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中国大痣小蜂属食植群记述(膜翅目:长尾小蜂科) 被引量:14
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作者 徐志宏 何俊华 《Entomotaxonomia》 CSCD 1995年第4期243-253,共11页
本文报导中国大痣小峰属Megastigmus食植群Phytophagousgroup12种,其中包括5新种:黄杉大痣小蜂Megastigmuspseudotsugaphilusspnov(寄生华东黄杉Pseudots... 本文报导中国大痣小峰属Megastigmus食植群Phytophagousgroup12种,其中包括5新种:黄杉大痣小蜂Megastigmuspseudotsugaphilusspnov(寄生华东黄杉Pseudotsugagaussenii),拟海棠大痣小蜂Megastigmuspseudomalisp.n.(寄主不明),基室大痣小蜂Megastigmuscellssp.nov.(寄主不明),滇柏大痣小蜂Megastigmusduclouxianaesp.nov.(寄生云南滇柏Cupressusduclouxiana)和横脊大痣小蜂Megastigmuscarinussp.nov.(寄生云南滇柏);2中国新记录种:云杉大痣小蜂Megastigmusezomatsuanus(寄生西伯利亚云杉Piceaobvata),冷杉大痣小蜂Megastigmuslarsiocarpae(寄生西伯利亚冷杉Abiessibirica)。新种模式标本存浙江农业大学生物防治研究室。 展开更多
关键词 膜翅目 长尾小蜂科 大痣小蜂属 新种 植群
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中国大痣小蜂属食植群种类特征及检索 被引量:5
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作者 徐志宏 何俊华 《森林病虫通讯》 北大核心 1996年第2期12-14,共3页
本文列出我国大痣小蜂属食植群12种的检索表并附图.
关键词 大痣小蜂属 植群 检索 森林 害虫
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夏玉米辣椒间作的植群生态效应研究 被引量:13
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作者 李学敏 《河北农业科学》 1994年第4期25-27,共3页
夏玉米、辣椒间作植群中的叶层结构为光的透射创造了条件,植群中光的分布状况不仅有利于夏玉米和辣椒生长发育,而且玉米对辣椒作物的适度遮荫有效地抑制了辣椒的“日灼病”,间作群体中小气候变化形成了稳定的温度自调能力,有利于作物生... 夏玉米、辣椒间作植群中的叶层结构为光的透射创造了条件,植群中光的分布状况不仅有利于夏玉米和辣椒生长发育,而且玉米对辣椒作物的适度遮荫有效地抑制了辣椒的“日灼病”,间作群体中小气候变化形成了稳定的温度自调能力,有利于作物生长、间作系统的互补与竞争动态变化,使间作具有明显的产量优势。 展开更多
关键词 间作 植群 光分布 小气候 夏玉米 辣椒 玉米
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自棕地到湿地--高雄中都湿地公园植群复育计划 被引量:1
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作者 赖荣一 堀込宪二 +1 位作者 郭城孟 郭中端 《中国园林》 北大核心 2011年第12期56-61,共6页
高雄市政府为贯彻"高雄市都会型湿地生态廊道串连计划",定于2010年完成开辟高雄市内9处与市区紧邻的湿地公园,作为动植物生态可自由迁移于都会区内的"带状湿地生态廊道"。中都湿地公园即是此计划完成的最后一处湿... 高雄市政府为贯彻"高雄市都会型湿地生态廊道串连计划",定于2010年完成开辟高雄市内9处与市区紧邻的湿地公园,作为动植物生态可自由迁移于都会区内的"带状湿地生态廊道"。中都湿地公园即是此计划完成的最后一处湿地工程。高雄的生态系丰富多样,其中包含森林生态系的热带季雨林、海洋生态系的海岸林以及河口生态系的红树林。中都湿地公园内规划各类植群的生长环境,期望复育成功后可诱发其所属生态系。本湿地公园完工后建议高雄市政府拟订公园内动物及植群监测计划,记录中都湿地的生态变迁,说明高雄在全球地理位置上所占的重要生态地位,并制定植群维护管理计划,使中都湿地公园可持续兼具生态及景观休憩机能。 展开更多
关键词 风景园林 生态复育 红树林 海岸林 植群监测
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神农架南坡小叶青冈+曼青冈常绿阔叶林主要木本植物生态位与种间联结
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作者 陈聪琳 赵常明 +7 位作者 刘明伟 徐凯 徐文婷 熊高明 葛结林 邓滢 申国珍 谢宗强 《生态学报》 CAS CSCD 北大核心 2024年第11期4889-4903,共15页
为揭示神农架南坡代表性常绿阔叶林主要木本植物的种间生态联系及群落演替趋势,以小叶青冈+曼青冈群系20个主要木本植物的190组种对为研究对象,通过生态位测定并区分生态位特化种和生态位泛化种以及种间联结性检验,分析该群落主要物种... 为揭示神农架南坡代表性常绿阔叶林主要木本植物的种间生态联系及群落演替趋势,以小叶青冈+曼青冈群系20个主要木本植物的190组种对为研究对象,通过生态位测定并区分生态位特化种和生态位泛化种以及种间联结性检验,分析该群落主要物种生态位与种间联结特征。主要结果:(1)该常绿阔叶林群落物种丰富,群落组成复杂,小叶青冈(Cyclobalanopsis myrsinifolia)的重要值(11.13%)和生态位宽度(58.3)均最大,占绝对优势,生态位宽度排序和重要值排序不一致,分布频度对生态位宽度影响较大。(2)将20种主要木本植物划分为生态位特化种(6种)、生态位泛化种(3种)、中性类群(11种),生态位分化程度较高,资源利用差异以及生境适应性是影响生态位分化的主要因素。(3)生态位宽度大的物种其生态位重叠和相似度较高,生态位重叠指数总体略低,大部分物种对环境或资源需求相似,但相似度不高,种间竞争较弱,种间关系比较稳定。(4)主要木本植物总体正联结显著(P<0.05),χ^(2)检验、联结系数AC、Spearman秩相关检验结果均显示种间正联结作用占优势,但大多数种对联结不显著,物种趋于独立分布。(5)通过聚类分析,将20种主要木本植物划分三大生态种组:建群种组,共生种组和边缘种组。研究表明,神农架南坡小叶青冈+曼青冈常绿阔叶林目前正处于相对稳定的演替中后期阶段,群落发育较成熟,生态位分化、生境选择以及资源需求互补或互利是影响该群落物种共存的主要原因。研究阐明了神农架南坡代表性常绿阔叶林主要物种之间实际相互作用以及群落特征,为深入理解群落物种共存原因以及群落演替规律提供依据。 展开更多
关键词 常绿阔叶林 种群 种间关系 生态种组 物种共存
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登山步道游憩冲击之长期监测——以玉山国家公园塔塔加步道为例 被引量:25
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作者 刘儒渊 曾家琳 《资源科学》 CSSCI CSCD 北大核心 2006年第3期120-127,共8页
本研究应用由植群覆盖度减少率(CR)、植相变异度(FD)及植株高度降低率(HR)等三项植群冲击介量所合成之植群冲击指数(IVI),与步道截面土壤冲蚀量之变化,自1991至2004年间,定期就游客践踏对塔塔加步道所造成之游憩冲击效应进行长期的调查... 本研究应用由植群覆盖度减少率(CR)、植相变异度(FD)及植株高度降低率(HR)等三项植群冲击介量所合成之植群冲击指数(IVI),与步道截面土壤冲蚀量之变化,自1991至2004年间,定期就游客践踏对塔塔加步道所造成之游憩冲击效应进行长期的调查监测,探讨其变迁与可能的影响因子。本文汇整14年来所完成之重要调查监测与研究成果,并提出若干建议事项供为游憩生态学之相关研究,与经营管理单位在制定或修正其步道冲击防治与管理策略时之参考。 展开更多
关键词 步道冲击 冲击监测 植群冲击指数(IVI) 土壤冲蚀
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The Influence of Plant Diversity and Functional Composition on Ecosystem Stability of Four Stipa Communities in the Inner Mongolia Plateau 被引量:65
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作者 白永飞 李凌浩 +1 位作者 黄建辉 陈佐忠 《Acta Botanica Sinica》 CSCD 2001年第3期280-287,共8页
