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1.
Analysis of the concentrations of chemical elements and the composition of diatoms in the surface layer of bottom sediments has been performed in a small reservoir at the mouth of dammed river to evaluate the levels of pollution and the impact of toxicants on diatom communities of the river ecosystem. Data on interrelations between the concentrations of chemical elements and the relationship between inorganic pollution and accumulation of diatoms in bottom sediments as an indicator of development of the diatom assemblage have been obtained using linear correlation analysis and graphical plotting.  相似文献   

2.
2012年7月对浙江省金华江流域18个监测断面进行了附着硅藻和水质调查,通过硅藻生态群落组成及SPI、BDI硅藻指数对水质进行了评价,并比较了硅藻指数评价与水质理化评价结果的异同性。本次调查共收集到硅藻75种(含变种和变型),隶属于2纲12科30属。硅藻生态类群组成显示各断面以喜中性、N自养、耐低污染和喜好很高氧饱和度硅藻为主。水质理化指标总体评价金华江各监测断面水质多为Ⅲ类及以上,仅有一个断面为V类,硅藻SPI和BDI指数评价各断面水质为中等及中等以上。二者评价结果总体上吻合,但同时存在一定差异。SPI与高锰酸盐指数和硝酸盐氮呈显著负相关,BDI与氨氮呈显著负相关。硅藻指数在金华江流域有一定的适用性,但其在国内其他流域的适用性、评价方法的指示性与稳定性有待进行更深入的研究  相似文献   

3.
为了揭示入湖河流的污染负荷对滇池福保湾沿岸带底栖硅藻群落的影响,在不同季节采集研究了该湖湾6个样点的底栖硅藻样品,分析其群落结构的物种组成、细胞密度和多样性指数等。研究发现:东部沿岸区在调查期间的大多数月份是极小曲壳藻(Achnanthes minutissima)占绝对或主要优势,其相对丰富度最高可达79.5%;在1~7月份,西部沿岸区的优势种类主要是异极藻属(Gomphonema〖WTBZ〗 spp.),污染最为严重的河口区是耐污性的具柄双眉藻〖WTBX〗(Amphora pediculus)和两栖菱形藻(Nitzschia amphibia)占优势,而在调查的中后期,极小曲壳藻逐渐发展为这两区的优势种类。同时发现底栖硅藻密度随着与河口间距离的增加而逐渐升高。以上结果表明入湖河流的污染负荷对受纳湖湾底栖硅藻的密度和时空变化有较大影响。  相似文献   

4.
Communities of Wood-Attacking Fungi in the Region of Oil and Gas Production   总被引:1,自引:0,他引:1  
The communities of xylotrophic fungi were studied in the northern and middle taiga subzones of western Siberia, in forests growing in the region of oil and gas production and exposed to various anthropogenic factors (emissions of petroleum gas flares, oil pollution, spills of mineralized oil-field water, etc.). Structural and functional rearrangements in these communities were revealed, and the prevalence of rot in the tree stand was assessed.  相似文献   

