首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 15 毫秒
1.
水电梯级开发进程中澜沧江干流鱼类群落演变特征   总被引:2,自引:2,他引:0  
澜沧江水能资源丰富,水电梯级开发盛行。研究结合历史数据搜集和现状调查,通过对比分析,揭示了水电梯级开发进程对澜沧江干流鱼类群落影响及其机制。结果表明,梯级水电站建设进程中,澜沧江渔业产量逐步增加,与水电装机容量呈极显著正相关关系(r=0.936,P<0.01),截至目前,已增长了约8倍,达到53930 t;鱼类多样性在水电开发初期因土著鱼类的消失而明显下降,但随着外来鱼类进入鱼类多样性水平出现回升。鱼类多样性指数DG-F在梯级开发之前(<1990)、之后(2008—2013)与当前(2018—2019)分别为0.67、0.47和0.67。在水电梯级开发进程中,鱼类生境类型由急流型为主逐渐演变为了以缓流型为主,产卵类型由以产沉性卵为主逐渐演变为了以产粘性卵为主,植食性、滤食性营养类型鱼类占比逐渐增加。水电站建设后,河流流速变缓、营养物质沉降富集为浮游植物生长繁殖提供了适宜的静水条件和丰富的物质基础,促进了鱼类生物量增加。生态环境变化协同外来鱼类胁迫导致鱼类生态类型发生变异。本研究初步为水电梯级开发生态环境效应评估和鱼类多样性保护提供了理论基础。  相似文献   

2.
The hillstream fish, Glyptothorax zanaensis (Wu et al., Oceanol Limnol Sin 12:74–79, 1981) is a freshwater teleost species belonging to the order Siluriformes, endemic to Nu River and Lancang River basin. Because wild stocks of G. zanaensis have declined substantially in recent years, owing to overexploitation, pollution, illegal fishing practices and the development of hydroelectricity in the Nu River, the populations of G. zanaensis have markedly declined in recent years. We studied the mitochondrial DNA cyt b gene to assess the genetic diversity of G. zanaensis in seven tributaries of the Nu River. Seventy variable sites defined 15 haplotypes in 153 individuals. Haplotype diversity and nucleotide diversity were 0.542 ± 0.014 and 0.011 ± 0.007, respectively. The Sunzu River site had the highest haplotype diversity (Hd, 0.893 ± 0.014) and nucleotide diversity ( Pi, 0.010 ± 0.012). Genetic diversity was low in the Dong River, Fengwei River and Mengtong River. Pairwise F ST values ranged from 0.00 to 1.00. Significant F ST values were found for Sunzu River sampled sites paired with all other populations and Mengtong river sampled site paired with the others. Furthermore, the Nanpeng River sampled site was significantly differentiated from the Luoming River, Dong River and Fengwei River sampled sites. Such knowledge is essential for developing appropriate policies for the rational management of G. zanaensis.  相似文献   

3.
水坝拆除引起河流连通性、水动力、河流地貌等一系列变化,直接影响了鱼类群落结构和空间分布。黑水河为金沙江左岸一级支流,其上共建四级电站,出于支流生境恢复需求,第四级水坝老木河水坝于2018年12月实行拆除。为探明低水头坝拆除对鱼类群落的影响,结合2018年6月和2019年6月黑水河下游60.4km河段10个点位的渔获物调查,对拆坝前后鱼类群落结构和生态类型变化、优势物种与单位捕捞努力量以及不同河段间的群落相似性进行了分析。结果表明,水坝拆除半年后优势物种仍以鲤科和鳅科为主,但物种数和丰度整体上增加;生态类型上以杂食、喜急流和产微粘性卵鱼为主;拆坝后鱼类群落空间分布变化明显,靠近河口的自然河段鱼类上溯洄游到原坝址的上下游,部分长江上游特有鱼类在原坝址附近发生定殖行为,且拆坝后各河段的鱼类组成结构有同质化趋势。总体上,老木河水坝的拆除对黑水河下游的鱼类群落结构和空间分布产生了积极的影响。  相似文献   

