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201.
中国南极长城站室内空气微生物状况   总被引:3,自引:0,他引:3  
空气微生物是空气洁净程度的重要指标、环境污染状况的真实反映[1] .十年来 ,位于南极半岛的中国长城站常年有考察队员居住和工作 ,尤其在南极之夏 ,不时有各国考察、旅游、观光者出入 .这些都给长城站空气微生物的变化带入了外来因素[2 ] .我们于 1994年 2月 ,随机对站上 19个室内测点作空气微生物考察 ,以监测和比较室内空气微生物含量状况 ,为进一步了解空气微生物的卫生学意义 ,并服务于提高南极考察队员的身体素质 ,加深对南极生态系统的理解而提供一些资料 .1 材料与方法1 .1 测点1994年 2月份分 6天对 19个室内空间作了 2 0次测定 …  相似文献   
202.
Females capable of adjusting the sex ratio of their offspring should be more fit than females lacking such an ability. In polygynous birds where breeding success in males is more strongly influenced by body size and/or attractiveness than in females, females might produce more sons when predicting good conditions or when mating with attractive males. Polygynous great reed warbler, Acrocephalusarundinaceus, males direct most of their feeding effort to the primary (first-hatching) nest and in these nests increase their feeding effort in relation to the brood sex ratio (proportion of sons). Therefore, with the expectation of well-nourished sons, we would predict that females which start breeding first within harems might produce more sons than those which start breeding later, and in anticipation of sons with good genes, that females mated to polygynous males might produce more sons than females mated to monogamous males. I took blood samples from hatchlings and determined the sex using DNA markers. The sex ratio of primary (monogamous and polygynous primary) broods is more male-biased (mean 0.58 males, n = 50) than that of secondary (polygynous secondary and tertiary) broods (mean 0.46, n = 25). Moreover, in the secondary broods with the largest clutch (five eggs), in which offspring are most likely to suffer food shortage, the sex ratio was distinctively female biased (mean 0.33, n = 10). In the primary broods, sex ratio was correlated to harem size. The results suggest that great reed warbler females modify the brood sex ratio to produce both well-nourished sons and sons with good genes, but the former effect is probably stronger than the latter factor. Received: 11 March 1998 / Accepted after revision: 23 May 1998  相似文献   
203.
江苏省高宝湖区湖泊群富营养化特征分析   总被引:2,自引:0,他引:2  
对江苏省高宝湖区高邮湖、宝应湖、邵伯湖和白马湖湖泊富营养化共性与差异性特征进行了分析。结果表明,2009—2014年,4个湖泊总体处于中营养—轻度富营养之间,综合富营养状态指数值在年内均呈波动变化,丰水期明显大于枯水期;主要营养因子水平在4个湖泊之间均存在较明显的差异,尤其是TN和SD 2项指标阶梯状差异较为明显,Chl-a也呈现不同程度的年内分布水平差异,并在春、夏季存在藻类暴发风险;各湖泊Chl-a与环境因子相关性差异较大,宝应湖、白马湖以及总体分析的高宝湖群Chl-a均与水温、TP相关性显著,TP应是高宝湖群藻类生长限制的主导营养因子;各湖泊富营养化特征存在差异性,总体上宝应湖与白马湖富营养化特征较为类似,与高邮湖差异较大,邵伯湖富营养化特征与高邮湖接近,又兼有与宝应湖、白马湖相似性特征。  相似文献   
204.
Ecosystem‐based management of the Laurentian Great Lakes, which spans both the United States and Canada, is hampered by the lack of consistent binational watersheds for the entire Basin. Using comparable data sources and consistent methods, we developed spatially equivalent watershed boundaries for the binational extent of the Basin to create the Great Lakes Hydrography Dataset (GLHD). The GLHD consists of 5,589 watersheds for the entire Basin, covering a total area of approximately 547,967 km2, or about twice the 247,003 km2 surface water area of the Great Lakes. The GLHD improves upon existing watershed efforts by delineating watersheds for the entire Basin using consistent methods; enhancing the precision of watershed delineation using recently developed flow direction grids that have been hydrologically enforced and vetted by provincial and federal water resource agencies; and increasing the accuracy of watershed boundaries by enforcing embayments, delineating watersheds on islands, and delineating watersheds for all tributaries draining to connecting channels. In addition, the GLHD is packaged in a publically available geodatabase that includes synthetic stream networks, reach catchments, watershed boundaries, a broad set of attribute data for each tributary, and metadata documenting methodology. The GLHD provides a common set of watersheds and associated hydrography data for the Basin that will enhance binational efforts to protect and restore the Great Lakes.  相似文献   
205.
