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1.
李永民  聂传朋  王魏根  黄新  聂超  袁浩 《湖泊科学》2017,29(5):1195-1201
2013年6月-2015年6月,对安徽颍州西湖省级湿地自然保护区内农田区、河流湿地和湖泊湿地3种典型生境的鸟类进行调查,共记录到鸟类123种,属于14目33科69属.按照季节和生境的不同对鸟类多样性进行分析,结果表明:颍州西湖湿地保护区秋季鸟类的物种数和密度显著高于其他季节,而夏季拥有最高的物种多样性指数和均匀度指数;在颍州西湖湿地保护区3种典型生境中,湖泊湿地的鸟类物种数显著多于河流湿地和农田区,同时,湖泊湿地和农田区鸟类密度、物种多样性指数、均匀度指数显著高于河流湿地,而河流湿地拥有最高的优势度指数.就科属水平上的多样性而言,该保护区鸟类群落科属间多样性为0.76.颍州西湖湿地是鸻鹬类和雁鸭类等迁徙鸟类的重要中途停歇地和越冬地.  相似文献   

2.
三峡运行以来,气候变化与人类活动共同驱动了鄱阳湖水文情势的急剧变化,并对其湿地植被产生了显著影响,但当前研究尚未系统量化鄱阳湖湿地植被在此条件下的演变规律与趋势。因此,本研究以增强型植被指数EVI(enhanced vegetation index)的时段最高值作为表征湿地植被生产力的代用指标,定量揭示了后三峡工程时代鄱阳湖湿地植被生产力的气候态特征及其变化,包括变化的量级、显著性及阶段性。结果表明:(1) 2000—2020年,鄱阳湖湿地植被EVI最高值在全年及春、秋两季分别为0.37、0.30和0.33,入湖河流三角洲及碟形洼地边滩是其生产力中心;春季EVI最高值在此区域高于秋季,而在湖心区低于秋季。(2)三峡运行后的湿地植被生产力变化在全年及春、秋两季均有极大空间异质性,在湖心深泓线附近显著增加,而在入湖河流三角洲及湿地边缘下降。春季EVI增长区域面积占比极大(84.2%),而秋季增长区面积占比较小(71.2%),即有较大面积区域EVI在秋季下降(38.8%)。(3)三峡运行后,鄱阳湖湿地植被生产力中心经历了原位增长、空间扩张以及湖心向转移3个阶段,最终完成了由支流三角洲向湖心区...  相似文献   

3.
为了解西藏拉鲁湿地浮游植物群落时空分布特征及其驱动因子,于2021年7月、10月和2022年5月在拉鲁湿地主要水系进行定性和定量样品采集,共采集浮游植物水样126个,从不同季节和不同生境浮游植物种类组成、多样性等方面入手,探讨拉鲁湿地浮游植物群落时空分布特征及其驱动因子,为研究拉鲁湿地生态系统和稳定发展提供基础资料。结果表明:1)拉鲁湿地共鉴定出浮游植物532种(含变种和变型),隶属于8门13纲36目74科130属,物种组成表现为硅藻-绿藻-蓝藻型。2)拉鲁湿地浮游植物群落特征参数在不同季节和不同生境之间存在差异。夏季浮游植物群落的Shannon-Wiener多样性指数显著高于秋季和春季,Simpson优势度指数显著高于秋季。秋季浮游植物群落的Pielou均匀度指数显著低于夏季和春季。春季浮游植物群落的Margalef丰富度指数显著低于夏季和秋季。沼泽生境的浮游植物群落的Margalef丰富度指数显著高于湿草甸生境。3)季节是浮游植物群落组成差异的关键因素,生境对浮游植物群落组成的影响较弱,夏季的距离衰减模式比秋季和春季更强。4)拉鲁湿地不同的浮游植物群落参数与不同环境因子之间存在显著的关联。5)空间因素在解释浮游植物群落变异方面具有显著贡献,而快速变化的水质变量在决定浮游植物的季节变化中起着重要作用。季节和缓慢变化水质因子的解释能力相对较弱,但仍对浮游植物群落的变异有一定影响。  相似文献   

