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1.
1993年5月1994年10月两次对江西乐安江-鄱阳湖湖口的浮游动物进行了生态调查,分析了浮游动物群落结构与功能特征及其与水质的相互关系,并结合丰水期和枯水期的资料进行了水质的综合评介。结果表明:6个采样站浮游动物结构与功能参数的变化与重金属的含量关系密切,上游受铜矿废水污染严重的采样站,种类数,个体数量,生物量,多样性指数d值和PFU原生动物的群集速度都很低,至中、下游采样站,重金属浓度明显下降  相似文献   

2.
乐安江重金属污染对浮游植物群落结构的影响   总被引:6,自引:1,他引:6  
1993年和1994年对乐安江6个采样站浮游植物的两次调查结果表明,藻类的群落结构因不同河段水质状况不同而不同:未受矿山废水污染的上游海口站,藻类多样性指数较高,密度较低,优势种多为清洁神和耐中污的种类,水质较好;接纳大量矿山及采矿化工废水和生活污水的沽口站,藻类受到明显抑制,多样性指数极低,耐污种占绝对优势,水质极差;随流程和净化时间的延长,下游各站藻类的种类、数量、多样性指数、种类数比均不断上升,优势比不断下降,体现出明显的水质净化趋势.乐安江水体Cu2+浓度与藻类的种类、数量、种类多样性指数、种类数比呈负相关的关系,Cu2+浓度与藻类的优势比呈正相关关系;pH值与上述指标关系正好与Cu2+所呈现的关系相反.藻类群落结构在春季丰水期与秋季枯水期的变化表明,春季乐安江水质好于秋季.  相似文献   

3.
贵州草海高原湿地浮游动物群落结构与水质评价   总被引:1,自引:0,他引:1  
由于处于食物链的中间位置,浮游动物在水生生态系统中起着至关重要的作用,其群落特征、动态演替等很大程度上受到水体理化因子的性质和相互作用的影响;研究浮游动物群落结构的变化及其与水环境之间关系,对了解水生生态系统的变化、生态过程、水质状况等有着重要意义。为了解贵州草海高原湿地浮游动物群落特征、长期变化以及水质现状,笔者于2014年夏季(8月)和秋季(11月)对草海浮游动物和主要水质指标进行了两次调查采样,分析了浮游动物种类、多样性、空间分布及其水质评价,并通过和以往同季的研究数据进行对比,探讨了30年来草海浮游动物的变化状况。结果表明,草海浮游动物种类丰富,研究共检出浮游动物83属151种,其中原生动物31属60种,轮虫26属55种,桡足类15属18种,枝角类11属18种;优势种有5种,主要的优势种为桡足类的大型中镖水蚤(Sinodiaptomus sarsi);草海浮游动物Shannon-Wiener多样性指数和Margalef丰富度指数较低,年均值分别为1.14和0.47。草海浮游动物群落结构季节变化明显,种类组成上,夏季110种,秋季75种,夏秋共有种有34种,季节更替率达77.5%;数量构成上,夏季丰度为1 505.53 ind·L~(-1),秋季丰度506.66 ind·L~(-1),夏季明显高于秋季。利用综合营养状态指数和浮游动物群落参数对草海水质进行评价,结果显示2014年草海水质处于中营养-中污染水平。与历史时期相比,草海浮游动物种类变幅较小,但浮游动物丰度却大幅度降低了,优势种也发生了较大的改变,这可能与草海水质的剧烈变化有关,但具体的生态过程和驱动机制还需深入研究和长期监测。  相似文献   

4.
为研究阜阳城区各水体浮游动物结构特征、多样性水平以及各水体浮游动物的生物量与主要水质指标的相关性,于2011年3月到2012年2月设点采样并进行分析。结果:各水体浮游动物密度有一致特征,一年中分别在4—5月和10月出现高峰,相应密度高峰后一个月左右生物量也出现高峰;与水质检测结果对照,浮游动物密度年平均值大的水域污染明显,相应多样性指数、丰富度指数及均匀度指数都低,而浮游动物密度年均值相对小的水体污染较轻,相应多样性指数、丰富度指数及均匀度指数都高;相关分析表明,浮游动物生物量与相应水体检测指标(CODCr、BOD、DO、TP、NH3-N)显著相关。结论:阜阳城区各水体浮游动物生物量与水体污染程度关系明显,水体水质可凭相应浮游动物生物量来评价,但水生态环境受多种因素的影响,情况复杂,综合分析各层面因素便于得出客观结论。  相似文献   