4.
Lajczak  A. 《Hydrobiologia》2003,494(1-3):43-49
The rate of suspended material transported with the current and its deposition in the Vistula River and its main tributaries was estimated to determine the effects of river regulation in the following periods: (1) between the beginning of engineering works on the Vistula River and the construction of the first dams on its tributaries, (2) in the years 1946-1995 when transport measurements were taken, (3) after the planned completion of the dam system. Those estimates were based on the results of long-term measurements of the rivers, carried out by the State Hydrological Survey at numerous gauging stations, as well as on analysis of maps published after 1780. The combined methods allowed estimating both the differences in deposition of the suspended material along the river and the long-term variability of that process. The initial increase in transport and deposition of the suspended material in the Vistula River during the four decades succeeding the river regulation (1890s–1930s) was followed by a rapid decrease of the material transport caused by the construction of dams and changes in land-use in the river basin.  相似文献   

5.
The Lancang-Mekong River basin contains a diverse assemblage of freshwater fish species; however, their populations are threatened by current and planned dam construction along the river. Fish assemblages are sensitive indicators of environmental degradation and can be used to assess aquatic ecosystem health. This research compared the fish fauna at the Xiaowan hydropower dam located on the middle reaches of the Lancang-Mekong River at three time periods: in 2008 (before impoundment), 2010 (water storage) and 2011 (full operation). A modified fish index of biological integrity (modified F-IBI) was developed and it synthesized information on the taxonomic composition, trophic guilds, and tolerance levels of the fish and habitat diversity to quantitatively assess the condition of fish populations before and after damming. This index also was used to assess the longitudinal diversity of the fish fauna along the river channel and could assess the barrier effect associated with the dam. Jaccard's index of similarity was used as a feasible tool to assess fish diversity loss and biotic homogenization. The analysis clearly showed a homogenization of the fish communities after damming, and the reservoir impoundment region showed much more serious homogenization than the downstream region. The Xiaowan dam had an immediate and profound effect on the fish fauna in this region of the Lancang-Mekong River. A total of eight cascading dams are planned for development in this region, and, unless conservation mitigation efforts are considered, the results could be devastating on the native fish populations of middle reaches of the Lancang-Mekong River basin.  相似文献   

6.
7.
Conditions of reproduction and distribution of the Black Sea trout Salmo trutta labrax in the basin of the Mzymta River after Olympic objects′ construction are considered. In the main river channel of the Mzymta, the structure of spawning and nursery grounds are destroyed along 57 km from the river mouth. The total area of these grounds in the Mzymta basin is 572800 m2, and 49% of this area is situated above the dam of the Krasnopolyanskaya Power Plant and is inaccessible for spawners of the migratory form of the Black Sea trout listed in the Red Data Book of the Russian Federation. Consequently, natural reproduction of the migratory form discontinued. The resident form of trout still exists in the upper parts of the Mzymta and in 19 of its tributaries not affected by construction. On the 2.4-km-long stretch of the riverbed situated below the inflow of the Pslukh tributary, the substrate is in the process of natural restoration due to the descent of mudslides followed by washing of the substrate by the flow. The river is partially inhabited by trout individuals from habitats not affected by construction.  相似文献   

8.
付贵权  秦涛  陈小勇  雷春云  李光华 《生态学报》2021,41(24):9557-9573
根据2018-2020年澜沧江西双版纳段5次鱼类资源调查数据,结合相关文献资料,对该流域鱼类组成及物种多样性进行了分析。结果显示:澜沧江西双版纳段此次共调查到鱼类119种,隶属于11目28科79属,而历史记录鱼类共179种,隶属于12目34科106属。随着调查的不断深入,土著鱼类种数逐渐增多,但占比却逐渐下降,外来鱼类种数逐渐增多,占比也逐渐升高;本次调查到土著鱼类92种,占鱼类种数的77.31%,占比进一步下降;外来鱼类27种,占鱼类种数的22.69%,占比进一步升高。该区域鱼类优势种为云南吻孔鲃Poropuntius huangchuchieni和少鳞舟齿鱼Scaphiodonichthys acanthopterus,常见种为长臀鲃Mystacoleucus marginatus和宽额鳢Channa gachua。有《国家重点保护野生动物名录》(2021年)鱼类5种,《中国生物多样性红色名录脊椎动物卷》(2015年)受威胁鱼类8种。相对于我国其他江河,澜沧江西双版纳段有极高水平的鱼类物种多样性,其中澜沧江干流鱼类物种多样性相对于左、右岸支流较低,左岸支流鱼类多样性高于右岸,罗梭江鱼类多样性高于其他一级支流。虽然澜沧江西双版纳段鱼类物种多样性维持在较高水平,但土著鱼类占比下降趋势明显,仍面临着严重威胁,本文分析了受威胁因素,并提出了保护建议。  相似文献   