4.
The managed realignment of coastal defences and subsequent creation of intertidal habitats is one of several 'soft' engineering options that could reduce the costs of maintaining embankments and at the same time deliver environmental benefits. The managed realignment at Tollesbury was one of the first in the UK, undertaken as an experimental test case to improve understanding of the practical techniques and processes involved. Independent studies were undertaken on the development of soils, benthic invertebrates and vegetation within the site in addition to methods of enhancing the process of natural colonisation of saltmarsh plants. Bathymetric and vegetation monitoring were undertaken on the adjacent estuary to determine any breach effect that may be attributed to the realignment. This paper summarises the results from the vegetation, sedimentation and invertebrate monitoring and discusses the implications for other managed realignment schemes in the UK.  相似文献   

5.
The Homebush Bay area, Sydney, site of the Olympic Games 2000, has been largely occupied for nearly a century by an abattoir, brickworks, armaments depot and waste dumps. However, it contains remnants of original ecosystems, including two estuarine wetlands, and the Olympic Co-ordination Authority (OCA), set up to manage the redevelopment of the site, is committed to the rehabilitation of these ecosystems. The ecological approaches and rehabilitation measures used for one of the wetlands are detailed. Apart from a history of disturbance, it has for 10 years been without tidal flushing. However, these wetlands are the largest remaining in the Sydney estuary, and are significant for a number of reasons including biodiversity and waterbird conservation. The ecological parameters of the site, the results of a ‘before-restoration-impact' study, and the iterative links between science and management in the introduction of the rehabilitation measures, are presented. Criteria for success are discussed, along with biomonitoring strategies to test success.  相似文献   

6.
为探明长江中游大型水库水质状况,并为饮用水源安全保障提供科学依据,于2013 2014年按季节对湖北红安金沙河水库浮游植物群落结构及其多样性进行调查,并运用多元统计定量分析浮游植物群落结构与环境因子之间的关系.共鉴定出浮游植物8门94属216种,其中绿藻门为优势种群,其种类数占总物种数的51.39%,其次是硅藻门和蓝藻门.金沙河水库优势种随季节变化而变化,夏季以尖针杆藻(Synedra acus)的优势度最大(0.195),秋季以小胶鞘藻(Phormidium tenus)(0.180)和中华尖头藻(Raphidiopsis sinensia)(0.171)的优势度最大,冬季以具星小环藻(Cyclotella stelligera)(0.220)和圆筒锥囊藻(Dinobryon cylindricum)(0.234)的优势度最大,春季则是链状曲壳藻(Achanthidum catenatum)成为绝对优势种(0.910);金沙河水库浮游植物群落总的变化规律为夏季的硅藻门、蓝藻门和绿藻门,秋季的蓝藻门、绿藻门、硅藻门和隐藻门,向冬季的硅藻门和金藻门转变,春季则是硅藻门为绝对优势类群.Shannon-Wiener多样性指数和Pielou均匀度指数显示,浮游植物在秋季的多样性和均匀度较高,春季的多样性指数和均匀度指数显著低于其它季节,这是因为春季有绝对单一的优势物种,而秋季没有,且秋季的物种数最多,因此其Margalef丰富度指数也最高.将各季节优势种和经Pearson相关性分析筛选出的环境因子进行冗余分析,结果表明筛选的环境因子中磷酸盐、总磷和溶解氧浓度是影响金沙河水库浮游植物群落结构的主要环境因子.从藻类季节变化规律来看,金沙河水库夏、秋季水质污染程度较春、冬季严重;但从藻类丰度和多样性指数来看,春、夏季水质较秋、冬季污染严重.  相似文献   

