全文获取类型
收费全文 | 221篇 |
免费 | 12篇 |
国内免费 | 3篇 |
专业分类
安全科学 | 4篇 |
废物处理 | 1篇 |
环保管理 | 89篇 |
综合类 | 25篇 |
基础理论 | 58篇 |
环境理论 | 1篇 |
污染及防治 | 14篇 |
评价与监测 | 6篇 |
社会与环境 | 16篇 |
灾害及防治 | 22篇 |
出版年
2024年 | 1篇 |
2023年 | 1篇 |
2022年 | 1篇 |
2021年 | 4篇 |
2020年 | 2篇 |
2019年 | 5篇 |
2018年 | 5篇 |
2017年 | 12篇 |
2016年 | 12篇 |
2015年 | 6篇 |
2014年 | 10篇 |
2013年 | 29篇 |
2012年 | 7篇 |
2011年 | 16篇 |
2010年 | 6篇 |
2009年 | 17篇 |
2008年 | 11篇 |
2007年 | 11篇 |
2006年 | 13篇 |
2005年 | 7篇 |
2004年 | 11篇 |
2003年 | 8篇 |
2002年 | 4篇 |
2001年 | 4篇 |
2000年 | 5篇 |
1999年 | 3篇 |
1998年 | 3篇 |
1997年 | 2篇 |
1996年 | 3篇 |
1993年 | 2篇 |
1987年 | 3篇 |
1986年 | 6篇 |
1984年 | 1篇 |
1982年 | 1篇 |
1981年 | 2篇 |
1977年 | 1篇 |
1972年 | 1篇 |
排序方式: 共有236条查询结果,搜索用时 15 毫秒
141.
John Magrath 《Local Environment》2013,18(9-10):891-901
Farmers and pastoralists in Africa are remarkably consistent across countries in how they report climate is changing. These changes are still relatively small but, combined with the effects of chronic poverty, disease and environmental degradation, are already having severe human consequences. The changes are consistent with what is expected to occur due to man-made global warming and will increase. Women are especially impacted. Africa is least responsible for greenhouse gas emissions, but will suffer some of the most damaging consequences. Adaptation is essential. This will require finance from international sources. However, there is much African governments can and should do to start. Boosting adaptation to current climatic variability and shocks and tackling poverty will bring benefits today and for the future. 相似文献
142.
Stephanie Ann Farquhar Edith A. Parker Amy J. Schulz Barbara A. Israel 《Local Environment》2013,18(3):259-274
Abstract This article examines results from in-depth interviews conducted with parents of children with asthma living in an urban environment. We examine themes from the in-depth interviews related to participants' perceptions of the influence of their physical environment on their mental and physical health, and the actions that they take in an effort to protect their health within this context. The findings from this study suggest several implications for understanding the interface between the physical environment of urban communities and residents' health, as well as for the policy and practice of risk assessment strategies. 相似文献
143.
John R. Poulsen Cooper Rosin Amelia Meier Emily Mills Chase L. Nuñez Sally E. Koerner Emily Blanchard Jennifer Callejas Sarah Moore Mark Sowers 《Conservation biology》2018,32(3):559-567
Poaching is rapidly extirpating African forest elephants (Loxodonta cyclotis) from most of their historical range, leaving vast areas of elephant‐free tropical forest. Elephants are ecological engineers that create and maintain forest habitat; thus, their loss will have large consequences for the composition and structure of Afrotropical forests. Through a comprehensive literature review, we evaluated the roles of forest elephants in seed dispersal, nutrient recycling, and herbivory and physical damage to predict the cascading ecological effects of their population declines. Loss of seed dispersal by elephants will favor tree species dispersed abiotically and by smaller dispersal agents, and tree species composition will depend on the downstream effects of changes in elephant nutrient cycling and browsing. Loss of trampling and herbivory of seedlings and saplings will result in high tree density with release from browsing pressures. Diminished seed dispersal by elephants and high stem density are likely to reduce the recruitment of large trees and thus increase homogeneity of forest structure and decrease carbon stocks. The loss of ecological services by forest elephants likely means Central African forests will be more like Neotropical forests, from which megafauna were extirpated thousands of years ago. Without intervention, as much as 96% of Central African forests will have modified species composition and structure as elephants are compressed into remaining protected areas. Stopping elephant poaching is an urgent first step to mitigating these effects, but long‐term conservation will require land‐use planning that incorporates elephant habitat into forested landscapes that are being rapidly transformed by industrial agriculture and logging. 相似文献
144.
