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241.
William T. Mason Jr. 《Environmental monitoring and assessment》1998,50(2):101-130
The macrobenthos in the oligohaline 132 km reach of the Lower St. Johns River, Florida, is an unusual blend of freshwater and marine organisms within the annelid, mollusk, aquatic insect, and crustacean groups. During 1993–1994, the community composition was freshwater-oriented in the 47 km (seg I) and estuarine-dominated in the lower 85 km (seg II). Of the total 146 taxa collected, 89% were euryecious 'eutrophic' and 'pollution-tolerant' organisms. Densities ranged between 5000 and 20 000 individuals/m2 ann av and maximum densities (85 000 individuals/m2) occurred in the muck substrate at the confluence of major tributaries and embayments. Throughout the lake-like seg II, benthic hypoxia existed during much of summer through fall. Biotic index values for grab, artificial substrate, and sled trawl samples reflected greatest stresses to the macrobenthos then. Both low taxonomic diversity and densities of organisms at the most downriver stations nearest the port of Jacksonville indicated that toxic substances also adversely affected the macrobenthos. Maintenance of the narrow band of littoral submerged aquatic vegetation (SAV) and adjacent shoreline riparian vegetation is important to sustain macrobenthic communities and other kinds of aquatic life in the river. 相似文献
242.
Overall, the greatest threats to Canadian and global biodiversity are associated with conversions of natural ecosystems to anthropogenic ones, and over-exploitation of biological resources. This circumstance does not, however, trivialize the importance of atmospheric influences. Although scientific understanding of the risks is incomplete, it is nevertheless clear that anthropogenic changes in atmospheric stressors are potentially damaging to biodiversity and other ecological values over medium- and longer-term scales. It is important that greater investments be made in support of longer-term monitoring and research designed to understand the effects of atmospheric and other environmental stressors on the biodiversity and structure and function of Canadian ecosystems. 相似文献
243.
A Systems Approach to Biodiversity Conservation Planning 总被引:1,自引:0,他引:1
Nina-Marie E. Lister 《Environmental monitoring and assessment》1998,49(2-3):123-155
With a recent media-fueled transition from a scientific to a political perspective, biodiversity has become an issue of ethics and ensuing values, beyond its traditional ecological roots. More fundamentally, the traditional perspective of biodiversity is being challenged by the emergence of a post-normal or systems-based approach to science. A systems-based perspective of living systems rests on the central tenets of complexity and uncertainty, and necessitates flexibility, anticipation and adaptation rather than prediction and control in conservation planning and management. What are the implications of this new perspective? This paper examines these challenges in the context of biodiversity conservation planning. The new perspectives of biodiversity are identified and explored, and the emergence of a new ecological context for biodiversity conservation is discussed. From the analysis, the challenges and implications for conservation planning are considered, and a systems-based or post-normal approach to conservation planning and management is proposed. In light of the new perspectives for biodiversity, conservation planning and management approaches should ultimately reflect the essence of living systems: they should be diverse, adaptive, and self-organizing, accepting the ecological realities of change. 相似文献
244.
Antonio Finizio Antonio Di Guardo Lara Cartmale 《Environmental monitoring and assessment》1998,49(2-3):327-336
Atmospheric change comprises many phenomena, namely climate change, acidic deposition, stratospheric ozone depletion, SMOG, increasing trend of suspended particulate matter, and hazardous air pollutants (HAPs). Among HAPs, a particular group of Persistent Organic Pollutants (POPs), such as some organochlorine pesticides, has shown a variety of toxic effects, altering the biodiversity of many ecosystems. Because of their persistence in the environment, and of their long range transport, the study of the global cycle of POPs is important in understanding how they can affect biodiversity. This can be accomplished by coupling different approaches: toxicity and ecological studies, emission estimates, and the use of global models. 相似文献
245.
Wild foods contribute to the food security of multiple communities in tropical areas of Africa, Asia and Latin America. However, wild foods are not regularly considered in the planning of strategies for food and nutrition security mainly due to the lack of technical and/or scientific knowledge so that they can be considered suitable for human consumption. This paper proposes a multidisciplinary method that estimates the potential of wild foods as alternative resources when planning interventions in favour of food and nutrition security in tropical forest territories. When designing the method, four dimensions were identified in science, technology and innovation (STI) that define this potential as well as ten assessment criteria. The wild foods chosen for applying the method were Alibertia patinoi (a fruit commonly known as Borojó) and Proechimys semispinosus (Mouse of thorns), which are two of the main wild foods traditionally used by human communities in a tropical forest territory in the northwest of Colombia. In both cases, although there are significant advances in STI, compliance with some criteria is still required to regard them as viable alternatives for nutrition and food security within this territory. This research is useful for promoting the inclusion of wild food in food security programmes for communities where this food is already included in their traditional pattern of consumption and identifies the progress needed in STI to achieve this purpose. It may also promote the early recognition of possible traditional and cultural practices with high risk of transmission of pathogenic elements by the handling and/or inadequate consumption of wild foods. This early recognition could contribute to the prevention of diseases of wild animal origin, including those of rapid global spread. 相似文献
246.