7.
以安徽省升金湖湿地为研究对象,使用1989年、1996年、2003年、2010年和2017年四季Landsat系列遥感数据,构建景观生态风险评价模型,计算不同季节景观生态风险指数,分析风险空间分布及其变化特征,并使用Pearson相关系数分析季节间、季节与年度间景观生态风险相关性.结果显示:(1)不同季节景观生态风险指数有显著差异,生态风险从高到低依次为夏季、冬季、秋季和春季,夏、冬季风险指数平均高出春、秋季37.03%.(2) 1989—2017年升金湖湿地景观生态风险指数明显增加,湖区内泥滩、草滩等重要景观类型极易受人类活动影响,逐渐由中风险、较高风险区转变成较高风险、高风险区,且人造表面与草滩面积与较高风险和高风险区面积呈现出一定的协同变化特征.总体上,升金湖湿地以较低景观生态风险和中景观生态风险为主,较高景观生态风险与高景观生态风险主要位于上、下湖区.(3)季节间景观生态风险相关性最高的为秋季与冬季;年度生态风险与冬季生态风险高度相关.因此,近30年升金湖不同季节湿地景观生态风险时空演变趋势体现了该湿地景观格局变化对景观生态系统干扰的压力响应,且秋季与冬季湖区湿地需引起高度重视.  相似文献   

8.
As part of the Humber flood defence upgrade works (Urgent works) undertaken by the Environment Agency, the Paull Holme Strays site was identified as one of twelve potential managed realignment sites within the Humber catchment. The site was breached in September 2003, creating 80 hectares of new intertidal habitat. Initial accretion monitoring commenced in December 2003 with annual surveys of invertebrate colonisation commencing in October 2004. The present study gives details of the physical development of the newly created mudflat within the site, together with invertebrate colonisation and benthic community change over time. Comparisons between the newly created habitat and the existing mudflat outside the old sea wall are made. The macrofaunal communities found within the area as a whole are considered to be characteristic of the area with low species diversity, high abundance and small body size. The community within the managed realignment site is still in an early successional stage with low abundance and diversity in comparison with other sites within this part of the Humber. However the community biomass increased considerably between 2004 and 2005. Colonisation within the managed realignment site is still primarily concentrated in the areas around the two breach sites and is thought to be restricted in other areas due to infrequent tidal inundation.  相似文献   

9.
《Marine pollution bulletin》2008,56(10-12):564-578
As part of the Humber flood defence upgrade works (Urgent works) undertaken by the Environment Agency, the Paull Holme Strays site was identified as one of twelve potential managed realignment sites within the Humber catchment. The site was breached in September 2003, creating 80 hectares of new intertidal habitat. Initial accretion monitoring commenced in December 2003 with annual surveys of invertebrate colonisation commencing in October 2004. The present study gives details of the physical development of the newly created mudflat within the site, together with invertebrate colonisation and benthic community change over time. Comparisons between the newly created habitat and the existing mudflat outside the old sea wall are made.The macrofaunal communities found within the area as a whole are considered to be characteristic of the area with low species diversity, high abundance and small body size. The community within the managed realignment site is still in an early successional stage with low abundance and diversity in comparison with other sites within this part of the Humber. However the community biomass increased considerably between 2004 and 2005. Colonisation within the managed realignment site is still primarily concentrated in the areas around the two breach sites and is thought to be restricted in other areas due to infrequent tidal inundation.  相似文献   

10.
Over‐bank flooding is one of the driving forces controlling ecological integrity of riparian wetlands. Indentifying natural over‐bank flooding regime and its temporal variations is crucial for developing conservation and restoration plans and making water resources management policies for these ecosystems. Along the midstream of the Wei River in Xi'an, China lies the Jingwei riparian wetland, which was well preserved until the 1970s. Based on historical record of hydrological and morphological data of the Wei River from 1951 to 2000, we analysed temporal variations of over‐bank flooding frequency, duration, and timing in this paper. The natural annual over‐bank flooding regime was identified as having an occurrence frequency of 2·2 times a year and average duration of 5·3 days; these flooding events typically occur between June and September with occasional occurrence in late spring and late autumn. Over‐bank flooding occurrence frequency and duration decreased significantly during the 1990s, seasonal events of over‐bank floods were changed through reduced flooding frequency during summer and disappearing flooding events in late spring and late autumn. Further investigations showed that reduced discharge in the Wei River was the principal cause for these changes in over‐bank flooding dynamics. Our analysis also showed that decreased discharge of the Wei River during the 1990s was attributed near equally to disturbances from human activities and decreased regional precipitation. Results from this study may help reestablish natural over‐bank flooding dynamics in order to ensure successful restoration of Jingwei riparian wetland. Copyright © 2010 John Wiley & Sons, Ltd.  相似文献   

