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301.
302.
Deer movements around surface coal mines were investigated in Preston Country, West Virginia, USA. Seventy-two deer crossings were counted on 29 surface mines with only 8% found on highwalls with more than 20% rock or stone. Thus, although slope was important, the percentage of dirt on the highwall determined use as a crossing location for deer. The average distance between all deer crossing was 209.7 m but the distance between the end of the highwall and the nearest highwall crossing was 248.7 m indicating reluctance of deer to cross mines when they could walk around them. Winter snow track counts showed fewer deer within 90 m of the top edge of the highwall. Four land bridges traversed the highwall and were heavily utilized by deer, especially in March, April, May, October and November. The surface mine bench was used as a fawn bedding area, but little feeding occurred on this portion of the mine. 相似文献
303.
An understanding of the scaling laws governing aerosol sampler performance leads to new options for testing aerosol samplers at small scale in a small laboratory wind tunnel. Two methods are described in this paper. The first involves an extension of what is referred to as the "conventional" approach, in which scaled aerosol sampler systems are tested in a small wind tunnel while exposed to relatively monodisperse aerosols. Such aerosols are collected by test and reference samplers respectively and assessed gravimetrically. The new studies were carried out for a modified, low flowrate version of the IOM personal inhalable aerosol sampler. It was shown that such experiments can be carried out with a very high level of repeatability, and this supported the general validity of the aerosol sampler scaling laws. The second method involves a novel testing system and protocol for evaluating the performances of aerosol samplers. Here, scaled aerosol samplers of interest are exposed to polydisperse aerosols, again in a small wind tunnel. In this instance, the sampled particles are counted and sized using a direct-reading aerodynamic particle sizer (the APS). A prototype automated aerosol sampler testing system based on this approach was built and evaluated in preliminary experiments to determine the performance of another modified version of the IOM personal inhalable aerosol sampler. The design of the new test system accounts for the complex fluid mechanical coupling that occurs near the sampler inlet involving the transition between the external flow outside the sampler and the internal airflow inside the sampler, leading in turn to uncontrolled particle losses. The problem was overcome by the insertion of porous plastic foam plugs. where the penetration characteristics are well understood, into the entries of both the test and the reference samplers. Preliminary experiments with this new system also supported the general validity of the aerosol sampler scaling laws. In addition, they demonstrated high potential that this approach may be applied in a standardised aerosol testing method and protocol. 相似文献
304.
Samuel E. Kakulu 《Environmental monitoring and assessment》1993,28(2):137-143
The epiphytic moss Polytrichum juniperinum and the tree bark of Azardirachta indica were used to determine the atmospheric Cd, Cu, Pb, Mn, Fe, Ni and Zn levels in the North-East region of Nigeria. A good correlation exists between levels in the moss and the tree barks. The Pb, Zn and Fe levels in both sample types were higher than other metals in most sites. There was no significant difference in the levels of Cd, Cu, Ni and Mn recorded for inhabited and forest sites. The area derives its atmospheric metal contamination from vehicular, urban, industrial and agricultural sources. 相似文献
305.
In the Adayar riverbed and its estuary 5 undisturbed sediment cores were drilled using a petrol-driven hammer. Cores of a depth of 4-5 m were sampled in 0.5 m steps. The distribution of heavy metals (Cr, Mn, Ni, Cu, Zn, Cd and Pb) in the top layers of fluvial and estuarine sediments indicates recent anthropogenic input: Revealing that the river acts as a sink for drainage from the residential and industrial zones. In this study, the mobilization of heavy metals into greater depths and their probable effects on the groundwater body are discussed. The high concentration of heavy metals and the influent character of the river Adayar allow the mobilization of metal ions and their transport into the deeper layers of the sediment. A changing environment due to effects such as saltwater intrusion and monsoon floods is the driving force for this phenomenon. 相似文献
306.
Swaminathan Shiva Fankhauser Samuel 《Mitigation and Adaptation Strategies for Global Change》2000,5(2):171-187
An application is presented of the methodology used bythe Global Environment Facility (GEF) to measureincremental costs. Incremental cost estimates are usedby the GEF to determine its financial contribution toprojects that protect the global environment, such asinvestments in renewable energy. The importance ofadopting a system-wide view in certain types ofprojects (such as investments in grid-connected power)is illustrated using the case of wind power inMorocco. A narrow plant-by-plant comparison wouldneglect the adjustments in the system expansion planthat may be warranted when one type of plant (e.g., acoal fired thermal plant) is replaced by another (e.g.,a wind farm). 相似文献
307.
