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1.
寿昌江流域及邻近山区溶岩洞穴大型水生底栖动物   总被引:3,自引:0,他引:3  
灵栖洞、灵山洞、瑶琳洞为浙江西部山区已开发的著名观光溶岩洞穴群,灵栖洞位于寿昌江流域支流小江溪的源头附近,由灵泉、清风、霭云三洞组成,灵山洞由清虚洞、仙桥洞组成.三洞穴群内大型水生动物隶属2门3纲5目11科.灵栖洞大型水生动物群落主要由放逸短沟蜷和掌指米虾组成,灵山洞主要由硬环棱螺、放逸短沟蜷、格氏短沟蜷及水生昆虫幼体组成,瑶琳洞内主要由锯齿新米虾和扁卷螺组成.灵泉洞洞穴有光带主要分布有掌指米虾和放逸短沟蜷,弱光带主要分布有锯齿新米虾、掌指米虾和硬环棱螺,黑暗带主要分布有锯齿新米虾、掌指米虾和扁卷螺,灵泉洞有光带动物种类的多样性、均匀度指数最高,分别为0.9832和0.6109,黑暗带最低,分别为0.0983和0.1418;优势度在黑暗带最高,其值为0.6250.表3参18  相似文献   

2.
濒危植物脱皮榆种群结构与分布格局研究   总被引:12,自引:0,他引:12  
对山西南部中条山和霍山脱皮榆的种群结构与分布格局进行了研究,其中根据大小结构图和存活曲线分析脱皮榆种群动态,应用扩散系数、聚集指数、平均拥挤度、聚块性指数、聚集强度、Cassie指数(1/K)、Poisson分布和负二项分布的χ2拟合检验等方法研究分布格局.结果表明,脱皮榆种群幼苗个体比例较大,总体上近于增长型种群.脱皮榆分布格局呈聚集型,这主要与物种本身的生物学和生态学特性密切相关,同时受群落内生境异质性的影响.图2表2参14  相似文献   

3.
种群分布格局是植物群落的重要特征,研究种群分布格局是理解植物群落形成和构建的基础。采用Poisson数学模型和方差均值法检验广东康禾自然保护区地面苔藓种群分布格局的类型,利用双向轨迹方差法(TTLQV)分析其格局变化。结果显示,研究区苔藓植物整体呈集群分布,优势种东亚拟鳞叶藓(Pseudotaxiphyllum pohliaecarpum)平均拥挤指数最高(m*=13.04),聚块性指数最低(m*/m=1.15),细叶小羽藓(Haplocladium microphyllum)和细指苔(Kurzia gonyotricha)的平均拥挤指数次之,分别为11.85、10.00;而非优势物种树生扁萼苔(Radula obscura)和长叶羽苔(Plagiochila flexuosa)聚快性指数最高,分别为14.79、14.45;说明优势物种的种间竞争更强烈,非优势物种分布更聚集。种群格局变化表明,研究区苔藓植物的格局规模以小斑块聚集居多,如细指苔、神山细鳞苔(Lejeunea eifrigii)、东亚拟鳞叶藓及南方小锦藓(Brotherella henonii)等多个物种在区组4、5、15、22、24呈现斑块聚集,其格局规模的差异可能与苔藓植物的生存策略和生长环境密切相关。苔类植物与苔藓植物的整体格局变化更接近,在区组4都呈大斑块聚集,整体为镶嵌格局;而藓类植物在区组5、16、22均有较大的峰值波动,为大斑块聚集;说明苔类植物优势种群组在群落中占主导地位。不同苔藓物种呈现不同的格局变化,主要受其生物学特性与种间竞争的影响,生境异质性则是其集群分布的主要原因。  相似文献   

