全文获取类型
收费全文 | 65篇 |
免费 | 5篇 |
专业分类
安全科学 | 4篇 |
废物处理 | 2篇 |
环保管理 | 11篇 |
综合类 | 9篇 |
基础理论 | 30篇 |
污染及防治 | 9篇 |
评价与监测 | 4篇 |
社会与环境 | 1篇 |
出版年
2022年 | 1篇 |
2021年 | 2篇 |
2020年 | 4篇 |
2019年 | 2篇 |
2018年 | 2篇 |
2017年 | 3篇 |
2016年 | 2篇 |
2015年 | 2篇 |
2014年 | 2篇 |
2013年 | 3篇 |
2012年 | 3篇 |
2011年 | 4篇 |
2009年 | 6篇 |
2008年 | 2篇 |
2007年 | 3篇 |
2006年 | 3篇 |
2005年 | 2篇 |
2004年 | 3篇 |
2003年 | 3篇 |
2002年 | 2篇 |
1998年 | 1篇 |
1997年 | 1篇 |
1996年 | 2篇 |
1995年 | 2篇 |
1994年 | 3篇 |
1993年 | 2篇 |
1990年 | 1篇 |
1988年 | 1篇 |
1980年 | 1篇 |
1979年 | 1篇 |
1978年 | 1篇 |
排序方式: 共有70条查询结果,搜索用时 15 毫秒
51.
P. Stockley J. B. Searle D. W. Macdonald C. S. Jones 《Behavioral ecology and sociobiology》1994,34(1):71-78
The common shrew (Sorex araneus) is a solitary small mammal with a promiscuous mating system. Previous studies of this species suggest that females typically mate multiply, and that males may adopt alternative mate-searching tactics. We studied two generations of common shrews in a population near Oxford, England. Males were found to adopt two different mate-searching tactics. Those classed as type A occupied relatively small exclusive ranges during March, and made repeated long-distance movements to visit female ranges around the time of first oestrus in April. Males classed as type B established large overlapping ranges in areas of relatively high female density during March, and maintained these ranges throughout April. Type B males were larger than type A males at an early stage of sexual maturation, but there was no difference in the adult body size of the two types of male. Type A males had significantly higher epididymal sperm counts than type B males. Paternity analyses of litters born during the first year of the study reveal that the mean number of offspring fathered by type B males was greater than the mean number fathered by type A males. It is concluded that different mate-searching tactics may be conditional upon the timing of sexual maturation. Differences in sperm production are discussed in relation to sperm competition theory. 相似文献
52.
Elena P. Kruchenkova Michael Goltsman Sergei Sergeev David W. Macdonald 《Die Naturwissenschaften》2009,96(4):457-466
The Arctic Fox Alopex lagopus semenovi population on Mednyi Island is completely isolated and subsists largely by scavenging on seabird colonies, which have remained
abundant and spatio-temporally predictable for many years. We compared population data at the beginning of 1976/1978 and some
time after 1994–2005, finding an 85% decline in fox numbers due to disease, to assess the effect of population size on social
structure. A total of 81 groups of known size and composition was observed during this 29-year period. Overall, helpers (usually
non-lactating yearling females) occurred in 25.7% of groups, and in 32.4% of groups there were two or three lactating females.
Female engagement in alloparental behaviour decreased, but not statistically significantly, after the decline in population
density. Total food availability was apparently constant throughout the study period, and therefore, the amount available
per individual was much higher later in the study. Both communally nursing females and helpers brought food and helped to
guard the litter. However, the benefits of communal rearing were unclear. While cubs were left without guards significantly
more rarely in the groups with an additional adult, the number of cubs weaned per lactating female was greater in groups with
one (3.93 ± 1.60), as opposed to two or three (3.06 ± 0.92), lactating females. Survival of cubs to 1 year of age in the groups
with two lactating females and/or with helpers was lower than that in the families with one lactating female without helpers (22.2% vs 32.2%). Fewer second-generation litters were
born to foxes produced by composite families than to those produced by pairs. Reproductive adults producing by pairs had,
on average, 1.23 (±1.72) second-generation litters. In groups that initially included additional adults, the average number
of second-generation litters per reproductive female was 0.21 (±0.49) and 0.46 (±0.81) litters per male. Thus, according to
three measures, increased group size had no apparent positive impact on reproductive success. The increased parental investment
and enhanced guarding of the cubs in the larger families could be beneficial under conditions of high population density and
a saturated biotope to which the island fox population was presumably adapted before the population crash in the late 1970s. 相似文献
53.