Fritz Kleinschroth John R. Healey Sylvie Gourlet‐Fleury Frédéric Mortier Radu S. Stoica 《Conservation biology》2017,31(2):469-480
Forest degradation in the tropics is often associated with roads built for selective logging. The protection of intact forest landscapes (IFL) that are not accessible by roads is high on the biodiversity conservation agenda and a challenge for logging concessions certified by the Forest Stewardship Council (FSC). A frequently advocated conservation objective is to maximize the retention of roadless space, a concept that is based on distance to the nearest road from any point. We developed a novel use of the empty‐space function – a general statistical tool based on stochastic geometry and random sets theory – to calculate roadless space in a part of the Congo Basin where road networks have been expanding rapidly. We compared the temporal development of roadless space in certified and uncertified logging concessions inside and outside areas declared IFL in 2000. Inside IFLs, road‐network expansion led to a decrease in roadless space by more than half from 1999 to 2007. After 2007, loss leveled out in most areas to close to 0 due to an equilibrium between newly built roads and abandoned roads that became revegetated. However, concessions in IFL certified by FSC since around 2007 continuously lost roadless space and reached a level comparable to all other concessions. Only national parks remained mostly roadless. We recommend that forest‐management policies make the preservation of large connected forest areas a top priority by effectively monitoring – and limiting – the occupation of space by roads that are permanently accessible. 相似文献
145.
LYNDON D. ESTES LYDIE‐LINE PAROZ BETHANY A. BRADLEY JONATHAN M.H. GREEN DAVID G. HOLE STEPHEN HOLNESS GUY ZIV MICHAEL G. OPPENHEIMER DAVID S. WILCOVE 《Conservation biology》2014,28(2):427-437
Much of the biodiversity‐related climate change impacts research has focused on the direct effects to species and ecosystems. Far less attention has been paid to the potential ecological consequences of human efforts to address the effects of climate change, which may equal or exceed the direct effects of climate change on biodiversity. One of the most significant human responses is likely to be mediated through changes in the agricultural utility of land. As farmers adapt their practices to changing climates, they may increase pressure on some areas that are important to conserve (conservation lands) whereas lessening it on others. We quantified how the agricultural utility of South African conservation lands may be altered by climate change. We assumed that the probability of an area being farmed is linked to the economic benefits of doing so, using land productivity values to represent production benefit and topographic ruggedness as a proxy for costs associated with mechanical workability. We computed current and future values of maize and wheat production in key conservation lands using the DSSAT4.5 model and 36 crop‐climate response scenarios. Most conservation lands had, and were predicted to continue to have, low agricultural utility because of their location in rugged terrain. However, several areas were predicted to maintain or gain high agricultural utility and may therefore be at risk of near‐term or future conversion to cropland. Conversely, some areas were predicted to decrease in agricultural utility and may therefore prove easier to protect from conversion. Our study provides an approximate but readily transferable method for incorporating potential human responses to climate change into conservation planning. Uso de Cambios en la Utilidad Agrícola para Cuantificar Riesgos Futuros para la Conservación Inducidos por el Clima 相似文献
146.
Abstract: In East Africa fire and grazing by wild and domestic ungulates maintain savannas, and pastoralists historically set fires and herded livestock through the use of temporary corrals called bomas. In recent decades traditional pastoral practices have declined, and this may be affecting biodiversity. We investigated the effects of prescribed fires and bomas on savanna bird communities in East Africa during the first and second dry seasons of the year (respectively before and after the rains that mark the onset of breeding for most birds). We compared abundance, richness, and community composition on 9‐ha burned plots, recently abandoned bomas, and control plots in the undisturbed matrix habitat over a 3‐year period. Generally, recently burned areas and abandoned bomas attracted greater densities of birds and had different community assemblages than the surrounding matrix. The effects of disturbances were influenced by interactions between primary productivity, represented by the normalized difference vegetation index, and time. Bird densities were highest and a greater proportion of species was observed on burned plots in the months following the fires. Drought conditions equalized bird densities across treatments within 1 year, and individuals from a greater proportion of species were more commonly observed on abandoned bomas. Yearly fluctuations in abundance were less pronounced on bomas than on burns, which indicate that although fire may benefit birds in the short term, bomas may have a more‐lasting positive effect and provide resources during droughts. Several Palearctic migrants were attracted to burned plots regardless of rainfall, which indicates continued fire suppression may threaten their already‐declining populations. Most notably, the paucity of birds observed on the controls suggests that the current structure of the matrix developed as a result of fire suppression. Traditional pastoralism appears critical to the maintenance of avian diversity in these savannas. 相似文献
147.