Biodiversity versus emergencies: the impact of restocking on Animal Genetic Resources after disaster
Heffernan C 《Disasters》2009,33(2):239-252
Restocking is a favoured option in supporting livelihoods after a disaster. With the depletion of local livestock populations, the introduction of new species and breeds will clearly affect biodiversity. Nevertheless, the impact of restocking on Animal Genetic Resources has been largely ignored. The aim of this paper, therefore, is to examine the consequences of restocking on biodiversity via a simple model. Utilising a hypothetical project based on cattle, the model demonstrates that more than one-third of the population was related to the original restocked animals after three generations. Under conditions of random breed selection, the figure declined to 20 per cent. The tool was then applied to a donor-led restocking project implemented in Bosnia-Herzegovina. By restocking primarily with Simmental cattle, the model demonstrated that the implementation of a single restocking project is likely to have accelerated the decline of the indigenous Buşa breed by a further nine per cent. Thus, greater awareness of the long-term implications of restocking on biodiversity is required. 相似文献
247.
Canada responded to the Global Biodiversity Convention by completing the Canadian Biodiversity Strategy in 1995. At the same time, Environment Canada also completed a national Science Assessment on Biodiversity. During this period, the Smithsonian Institution, in partnership with Parks and Environment Canada, initiated the implementation of a global biodiversity monitoring program in Canada. Under the auspices of the United Nations Man and the Biosphere Program, the SI/MAB monitoring protocols and plots have spread across Canada at an unprecedented rate. National champions in the science and educational sectors, working within an inter-disciplinary ecological framework, have guided the development, education, quality control and sharing of atmosphere-biodiversity observations electronically.Atmospheric-Biodiversity Networks and Networking have traditionally operated within separate mandates with little degree of integration. Air-Bio Networks were designed within an integrated framework to better understand the atmospheric stress on biodiversity and the adaptation actions, nationally and regionally. Detailed examples of the cumulative effects of climate change, stratospheric ozone depletion, acid deposition, ground-level ozone, suspended particulate matter and hazardous air pollutants on biodiversity will be discussed using a Southern Ontario case study. In addition, recommendations will be presented for future paired SI/MAB plots, linked networks and networking for adaptation within the context of climate, chemical and ecological gradients. 相似文献
248.
湖北省湿地冬季水鸟多样性研究 总被引:11,自引:1,他引:11
报道了2004年1~4月湖北冬季水鸟调查结果,记录水鸟 66 种,种群数量 59 613 只,分属8目15科,其中列入国家重点保护的一级鸟类 4 种,115 只,国家二级 7 种,2 968 只。分析了冬季水鸟群落结构、分布和种群变动,并用生物多样性指数、物种丰富度与生物量3个不同的测度指标对其中12个湖泊的水鸟群落进行了评价,认为沉湖、梁子湖、龙感湖和网湖是较为成熟稳定的群落;并从沉湖东方白鹳(Ciconia boyciana)、龙感湖白头鹤(Grus monacha)、洪湖鸭科水鸟近40年的种群动态探讨了湿地水鸟现状,认为种群衰退趋势明显、湿地干扰和威胁严重。对此提出了加强湿地保护区的建设,理顺管理体制,合理规划与发展湿地产业和保护湿地资源对策。 相似文献
249.
Xu Jingwei Li Chuanrong Li Qi Zheng Li & Wang Weidong Beijing Forestry University Beijing China Shandong Acdemy of Forestry Jinan China College of Forestry Shandong Agricultural University Taian China Shandong Normal University Jinan China 《中国人口.资源与环境(英文版)》2005,3(3)
Evaluating the biodiversity of previous and current species in a forest community is an important task. Some methodological researches and effective applications have been carried out widely in the temperate upland zone. However, they lack related researches in coastal shelter forests. This paper attempts to analyze them for Jiaonan coastal forest communities from the following three aspects, the relationship between plant biodiversity structure and its environment, the nexus between biodivers… 相似文献
250.
重庆三峡库区鸟类生物多样性研究 总被引:11,自引:2,他引:9
通过1996-1997年的调查,记录三峡工程重庆库区鸟类293种,分属17目45科,159属,比文献记录新增加33种,其中重庆市鸟类新记录9种。鸟类区系成分以东洋界为主体。国家重点保护动物29种,Ⅰ类2种,Ⅱ类27种;除红腹锦鸡种群数量较多外,其余都较稀少。从分布上看,库区东段的种类和数量比西段多;海拔1200m以上物种丰富;1200m以下为强度农耕区,种类较为贫乏,主要是一些与人为活动相关的种类。表1参9 相似文献