5.
The impact of contemporary agriculture on Danish lakes is acknowledged to be extreme. In particular, high loading of nutrients from agricultural soils contributes to the eutrophic conditions found in many of Denmark’s lakes. Palaeolimnological studies have shown that human disturbance of the Danish landscape since the introduction of agriculture around 6,000 years ago has had a major impact on lake ecosystems. The European Union’s Water Framework Directive requires an evaluation of reference conditions for lakes, the conditions expected with only minimal human impact. Monitoring data and palaeolimnological studies of Danish lakes demonstrate that many of the most detrimental effects of eutrophication have been experienced in recent decades. A new study has suggested that the reference status for Danish lakes may be set to the status in ad 1850–1900, probably providing attainable, realistic restoration targets for many sites. The aims of this study were to explore the impacts of past and contemporary land-use on Danish lakes, and to consider how appropriate the use of 1850 as a date to define reference status is for these sites. Catchment land-cover data for ad 1800, taken from historical maps, and sedimentary diatom assemblages of the same age, from dated sediment cores, were used to assess the impact of pre-industrial land-use on 20 Danish lakes. Analysis of contemporary land-cover data and surface-sediment diatom assemblages for the 20 sites was also made. In-lake total phosphorus (TP) concentrations were estimated using the sedimentary diatom assemblages and an existing calibration dataset for Danish lakes. The percentage of the lake catchment that was agricultural land in ad 1800 explained 8.8% of the total variation in the diatom data. The land-cover variables ‘built-up areas’ and ‘plantations’, together explained 16.9% of the variation in the diatom data for the modern samples. Diatom-inferred TP concentrations were high for both ad 1800 (mean 112 μg TP L−1) and the present (mean 122 μg TP L−1), the latter estimates reflecting efforts in recent decades to reduce nutrient loading to Danish lakes following very high levels of nutrient enrichment post-1950. The data presented highlight the impact that human activities 200 years ago, particularly agriculture, had on Danish lake systems. The long cultural history and major anthropogenic disturbance of the Danish landscape mean that true reference conditions for lakes (or ‘baseline’ conditions, those found prior to human impacts) can be found only by considering century to millennial timescales.  相似文献   

6.
The consequences of anthropogenic impact on the water area of Amur Bay (the Sea of Japan) near Vladivostok include the eutrophication of coastal waters and littering with various objects used as artificial substrates, which protect sedentary animals from predators and contribute to the survival of their larvae. An indicator of eutrophication, the diatom Skeletonema costatum accounting for 81–96% of the total abundance of phytoplankton (Stonik and Selina, 1995), is consumed mainly by barnacles and the Pacific oyster. Thus, these animals gain an advantage in the colonization of artificial substrates. The results of the study suggest that eutrophication will lead to changes in the structure of the marine community.  相似文献   

7.
This paper examines the implications of oil palm estate development in Indonesia’s frontier province of Papua. Government planners believe that oil palm investment will develop the local economy, create jobs and reduce poverty. Using the input–output approach, we find that, in aggregate terms, oil palm investments boost the economic output in the province, generate jobs and increase worker salaries. However, the oil palm subsector operates in isolation and has limited economic multipliers. The number of jobs is potentially large, but those best positioned to benefit from them are mostly skilled migrants, not local poor. The government should reduce the size of plantation investments and plan their implementation as part of a broader development package to allow greater economic integration and skill acquisition by local communities. The priority areas for plantation development should be degraded, non-forest land.  相似文献   

8.
The effects of a recent bunker oil spill on the marine environment were assessed through investigation of the rocky shore fauna, phytoplankton population and macrobenthic communities over a study period of 150 days. In addition, toxicity experiments were carried out in the laboratory to ascertain the toxic effects of the oil-plus-dispersant on selected test organisms. The impacts of the spill on the marine fauna were minimal with no visible reduction in species and individual numbers. Possible reasons were the small amount of oil spilled, the rapid containment and dispersion in the clean-up operations, and the less toxic effects of the heavy bunker oil. On Hong Kong shores, the limpets can be identified as indicator species to oil pollution. A quick survey of the limpet fauna on the rocky shores immediately after a spill provides an initial assessment of the impacts on the shoreline. However, faunal recovery over a long-term period may be difficult to assess in view of the lack of baseline data on most of the marine biological communities in Hong Kong waters.  相似文献   

9.
河流型硅藻水华研究进展   总被引:7,自引:0,他引:7  
通过对硅藻水华发生机制相关文献的研究分析,对硅藻水华发生机制做了一般性探讨,并重点关注了河流型水华的发生机制的独特点。河流水华种类主要为中心硅藻纲,静水生态系统水华种类除中心硅藻纲还包括部分羽纹硅藻纲种类。河流水华硅藻种类对营养盐浓度、温度和光照等环境因子具有一定的适应范围。与静水生态系统相比,河流硅藻水华受气象和水文等物理指标的影响更为明显。河流硅藻水华中常具有时滞现象,其中由气象和水文因素引起的时滞现象最为明显。目前河流硅藻水华的防治仍然以上游水库下泄稀释为主,但是这种方法会造成一定的水资源浪费。河流水华硅藻的生理属性、硅藻水华对生态系统的影响、节水与抑制水华的统筹以及其他控制水华的方法都是未来河流硅藻水华研究的重点。  相似文献   