4.
种群空间格局是种群生态学和空间生态学的核心问题之一。采集扎龙湿地1981—2008年丹顶鹤种群巢址定位数据,采用平均中心模型和最近邻体分析等方法研究了该研究区丹顶鹤种群空间分布格局及其动态,探讨了变化的原因与机制。结果表明:近30 a间,空间格局总体分布由研究区域核心区中部转移至西南部,再转移至东北区域,丹顶鹤个体间的离散程度经历了逐渐增大→逐渐减小→迅速增大→逐渐减小的过程,各时期空间分布型均为聚集分布,但不同时期聚集强度差异明显。生境条件的剧烈变化,即湿地缺水加剧以及人类活动干扰(如湿地内修建的各种大型工程)是导致丹顶鹤空间格局变化的主要原因,突发性干扰(如火灾)对空间格局也产生了极大的影响。  相似文献   

5.
采用相邻格子样方法设立并行条形样地,以胸径分组研究远安大堰自然保护区马尾松天然种群结构,并采用6个离散分布模型和3个聚集强度指数研究格局分布型及强度,利用双向轨迹方差(TTLQV)分析马尾松种群格局规模变化.结果表明:种群内马尾松个体径级较大,古树级个体占比较大;V_(pi)为25.44%,由于缺乏更新层,种群为衰退型;马尾松种群为典型Poisson分布,聚集强度不高,格局斑块规模分别为10 m~15 m和35 m~40 m.种群的更新与保护应施加人工正向干扰,使马尾松林复层化、异龄化和混交化.  相似文献   

6.
玄武湖菹草种群空间格局分析及其环境效应   总被引:7,自引:0,他引:7  
王天阳  王国祥 《生态环境》2007,16(6):1660-1664
大型水生植物的分布格局与空间尺度有着密切关系,传统的分析方法只能分析一种尺度下的格局。引入点格局分析,以种群空间分布坐标点图为基础,分析各种尺度下的种群格局。运用点格局分析对玄武湖菹草种群的空间分布格局进行研究,并结合N、P等水质指标探讨其环境效应。结果表明,玄武湖菹草种群分布集群特征明显,且在尺度232~344m内聚集最为明显。从水质监测结果看,菹草种群有利于改善水体环境,无种群区的TN、TP和NO3-N浓度明显高于有种群区;溶解氧(DO)则表现为有种群区高于无种群区。菹草在空间分布上的明显规律性,会进一步导致水质参数的空间异质性。  相似文献   

7.
兰州市郊红砂种群数量动态与分布格局   总被引:1,自引:0,他引:1  
对兰州市南北两山天然分布的红砂种群数量动态和空间分布格局进行研究。利用地径回归得到红砂种群年龄结构,编制静态生命表,进行生存分析及谱分析,计算红砂种群年龄结构动态指数,以揭示种群数量动态特征;采用扩散系数、负二项指数、平均拥挤度、聚块性指数、扩散型指数、丛生指数、Cassie指数和Green指数8个分布指标判断红砂种群时空尺度上的格局类型。结果表明,南北两山红砂种群密度、盖度适宜,动态指数均大于0,呈现增长型,并存在明显的周期性;种群以中幼龄植株为主体,各龄级的死亡率基本平稳,但在第Ⅱ过渡到第Ⅲ龄级时,出现死亡高峰,存活曲线趋于Deevey-Ⅲ型。种群时空异质性明显,阳坡的红砂种群呈现聚集分布,阴坡则多呈现均匀分布;不同发育阶段红砂种群分布格局呈现明显递变规律,幼龄阶段聚集度高,随着年龄增大,聚集性大幅减弱。  相似文献   

8.
中亚热带红壤丘陵区农业流域景观格局对水文过程的影响   总被引:1,自引:0,他引:1  
景观格局是影响流域水文过程和水分循环要素分配的重要因素,研究景观格局对流域水文过程的影响可以为流域水资源管理和合理利用提供科学依据。以湖南省长沙县金井流域为例,利用2010—2014年实测水文、气象资料和土地利用遥感图,基于Pearson相关分析和多元线性逐步回归模型,分析流域景观格局对水文过程(河川径流与基流)的影响。结果表明:(1)流域河川径流流量季节性波动剧烈,而基流流量的季节性变化相对较小;(2)流域景观格局显著影响水文过程,平枯水期河川基流量与香农多样性指数(SHDI)、斑块密度(PD)和边界密度(ED)呈显著正相关,与蔓延度指数(CONTAG)、最大拼块面积所占景观面积比例(LPI)、聚集指数(AI)和斑块凝聚度(COHESION)呈显著负相关(P0.05);(3)全年和平枯水期流域河川径流系数和基流量可以用流域内土地利用方式面积比例和景观格局指数预测,对流域景观的合理规划有利于中亚带红壤丘陵区农业流域水资源的科学管理和合理利用。  相似文献   