11.
Arne saltmarsh, an RSPB reserve, is situated in Poole Harbour on the English south coast. In recent years, there has been concern about possible changes in the suitability of the site for Redshank (Trigna totanus) due to sika deer (Cervus nippon) grazing. In order to assess these changes, 50 plots were established in three different locations: 20 in grazed areas, 20 in ungrazed areas and 10 fenced enclosures. Deer grazing was found to significantly affect structural and species diversity of the saltmarsh vegetation. Spartina anglica dominated in ungrazed areas whilst Salicornia ramosissima and, to a lesser extent, Puccinellia maritima dominated in grazed sites. In grazed areas the vegetation cover was significantly lower, as was vegetation height and volume. In addition, significant changes were observed in the root biomass, which was lower in grazed areas. Infaunal diversity was generally low throughout the survey area. However, significant variations were observed. Invertebrates abundance was more abundant in grazed plots than in ungrazed plots, and least abundant in fenced plots. The study indicated that in its current condition, localised areas of Arne saltmarsh do not provide adequate habitat requirements for Tringa totanus.  相似文献   

12.
扎龙国家级自然保护区硅藻植物特征及其环境指示作用   总被引:3,自引:0,他引:3  
易映彤  李慧  刘妍  范亚文 《湖泊科学》2015,27(6):1035-1041
2011年春、夏、秋季对扎龙国家级自然保护区内的硅藻群落结构进行研究.通过鉴定,共发现硅藻门植物112个分类单位,包括96种16变种,隶属于2纲6目9科32属.通过对硅藻植物的种类组成、聚类分析等方法,对扎龙国家级自然保护区内的硅藻植物分布情况进行初步研究,结果表明,扎龙国家级自然保护区内硅藻植物种类较为丰富,保护区内水体普遍为受轻污染或中度污染状态,个别水域存在富营养化情况,春、夏、秋季节中,秋季的富营养情况较为严重.结合水体的理化指标,通过对扎龙国家级自然保护区水体中硅藻的优势种、指示种的分析,发现该水域喜碱性、半咸水种类及中污带的种类较多,说明保护区水体受到轻微的污染,个别水域出现富营养状态.扎龙国家级自然保护区水体呈中-弱碱性、微盐,表明该区域受到了土地盐碱化的影响.  相似文献   

13.
为了解山东省战略水源地峡山水库在多水源(本地湖库水、长江水及黄河水)共存条件下,浮游植物优势种生态位季节变化和群落结构稳定性状况,于2019年对峡山水库10个代表样点进行浮游植物季度采样,并运用生态位宽度、生态位重叠值、方差比率法、卡方检验及联结系数对优势种生态位及种间关联性进行分析。结果显示,峡山水库四个季度共鉴定到浮游植物7门78属95种,其中优势种4门12属12种,除春季外,其他三季均以蓝藻类群为绝对优势,其中赖氏泽丝藻(Limnothrix redekei)、阿氏浮丝藻(Planktothrix agardhii)以及项圈假鱼腥藻(Pseudanabaena moniliformis)为全年优势种。多样性指数显示出较为一致的趋势,即春季浮游植物多样性较高,夏季多样性最低。优势种生态位宽度差异较大,变化范围在0.526~2.224,最大值、最小值分别为秋季的项圈假鱼腥藻和春季的小金色藻(Chromulina sp.)。项圈假鱼腥藻在多个季节具有最大的生态位宽度及较强的适应多样化生境的能力。生态位重叠显示项圈假鱼腥藻与其他多个优势蓝藻在不同季节具有最大的生态位重叠值,且其是唯一一个在春、夏和秋三季处于衰退期,而在冬季迅速发展的优势蓝藻。四个季度优势种总体关联性差异较为明显,群落结构不稳定。卡方检验显示76%的物种对为显著正联结关系,形成以项圈假鱼腥藻为主导,与其他优势蓝藻共同占有同一资源和空间的稳定演替模式。建议水库管理及调水除关注夏秋季可能的藻华外,还需密切关注低温季节藻类的异常增殖,尤其是冬季的项圈假鱼腥藻。研究可为胶东调水工程相关水库的水华预警和多水源调度提供理论依据和数据支撑。  相似文献   