10.
Understanding resource-based communities (RBCs) as potential casualties of Canada's economic proclivity towards resource extraction projects may help us to generate political support for these communities at both local and national scales. The media has a critical role to play in promoting the development of this type of political discourse. This study examines how traditional print media coverage affects Canadians' perceptions of the Athabasca oil sands. A quantitative media analysis examines scope and thematic content of articles appearing in major Canadian newspapers between 2003 and 2013. We find that most coverage concerning the Athabasca oil sands over this period appears predominantly in western Canadian newspapers, with coverage primarily focusing on specific events. We argue that this geographic disparity in coverage does not provide Canadians with the adequate coverage necessary to develop an informed opinion on what the implications of ongoing oil sands development are at both a local and a national scale.  相似文献   

11.
Specific ecological features of ground beetles inhabiting city parks and suburban areas were studied in the large industrial city of Nizhnii Tagil (Sverdlovsk oblast). Carabid cenoses of city parks retained considerable species diversity but proved to be strongly dominated by a limited number of species. An analysis of their state before and after recreational impact revealed changes in the species composition of communities, the set of dominant species, the degrees of their dominance, and the ratio between classes of life forms. The results show that the stronger the recreational impact, the more significant the decrease in the species diversity of the carabid community.  相似文献   

12.

Agrarian communities in different regions develop diverse coping strategies to address the environmental changes they face. In this work, we test how to stimulate farmers’ social learning across diverse regions to promote informed responses to soil degradation. We invited 117 randomly selected members of 16 randomly selected Sumatran communities to three 3-day networking and training events in regions with diverse socio-environmental histories. One event was held in the respondents’ remote rural district (Tanggamus), the second was held in a more densely populated region on Sumatra Island (Kalianda), and the third was held in a heavily populated region on Java Island (Garut and Ciamis). Eighteen months later, we surveyed the information-sharing networks and agricultural practices of 370 members of these communities. The participants had become popular sources of agricultural advice, but the strength of this impact depended on the region in which their networking intervention was conducted. The participants in the event on Java had become the most central members of their communities. Although all the participants received the same formal information, those who interacted with the farmers in a region with the longest history of population pressure and land degradation management were more likely to adopt the recommended practices. The participants in this intervention doubled their odds of adopting organic fertilizers compared with those who networked only with peers in their local environment. Environmental memory of coping with change can be shared between regions through social learning, which can be stimulated by simple interventions.

  相似文献   

13.
Classification of the mode of life and behavior of zoobenthic, nektobenthic, and neustonic organisms was used as a basis for elucidating the formation of ethological structure of their communities in small lakes and streams of northeastern Fennoscandia. It is shown that the general response of these communities to anthropogenic impact is manifested in the reduction of the number of ethological groups. The specific response to eutrophication and heat pollution involves a decrease in the relative biomass of clingers and burrowers and an increase in the biomass of sprawling–walking and wormy animals; the response to toxic pollution and acidification is manifested in the prevalence of sprawlers–walkers.  相似文献   

14.
以长江中下游典型草型湖泊龙感湖为研究对象,借助生物指标(沉积物表层硅藻),通过硅藻分析、DCA分析、聚类分析以及硅藻属种指示的湖泊营养特征分析,探究龙感湖沉积物表层硅藻属种分类、影响硅藻的潜在环境梯度、表层沉积硅藻属种的空间分布特征以及分析表层沉积硅藻属种指示的湖泊营养特征。研究表明:龙感湖表层沉积硅藻属种分布存在空间差异;表层硅藻属种的分布主要由第一轴的环境因子所解释,反映的样点的排列受第一轴的控制,第二轴反映的环境意义不显著;龙感湖硅藻组合是以富营养的浮游种为优势,已经接近富营养态,以半浮游种Aulancoseira granulata为最大优势种,而Aulancoseira granulata在中营养湖泊中占绝对优势。主要出现在富营养湖泊中能较好指示富营养化的浮游、半浮游种Cyclotella atoms和C.meneghiniana、Aulacoseira alpigea、Cyclostephanos dubius、Stephanodiscus parvus、S.hantzschii出现在龙感湖内;以浮游种为优势种的东部湖区比以附生底栖种为优势种的西部湖区富营养化更严重,研究以期为湖泊治理提供一定的理论依据。  相似文献   