Young Nile crocodiles Crocodylus niloticus start to produce calls inside the egg and carry on emitting sounds after hatching. These vocalizations elicit maternal care
and influence the behaviour of other juveniles. In order to investigate the acoustic structure of these calls, focusing on
a possible individual signature, we have performed acoustic analyses on 400 calls from ten young crocodiles during the first
4 days after hatching. Calls have a complex acoustic structure and are strongly frequency modulated. We assessed the differences
between the calls of the individuals. We found a weak individual signature. An individual call-based recognition of young
by the mother is thus unlikely. In other respects, the call acoustic structure changes from the first to the fourth day after
hatching: fundamental frequency progressively decreases. These modifications might provide important information to the mother
about her offspring—age and size—allowing her to customize her protective care to best suit the needs of each individual.
Electronic supplementary material Supplementary material is available in the online version of this article at and is accessible for authorized users. 相似文献
308.
Adaptation investments: a resource allocation framework 总被引:1,自引:0,他引:1
Rhona Barr Samuel Fankhauser Kirk Hamilton 《Mitigation and Adaptation Strategies for Global Change》2010,15(8):843-858
Additional finance for adaptation is an important element of the emerging international climate change framework. This paper
discusses how adaptation funding may be allocated among developing countries in a transparent, efficient and equitable way.
We propose an approach based on three criteria: the climate change impacts experienced in a country, a country’s adaptive
capacity and its implementation capacity. Physical impact and adaptive capacity together determine a country’s vulnerability
to climate change. It seems both efficient and fair that countries which are more vulnerable should have a stronger claim
on adaptation resources. The third dimension, implementation capacity, introduces a measure of adaptation effectiveness. Rough
indicators are proposed for each of the three dimensions. The results are indicative only, but they suggest a strong focus
of initial adaptation funding on Africa. African countries are highly vulnerability in part because of the severity of expected
impacts, but also because of their very low adaptive capacity. However, their implementation capacity is also limited, suggesting
a need for technical assistance in project implementation. 相似文献
309.
The city is a growing centre of humanitarian concern. Yet, aid agencies, governments and donors are only beginning to comprehend the scale and, importantly, the complexity of the humanitarian challenge in urban areas. Using the case study of the Kathmandu Valley, Nepal, this paper examines the analytical utility of recent research on complex urban systems in strengthening scholarly understanding of urban disaster risk management, and outlines its operational relevance to disaster preparedness. Drawing on a literature review and 26 interviews with actors from across the Government of Nepal, the International Red Cross and Red Crescent Movement, non‐governmental organisations, United Nations agencies, and at‐risk communities, the study argues that complexity can be seen as a defining feature of urban systems and the risks that confront them. To manage risk in these systems effectively, preparedness efforts must be based on adaptive and agile approaches, incorporating the use of network analysis, partnerships, and new technologies. 相似文献
310.
Samuel Shephard Bryce Beukers-Stewart Jan G. Hiddink Andrew R. Brand Michel J. Kaiser 《Marine Biology》2010,157(1):91-97
There is evidence that ocean warming has effects on the ecology, including recruitment dynamics, of marine organisms. In association
with rising mean spring temperatures in the Irish Sea, a time-series of juvenile scallop Pecten maximus density around the Isle of Man showed a significant increasing trend since 1991. Favorable conditions (warmer water and correspondingly
greater food availability) during gonad development can increase scallop gamete production. We examined the possibility that
ocean warming has directly increased recruitment of exploited P. maximus around the Isle of Man by enhancing gonad development. From 1991–2007, there was a significant positive correlation between
scallop recruitment and mean spring (the main period of gonad development) temperature in the year of larval settlement. Detrended
(i.e., accounting for a time effect) recruitment data showed a marginally non-significant correlation to temperature. Gonadal
somatic index of adult scallops and temperature were positively correlated. These relationships support the hypothesis that
greater gamete production associated with ocean warming may be primarily responsible for observed increases in recruitment
success and CPUE in a commercially important shellfish stock. 相似文献