Claudien Habimana Simbi Jianyi Lin Dewei Yang Jean Claude Ndayishimiye Yang Liu Huimei Li Lingxing Xu Weijing Ma 《环境科学学报(英文版)》2021,33(4):85-98
The potential for mitigating climate change is growing worldwide, with an increasing emphasis on reducing CO2 emissions and minimising the impact on the environment. African continent is faced with the unique challenge of climate change whilst coping with extreme poverty, explosive population growth and economic difficulties. CO2 emission patterns in Africa are analysed in this study to understand primary CO2 sources and underlying driving forces further. Data are examined using gravity model, logarithmic mean divisia index and Tapio's decoupling indicator of CO2 emissions from economic development in 20 selected African countries during 1984?2014. Results reveal that CO2 emissions increased by 2.11% (453.73 million ton) over the research period. Gravity centre for African CO2 emissions had shifted towards the northeast direction. Population and economic growth were primary driving forces of CO2 emissions. Industrial structure and emission efficiency effects partially offset the growth of CO2 emissions. The economic growth effect was an offset factor in central African countries and Zimbabwe due to political instability and economic mismanagement. Industrial structure and emission efficiency were insufficient to decouple economic development from CO2 emissions and relieve the pressure of population explosion on CO2 emissions in Africa. Thus, future efforts in reducing CO2 emissions should focus on scale-up energy-efficient technologies, renewable energy update, emission pricing and long-term green development towards sustainable development goals by 2030. 相似文献
148.
Macdonald DW Johnson PJ Albrechtsen L Dutton A Seymour S Dupain J Hall A Fa JE 《Conservation biology》2011,25(6):1220-1228
Spatially extensive patterns of bushmeat extraction (and the processes underlying these patterns) have not been explored. We used data from a large sample (n= 87) of bushmeat trading points in urban and rural localities in Nigeria and Cameroon to explore extraction patterns at a regional level. In 7,594 sample days, we observed 61,267 transactions involving whole carcasses. Rural and urban trading points differed in species for sale and in meat condition (fresh or smoked). Carcass price was principally associated with body mass, with little evidence that taxonomic group (primate, rodent, ungulate, or mammalian carnivore) affected price. Moreover, meat condition was not consistently associated with price. However, some individual species were more expensive throughout the region than would be expected for their size. Prices were weakly positively correlated with human settlement size and were highest in urban areas. Supply did not increase proportionally as human settlement size increased, such that per capita supply was significantly lower in urban centers than in rural areas. Policy options, including banning hunting of more vulnerable species (those that have low reproductive rates), may help to conserve some species consumed as bushmeat because carcass prices indicate that faster breeding, and therefore the more sustainable species, may be substituted and readily accepted by consumers. 相似文献
149.
Many countries in sub‐Saharan Africa have adopted similar approaches to tackle the challenges of rural water supply, including community‐based management, community participation and the demand‐responsive approach. These are often combined with nationwide programmes of capacity‐building and decentralization. This paper first shows how Uganda has adopted these approaches in its rural water supply programme. Based on Government documents, we construct an organizational framework that illustrates the overall programme and outlines the roles and responsibilities which actors are expected to fulfil. Second, based on interviews with sector staff and a review of Government documents, the paper examines challenges to successfully “walk the talk”; that is, it provides insight into challenges affecting programme implementation. Among numerous difficulties, two key issues are highlighted: local political interference and the weak capacity of local governments. Concerning local political interference, local planning processes need to be reformed so that local politicians commit more strongly to improving water supply. Regarding local government capacity, the Government department responsible for the programme has established eight regional units that provide support to local governments. This promising strategy, combined with more appropriate engagement and the commitment of local politicians, should help to improve the implementation of the rural water supply programme in Uganda. 相似文献
150.
In recent years, policy mechanisms to support a formalized artisanal and small‐scale mining (ASM) sector in sub‐Saharan Africa have gained increasing currency. Proponents of formalization argue that most social and environmental problems associated with the sector stem from the fact that ASM is predominantly unregulated and operates outside the legal sphere. This paper critically examines recent efforts to formalize artisanal and small‐scale mining in West Africa, drawing upon recent fieldwork carried out in Sierra Leone, Ghana and Mali. In exploring the sector's livelihood dimensions, the analysis suggests that bringing unregulated, informal mining activities into the legal domain remains a considerable challenge. The paper concludes by confirming the urgent need to refocus formalization strategies on the main livelihood challenges and constraints of small‐scale miners themselves, if poverty is to be alleviated and more benefits are to accrue to depressed communities in mineral‐rich regions. 相似文献