5.
为研究浮游动物对广东大宝山矿区外排酸性废水的响应,以评估周边及下游水域的水生态环境现状,于2010年9月采样调查了广东大宝山矿区周边河流的浮游动物状况,对比分析了受矿山酸性废水影响严重的水域与影响较小的水域浮游动物的种类组成、丰度、生物多样性指数及均匀度等指标差异,并探讨了浮游动物群落与环境因子之间的关系.结果表明,检出的46种浮游动物中轮虫类种类最多,有24种,枝角类和桡足类分别为10种和9种,原生动物仅有3种.其中受污染较为严重的受损组(S1~S3)几乎未发现浮游动物,臂尾轮虫和异尾轮虫在相对受污染影响较小的恢复组(S4~S7)占有较大优势.调查得到的浮游动物最大丰度及生物量分别为378.26 ind./L和1.990 1 mg/L.相关分析表明,pH、总氮、氨氮、高锰酸盐指数(CODMn)、硅酸盐及重金属铅和铬等环境因子对浮游动物群落分布影响显著.  相似文献   

6.
为研究河蟹生态养殖池塘后生浮游动物群落结构及水体健康状况,于2017年5—10月在江苏省宜兴市高塍镇滆湖渔场河蟹生态养殖池塘和池塘进水处进行采样,对后生浮游动物进行种类鉴定和定量分析,并采用生物多样性指数对水体进行生态学评价.调查共发现49种后生浮游动物,包括22种轮虫类、15种枝角类和12种桡足类.轮虫类的壶状臂尾轮...  相似文献   

7.
应用国家标准《水质—微型生物群落监测—PFU法》对位于广东省韶关的凡口铅锌尾矿废水处理系统中的原生动物群落进行了研究.分析了在该处理系统中原生动物群落的结构和群集过程的特征,并结合水质的理化参数对该处理系统的效能进行了评价.结果表明:在该处理系统中,以动物性鞭毛虫和腐生性纤毛虫为原生动物群落的主要组成部分;随着采样点距排污口的距离延长,原生动物群落的种类数和密度明显增加;群落多样性指数也随之上升.通过对原生动物群落组成与污染物浓度的统计学处理,显示出群落的种类数与各污染物的浓度间存在着显著的负线性相关.各采样点PFU原生动物群落群集过程也可以反映出各样点环境间的差异.各采样点数据间的差异说明由于该处理系统中香蒲植物的作用,使得废水中大量的颗粒性悬浮物得到沉降,重金属浓度也明显降低,从而促进了原生动物群落在一定程度上的恢复  相似文献   

8.
为研究受铅锌矿区不同程度尾矿砂重金属污染土壤的纵向微生物群落结构及其与重金属含量之间的关系,在尾矿砂坝坍塌冲刷形成的河谷岸边、距离河谷800 m的柑橘园以及距离河谷2 000 m的水稻田3个采样点对垂直深度为0—20、20—40、40—60、60—80 cm处的土壤进行取样,测定土样中的重金属含量、理化性质以及土壤的微生物群落结构。结果表明:重金属在该地区土壤中存在明显的纵向迁移,重金属污染越严重的土壤中的纵向迁移就越明显;Cd污染为该地区土壤最主要的重金属污染,潜在生态危害达中等程度以上。各采样点土壤的含水率(MC)、pH在不同采样深度处无明显差异,而TC、TN与TS在不同采样深度处差别较大;通过土样重金属含量与理化性质的冗余分析发现,TN、TC以及pH与各类重金属含量呈正相关关系,而MC以及TS和各类重金属含量表现出负相关关系。受植物根系的影响,柑橘园的20—40 cm深度与水稻田的0—20 cm深度处土壤微生物群落的多样性比其他土样高。属分类水平上,各采样点纵向微生物群落差异很大,分布极其不均匀。土壤纵向微生物优势菌属与重金属含量的冗余分析表明,纵向微生物优势菌属与重金属含量关系紧密,其中Luteibacter、Effusibacillus、Solibacter、Stenotrophomonas、Tumebacillus和Paucimonas 6个菌属与土样重金属含量呈现较强的正相关关系,而Paraburkholderia、Ramlibacter、Bacillus、Pseudarthrobacter、Pseudoduganella、H16和Nitrososphaera7个菌属与土样重金属含量相关关系接近于0,这些菌属均可能具有一定的重金属耐受能力,具有被开发为土壤重金属污染微生物原位修复菌剂的潜力。  相似文献   