9.
Panaqolus tankei is described from the Xingu River, Brazil. The new species is diagnosed from P. albomaculatus, P. dentex, P. nix, P. nocturnus, and P. koko by its color pattern consisting of dark and light diagonal bars on the body and bands on the fins (vs. body and fins without bars or bands); from P. albivermis, P. maccus, and P. purusiensis by the width of the dark bars being more or less the same of the light bars (vs. dark bars at least two or three times wider than light bars) and from P. changae by the absence of vermiculation on the head (vs. vermiculation present on head). The new species differs from P. gnomus by the orientation of the bars from posterodorsal to anteroventral direction (vs. anterodorsal to posteroventral direction), and from P. claustellifer by the orientation of the bands in the dorsal fin that are not parallel to the margin (vs. parallel to the margin). The barcoding region (COI) was sequenced for the new species, sequences were deposited in GenBank and were compared with congeners from other drainages. With regard to the current construction of a hydroelectric power plant (a so-called mega dam) in the Xingu River, herewith we increase knowledge of the river Xingu’s ichthyofauna and, thus improve the assessment of the impacts of that construction on the river.  相似文献   

10.
Alterations to the hydrologic regime downstream from hydroelectric dams include thermal disturbances which may have an impact on the reproductive success of fish. In order to make a comparative analysis of forage fish reproduction in two sections of the São Francisco River downstream from the Três Marias hydroelectric power plant, we captured 606 specimens of Astyanax fasciatus (n?=?465) and A. bimaculatus (n?=?141) at 2-month intervals between November 2009 and October 2010. Fish were captured in two sections of the São Francisco River: section 1, encompassing the first 34 km immediately downstream from the dam; section 2, after the confluence with the Abaeté River, 34–54 km downstream from the dam. The canonical correlation test indicated that for both species, female reproduction is more dependent on environmental factors than male reproduction. Compared to section 1, the specimens captured in section 2 were more abundant and the females of both species presented larger total length, body weight, gonadosomatic index and fecundity values. Higher values of water temperature, dissolved oxygen and turbidity during the rainy season (September to February) were also recorded for section 2, when compared to section 1 where the physical–chemical conditions of the water do not favour reproduction. Based on this analysis of reproductive parameters, this study shows, for the first time, that the reproductive activity of two species of forage fishes, A. fasciatus and A. bimaculatus, from the section of the São Francisco River immediately downstream from the Três Marias dam is disrupted and that the Abaeté River is an important tributary for the reproductive success of these species.  相似文献   

11.
李晋鹏  董世魁  彭明春  吴宣  周芳  于音 《生态学杂志》2017,28(12):4101-4108
底栖动物是对水生态系统退化和生境条件改变最为敏感的生物类群之一,同时也是开展梯级水坝水生态系统变化和演替研究的指示生物.本研究以国际生物多样性保护及水电梯级开发生态影响研究的热点地区澜沧江中下游为例,以澜沧江干流兴建的第一座水坝漫湾库区为研究区域,分别于2011和2016年开展底栖动物定点采样,并结合其蓄水前(自然河段,1996年)和单级水坝蓄水初期(1997年)的历史调研数据,全面分析了梯级水坝运行前后漫湾库区底栖动物群落的结构、分布格局及演变趋势.结果表明: 漫湾库区底栖动物群落的优势种组成逐渐由寡毛纲和昆虫纲种类演变为软体动物门类占绝对优势;沿库区生境的纵向梯度变化,底栖动物密度和生物量均表现为升高的趋势,而静水区增加更为显著;对底栖动物功能摄食群的分析表明,静水区由掠食者和收集者占优势演变为滤食者类占绝对优势;梯级水坝运行后,采用生物指数评价结果表明,2016年库区综合水质指标明显优于2011年.漫湾库区底栖动物群落的演变与上游梯级小湾水坝的调度运行及库区的水文状况和泥沙淤积情况密切相关,并随着梯级水坝的运行处于动态变化之中.  相似文献   

