factor restricting the distribution of the wild fruit communities in the study area;3) The close relationship between the moisture content in the upper soil layer and the elevation reflected the influence of moisture conditions on both wild fruit and herb-layer communities;4) Nutrient differences not only indicated that the habitat conditions were different in themselves but also showed that the present nutrient conditions of the habitats were seriously affected by human activities.In summary,under complicated mountainous topographic conditions,the habitat conditions for the communities differed very significantly,and the combination of elevation,soil moisture content,total nitrogen,slope aspect,and pH value influenced and controlled the formation of community distribution patterns in the study area.

关键词：海拔梯度群落特征野生水果环境因素果树林山区 twinspan 土壤含水量