9.
2004年3月~11月对人工湿地循环处理的养殖水体中浮游动物的动态变化进行了研究,探讨不同的处理方式和放养类型对水体中浮游动物的影响及生物多样性指数的变化.结果表明,养殖水体经人工湿地处理后,水质改善,对浮游动物去除率在60%以上,几乎没有影响到浮游动物的群落结构,循环水量最大的1号塘浮游甲壳动物隆腺溞占优势,密度较其他塘低,而生物量则高;放养类型相同的循环塘3号塘和静态塘4号塘,浮游动物种类基本相同,但种类数3号塘明显多于4号塘;辛普森多样性指数显示:1号塘>2号塘>3号塘>4号塘,说明循环塘水质好于静态塘.图4表5参21  相似文献   

10.
长春市土壤重金属化学形态与土壤微生物群落结构的关系   总被引:6,自引:2,他引:4  
采用样品采集、室内分析和多种数据统计方法相结合的方法,研究了长春市土壤重金属化学形态与土壤微生物群落结构的关系.结果表明:长春市土壤重金属(Pb、Cd、Cu、Zn和Ni)不同化学形态对土壤微生物群落结构影响明显不同,碳酸盐结合态的Pb和Ni对放线菌的生长繁殖具有刺激作用,碳酸盐结合态Zn对细菌的生长繁殖具有刺激作用,铁锰氧化物结合态和有机结合态的Zn与有机结合态Cu对细菌、放线菌的生长繁殖具有刺激作用.土壤理化性质对重金属化学形态与微生物群落结构之间的关系影响很大,其掩盖了土壤重金属化学形态对土壤微生物群落结构特征的影响,有机质含量、电导率、阳离子交换量掩盖了重金属化学形态对细菌、放线菌和微生物总数的影响.自然含水率掩盖了重金属化学形态对多样性指数的影响.采用重金属的化学形态评价重金属对土壤微生物参数的影响更合理,而且在确定评价长春市土壤重金属污染状况指标时,应该剔除土壤理化性质的影响.选择有机结合态Cu、铁锰氧化物结合态Zn与微生物群落多样性指数相结合来评价长春城市土壤重金属Cu和Zn的污染状况.  相似文献   

11.
A bioblitz inexpensively and quickly generates biodiversity data, but bioblitzes are often conducted with haphazard, unreplicated sampling. Results tend to be taxonomically, geographically, or temporally biased, lack metadata, and consist of lists of observed taxa that do not enable further analyses or correction for imperfect detection. A rapid, recurring, structured survey (RRSS) uses a structured sampling design and temporal and spatial replication to survey randomly selected sites on a conservation property. We participated in a loosely structured bioblitz and a subsequent RRSS at Big Canoe Creek Nature Preserve in Springville (St. Clair County), Alabama (USA) to compare observed richness derived from the 2 survey approaches. The RRSS data structure enabled us to fit models that accounted for imperfect detection to estimate abundances, occupancy probabilities, and habitat associations. The loosely structured bioblitz data could not be used in such models. We present a new integrated multispecies abundance model that we applied to avian RRSS data. Our model extension enables estimation for the community, employs data augmentation to estimate the number of undetected species, and incorporates covariates. The RRSS generated a more comprehensive and less biased list of observed taxonomic richness than the loosely structured bioblitz (e.g., 73 vs. 45 bird species and 104 vs. 63 insect families from the RRSS vs. loosely structured bioblitz, respectively). Models fit to the RRSS data identified seasonal patterns in avian community composition and allowed for estimation of habitat–occupancy relationships for insect taxa. The RRSS protocol has potential for broad transferability as a standardized, quick, and inexpensive way to inventory biodiversity and estimate ecological parameters while providing an outreach opportunity.  相似文献   