12.
选择12对微卫星标记检测了于2011年采集自元江(红河上游中国江段)5个样点192尾鲤的群体遗传多样性.共检测到201个等位基因,每个位点等位基因2-27个.各群体各位点平均等位基因(NA)12.25-14.67个,平均有效等位基因(NE)8.28-9.73个,平均观察杂合度(Ho)o.7765-0.8037,平均期望杂合度(HE)0.7761-0.8080,平均多态信息含量(PIC)0.7534-0.7843.元江鲤种群192个个体各位点NA、NE、Ho、HE、PIC分别为16.50、11.26、0.7927、0.8049、0.7966,种群遗传多样性水平高.元江鲤群体之间遗传分化小,可作为一个种群管理单元进行管理.增殖放流要防止遗传多样性丧失.  相似文献   

13.
三江并流地区干旱河谷植物物种多样性海拔梯度格局比较   总被引:1,自引:0,他引:1  
在滇西北三江并流地区典型干旱河谷段, 在怒江、澜沧江和金沙江的东、西坡共设置了6条海拔梯度样带, 通过标准样地的植物群落调查, 分析各条样带植物的物种丰富度、物种更替率的海拔梯度格局, 并比较了地理和植被变量对分布格局的解释。干旱河谷植被带位于海拔3,000 m以下, 以灌丛和灌草丛为主, 其在各河谷的分布上限自西向东依次升高。植物物种丰富度的分布主要与海拔、流域、经纬度和植被带有关, 沿纬度和海拔梯度升高而显著增加的格局主要表现在草本层和灌木层, 灌木物种丰富度还呈现自西向东显著增加的趋势。怒江的灌木和草本种物种丰富度显著高于金沙江和澜沧江, 三条江的乔木种丰富度差异则不显著。森林带的样方草本物种丰富度显著低于灌草丛带样方, 并且还拥有后者没有的乔木种。不同样带的植物物种更替速率呈现了不一致的海拔梯度格局, 但均在样带海拔下部的灌草丛群落与海拔上部森林群落之间的交错带出现峰值。森林-灌草丛植被交错带在怒江样带处于海拔1,900-2,100 m处, 在澜沧江河谷位于海拔2,300-2,400 m, 在金沙江河谷位于海拔2,700-2,900 m。所有海拔样带的森林段或灌草丛段相对于同一样带不同植被段之间的物种更替程度为最小, 不仅小于同一流域不同样带相同植被段之间物种更替率的均值, 更小于所有样带相同植被段之间的更替率均值。在三条河流6条海拔样带的12个植被带段之间的物种更替变化中, 空间隔离因素可以解释34.2%, 而植被类型差异仅能解释不到0.5%。本研究结果显示了环境差异对不同植被类型物种丰富度的首要影响, 和各河流之间的空间隔离对植物群落构建和物种构成的主要作用。  相似文献   

14.

Background

The Pak-Mun dam is a controversial hydro-power project on the Mun River in Northeast Thailand. The dam is sited in a habitat of the freshwater snail Neotricula aperta, which is the intermediate host for the parasitic blood-fluke Schistosoma mekongi causing Mekong schistosomiasis in humans in Cambodia and Laos. Few data are available which can be used to assess the effects of water resource development on N. aperta. The aim of this study was to obtain data and to analyze the possible impact of the dam on N. aperta population growth.

Methodology/Principal Findings

Estimated population densities were recorded for an N. aperta population in the Mun River 27 km upstream of Pak-Mun, from 1990 to 2011. The Pak-Mul dam began to operate in 1994. Population growth was modeled using a linear mixed model expression of a modified Gompertz stochastic state-space exponential growth model. The N. aperta population was found to be quite stable, with the estimated growth parameter not significantly different from zero. Nevertheless, some marked changes in snail population density were observed which were coincident with changes in dam operation policy.