The main purpose of this study was to examine the effects of plant species diversity and functional composition (the identity of the plant functional groups) on ecosystem stability of Stipa, communities in the Inner M... The main purpose of this study was to examine the effects of plant species diversity and functional composition (the identity of the plant functional groups) on ecosystem stability of Stipa, communities in the Inner Mongolia Plateau. The research work was based on a 12-year study (from 1984 to 1995) of species abundance, diversity, and primary productivity of four Stipa communities, i.e. S. baicalensis Roshev., S. grandis P. Smirn., S, krylovii Roshev., and S. klemenzii Roshev. respectively. The Shnnon-Wiener index was used as a measurement of plant diversity, while functional composition was used to differentiate the functional groups that were included in the communities. The plant species of four Stipa communities were classified into functional groups based on the differences in life forms and ecological groups, which influence their performance in resource requirements, seasonality of growth, tolerance to water stress, and life history. Plant species were classified into five functional groups based on their differences in life form, shrubs and half shrubs, perennial bunch grasses, perennial rhizome grasses, forbs, annuals and biennials. Based on their differences in water requirement these species were classified into four functional groups: xerads, intermediate xerads, intermediate mesophytes, and mesophytes. The results showed: 1) Plant species diversity stabilized ecosystem processes. Shannon-Wiener index were 2.401 4, 2.172 0, 1.624 8, 0.354 3 from S. baicalensis community to S. grandis, S. krylovii and S. klemenzii community, respectively. The dynamics of the aboveground net primary productivity (ANPP) for a 12-year's period showed a reverse pattern, the coefficients of variation of the four communities were 21.94%, 20.63%, 29.21% and 39.72% respectively. 2) The Life form functional group component of diversity was a greater determinant of the ecosystem processes than the species component of diversity. The effects of perennial bunch grasses, perennial rhizome grasses and forbs on community stability were highly significant. 3) The ecological group component of diversity was also a great determinant of the ecosystem processes. The effects of xerads, intermediate xerads, and mesophytes on community stability were also very strong. 展开更多
关键词 Inner Mongolia Plateau Stipa communities the aboveground net primary productivity species diversity functional composition
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Characteristics,classification and ordination of riparian plant communities in the Three-Gorges areas 被引量:12
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作者 江明喜 邓红兵 蔡庆华 《Journal of Forestry Research》 SCIE CAS CSCD 2002年第2期111-114,163-164,共4页
Sixteen different vegetation types of grassland and shrubland were selected to study the component and diversity of plant species of riparian plant communities along main channel in the Three-Gorges areas. Species ric... Sixteen different vegetation types of grassland and shrubland were selected to study the component and diversity of plant species of riparian plant communities along main channel in the Three-Gorges areas. Species richness (s), Simpson index (D), and Shannon-Weiner index (H) were used to study the biodiversity and the hierarchical classification was carried out by the methods of TWINSPAN and DCA ordination. The results showed that the components of flora were complex and dominated by the temperate type in the riparian plant communities. Species diversity was not different between the communities, but Shannon-Weiner indexes of different layers in some grassland were significantly different. TWINSPAN and DCA indicated that riparian plant communities distributed along the gradient of moisture. 展开更多
关键词 Three-Gorges areas Riparian zone Plant community CLASSIFICATION ORDINATION TWINSPAN DCA
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Study on complexity of plant communities at different altitudes on the Northern Slope of Changbai Mountain 被引量:4
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作者 郝占庆 于德永 +1 位作者 邓红兵 姜萍 《Journal of Forestry Research》 SCIE CAS CSCD 2002年第1期17-20,82,共4页