14.
A key question in designing any managed retreat site concerns the nature of the habitats which will be created, and their likely long‐term sustainability and development. Studies of historical sea wall failures in Essex have shown that former reclaimed areas may respond to renewed tidal ?ooding in different ways depending on a number of factors, most importantly the elevation of the land at the time of breach, which governs the frequency and duration of tidal ?ooding. This paper demonstrates how digital terrain modelling using airborne lidar data can be used to calculate the elevation of the land behind a breach and to predict the likely habitats which will be created. When combined with data from sites of historical sea wall failure, predictions can also be made about the likely geomorphological and biological evolution of the created habitats in the longer term. At Abbotts Hall on the northern side of Salcott Creek, Essex, where a managed retreat scheme was activated in October 2002, the highest areas above 2·35 m OD were predicted to develop stable saltmarsh, intermediate areas between 2·1 and 2·34 m OD to develop potentially unstable saltmarsh which is likely undergo internal dissection, and the lowest areas below 2·1 m OD to remain as mud?at or lagoon. Approximately 38 per cent of the site was predicted to develop stable saltmarsh, and nearly 50 per cent to remain as lagoon or mud?at. Monitoring is now being undertaken but it will be several years before the accuracy of the predictions can be assessed. Copyright © 2004 John Wiley & Sons, Ltd.  相似文献   

15.
运用多元分析方法对安邦河湿地春、夏浮游植物群落进行划分,结果表明,两季节均可分为3个组群:(1)核心区组群,春季为绒毛平板藻.四角盘星藻群落,夏季为四角盘星藻群落;(2)边缘区组群,春季为梅尼小环藻-尖针杆藻群落,夏季为鱼腥藻-铜绿微囊藻.梅尼小环藻群落;(3)莲花池组群,春季为地中尖头藻群落,夏季为银灰平裂藻群落.各群落的种类组成、数量及多样性存在季节差异,与寒区环境因子季节变化相关.  相似文献   

16.
陈越  潘保柱  吴利  胡恩  赵耿楠  张森 《湖泊科学》2022,34(5):1630-1641
浮游动物作为食物链中重要的初级消费者,其群落结构特征是水生态系统健康评价的重要指标之一.本研究于2017年秋季和2018年春季对渭河干流及秦岭北麓五条典型支流开展了系统的水环境及浮游动物群落调查.结果表明,渭河干流营养盐浓度整体高于秦岭北麓支流,干流浊度远高于支流.两次调查共鉴定出浮游动物种类数136种(原生动物65种,轮虫44种,枝角类15种,桡足类12种),其中2017年秋季渭河干流浮游动物种类数、密度和生物量分别为14种、9.02 ind./L和0.0051 mg/L,秦岭北麓支流为37种、42.78 ind./L和0.0229 mg/L;2018年春季渭河干流浮游动物种类数、密度和生物量分别为52种、292.89 ind./L和0.1734 mg/L,秦岭北麓支流为68种、70.15 ind./L和0.0508 mg/L.秋季渭河干流下游浮游动物种类数、密度和生物量最低,而春季随上、中、下游三者均依次增大;秋季秦岭支流中罗敷河浮游动物密度和生物量最高,而春季灞河最高.春、秋两季干支流间浮游动物优势种差异较小,但秋季优势种种类数少于春季.秋季渭河干流中游Shannon-Wiene...  相似文献   

17.
2007年太湖五里湖浮游植物生态学特征   总被引:18,自引:5,他引:13  
研究了2007年太湖五里湖浮游植物的生态学特征.结果表明:五里湖共检出浮游植物8门123种;其中绿藻种类最多,共57种,占浮游植物总种数的46.3%;硅藻次之,共23种,占浮游植物总种教的18.7%;浮游植物种数以冬春季多、夏秋季少.调查期间.浮游植物数量和生物量分别变化在386.2×10~4-5581.9×10~4cells/L和0.541-3.491mg/L,均以绿藻最高;浮游植物数量的季节变化表现为夏季>春季>秋季>冬季;且除绿藻外,浮游植物的季节演替规律与PEG模型基本一致.相似性分析显示,五里湖1、3、4、5月份的生境相似,6、7、8、9、11月份的生境相似.优势度分析显示,五里湖各个月份的浮游植物优势种都在2种以上,优势种主要有小球藻(Chlorella vulgaris)、小球衣藻(ChLamydomonas microsphaera)、尖尾蓝隐藻(Chroomonas acuta)、铜绿微囊藻(Microcystis aeruginisa)等14种,优势种种数较多且优势度不高,变化在0.02-0.78之间;多样性和均匀度分析显示,五里湖浮游植物多样性指数和均匀度指数分别变化在1.5-2.7和0.26-0.59之间,多样性和均匀度都较好:表明2007年五里湖浮游植物群落结构比较复杂、处于较完整状态.  相似文献   