After the Great East Japan Earthquake and Tsunami, volunteers participated in the recovery of lost photographs. This effort—which we call the Picturescue Movement—subsequently began to organise photograph restoration gatherings. We conducted field research during the gatherings in Noda, one of the tsunami-stricken areas. We have also carried out research on restoration gatherings in the city of Rikuzentakata. A comparison of findings across these two localities identifies two approaches to photograph restoration gatherings: ‘aiming’ and ‘staying'. The aiming approach, employed in Rikuzentakata, emphasises returning photographs to their owners quickly, whereas the latter approach, used in Noda, is one in which volunteers stay with survivors for some time and encourage them to recall the past at their own pace. We conclude that the staying approach is more likely than the aiming approach to promote disaster recovery among survivors.  相似文献   
206.
207.
ABSTRACT: A new screening approach is applied to a large‐scale multiple criteria water management problem to remove actions that cannot possibly be in the best subset. An inherent advantage of the approach is its ability to identify inferior actions by examining them individually, rather than within subsets. In a case study involving the selection of actions to address high water levels in the Great Lakes‐St. Lawrence Basin, two statistical indicators, the mode and the mean, are used to aggregate the opinions of experts and representatives of interest groups on the impacts of actions according to various criteria. Application of the screening approach shows that some of the proposed actions can be removed as they can never be in the optimal subset, thereby reducing the size of the problem.  相似文献   
208.
The Science Advisory Board of the US Environmental Protection Agency has recommended that risk reduction strategies become the centerpiece of environmental protection. The goal in developing such strategies is to identify opportunities for greatest reduction of ecological risks. This is a perspective that is significantly more comprehensive than the traditional focus on human health risks arising from environmental degradation. The identification of ecological risks upon which environmental protection efforts should be focused requires an ecological risk assessment methodology that is based on anthropogenic stressors affecting an ecosystem and a set of impaired use criteria. A methodology based on this concept is developed and discussed in this article. The methodology requires that risk values be assigned to each ecosystem stressor-impaired use pair that reflect the degree to which the given stressor contributes to ecosystem risk as measured by the given impaired use criterion. Once these data are available, mathematical analyses based on concepts from fuzzy set theory are performed to obtain a ranking of ecosystem stressors. The methodology has been tested by applying it to a case study involving Green Bay of Lake Michigan. A workshop was held in which 11 persons with extensive knowledge of the Green Bay ecosystem determined risk values through a group-consensus process. The analytical portion of the methodology was then used to rank the ecosystem risks (stressors) from several perspectives, including prevention management and remediation management. The overall conclusion of the workshop participants was that the fuzzy set decision model is a useful and effective methodology for differentiating environmental risk.  相似文献   
209.
As part of the commitments made by the governments of Canada and the United States in the Great Lakes Water Quality Agreement, Remedial Action Plans (RAPs) are being developed and implemented at Great Lakes Areas of Concern. The Areas of Concern are specific places around the Great Lakes basin ecosystem where environmental quality is degraded to the point that certain beneficial uses (the ability of fish, wildlife and humans to thrive) are impaired. According to the United States and Canada Great Lakes Water Quality Agreement of 1987, the federal governments, in cooperation with state and provincial governments, are to ensure the public is consulted throughout the development and implementation of the RAPs. While not explicit in the Agreement, it is logical to posit that given the effort and investment in environmental improvements, community capacity to sustain the recovery of beneficial uses beyond the life of the RAP should be a product of the RAP. This report examines a case study to test the hypothesis that public ownership of the RAP process can result in the development of community capacity to sustain environmental recovery. The question is, were the principles of the RAP, 10 years after delisting, taken into account to ensure sustainability of growth along the waterfront and within the Town? To arrive at the answer it is important to explore the approach used in the Collingwood Harbour RAP process, and concepts and principles of sustainable cities and towns. This paper provides evidence that such principles are being applied in Collingwood and were nurtured during the development and implementation of the RAP.  相似文献   
210.
Continued resource degradation in various areas of the Great Lakes has led to doubts of the adequacy of conventional science and management approaches. The need for a more holistic approach, identified as an ecosystem approach, appears now to be more widely accepted although progress with implementation is slow. We argue here that ecosystem science is an integral part of an ecosystem approach and is a prerequisite to effective management planning.One of the problems of implementing an ecosystem approach is forging the link between ecosystem based research and management. For Green Bay, Wisconsin, USA, certain structural and functional qualities of the ecosystem have been used to define operational guides and to formulate management objectives. These objectives are being utilized in the development of a remedial action plan for Green Bay.Deceased 5 February 1986.  相似文献   
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