By the method of gradient pattern analysis, twenty plots were set at altitudes of 700-2600 m with an interval of 100 m on the northern slope of the Changbai Mountain. The dissimilarity of respective sub-plots in the s... By the method of gradient pattern analysis, twenty plots were set at altitudes of 700-2600 m with an interval of 100 m on the northern slope of the Changbai Mountain. The dissimilarity of respective sub-plots in the same community was measured and the complexity of plant communities at different altitudes was analyzed. The result from binary data of tree species in canopy tree indicated that the sub-plots in the communities, except subalpine Betula ermanii forest, showed comparatively high dissimilarity in species composition. Especially, the dissimilarity index (0.7) of broadleaved/Korean pine forest at low altitudes was obviously higher than other communities. The differences are not obvious between communities referring to dark coniferous forest. Comparatively, the dissimilarity in sub-plots of the communities at altitude of 1400 m was slightly higher than that of other communities, which reflected the complexity of tree species compositions of transitory-type communities. For subalpine Betula ermanii forest, tree species composition was simple and showed a high similarity between sub-plots. The results derived from binary data of shrub showed that the dissimilarity index of shrub species in broadleaved/Korean pine forest at low altitudes was higher than that in other communities, but the divergence tendency wasn抰 so obvious as that of arbor species. The dissimilarity derived from binary data of herb and all plant species at different altitudes showed greatly close tendency, and the differences in herb and all plant species between sub-plots were the greatest for the communities of broad-leaved-Korean pine forest and alpine tundra zone.. 展开更多
关键词 Changbai Mountain COMPLEXITY Plant community Altitude gradient
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Quantity of plant leaf area on three major public squares in Kunming City, China 被引量:8
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作者 董燕 赵林森 赵宇翔 《Journal of Forestry Research》 SCIE CAS CSCD 2004年第4期291-294,共4页
Regressive formulae to calculate the quantity of plant leaf area for 13 species of ornamental plants were set up based on investigation data of 30 species on 3 major public squares (Dongfeng square, Shengli square and... Regressive formulae to calculate the quantity of plant leaf area for 13 species of ornamental plants were set up based on investigation data of 30 species on 3 major public squares (Dongfeng square, Shengli square and Guandu square) in Kun-ming City, China, which were applied to calculate quantities of plant leaf area of these 13 species. The quantities of plant leaf area for the other 17 ornamental plant species on these squares were directly measured, and the total quantity of plant leaf area of each studied square was obtained individually. The results showed that the quantity of plant leaf area on Shengli square with ornamental plants structure composed of arbor tree species, shrub tree species and turf grass was highest among the three squares. It is believed that the design model of multi-storied vertical structure and proper tending of plant community could not only increase the quantity of plant leaf area, but also play an important role in generating ecological and landscaping benefits. Some corresponding suggestions were put forward on the basis of comprehensive analyses on the plant leaf area quantity of the three representative squares in Kunming urban area. 展开更多
关键词 SQUARE Ornamental plants Quantity of plant leaf area Kunming
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Study on the Characteristics of Main Vegetation Communities in the Limestone Region of Taihang Mountain 被引量:4
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作者 弓运泽 周大迈 任士魁 《Agricultural Science & Technology》 CAS 2011年第12期1932-1936,共5页