12.
Land-use change via human development is a major driver of biodiversity loss. To reduce these impacts, billions of dollars are spent on biodiversity offsets. However, studies evaluating offset project effectiveness that examine components such as the overall compliance and function of projects remain rare. We reviewed 577 offsetting projects in freshwater ecosystems that included the metrics project size, type of aquatic system (e.g., wetland and creek), offsetting measure (e.g., enhancement, restoration, and creation), and an assessment of the projects’ compliance and functional success. Project information was obtained from scientific and government databases and gray literature. Despite considerable investment in offsetting projects, crucial problems persisted. Although compliance and function were related to each other, a high level of compliance did not guarantee a high degree of function. However, large projects relative to area had better function than small projects. Function improved when projects targeted productivity or specific ecosystem features and when multiple complementary management targets were in place. Restorative measures were more likely to achieve targets than creating entirely new ecosystems. Altogether the relationships we found highlight specific ecological processes that may help improve offsetting outcomes.  相似文献   

13.
Protected areas (PAs) are often implemented without consideration of already existing PAs, which is likely to cause an overrepresentation of certain biophysical conditions. We assessed the representativeness of the current PA network with regard to the world's biophysical conditions to highlight which conditions are underprotected and where these conditions are located. We overlaid terrestrial and marine PAs with information on biophysical conditions (e.g., temperature, precipitation, and elevation) and then quantified the percentage of area covered by the PA network. For 1 variable at a time in the terrestrial realm, high temperature, low precipitation, and medium and very high elevation were underrepresented. For the marine realm, low and medium sea surface temperature (SST), medium and high sea surface salinity (SSS), and the deep sea were underrepresented. Overall, protection was evenly distributed for elevation across the terrestrial realm and SST across the marine realm. For 2 variables at a time, cold and very dry terrestrial environments had mostly low protection, which was also the case for low SST and low and medium SSS across most depths for marine environments. Low protection occurred mostly in the Sahara and the Arabian Peninsula for the terrestrial realm and along the Tropic of Capricorn and toward the poles for the marine realm. Although biodiversity measures are of prime importance for the design of PA networks, highlighting biophysical gaps in current PAs adds a frequently overlooked perspective. These gaps may weaken the potential of PAs to conserve biodiversity. Thus, our results may provide useful insights for researchers, practitioners, and policy makers to establish a more comprehensive global PA network.  相似文献   

14.
Summary The adaptation of defensive secretions to their target organisms was examined for the abdominal gland secretions ofBledius furcatus, B. spectabilis andB. arenarius. Therefore the target organisms of the secretion of theseBledius species (i.e. their predators) had to be identified. At the collection sites examined these were the earwigLabidura riparia, the antCataglyphis bicolor, the flyLispe candicans, different carabids of the generaPogonus, Dichirotrichus, Dyschirius, Bembidion andCalathus and the wading birdsHaematopus ostralegus andCalidris alba. The secretion of the abdominal glands contains the toxin ptoluquinone dissolved in either-dodecalactone and 1-undecene (B. furcatus andB. spectabilis) or in octanoic acid and octyloctanoate (B. arenarius). The ratio of these solvents is species-specific. Application experiments using some of the natural insect predators (L. riparia, C. bicolor, Pogonus, Di. gustavii, Dyschirius) revealed that these solvent ratios provided a more effective deterrent than other possible ratios. Thus by combining the solvents in certain ratios, the capability of cuticular penetration and therefore the effectiveness of the defensive secretions are adapted to their natural targets.  相似文献   