9.
西藏色季拉山川滇高山栎种群的空间格局与调节   总被引:1,自引:0,他引:1  
川滇高山栎是青藏高原具有代表性的常绿阔叶树种,在藏东南林区大面积连续分布,对高山峡谷地带的水土保持和水源涵养具有重要的防护作用和较大的生态效益.采用聚集度指标、以空间推时间法的Logistic方程和种群调节的乘幂函数拟合分别对西藏色季拉山川滇高山栎种群的空间分布格局、增长与调节规律进行了研究.结果表明,川滇高山栎幼苗多呈聚集分布,随着演替的进展,川滇高山栎种群的聚集强度减小;川滇高山栎种群增长的环境容纳量为15.2085m2hm-2,内禀增长率为0.614;种群最大增长速率出现在胸断面积9.66m2hm-2处,种群在平均胸断面积46.23cm2(均胸径7cm)~198.723cm2(均胸径15.91cm)阶段自疏强度最大.川滇高山栎种群聚集强度随演替过程逐渐减弱,是种群在有限的环境容量中自疏和自我调节特征的明显表现.Logistic方程即反映了生物种群增长速度的变化和环境容量限制的时滞效应这一重要特征,种群调节的幂函数拟合则有效刻画了生物种群在大量繁殖之后,随着个体增大,个体间资源竞争增强,种群内部出现优胜劣汰的自我调节过程.图4表2参32  相似文献   

10.
2008年夏季采用样带样方法对塔里木河下游典型绿洲边缘7个断面进行植被调查,采用α多样性指数(丰富度指数、Shannon-Wiener多样性指数、Simpson优势度指数和Pielou均匀度指数)和β多样性指数(Whittacker指数和Cody指数)分析环境梯度下种群多样性变化规律,利用种群分布格局指标(扩散系数、负二项参数、平均拥挤度、丛生指标和聚块性指标)定量分析绿洲边缘10个植物种群格局特征.结果表明:塔里木河下游典型绿洲边缘物种多样性特征受到土壤水分、盐分等因素限制,物种丰富度整体处于较低水平;α多样性指数表现为绿洲>过渡带>流动沙丘;从绿洲、过渡带到流动沙丘β多样性指数呈下降趋势;种群分布格局分析结果表明绿洲边缘10个植物种群均呈聚集分布,集群分布状态反映了干旱区植物种群对生存环境的适应特征.  相似文献   

11.
The Sarno river basin covers an area of 500 km2 collecting the waters of Solofrana and Cavaiola tributaries. Originally it manly represents a source of livelihood for inhabitants by fishing and transporting goods; currently, the Sarno river, still partially used for irrigation, is affected by an extreme environmental degradation as a result of uncontrolled outflow of industrial waste. Within the framework of a wider geochemical prospecting project aiming at characterizing the whole territory of the Campania region, 89 stream sediment samples with a sampling density of 1 sample per 5 km2 were collected in the river basin and analyzed by means of inductively coupled plasma-mass spectrometry in order to assess the environmental conditions at a regional scale. A GIS-aided technique, based on both the actual distribution of potentially harmful elements and their regional background values, was used to generate the maps of the contamination factors and of the contamination degrees for As, Cd, Cr, Cu, Hg, Pb and Zn. Furthermore, a factor analysis was performed to assess the nature and the extent of contamination sources for the river sediments. Results showed that the Sarno river basin could be divided in two “environmental status” units: one, low contaminated, corresponding to the hilly and mountain areas, and the second, from moderately to very highly contaminated, corresponding to the economically developed areas of the valley floor characterized by a high population density. This work was developed within a project that aims to investigate the relationships between environmental pollution and human health by analyzing environmental media (stream sediments, water, soil and vegetation) together with human hair of resident population. In this context, the spatial correlation between the extremely compromised environmental conditions of developed areas and the incidence rate of liver cancer in the same area was also explored posing the need of a careful costs/benefits analysis to assess whether the deterioration of the environment, that could adversely affect the conditions of public health, is worth the economic development.  相似文献   