[Objective] The aim was to study the characteristics of main vegetation communities in the limestone region of Taihang Mountain,so as to lay foundation for the further improvement of site conditions and the scientific... [Objective] The aim was to study the characteristics of main vegetation communities in the limestone region of Taihang Mountain,so as to lay foundation for the further improvement of site conditions and the scientific breeding of vegetation used to restore the mountain field in limestone region.[Method] Based on the investigation of various vegetation communities in controlled test area,forbidden region and barren hillsides in Daqing Mountain basin,Beishui Valley,Mancheng County,Hebei Province,the difference among controlled region,forbidden region and barren hillsides could be found through data analysis and composite score,and the modes of vegetation communities in controlled region and forbidden region were compared to select predominant species of arbor,shrub and grass in limestone region.[Result] Under the similar site conditions,nutrient content and physical properties of soil in controlled region and forbidden region were superior to those of barren hillsides,and persimmon had high nutrient content and better physical properties compared with oriental arborvitae in controlled region;soil water maintenance and litter characters in controlled region and forbidden region improved more obviously than that of barren hillsides,and shrubbery in forbidden region was the most excellent,arborvitae and persimmon in controlled region the second;the biomass and the coverage rate of vegetation communities in controlled region and forbidden region were higher than those of barren hillsides,and those of shrubbery in forbidden region were better than tussock in closing hill,while persimmon was better than arborvitae in controlled region.The predominant species of arbor,shrub and herbage were obtained through composite score.[Conclusion] From the aspects of soil nutrient,physical properties,soil water maintenance,litter characters,vegetation biomass,canopy density and coverage,controlled region and forbidden region were superior to barren hillsides,and the selection of predominant species of arbor,shrub and herbage considered both ecological and economic benefits. 展开更多
关键词 LIMESTONE Vegetation community Vegetation restoration Preponderant species
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Genetic Structure of Reaumuria soongorica Population in Fukang Desert, Xinjiang and Its Relationship with Ecological Factors 被引量:13
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作者 徐莉 王祎玲 +5 位作者 王戌梅 张林静 岳明 顾峰雪 潘晓玲 赵桂仿 《Acta Botanica Sinica》 CSCD 2003年第7期787-794,共8页
Genetic structure and differentiation of Reaumuria soongorica (Pall.) Maxim population from the desert of Fukang, Xinjiang, were assessed by means of random amplified polymorphic DNA (RAPD) markers. High genetic diver... Genetic structure and differentiation of Reaumuria soongorica (Pall.) Maxim population from the desert of Fukang, Xinjiang, were assessed by means of random amplified polymorphic DNA (RAPD) markers. High genetic diversity and differentiation were revealed in the population of R soongorica by 15 random primers. One hundred and thirty-six individuals from seven subpopulations were sampled in the study. Seventy-one loci have been detected, and among them 69 were polymorphic. The mean proportion of polymorphic loci (PPB) was 97.18%. The analyses of Shannon information index (0.307 5), Nei's gene diversity (0.312 7) and G(ST)(0.312 0) indicated that there were more genetic variations within the subpopulations than those among the subpopulations. The results of AMOVA analysis showed that 61.58% of the genetic variations existed within subpopulations, and 38.02% among the subpopulations. The gene flow among the subpopulations of R soongorica (Nm = 1.102 8) was much less than that of the common anemophytes (Nm = 5.24), so genetic differentiation among the subpopulations occurred to some extent. Additionally, through the use of clustering and the correlation analyses, we found that the genetic structure of natural population of R soongorica was related to some ecological factors (soil factors mainly) of the oasis-desert transition zone. The genetic diversity level of R soongorica had negative correlation with the content of total soil P and Cl significantly (P < 0.05). On the contrary, it had significant positive correlation with CO32- (P < 0.05), showing that the distribution of the individuals of R soongorica in the sampled areas correlates with certain soluble salt. Furthermore, the genetic diversity of the natural population of R soongorica increased with the decreasing of the content of soil organic matters, water, total N and total P in soil. The paper concluded that the microenvironment ecological factors played an important role in the adaptive evolution of R soongorica population. 展开更多
