全文获取类型
收费全文 | 77篇 |
免费 | 0篇 |
专业分类
环保管理 | 28篇 |
综合类 | 15篇 |
基础理论 | 16篇 |
污染及防治 | 9篇 |
评价与监测 | 3篇 |
社会与环境 | 5篇 |
灾害及防治 | 1篇 |
出版年
2022年 | 2篇 |
2021年 | 2篇 |
2020年 | 2篇 |
2019年 | 1篇 |
2018年 | 2篇 |
2017年 | 3篇 |
2016年 | 3篇 |
2015年 | 2篇 |
2014年 | 2篇 |
2013年 | 5篇 |
2012年 | 2篇 |
2011年 | 4篇 |
2010年 | 2篇 |
2009年 | 4篇 |
2008年 | 5篇 |
2007年 | 12篇 |
2006年 | 4篇 |
2005年 | 2篇 |
2004年 | 2篇 |
2003年 | 2篇 |
2002年 | 1篇 |
2001年 | 2篇 |
2000年 | 1篇 |
1998年 | 1篇 |
1997年 | 1篇 |
1995年 | 1篇 |
1994年 | 1篇 |
1993年 | 1篇 |
1991年 | 1篇 |
1986年 | 1篇 |
1985年 | 2篇 |
1984年 | 1篇 |
排序方式: 共有77条查询结果,搜索用时 375 毫秒
41.
Gerd Sparovek Alberto Barretto Goran Berndes Sergio Martins Rodrigo Maule 《Mitigation and Adaptation Strategies for Global Change》2009,14(3):285-298
Governments are promoting biofuels and the resulting changes in land use and crop reallocation to biofuels production have
raised concerns about impacts on environment and food security. The promotion of biofuels has also been questioned based on
suggested marginal contribution to greenhouse gas emissions reduction, partly due to induced land use change causing greenhouse
gas emissions. This study reports how the expansion of sugarcane in Brazil during 1996–2006 affected indicators for environment,
land use and economy. The results indicate that sugarcane expansion did not in general contribute to direct deforestation
in the traditional agricultural region where most of the expansion took place. The amount of forests on farmland in this area
is below the minimum stated in law and the situation did not change over the studied period. Sugarcane expansion resulted
in a significant reduction of pastures and cattle heads and higher economic growth than in neighboring areas. It could not
be established to what extent the discontinuation of cattle production induced expansion of pastures in other areas, possibly
leading to indirect deforestation. However, the results indicate that a possible migration of the cattle production reached
further than the neighboring of expansion regions. Occurring at much smaller rates, expansion of sugarcane in regions such
as the Amazon and the Northeast region was related to direct deforestation and competition with food crops, and appear not
to have induced economic growth. These regions are not expected to experience substantial increases of sugarcane in the near
future, but mitigating measures are warranted. 相似文献
42.
With the Brazilian military governments of the 1960s, systematic economic development of the Amazon began. Social and environmental concerns have entered Amazonian discourses and policies only since the 1990s. Since then, reports of threats to forests and indigenous people have alternated with reports of socio-economic progress and environmental achievements. These contradictions often arise from limited thematic, sectoral, temporal, or spatial perspectives, and lead to misinterpretation. Our paper offers a comprehensive picture of discourses, policies, and socio-environmental dynamics for the entire region over the last five decades. We distinguish eight historical policy phases, each of which had little effect on near-linear dynamics of demographic growth and land-use expansion, although some policies showed the potential to change the course of development. To prevent local, national, and international actors from continuing to assert harmful interests in the region, a coherent long-term commitment and change in the collective mindset are needed. 相似文献
43.
Investigations of land use/land cover (LULC) change and forest management are limited by a lack of understanding of how socioeconomic
factors affect land use. This lack also constrains the predictions of future deforestation, which is especially important
in the Amazon basin, where large tracts of natural forest are being converted to managed uses. Research presented in this
article was conducted to address this lack of understanding. Its objectives are (a) to quantify deforestation in the Northern
Ecuadorian Amazon (NEA) during the periods 1986–1996 and 1996–2002; and (b) to determine the significance and magnitude of
the effects of socioeconomic factors on deforestation rates at both the parroquia (parish) and finca (farm) levels. Annual
deforestation rates were quantified via satellite image processing and geographic information systems. Linear spatial lag
regression analyses were then used to explore relationships between socioeconomic factors and deforestation. Socioeconomic
factors were obtained, at the finca level, from a detailed household survey carried out in 1990 and 1999, and at the parroquia
level from data in the 1990 and 2001 Ecuadorian censuses of population. We found that the average annual deforestation rate
was 2.5% and 1.8%/year for 1986–1996 and 1996–2002, respectively. At the parroquia level, variables representing demographic
factors (i.e., population density) and accessibility factors (i.e., road density), among others, were found to be significantly
related to deforestation. At the farm level, the factors related to deforestation were household size, distance by road to
main cities, education, and hired labor. The findings of this research demonstrate both the severity of deforestation in the
Northern Ecuadorian Amazon and the array of factors affecting deforestation in the tropics. 相似文献
44.