Conclusions/Significance

The study found that there has been no marked increase in N. aperta population growth following operation of the Pak-Mun dam. The analysis did indicate a large and statistically significant increase in population density immediately after the dam came into operation; however, this increase was not persistent. The study has provided the first vital baseline data on N. aperta population behavior near to the Pak-Mun dam and suggests that the operation policy of the dam may have an impact on snail population density. Nevertheless, additional studies are required for other N. aperta populations in the Mun River and for an extended time series, to confirm or refine the findings of this work.  相似文献   

15.
流域库坝工程开发的生物多样性敏感度分区   总被引:3,自引:0,他引:3  
李亦秋  鲁春霞  邓欧  刘艺 《生态学报》2014,34(11):3081-3089
流域生态敏感性是流域生态系统遇到干扰时产生生态失衡与生态环境问题的难易程度和可能性大小,生物多样性是其影响最为重要的生态因子。主要考虑物种丰富度、珍稀程度、濒危程度、保护等级和生态系统类型等生物多样性敏感因子,借助GIS强大的空间数据采集和建模分析能力,在专家打分求取敏感因子权重基础上,通过空间模型计算生物多样性敏感度综合得分。基于二级流域综合得分最大值,采用ARCGIS自然间断点法实现敏感度分区,结果表明:极敏感区域主要分布在长江区的岷沱江、金沙江石鼓以下、金沙江石鼓以上、宜宾至宜昌、嘉陵江流域,珠江区的郁江、红柳河和西江流域,西南诸河区的澜沧江、红河和怒江及伊洛瓦底江流域,黄河区的龙羊峡以上流域等,这些区域水生生物特有种和受威胁物种丰度大,国家级自然保护区密集,是陆地生物多样性最丰富的地区。不敏感区域主要分布在松花江区除第二松花江以外流域,西北诸河区的塔里木盆地荒漠、古尔班通古特荒漠、中亚西亚内陆河、塔里木河干流等荒漠区,松花江区低温高寒,具有大森林、大草原、大湿地、大农田和大水域的特点,库坝工程对其生物多样性产生影响的可能性较小,西北诸河的荒漠区生境严酷,生物多样性贫乏,也不具备修建大型水库的条件,生物多样性敏感度也较低。其它区域介于二者之间,因其所处的生态系统类型、物种丰富度、珍稀程度、濒危程度和保护等级不一样,生物多样性敏感度各异。对流域库坝工程产生的生物多样性敏感度进行辨识,可为未来流域水资源合理和适度开发提供科学依据。  相似文献   

16.
The main purpose of this study was the development of an impact evaluation model to effectively assess and map possible ecological impacts due to a dam construction on habitats and species from the nearest Natura 2000 sites. A new approach has been developed in order to assess and map possible impacts on habitats due to a dam construction at both construction and operation phase. This methodology includes procedures in order to assess impacts and by calculating evaluation scores. Using Geographical Information Systems (GIS) evaluation scores were assigned to grouped habitat regions at construction and operation dam phase. The construction may affect the presence of the species Lutra at the site near the river but will have no effect at the area where the dam basin and the Natura 2000 site intersect. The other species are not expected to be affected from the dam construction. During the operation phase, the presence of water will influence species like Bombina in a very positive way. The dam operation itself will not have negative effects on the rest of habitats but due to the presence of water, factors like a possible increase on traffic and population may affect negatively the habitats especially near the village areas. The proposed methodology offers an alternative point of view on impact assessment and it is expected to serve as become a valuable tool for decision makers to evaluate potential impacts to threatened species and habitats due to a technical project at construction and operation phase.  相似文献   

17.
王强  庞旭  李秀明  王志坚  袁兴中  张耀光 《生态学报》2019,39(15):5508-5516
河流物理生境是维持河流生物多样性及生态功能的关键因素。生境质量的好坏能反应河流健康的程度。以我国西南地区的五布河和藻渡河为例,采用河流生境调查方法(RHS)和树状水系连通性指数(DCI)定量评估水电梯级开发和水坝建设对河流物理生境质量和河流纵向连通性的影响。结果表明,水电梯级开发后,五布河干流未受水坝明显影响河段、库区河段、减水河段分别为20.48、43.34、18.09 km,占总长度的25.0%、52.9%、22.1%。藻渡河干流河口至双河口段未受水坝明显影响河段、库区河段、减水河段分别为58.61、8.28、18.99 km,占总长度的68.2%、9.6%、占22.1%。水电梯级开发后,五布河干流河流片段由26个增至29个,藻渡河干流河流片段由2个增至5个。两条河流纵向连通性分别降低了7.8%和38.0%。五布河坝下减水河段生境质量降低14.1%,库区河段生境质量变化不明显。藻渡河减水河段生境质量与近自然河段无显著差异;两座坝后式电站库区河段生境质量明显低于近自然河段。水电梯级开发对两条河流物理生境的影响与水坝位置选择、建坝前的自然阻隔数量与分布、河流地貌特征、水电资源开发方式等密切相关。  相似文献   