关键词 Reaumuria soongorica genetic structure ecological factors desert plant
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Flora and ecological characteristics of rare plant communities on the southern slope of Shennongjia Mountain 被引量:5
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作者 邓红兵 江明喜 +1 位作者 吴金清 葛继稳 《Journal of Forestry Research》 SCIE CAS CSCD 2002年第1期21-24,82-83,共4页
According to the investigation of sampling area of 6800 m2 on the south slope of Shennongjia Mountain, there were 126 vascular plant species, belonging to 108 genera and 64 families, in the investigated rare plant com... According to the investigation of sampling area of 6800 m2 on the south slope of Shennongjia Mountain, there were 126 vascular plant species, belonging to 108 genera and 64 families, in the investigated rare plant communities, of which 9 rare plant species were recorded, accounting for 27.3% of the total rare plants. The communities were about 30 m in height and were divided into three layers as tree layer, shrub layer, and herb layer. The flora of the communities had obvious temperate character. Phanerophytes (accounted for 65.9%), Mesophyllous (62.7%), Papyraceous (84.1%), simple leaf (83.3%), un-entire leaf (69.8%) were dominant in life form, leaf size class, leaf texture, leaf form, and leaf margin respectively. According to important value of species, the communities were divided into three types as Davidia involucrata + Litsea pungens community, Cercidiphyllum japanicum + Padus wilsonii community, and Padus wilsonii + Acer mono community. The indexes of species diversity of tree layer had little difference among communities and evenness was high. The results indicated that the communities had complex structure and relative stability. 展开更多
关键词 Rare plant community FLORA Ecological characteristics Shennongjia Mountain
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The changes of co-possession of plant species between communities with altitudes on northern slope of Changbai Mountain 被引量:3
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作者 邓红兵 郝占庆 王庆礼 《Journal of Forestry Research》 SCIE CAS CSCD 2001年第2期89-92,146,共4页
Twenty plots were investigated on northern slope of Changbai Mountain at an attitude interval of 100 m (from 700 to 2600 m). The species co-possession between plant communities at different altitudes was analyzed by J... Twenty plots were investigated on northern slope of Changbai Mountain at an attitude interval of 100 m (from 700 to 2600 m). The species co-possession between plant communities at different altitudes was analyzed by Jaccard index. The analytical results showed that the co-possession calculated according to species in different layers or all species between adjacent communities was higher than that between disjunct communities. The co-possessions between adjacent communities calculated by species in different layers had comparability and dissimilarity. If the two adjacent communities belong to different types of vegetation, then their co-possession was lower. The peak values and valley values of species co-possession between communities along elevation gradient just matched vegetation gradient patterns, and species subrogation of shrubs had more obvious rule on northern slope of Changbai Mountain. Co-possessions between communities with same altitude difference were much similar, and it decreased as the increase of elevation difference, which showed that species compositions in different layers of the communities were highly related. 展开更多
关键词 Changbai Mountain Co-possession Plant community Altitude gradient
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A Comparison of Macrofauna Communities in Different Mangrove Assemblages 被引量:9