18.
春秋两季鄱阳湖浮游动物的编目、数量分布与变动   总被引:5,自引:1,他引:4  
分析鉴定了1999年春、秋两季,在鄱阳湖区8个断面24个采样站采得的水样.共观察到各类浮游动物共150种.其中轮虫动物物种最为丰富,为96种,占总种数的64.0%,且单位体积的数量亦呈明显优势,说明轮虫动物是该湖区浮游动物的优势类群;其次为原生动物.24个采样站中,原生动物、轮虫动物、枝角类、桡足类这四类浮游动物个体数量分布的差异极大,其中第10、12、13和23号站中的个体数量较高,超过100ind/L最大数量出现在13号站,个体数量高达1101.60ind/L鄱阳湖浮游动物的数量有明显的季节变动,尤属轮虫的变动最大.本次调查中轮虫和枝角类的数量春季大于秋季,而原生动物和桡足类则秋季大于春季.  相似文献   

19.
Water is a major limiting factor in desert ecosystems. In order to learn how plants cope with changes in water resources over time and space, it is important to understand plant–water relations in desert region. Using the oxygen isotopic tracing method, our study clarified the seasonal changes in the water use strategies of three co‐occurring desert shrubs. During the 2012 growing season, δ18O values were measured for xylem sap, the soil water in different soil layers between 0 and 300 cm depth and groundwater. Based on the similarities in δ18O values for the soil water in each layer, three potential water sources were identified: shallow soil water, middle soil water and deep soil water. Then we calculated the percentage utilization of potential water sources by each species in each season using the linear mixing model. The results showed that the δ18O values of the three species showed a clear seasonal pattern. Reaumuria songarica used shallow soil water when shallow layer was relatively wet in spring, but mostly took up middle soil water in summer and autumn. Nitraria tangutorum mainly utilized shallow and middle soil water in spring, but mostly absorbed deep soil water in summer and autumn. Tamarix ramosissima utilized the three water sources evenly in spring and primarily relied on deep soil water in summer and autumn. R. songarica and N. tangutorum responded quickly to large rainfall pulses during droughts. Differential root systems of the three species resulted in different seasonal water use strategies when the three competed for water. Copyright © 2013 John Wiley & Sons, Ltd.  相似文献   

20.
在博斯腾湖选取了13个点位,于2012年5、8、10月测定表层和底层水体中的颗粒有机碳、溶解有机碳、颗粒有机氮和叶绿素a含量.结果显示颗粒和溶解有机碳在表层水体中的浓度与底层相近.博斯腾湖水体中颗粒有机碳的季节变化十分明显,其平均浓度从春季(0.64 mg/L)到夏季(0.71 mg/L)变化不大,但在秋季变化十分显著(浓度达1.58 mg/L).其中西北湖区和湖心区颗粒有机碳的季节变化最明显,东部湖区颗粒有机碳的季节变化相对较小.博斯腾湖水体的颗粒有机碳在春、秋两季主要来自外源输入,在夏季受水体中浮游生物的影响较大.博斯腾湖水体中溶解有机碳也具有一定的季节变化,夏季浓度(平均为9.3 mg/L)略低于春、秋两季(平均为10.3 mg/L).溶解有机碳在河口区的季节变化最强,其夏季浓度明显偏低,主要是由于开都河河水的稀释作用.总体上,博斯腾湖水体中溶解有机碳浓度的变化主要受外部因素的影响.  相似文献   

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