15.
The politics of development includes subtexts of choice, as underpinned by community consensus (or lack of it), against the larger backdrop of a liberal democracy, with its intricate power structures that influence the choice of concepts and often lead to complicity rather than consent. A dilemma exists between the understanding of field-level practitioners and that of academics, whose understandings of progress differ. Progress can (and often does) imply long-term change across generations whereas development is often more a matter of crisis management and delivering tangible results to end-users. This makes it a bone of contention across political systems, irrespective of local or global dynamics. Development can emerge as a tool to be wielded for power and further political mileage at the expense of progress. Progress cannot be studied as a counterpoint to development as the sense of history is often missing in development interventions. Development tends to be piecemeal as its very logic often stems from the rationale of power. This is not to suggest, however, that development is only about politics; it is definitely more than the politics of everyday life and involves all of civil society that requires its critical and immediate attention. In this sense, it has become a priority for politicians with an underlying agenda designed to out-manouevre dissent and all statements of protest.  相似文献   

16.
An argument is presented in which areas of natural arsenic contamination of modern groundwaters throughout Asia have a common origin. Arsenic originally accumulated in oceanic ferro-manganoan sediments of the eastern Palaeo-Tethys. This was further concentrated through oceanic crustal extinction in what later became the south-east Chinese accreted mineralised terrain. Proto-Himalayan uplift of this area created the palaeo-drainage systems of the Ganges – Brahmaputra, Irrawaddy, Mekong, and Red Rivers, with consequent headwater erosion of arsenic-rich sediments. Their downstream deposition as immature and easily redistributed Neogene sandstones, silts, and iron-rich clays has created secondary and tertiary reservoirs of adsorbed and authigenic arsenic, from which the current arsenic-rich groundwaters have evolved. Considering river basins within the above palaeo-hydrogeological framework provides a basis for assessing the risk of arsenic in groundwater basins of south and south-eastern Asia.  相似文献   

17.
As landscapes continue to fall under human influence through habitat loss and fragmentation, fencing is increasingly being used to mitigate anthropogenic threats and enhance the commercial value of wildlife. Subsequent intensification of management potentially erodes wildness by disembodying populations from landscape-level processes, thereby disconnecting species from natural selection. Tools are needed to measure the degree to which populations of large vertebrate species in formally protected and privately owned wildlife areas are self-sustaining and free to adapt. We devised a framework to measure such wildness based on 6 attributes relating to the evolutionary and ecological dynamics of vertebrates (space, disease and parasite resistance, exposure to predation, exposure to limitations and fluctuations of food and water supply, and reproduction). For each attribute, we set empirical, species-specific thresholds between 5 wildness states based on quantifiable management interventions. We analysed data from 205 private wildlife properties with management objectives spanning ecotourism to consumptive utilization to test the framework on 6 herbivore species representing a range of conservation statuses and commercial values. Wildness scores among species differed significantly, and the proportion of populations identified as wild ranged from 12% to 84%, which indicates the tool detected site-scale differences both among populations of different species and populations of the same species under different management regimes. By quantifying wildness, this framework provides practitioners with standardized measurement units that link biodiversity with the sustainable use of wildlife. Applications include informing species management plans at local scales; standardizing the inclusion of managed populations in red-list assessments; and providing a platform for certification and regulation of wildlife-based economies. Applying this framework may help embed wildness as a normative value in policy and mitigate the shifting baseline of what it means to truly conserve a species.  相似文献   