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作者 唐以杰 余世孝 吴延勇 《Zoological Research》 CAS CSCD 北大核心 2007年第3期255-264,共10页
The characteristics of macrofauna communities in three mangrove assemblages [Avicennia marina+Acgiceras corniculatum (MC)community, A.corniculatum (C) community and Bruguiera gymnorrhiza+A.corniculatum (GC) co... The characteristics of macrofauna communities in three mangrove assemblages [Avicennia marina+Acgiceras corniculatum (MC)community, A.corniculatum (C) community and Bruguiera gymnorrhiza+A.corniculatum (GC) community] were studied in Zhanjiang Mangrove Nature Reserves during 2005 and 2006. Of the three mangrove assemblages, the macrofauna species number, density, biomass, Richness index and Shannon-Wiener index were the highest, and the Simpson dominance index was medial at MC community. However the Pielou Evenness index of MC community was slightly lower than that at C community. At C community, the number of macrofauna species obviously reduced, especially infaunal, caving and adhering life forms, and the biomass and density were the lowest. Because of the even distribution of individuals of different species, the Simpson dominance index was the lowest and the evenness index was the highest. Although the Richness index at C community was slightly lower than that at MC community, the Shannon-Wiener index was near to that at MC community. At GC community, the number of macrofauna species, especially infaunal and caving life forms, continued to decrease comparing C community, but the biomass and density increased slightly. As the distribution of individuals of different species was uneven, the Simpson dominance index was the highest and the Pielou Evenness index was the lowest. Furthermore, the Richness index dropped to the lowest. The Shannon-Wiener index also dropped accordingly to the lowest. The dominant life forms of MC were infaunal and caving, while those of C and GC community were both caving. The ratio of the GS/GSB of macrofauna communities in the three mangrove assemblages were 0.48, 0.63 and 0.80, respectively. The community structures at the same mangrove assemblages were all quite similar, with those at GC community being most similar. However, there were obvious differences among the community structures at the three different mangrove assemblages. These results implied that the different mangrove assemblages had different affects on the macrofauna communities and shed light on the macrofauna adaptation capability to specific habitats. 展开更多
关键词 Mangrove community MACROFAUNA Community structure
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Spatial and environmental effects on plant communities in the Yellow River Delta, Eastern China 被引量:8
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作者 宋创业 刘高焕 刘庆生 《Journal of Forestry Research》 SCIE CAS CSCD 2009年第2期117-122,I0002,共7页
Types and structure of plant communities in the Yellow River Delta were investigated by using detrended canonical correspondence analyses (DCCAs) and a two-way indicator species analysis (TWINSPAN). The distributi... Types and structure of plant communities in the Yellow River Delta were investigated by using detrended canonical correspondence analyses (DCCAs) and a two-way indicator species analysis (TWINSPAN). The distribution pattern and influential factors of the plant communities were also analyzed by testing elevation, slope, soil characteristics, longitude and latitude of 134 vegetation samples collected by representative plot sampling methods. Results showed that all the 134 vegetation samples could be divided into seven vegetation groups, separately dominated by Robinia pseucdoacacia, Imperata cylindrical, Miscanthus saccharifleus, Suaeda salsa, Aeluropus sinensis, Phragmites australis and Tamarix chinensis. The vegetation distribution pattern was mainly related to elevation, ground water depth and soil characteristics such as salinity and soluble potassium. Among the factors affecting distribution pattern of the plant communities, the species matrix explained by non-spatial environmental variation accounts for 45.2% of total variation. Spatial variation and spatial-structured environmental variation explain 11.8%, and 2.2%, respectively. Remained 40.8% of undetermined variation is attributed to biological and stochastic factors. 展开更多