Thomas Merckx Ruth E. Feber Rebecca L. Dulieu Martin C. Townsend Mark S. Parsons Nigel A.D. Bourn Philip Riordan David W. Macdonald 《Agriculture, ecosystems & environment》2009,129(1-3):302-309
Agri-environment schemes (AES) are widely used policy instruments intended to combat widespread biodiversity declines across agricultural landscapes. Here, using a light trapping and mark-release-recapture study at a field-scale on nine common and widespread larger moth species, we investigate the effect of wide field margins (a popular current scheme option) and the presence of hedgerow trees (a potential scheme option in England) on moth abundance. Of these, we show that wide field margins positively affected abundances, although species did not all respond in the same way. We demonstrate that this variation can be attributed to species-specific mobility characteristics. Those species for which the effect of wide margins was strongest covered shorter distances, and were more frequently recaptured at their site of first capture. This demonstrates that the standard, field-scale uptake of AES may be effective only for less mobile species. We discuss that a landscape-scale approach, in contrast, could deliver significant biodiversity gains, as our results indicate that such an approach (perhaps delivered through targeting farmers to join AES) would be effective for the majority of wider countryside species, irrespective of their mobility level. 相似文献
54.
Angus H. H. Macdonald Eugenia M. Sampayo Tyrone Ridgway Michael H. Schleyer 《Marine Biology》2008,154(2):209-217
Studies on latitudinal gradients in Symbiodinium diversity on scleractinian corals are largely restricted to warm-water low latitude locations, and it appears that there
is a shift in symbiont distributions with increasing latitude. The Symbiodinium assemblages of high latitude coral communities have largely been undocumented despite occupying an important transitional
zone between tropical and temperate regions. Using a combination of the internal transcribed spacer region 2 (ITS2) and denaturing
gradient gel electrophoresis (DGGE), we assessed the cladal and subcladal variability of Symbiodinium in the widely distributed species Stylophora pistillata along a latitudinal transect in southeast African waters which extended into high latitude locations. All colonies examined
belonged to clade C. Six unique ITS2-DGGE banding profiles (designated Cspa to Cspf) were observed, which showed a latitudinal distribution from north to south, most likely a result of a gradient in water
temperature and irradiance driven by riverine input in the southern regions. Sequence analysis revealed that all sequences
except one did not match previously identified clade C sub-types, probably due to the lack of regional information in the
Western Indian Ocean when compared to the Caribbean and Pacific. This study further supports the applicability of ITS2-DGGE
in studies on Symbiodinium diversity, and highlights that potentially ecologically informative biogeographic patterns may be overlooked when only cladal
designations are employed. 相似文献
55.
Macdonald NW Rediske RR Scull BT Wierzbicki D 《Journal of environmental quality》2008,37(5):1974-1985
Municipal solid waste landfill leachate must be removed and treated to maintain landfill cover integrity and to prevent contamination of surface and ground waters. From 2003 to 2007, we studied an onsite disposal system in Ottawa County, Michigan, where leachate was spray irrigated on the vegetated landfill cover. We established six 20-m-diameter circular experimental plots on the landfill; three were spray irrigated as part of the operational system, and three remained as untreated control plots. We quantified the effects of leachate application on soil properties, soil solution chemistry, vegetative growth, and estimated solute leaching. The leachate had high mean levels of electrical conductivity (0.6-0.7 S m(-1)), Cl (760-900 mg L(-1)), and NH(4)-N (290-390 mg L(-1)) but was low in metals and volatile organic compounds. High rates of leachate application in 2003 (32 cm) increased soil electrical conductivity and NO(3)-N leaching, so a sequential rotation of spray areas was implemented to limit total leachate application to <9.6 cm yr(-1) per spray area. Concentrations of NO(3)-N and leaching losses remained higher on irrigated plots in subsequent years but were substantially reduced by spray area rotation. Leachate irrigation increased plant biomass but did not significantly affect soil metal concentrations, and plant metal concentrations remained within normal ranges. Rotating spray areas and timing irrigation to conform to seasonal capacities for evapotranspiration reduced the localized impacts of leachate application observed in 2003. Careful monitoring of undiluted leachate applications is required to avoid adverse impacts to vegetation or soils and elevated solute leaching losses. 相似文献
56.
Incidence of adverse biological effects within ranges of chemical concentrations in marine and estuarine sediments 总被引:118,自引:0,他引:118
Edward R. Long Donald D. Macdonald Sherri L. Smith Fred D. Calder 《Environmental management》1995,19(1):81-97
Matching biological and chemical data were compiled from numerous modeling, laboratory, and field studies performed in marine
and estuarine sediments. Using these data, two guideline values (an effects range-low and an effects range-median) were determined
for nine trace metals, total PCBs, two pesticides, 13 polynuclear aromatic hydrocarbons (PAHs), and three classes of PAHs.
The two values defined concentration ranges that were: (1) rarely, (2) occasionally, or (3) frequently associated with adverse
effects. The values generally agreed within a factor of 3 or less with those developed with the same methods applied to other
data and to those developed with other effects-based methods. The incidence of adverse effects was quantified within each
of the three concentration ranges as the number of cases in which effects were observed divided by the total number of observations.
The incidence of effects increased markedly with increasing concentrations of all of the individual PAHs, the three classes
of PAHs, and most of the trace metals. Relatively poor relationships were observed between the incidence of effects and the
concentrations of mercury, nickel, total PCB, total DDT and p,p′-DDE. Based upon this evaluation, the approach provided reliable
guidelines for use in sediment quality assessments. This method is being used as a basis for developing National sediment
quality guidelines for Canada and informal, sediment quality guidelines for Florida.