12.
Time series data on population change, economic development, climate change, water volume and quality and oasis land-use change were collected to study the interactions between these factors in the arid Tarim River Basin, China. The study reveals that precipitation and stream flow in headwater streams increased, but stream flow in the main Tarim River had reduced significantly over the past three decades. This implies that human activity, rather than climate change, dominated the recent environmental changes in the river basin. As a result of population growth and cultivated land expansion in the upper and middle reaches of the river, severe problems of water shortage, water pollution, death of natural vegetation, soil salinization, desertification and sand-dust storms have occurred, particularly in downstream areas of the river basin. These problems have had serious negative effects on the health of local people and sustainable social economic development in the region. Some development strategies are proposed to deal with these problems.  相似文献   

13.
The Shiyang River Basin is an inland river basin in the Hexi Corridor, Gansu Province, northwest China. Shiyang is the largest basin in terms of human population density and has the highest exploitation of water resources in the northwest. Serious water shortages constrain social and economic development, and the area has some of the worst ecological and environmental deterioration in China. From historical data and recent observations, we have analysed changes in water systems in the Minqin oasis, at the end of the river basin, and assessed impacts and consequences of a changing climate and intensive human activity. Historically, climate change has been the main cause of changes in the oasis. In the last 50 years, however, a major influence has been intense human activity in the basin. With increasing population (159% in 50 years), the amount of cultivated land has been greatly expanded (by 51%). Many reservoirs have been built by damming rivers and large-scale irrigation has been introduced in the middle reaches of the basin. The introduction of leakage-free canals and more extensive exploitation of underground water have further expanded the irrigated area. Water use by humans has exceeded the carrying capacity of the water resources of the basin, which has led to a dramatic shift in water allocation between the upper and lower reaches and a rapid drop in the water table in the Minqin oasis (by as much as 14 m). The oasis is shrinking, natural vegetation that relies on underground water is disappearing, and desertification is accelerating. An ancient oasis that can be traced back 2000 years is disappearing and this must be a warning sign for future generations.  相似文献   

14.
特定小流域水质模型的选择   总被引:2,自引:0,他引:2  
王蕾  尹澄清 《环境化学》1993,12(5):387-393
根据特定小流域的水文特点和实际要求,建立一个流域综合水质模型,它由三个子模型支持,即:河流水质模型、水库富养营化模型和非点源污染模型。本工作对河流水质模型(QUAL2EU)加以改进,使之适应W河的具体情况,并在QUAL2EU增加了模拟COD、网箱养鱼和底泥泛起的功能。完成了作了水源地的水库地的水库富营养化模型,解决了流域内农业耕作、污水灌溉等造成的非点源污染随降雨径流进入水体过程的模拟和计算,使之  相似文献   

15.
东江流域土壤、植被和悬浮物的碳、氮同位素组成   总被引:1,自引:0,他引:1  
碳、氮同位素值对监测流域植被组成、环境变迁是一种非常有效的指标,为中短时间尺度环境变化研究提供了一条新的途径。以亚热带山区的东江流域为例,以流域内的植被、土壤及水体悬浮物为研究对象,应用其有机质同位素组成(δ13C、δ15N),揭示流域植被的成分和环境变化的信息。研究发现:东江流域土壤碳同位素、C/N比值差值不大;植被的氮同位素差值明显,C/N比值差异较大。对东江流域悬浮物δ13C值近20年的监测表明:其值在早期逐年升高,近10年来转趋稳定并呈明显下降趋势,变化范围在-17.8‰~-26.1‰之间,反映了该流域植被破坏和恢复的过程以及土壤侵蚀状况的变化趋势。  相似文献   