18.
Abstract: In the United States, as elsewhere, a growing debate pits national energy policy and homeland security against biological conservation. In rural communities the extraction of fossil fuels is often encouraged because of the employment opportunities it offers, although the concomitant itinerant workforce is often associated with increased wildlife poaching. We explored possible positive and negative factors associated with energy extraction in the Greater Yellowstone Ecosystem (GYE), an area known for its national parks, intact biological diversity, and some of the New World's longest terrestrial migrations. Specifically, we asked whether counties with different economies—recreation (ski), agrarian (ranching or farming), and energy extractive (petroleum)—differed in healthcare (gauged by the abundance of hospital beds) and in the frequency of sexual predators. The absolute and relative frequency of registered sex offenders grew approximately two to three times faster in areas reliant on energy extraction. Healthcare among counties did not differ. The strong conflation of community dishevel, as reflected by in‐migrant sexual predators, and ecological decay in Greater Yellowstone is consistent with patterns seen in similar systems from Ecuador to northern Canada, where social and environmental disarray exist around energy boomtowns. In our case, that groups (albeit with different aims) mobilized campaigns to help maintain the quality of rural livelihoods by protecting open space is a positive sign that conservation can matter, especially in the face of rampant and poorly executed energy extraction projects. Our findings further suggest that the public and industry need stronger regulatory action to instill greater vigilance when and where social factors and land conversion impact biological systems.  相似文献   

19.
How should managers choose among conservation options when resources are scarce and there is uncertainty regarding the effectiveness of actions? Well‐developed tools exist for prioritizing areas for one‐time and binary actions (e.g., protect vs. not protect), but methods for prioritizing incremental or ongoing actions (such as habitat creation and maintenance) remain uncommon. We devised an approach that combines metapopulation viability and cost‐effectiveness analyses to select among alternative conservation actions while accounting for uncertainty. In our study, cost‐effectiveness is the ratio between the benefit of an action and its economic cost, where benefit is the change in metapopulation viability. We applied the approach to the case of the endangered growling grass frog (Litoria raniformis), which is threatened by urban development. We extended a Bayesian model to predict metapopulation viability under 9 urbanization and management scenarios and incorporated the full probability distribution of possible outcomes for each scenario into the cost‐effectiveness analysis. This allowed us to discern between cost‐effective alternatives that were robust to uncertainty and those with a relatively high risk of failure. We found a relatively high risk of extinction following urbanization if the only action was reservation of core habitat; habitat creation actions performed better than enhancement actions; and cost‐effectiveness ranking changed depending on the consideration of uncertainty. Our results suggest that creation and maintenance of wetlands dedicated to L. raniformis is the only cost‐effective action likely to result in a sufficiently low risk of extinction. To our knowledge we are the first study to use Bayesian metapopulation viability analysis to explicitly incorporate parametric and demographic uncertainty into a cost‐effective evaluation of conservation actions. The approach offers guidance to decision makers aiming to achieve cost‐effective conservation under uncertainty.  相似文献   

20.
Large, intact areas of tropical peatland are highly threatened at a global scale by the expansion of commercial agriculture and other forms of economic development. Conserving peatlands on a landscape scale, with their hydrology intact, is of international conservation importance to preserve their distinctive biodiversity and ecosystem services and maintain their resilience to future environmental change. We explored threats to and opportunities for conserving remaining intact tropical peatlands; thus, we excluded peatlands of Indonesia and Malaysia, where extensive deforestation, drainage, and conversion to plantations means conservation in this region can protect only small fragments of the original ecosystem. We focused on a case study, the Pastaza‐Marañón Foreland Basin (PMFB) in Peru, which is among the largest known intact tropical peatland landscapes in the world and is representative of peatland vulnerability. Maintenance of the hydrological conditions critical for carbon storage and ecosystem function of peatlands is, in the PMFB, primarily threatened by expansion of commercial agriculture linked to new transport infrastructure that is facilitating access to remote areas. There remain opportunities in the PMFB and elsewhere to develop alternative, more sustainable land‐use practices. Although some of the peatlands in the PMFB fall within existing legally protected areas, this protection does not include the most carbon‐dense (domed pole forest) areas. New carbon‐based conservation instruments (e.g., REDD+, Green Climate Fund), developing markets for sustainable peatland products, transferring land title to local communities, and expanding protected areas offer pathways to increased protection for intact tropical peatlands in Amazonia and elsewhere, such as those in New Guinea and Central Africa which remain, for the moment, broadly beyond the frontier of commercial development.  相似文献   

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