18.
19.
永宁河是长江上游右岸的一级支流,其干、支流上共建有20余座小型水坝。为探究梯级水电站对鱼类多样性的影响,在永宁河流域设置共42个采样点,覆盖干支流及各个水坝,分别于2018年7月、10月和2019年1月、4月进行了四次鱼类资源调查。调查期间通过刺网、地笼、电捕等方法共采集到鱼类69种7332尾,隶属于4目13科54属,其中有长江上游特有鱼类13种,列入《中国脊椎动物红色名录》濒危和易危鱼类3种,国家二级重点保护鱼类岩原鲤(Procypris rabaudi)1种。Pinkas相对重要性指数(IRI)值较大主要为宽鳍鱲(Zacco platypus)、鲫(Carassius auratus)乐山小鳔鮈(Microphysogobio kiatingensis)等小型鱼类,29种鱼类的IRI值小于10;平均全长<10cm的鱼类有24种3620尾,平均体重<50g的鱼类有47种6493尾,鱼类规格较小,小型化严重。永宁河干流下游种类最多,多样性最高,干流中游鱼类数量最多。受自然环境以及水坝等的影响,永宁河的鱼类分布具有明显的空间差异。水坝类型对鱼类多样性有显著影响;而季节对鱼类多样性影响不显著。无水坝阻隔河段鱼类多样性著高于低头坝和高头坝阻隔河段;夏季的短距离洄游鱼类种数显著高于冬季和春季,但由于数量较少对鱼类多样性的季节性变化影响不明显。各种结果表明水坝阻隔对永宁河鱼类多样性和时空分布存在明显影响,为保护受小型水电站影响河流的鱼类多样性,有必要修复重要鱼类栖息地,适当拆除部分小型水坝,并科学开展增殖放流。  相似文献   

20.
The impacts of small hydropower plants (SHPs) on zooplankton assemblages were investigated in six cascaded SHPs along the Xiangxi River in October 2005. Five sites were sampled at each SHP. Fifty-six rotifer species which belong to 21 genera of 13 families and a nauplius species were identified in this study. Most rotifers were benthic species. The dominant rotifer species were Rotaria tardigrada, R. rotatoria, Philodina erythrophthalma, Colurella adriati, C. uncinata, Cephalodella catellina, Euchlanus dilatata, Lecane crenata and Keratella cochlearis. The Jaccard similarity index among these sections was very low, ranging from 24.33 to 58.54. The chlorophyll a (Chl a) of phytoplankton ranged from 0.37 to 1.22 ug/l, and the highest appeared in Xiaodangyang SHP. The richness, Simpson, Shannon–Wiener and Margalef diversity indices of zooplankton ranged in 4.8–21.4, 0.53–0.89, 1.12–2.58 and 0.42–1.64, respectively. In Xiangxi River, zooplankton density was low, no more than 9000 ind./m3, and the highest was observed at the down section of the river, while the lowest was at the up section of the river. Nevertheless, the richness and density in Xiaodangyang SHP were very high, only second to those in Zhaojun SHP. Apart from Xiaodangyang SHP, richness and diversity indices of zooplankton increased gradually from the upstream to the downstream. Xiangxi River was disturbed by human activities due to the cascaded development of SHPs. From Xiaodangyang SHP to Cangpinghe SHP, the richness and diversity indices of zooplankton were relatively higher at Site 3, whereas in Houzibao SHP and Zhaojun SHP, the lowest were at Site 3. The dam of SHP had significant effects on the zooplankton community. The outlet of SHP had no effect on the zooplankton community.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号