16.
The rapid urbanization of China is causing a burden on their water resources and hindering their sustainable development. This paper analyzes effective methods to integrated river basin management (IRBM) using Longgang River basin of Shenzhen as an example, which is the city with the fastest rate of urbanization in China and even the whole world. Over the past 20 years, China has undergone a population boom due to the increase of immigrant workers and rapid development of laborintensive industries, which led to the sharp increase of water consumption and sewage discharge. However, the construction of the water infrastructure is still lagging far behind the environmental and social development, with only 32.7% of sewage in the district being treated. Currently, every water quality indicator of the Longgang River basin was unable to meet the required corresponding environmental standards, which further aggravated the water shortages of the region. Thus, an analytical framework is proposed to address the IRBM of the study area. The problems with the current management system include the lack of decentralization in decision-making, lack of enforcement with redundant plans, weak management capacity, financial inadequacy, and a poor system of stakeholder participation. In light of the principles of IRBM and the situation of the region, corresponding measures are put forward, including an increase of power given to sub-district offices, fewer but more feasible plans, capacity building among stakeholders, a combination of planning and marketing for overcoming financial inadequacy, and profound reform in the public participation system. The framework and institutional suggestions could inform similar processes in other representative river basins.  相似文献   

17.
徐荃  袁秀顺 《环境化学》1992,11(4):52-55
本文研究了嘉陵江水系Mo水环境背景值,将嘉陵江水系分成四个环境背景单元并比较了其背景值,本文还研究了采样点的合理布置,进行了异常值取舍,Mo背景值和分布类型的计算,最后探讨了季节变化对Mo背景的的影响。  相似文献   

18.
River basin management in China has focused on large rivers, such as the Yangtze and Yellow Rivers. However, there are also about 20,000 small river basins that deserve attention. The Biliu River basin in Liaoning Province, northeast China, which is 156 km in length, has many features common to small river basins, including divided jurisdiction among governments leading to vertical and horizontal fragmentation. In the Biliu basin, the key municipalities are Dalian with a population of almost 6 million people and Yingkou with about 2.28 million people. Each has different interests and needs, making coordination and collaboration difficult. The literature and practice suggest that effective integrated water resource management (IWRM) requires at least six features: (1) vision, policy and strategy; (2) a legislative or statutory basis to provide credibility and authority; (3) a river basin organization to coordinate development and management; (4) specification of functions and authority of the river basin organization; (5) public participation and community involvement; and (6) an IRWM strategy and plan. Water management in the Biliu River basin is assessed relative to these features of IWRM, with recommendations offered regarding changes to have water management in the Biliu River basin to reflect what is expected in an IWRM approach.  相似文献   

19.
电解锰产业集聚区河流锰污染演变趋势和时空分布特征   总被引:1,自引:0,他引:1  
松桃河流域是我国锰产业最为集中的区域之一,资源开发和利用形成的污染严重。通过对松桃河电解锰产业集聚区流域2015—2019年的8个典型断面的总锰监测数据的分析,用秩相关系数法探究了河流锰污染总体变化趋势,并用系统聚类分析法分析了河流锰的时空分布特征,结合聚类结果对污染趋势做进一步分析。秩相关系数分析结果表明,近年来松桃河锰产业集聚区流域的上游水质较好且稳定,而中游污染严重,干流均值超过地表水环境质量标准值(0.1 mg·L-1)3—7倍,下游水质有所恢复,流域主要断面锰浓度总体呈下降趋势;时间聚类分析表明,流域内河流锰污染的年内分布主要特征为丰水期(雨季)和枯水期(旱季)浓度较高而平水期相对较低;空间聚类结果显示,流域内河流锰污染呈现出中游支流>中游干流>下游和上游的特征,两条支流道水河和老卜茨小溪对中游相应区段的贡献率较大,分别为41.2%和23.5%;聚类结果分析显示,降雨、渣库分布和渗漏、水文地质条件和支流汇入是影响流域内河流锰浓度的重要因素;结合聚类结果的污染趋势分析得出,中游和下游的水质在枯水期和丰水期的年度变幅较大,但在2017年以后呈现明显的下降趋势,结果反映了期间政府进行综合整治的效果和流域污染源排放的随机性。  相似文献   

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