15.
于2010年5、8和11月,2011年2月,分别采集了金华江支流白沙溪4个断面附生硅藻样品,分析其硅藻群落结构及物种多样性,并利用多样性指数对水质进行了生物学评价;同时,应用典型对应分析揭示白沙溪硅藻群落结构与环境因子之间的关系。结果表明:(1)共鉴定附生硅藻92种(含变型和变种),隶属于2纲19科31属;多样性指数为140~248,总平均为189;均匀度指数为012~038,总平均为023;(2)硅藻群落结构呈现出季节上的变化。在季节变化上,物种丰富度及多样性指数以夏季(8月)最高,而以春季(5月)最低。白沙溪水体总体为α 中污水体;(3)典型对应分析结果表明,氨氮、水温和pH是影响白沙溪附生硅藻群落分布的主要因素,硅藻群落结构随着这些环境因子的变化表现出一定的空间差异  相似文献   

16.
New data on the present-day state of planktonic and benthic communities in the Sea of Azov were obtained during an expedition organized in 1997 and 1998. The analysis of their species composition and quantitative indices of biomass and abundance revealed two obvious tendencies in the structural dynamics of biocenoses. The first is directly produced by disturbances of the environment under anthropogenic impact, and the second reflects the effect of global natural factors.  相似文献   

17.
Coastal regions have long been settled by humans due to their abundant resources for livelihoods, including agriculture, transportation, and rich biodiversity. However, natural and anthropogenic factors, such as climate change and sea-level rise, and land subsidence, population pressure, developmental activities, pose threats to coastal sustainability. Natural hazards, such as fluvial or coastal floods, impact poorer and more vulnerable communities greater than more affluent communities. Quantitative assessments of how natural hazards affect vulnerable communities in deltaic regions are still limited, hampering the design of effective management strategies to increase household and community resilience. Drawing from Driving Forces–Pressure–State–Impact–Response (DPSIR), we quantify the associations between household poverty and the likelihood of material and human loss following a natural hazard using new survey data from 783 households within Indian Sundarban Delta community. The results suggest that the poorest households are significantly more likely to endure material and human losses following a natural hazard and repeated losses of livelihood make them more vulnerable to future risk. The results further suggest that salinization, tidal surge, erosion, and household location are also significant predictors of economic and human losses. Given the current and projected impact of climate change and importance of delta regions as the world’s food baskets, poverty reduction and increase societal resilience should be a primary pathway to strengthen the resilience of the poorest populations inhabiting deltas.  相似文献   

18.
Forests in and around the reserve located near the city of Chernogolovka (50 km northeast of Moscow), forests adjoining the city, and urban forests were examined during the period from 1992 to 2004. Differences between forests of the reserve proved to be less significant than those resulting from the impact of urban factors. The influence of a small city was found to change the structure of communities of small mammals in surrounding forests by reducing their diversity and enhancing the dominance of ecologically restrained synanthropic species.  相似文献   

19.
20.
The petrochemical and petroleum industries are two of the main sources of industrial air pollution in Taiwan. Data used in this study concern outdoor air pollution and the health of individuals living in communities in close proximity to oil refinery plants. The prevalence of delivery of preterm birth infants was significantly higher in mothers living near the oil refinery plants than in control mothers in Taiwan. After controlling for several possible confounders (including maternal age, season, marital status, maternal education, and infant sex), the adjusted odds ratio was 1.14 (95% CI=1.01-1.28) for delivery of preterm infants for mothers living near oil refinery plants. These data provide further support for the hypothesis that air pollution can affect the outcome of pregnancies.  相似文献   

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