The methods and guidelines presented in this report do not necessarily represent the policy of the National Oceanic and Atmospheric
Administration, Environment Canada, or Florida Department of Environmental Protection. 相似文献
57.
A school-based experiment was conducted in the Brazilian Amazon to examine the effects of passively received information versus active elaboration on the ‘perceptions’ of jaguars (Panthera onca) among students, and the effects of information communicated via illustrated book on those perceptions among student’s parents. Books distributed via school decreased fathers’ perceptions of social acceptance of jaguar killing, but the same books distributed via a conservation organization did not. This suggests that fathers were influenced not only by the information explicitly conveyed in the content of books, but also by the implicit message that jaguar conservation was socially supported. Elaboration alone produced more persistent effects than information alone, but some negative attitudes were reinforced. Information and elaboration combined created stronger and more enduring effects than either intervention alone. These findings are important in designing interventions for our coexistence with jaguars and other charismatic species worldwide. 相似文献
58.
Timothy Hodgetts Dawn Burnham Amy Dickman Ewan A. Macdonald David W. Macdonald 《Conservation biology》2019,33(2):250-259
We reviewed recent work concerning the impact of geopolitics on wildlife conservation (and vice versa) and identified future priorities in conservation geopolitics research. Geopolitics is understood as both an analytical focus on geopolitical practices (especially concerning the behavior) of countries with respect to territory and national security and a set of theories developed to explain and predict those behaviors. We developed a typology of core geopolitical practices of relevance to conservation: territorial practices of colonization and the management of migrations and borders, and security practices relating to military, economic, and environmental security. We identified research that considers how these practices affect conservation situations and outcomes, noting the recent emergence of conceptual developments such as “environmental geopolitics” and “geopolitical ecology” that draw on multiple fields within the social sciences to theorize the links between geopolitics and environmental management. We defined a "geopolitical perspective" as a focus on geopolitical practices combined with an explicit engagement with geopolitical theory and identified conservation situations where this perspective could contribute to analytical clarity. We suggest the most pressing questions in conservation research to which the geopolitical perspective might contribute are how political and economic differences between countries affect biodiversity outcomes, how geopolitical practices to address those differences facilitate or frustrate conservation efforts, how national borders and human and wildlife movements can be better managed for the benefit of both, and how the most effective conservation strategies can be best selected to suit existing (and future) geopolitical realities. 相似文献
59.
We evaluated wheat straw biochar produced at 450 °C for its ability to influence bioavailability and persistence of two commonly used herbicides (atrazine and trifluralin) with different modes of action (photosynthesis versus root tip mitosis inhibitors) in two contrasting soils. The biochar was added to soils at 0%, 0.5% and 1.0% (w/w) and the herbicides were applied to those soil-biochar mixes at nil, half, full, two times, and four times, the recommended dosage (H4). Annual ryegrass (Lolium rigidum) was grown in biochar amended soils for 1 month. Biochar had a positive impact on ryegrass survival rate and above-ground biomass at most of the application rates, and particularly at H4. Within any given biochar treatment, increasing herbicide application decreased the survival rate and fresh weight of above-ground biomass. Biomass production across the biochar treatment gradient significantly differed (p < 0.01) and was more pronounced in the case of atrazine than trifluralin. For example, the dose-response analysis showed that in the presence of 1% biochar in soil, the value of GR50 (i.e. the dose required to reduce weed biomass by 50%) for atrazine increased by 3.5 times, whereas it increased only by a factor of 1.6 in the case of trifluralin. The combination of the chemical properties and the mode of action governed the extent of biochar-induced reduction in bioavailability of herbicides. The greater biomass of ryegrass in the soil containing the highest biochar (despite having the highest herbicide residues) demonstrates decreased bioavailability of the chemicals caused by the wheat straw biochar. This work clearly demonstrates decreased efficacy of herbicides in biochar amended soils. The role played by herbicide chemistry and mode of action will have major implications in choosing the appropriate application rates for biochar amended soils. 相似文献
60.
This paper engages the existing literature on Urban Political Ecology (UPE) from the perspective of regulating urban expansion through greenbelts. The paper makes a contribution to a better understanding of suburbanisation and postsuburbanisation which have so far not been at the centre of the concerns of UPE. In an era of global suburbanisation greenbelts differ from similar boundary setting exercises in the past and are as varied as the suburbanisation processes and their governance themselves. While conscious of those varieties, we focus here on the Greater Golden Horseshoe (GGH) greenbelt in Ontario that was created by provincial legislation in 2005. With the 2005 legislation, the Ontario government declared 720,000 hectares off limits for conventional urban development. The Greenbelt Act created an expansive area under protection from the Niagara Peninsula in the south to the Bruce Peninsula in the north, the Niagara Escarpment in the west to a series of moraines in the east. We will argue that the GGH greenbelt has become a prime negotiation space for the overall re-regulation of urban political ecologies in Southern Ontario. Largely surrounding the booming Toronto region, the GGH greenbelt is expansion space and projection screen of a suburbanizing region in search of redefinition. 相似文献