关键词 detrended canonical correspondence analyses environmental factors plant communities spatial factors Yellow River Delta two-way indicator species analysis
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Phytoplankton Community Structure and Its Spatial Distribution along Anhui-Jiangsu Reaches of the Yangtze River in Autumn 2009 被引量:2
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作者 孟顺龙 陈家长 +4 位作者 胡庚东 吴伟 瞿建宏 范立民 裘丽萍 《Agricultural Science & Technology》 CAS 2012年第1期220-226,共7页
[Objective] Surveys of phytoplankton were taken during the autumn of 2009 along Anhui-Jiangsu reaches of the Yangtze River to understand the species com- position and their spatial distributions. [Method] Phytoplankto... [Objective] Surveys of phytoplankton were taken during the autumn of 2009 along Anhui-Jiangsu reaches of the Yangtze River to understand the species com- position and their spatial distributions. [Method] Phytoplankton species, their quanti- ties, biomass and the Mcnaughton's dominance indices were all measured and their spatial distribution characteristics were determined using cluster analysis. [Result] There were 27 species, belonging to 5 phyla, namely Chlorophyta, Bacillariophyta, Cyanophyta, Euglenophyta and Cryptophyta, of phytoplankton collected and identified from the surveys. Results showed that Bacillariophyta was the predominant phyto- plankton with 16 species collected which accounted for 59.3% of the total species identified. The number of species collected belonging to Chlorophyta, Cyanophyta, Cryptophyta and Euglenophyta were 6, 2, 2, and 1, accounting for 22.2%, 7.4%, 7.4% and 3.7% of the total number identified, respectively. At the species level, the predominant species were Fragilaria crotonensis, Melosira italica, Navicula crypto- cephala, Cyclotella striata and Chroomonas acuta. Phytoplankton abundance was ranging from 5.68×10^4 to 7.08×10^4 cells/L with its average of 6.01×10^4 cells/L. Phyto- plankton biomass was ranging from 30.43 to 34.73 μg/L with its average of 32.46 μg/L. Compared with the previous reports, the number of phytoplankton species was decreased but its abundance and biomass was increased along the Jiangsu reach of the Yangtze River. However, Bacillariophyta species were still the predominant species and the phytoplankton community structure had not significantly changed from the previous studies. [Conclusion] These results might be explained as that the water quality in the Yangtze River was deteriorated but had not come to the worst. The results of similarity analysis gave two clusters of phytoplankton community as Nanjing, Wuhu and Jiangyin sampling sites were clustered into one group and Tongling and Anqing were clustered into another group. 展开更多
关键词 PHYTOPLANKTON Community structure Yangtze River Anhui-Jiangsu reaches Spatial characteristics
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Variation of Water-Use Efficiency of Leymus chinensis and Cleistogenes squarrosa in Different Plant Communities in Xilin River Basin, Nei Mongol 被引量:6
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作者 陈世苹 白永飞 韩兴国 《Acta Botanica Sinica》 CSCD 2002年第12期1484-1490,共7页
Water is usually considered to be a key limiting factor for the growth and reproduction of steppe plants in the Xilin River Basin, Nei Mongol. Foliar delta C-13 values, an indicator of long-term intercellular carbon d... Water is usually considered to be a key limiting factor for the growth and reproduction of steppe plants in the Xilin River Basin, Nei Mongol. Foliar delta C-13 values, an indicator of long-term intercellular carbon dioxide concentration and thus of water-use efficiency (WUE) in plants, were measured on Leymus chinensis (Trin.) Tzvel. and Cleistogenes squarrosa (Trin.) Keng. in six communities of different habitats in die Xilin River Basin. The foliar delta C-13 values of both species tended to increase with decreasing soil water content (SWC) and a significant negative correlation was found between foliar delta C-13 Values and SWC in different soil layers, indicating that the two species could change WUE according to water availability. We also found relatively constant leaf water contents (LWC) of the two species in different habitats. Our results implied that the two steppe species might have adapted to different soil water regimes either through adjusting stomatal conductance to get a proper WUE, or through enhancing the osmosis-regulating ability to keep a relatively stable LWC. Our findings could partially explain why the two plant species have a wide distribution range and become dominant in the Xilin River Basin. 展开更多
