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231.
OrganiccontaminationintheGreatWallbay,Antarcticainaustralsummer¥PuJiabin,LiZongping,ShangLongshen,LiHong(InstituteofMarineEnv... 相似文献
232.
Runoff from human land-uses is one of the most significant threats to some coastal marine environments. Initiatives to reduce that runoff usually set runoff reduction targets but do not give guidance on how to prioritize the different options that exist to achieve them. This paper demonstrates an easy to interpret economic framework to prioritise investment for conservation projects that aim to reduce pollution of marine ecosystems caused by runoff from agricultural land-uses. We demonstrate how to apply this framework using data on project cost, benefit and feasibility with a subset of projects that have been funded to reduce runoff from subcatchments adjacent to the Great Barrier Reef. Our analysis provides a graphical overview of the cost-effectiveness of the investment options, enables transparent planning for different budgets, assesses the existence of trends in the cost-effectiveness of different categories, and can test if the results are robust under uncertainty in one or more of the parameters. The framework provided solutions that were up to 4 times more efficient than when omitting information on cost or benefit. The presented framework can be used as a benchmark for evaluating results from a range of prioritisation processes against the best possible conservation outcomes. 相似文献
233.
Valentin Amrhein Lars Erik Johannessen Lena Kristiansen Tore Slagsvold 《Behavioral ecology and sociobiology》2008,62(10):1633-1641
The costs and benefits of bird song are likely to vary among species, and different singing patterns may reflect differences
in reproductive strategies. We compared temporal patterns of singing activity in two songbird species, the blue tit (Cyanistes caeruleus) and the great tit (Parus major). The two species live side by side year round, and they have similar breeding ecology and similar rates of extra-pair paternity.
However, they differ in two aspects of reproductive strategy that may have an influence on song output: blue tits are facultatively
polygynous and have a fairly short breeding season with almost no second broods, whereas great tits are socially monogamous
but more commonly raise second broods. We found that great tit males continued singing at high levels during the egg-laying
and incubation periods, while monogamously paired blue tit males strongly reduced singing activity after the first days of
egg-laying by their female. Since males of both species sang much more intensely shortly before sunrise than after sunrise,
at midday or in the evening, this difference was most conspicuous at dawn. No differences in singing activity were found within
species when testing for male age. We suggest that in contrast to blue tits, great tit males continued singing after egg-laying
to defend the territory and to encourage the female for a possible second brood. 相似文献
234.
During the past several years, chlorine residuals and chlorinated organic compounds in drinking waters and aquatic environments have become a significant topic of study for scientists concerned about the quality of life in aquatic ecosystems as well as general public health. The effects of direct toxicity and/or carcinogenicity to human and aquatic life are the focal points for this concern.The effects of chloramines and chlorinated organic compounds present in the water distribution system after chlorination treatments are reviewed. Also discussed are the effects of chlorinated discharges from municipal secondary treatment plants and power plants on human health and aquatic life. The toxic significance of environmental chemicals are described. 相似文献
235.
天水地震台流体异常与汶川8.0级地震关系探讨 总被引:1,自引:0,他引:1
通过对天水台(包括子台)2008年流体资料分析,在汶川8.0地震前天水流体资料短临异常明显,同震效应突出。模拟水氡观测震前1~3月开始出现异常,5个测点基本同步变化,其特征表现为测值迅速下降,然后出现转折,在上升过程中发生地震。数字化水温资料则出现同震效应,表现为水温测值大幅下降或上升,然后在几小时内恢复。数字化水位资料出现了震后效应,表现为测值持续下降,逐渐放缓下降速率,并保持低值未恢复到原来状态。通过总结分析天水台流体资料异常,对天水台及邻区的地震趋势判断是有益的。 相似文献
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237.
This study provides a method for assessing a multiplicity of environmental factors in red spruce growth in the Great Smoky Mountains National Park (GSMNP) of Southeastern USA. Direct and indirect factors in the annual growth increment are first organized into a schematic input-output envirogram (ARIRS), and this information is then used to construct a simulation model (ARIM). The envirogram represents a structured conceptualization of most environmental factors involved in growth, as developed from relevant literature. This interdisciplinary synthesis distinguishes direct vs. indirect factors in growth and takes account of the systems ecology concept that indirect factors may be as important as or more important than direct ones in regulating growth. The ARIRS envirogram summarizes hierarchically organized, within- and cross-scale, local-to-global interactions, and its construction makes it obvious that growth is influenced by many cross-scale spatiotemporal interactions. More research on genecology is still needed to clarify the role of phenotypic plasticity and adaptive capacity in nutrient cycling, global change, and human disturbance. 相似文献
238.
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240.
Mercury, a toxic metal known to have several deleterious affects on human health, has been one of the principal contaminants of concern in the Great Lakes basin. There are numerous anthropogenic sources of mercury to the Great Lakes area. Combustion of coal, smelting of non ferrous metals, and incineration of municipal and medical waste are major sources of mercury emissions in the region. In addition to North American anthropogenic emissions, global atmospheric emissions also significantly contribute to the deposition of mercury in the Great Lakes basin. Both the USA and Canada have agreed to reduce human exposure to mercury in the Great Lakes basin and have significantly curtailed mercury load to this region through individual and joint efforts. However, many important mercury sources, such as coal-fired power plants, still exist in the vicinity of the Great Lakes. More serious actions to drastically reduce mercury sources by employing alternative energy sources, restricting mercury trade and banning various mercury containing consumer products, such as dental amalgam are as essential as cleaning up the historical deposits of mercury in the basin. A strong political will and mass momentum are crucial for efficient mercury management. International cooperation is equally important. In the present paper, we have analyzed existing policies in respective jurisdictions to reduce mercury concentration in the Great Lakes environment. A brief review of the sources, occurrence in the Great Lakes, and the health effects of mercury is also included. 相似文献