关键词 Xilin River Basin Leymus chinensis Cleistogenes squarrosa water-use efficiency delta C-13 value
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Role of Wind-Sand Disturbance in the Formation and Development of Tamarix taklamakanensis Community 被引量:9
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作者 何兴东 高玉葆 任安芝 《Acta Botanica Sinica》 CSCD 2003年第11期1285-1290,共6页
Formation, development and degeneration of Tamarix taklamakanensis M.T. Liu community may be affected by wind-sand disturbance. On the basis of field survey and experiments that took eight years from 1994, it was foun... Formation, development and degeneration of Tamarix taklamakanensis M.T. Liu community may be affected by wind-sand disturbance. On the basis of field survey and experiments that took eight years from 1994, it was found that the plant community was formed in wet and low-lying land, developed in sand burying land, and died out in the land with strong wind erosion and severe sand burying. In the initial stage of the community formation, the low-lying land that was formed by wind erosion provided a suitable habitat for seed germination and plant rooting, but salt stress from ground water reduced seedling survival rate. In the developing stage of the community, sand burying stimulated vigorous growth of the shrubs. In the degenerative stage of the community, the wind erosion and sand burying resulted in dying out of the shrubs. It is therefore concluded that wind-sand disturbance has a positive role in the formation and development of the community, and is in a close association with the process of the community degeneration. Taking the habitat of T taklamakanensis into account, it may be appropriate to note that, under the conditions of frequent disturbance and severe stress, desert pioneer species are adaptable and able to survive. This might be a supplement to the CSR strategy. 展开更多
关键词 Takla Makan Tamarix taklamakanensis wind-sand disturbance community formation and development plant strategy
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Study on the Biome Classification of Helophytes at Maqu Wetland 被引量:1
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作者 张怀山 赵桂琴 张吉宇 《Agricultural Science & Technology》 CAS 2012年第10期2202-2205,共4页
[Objective] This study aimed to accomplish a biome classification of helophytes at Maqu,the first bend of the Yellow River.[Method] Helophgtes in the Maqu wetland were investigated using quadrat sampling method with r... [Objective] This study aimed to accomplish a biome classification of helophytes at Maqu,the first bend of the Yellow River.[Method] Helophgtes in the Maqu wetland were investigated using quadrat sampling method with references to plant specimens.[Result] The helophyte communities at Maqu wetland could be divided into two categories:sedge marshes and non-sedge marshes,which can be further subdivided into 4 biomes.The constructive species mainly included Blysmus sinocompressus,Blysmocarex nudicarpa,Eleocharis valleculosa and Polygonum amphibian.The sub-constructive species consisted mainly of Carex brunnescens,Catabrosa aquatica,Kobresia kansuensis,Polygonum amphibium and Leontopodium alpinum.The total coverage of communities ranged from 5% to 90%,which were commonly found in areas permanently ponded with water,such as watercourse depressions,floodplains,valley depressions,terrace scarp depressions and riverhead depressions,with the underground water depth of 20-30 cm.[Conclusion] The biome classification of helophyte communities provided scientific basis for the ecological restoration and control of Maqu wetland prairie. 展开更多
关键词 WETLAND HELOPHYTES Biome classification Maqu County
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