Implications of Rural–Urban Migration for Conservation of the Atlantic Forest and Urban Growth in Misiones,Argentina (1970–2030) 总被引:2,自引:0,他引:2
Global trends of increasing rural–urban migration and population urbanization could provide opportunities for nature conservation,
particularly in regions where deforestation is driven by subsistence agriculture. We analyzed the role of rural population
as a driver of deforestation and its contribution to urban population growth from 1970 to the present in the Atlantic Forest
of Argentina, a global conservation priority. We created future land-use-cover scenarios based on human demographic parameters
and the relationship between rural population and land-cover change between 1970 and 2006. In 2006, native forest covered
50% of the province, but by 2030 all scenarios predicted a decrease that ranged from 18 to 39% forest cover. Between 1970
and 2001, rural migrants represented 20% of urban population growth and are expected to represent less than 10% by 2030. This
modeling approach shows how rural–urban migration and land-use planning can favor nature conservation with little impact on
urban areas. 相似文献
45.
The theory of collective action has been extensively used to explain the relationship between common-based property regimes and the conservation of natural resources. However, there are two key components of the theory that literature reports as puzzles in which no consensus exists about their effect on the performance of common-pool resources. These are group size and heterogeneity. This study analyzes the effects of these two key components on the effectiveness of community-based forestry, called ejidos, to protect their forest resources in northern Mexico. We used a multinomial logit model to determine the contribution of 16 explanatory variables to the dependent variable, a measure of success of ejidos defined by the presence of deforested, degraded, or forested conditions. The results show that corn yield, marginality, percent of forest area, total population, a forest value index, distance to markets, roads and towns, were all statistically significant in driving deforested conditions. Deforestation becomes more attractive for poor communities and as corn yield and distance to towns, roads, and markets decrease. In general, group size and heterogeneity had no significant effects on the presence of deforested conditions. Deforestation is driven by resource-specific characteristics, such as location and soil productivity, not by ejidos' attributes, such as total area or number of members. We argue that current institutional policies focusing on the structure of property right arrangements should be shifted (1) to provide better technology for land cultivation; (2) to reduce the marginality problem in poor communities; and (3) to strengthen local institutions. 相似文献
46.
Björn E. Berglund Junko Kitagawa Per Lagerås Koji Nakamura Naoko Sasaki Yoshinori Yasuda 《Ambio》2014,43(5):559-578
Traditional, pre-industrial farming was adapted to the natural environment—topography, geology, hydrology, climate, and biota. Traditional land use systems are still to be traced in Scandinavia as an “infield/outland landscape”, and in Japan as a “Satoyama landscape.” There are obvious similarities and differences in land use—the main difference being that pasturing of cattle and sheep has been less important in Japan. These land use systems can be traced back to early sedentary settlements 1500–2500 years ago. In both regions, traditional management almost ceased in the mid-twentieth century leading to afforestation and decreased biological diversity. Today, there is in Japan a growing movement for landscape restoration and promotion of a sustainable living countryside based on local agrarian and forestry production, local energy, tourism, etc. With this background, the so-called Satoyama Initiative has been organized and introduced as a global socio-ecological project with ecosystem services for human well-being. 相似文献
47.
The mountain-lowland debate: deforestation and sediment transport in the upper Ganga catchment 总被引:1,自引:0,他引:1
Wasson RJ Juyal N Jaiswal M McCulloch M Sarin MM Jain V Srivastava P Singhvi AK 《Journal of environmental management》2008,88(1):53-61
The Himalaya-Gangetic Plain region is the iconic example of the debate about the impact on lowlands of upland land-use change. Some of the scientific aspects of this debate are revisited by using new techniques to examine the role of deforestation in erosion and river sediment transport. The approach is whole-of-catchment, combining a history of deforestation with a history of sediment sources from well before deforestation. It is shown that deforestation had some effect on one very large erosional event in 1970, in the Alaknanda subcatchment of the Upper Ganga catchment, but that both deforestation and its effects on erosion and sediment transport are far from uniform in the Himalaya. Large magnitude erosional events occur for purely natural reasons. The impact on the Gangetic Plain of erosion caused by natural events and land cover change remains uncertain. 相似文献
48.
Brooke A. Williams Hedley S. Grantham James E. M. Watson Aurlie C. Shapiro Andrew J. Plumptre Samuel Ayebare Elizabeth Goldman Ayesha I. T. Tulloch 《Ambio》2022,51(9):2007
Many threats to biodiversity can be predicted and are well mapped but others are uncertain in their extent, impact on biodiversity, and ability for conservation efforts to address, making them more difficult to account for in spatial conservation planning efforts, and as a result, they are often ignored. Here, we use a spatial prioritisation analysis to evaluate the consequences of considering only relatively well-mapped threats to biodiversity and compare this with planning scenarios that also account for more uncertain threats (in this case mining and armed conflict) under different management strategies. We evaluate three management strategies to address these more uncertain threats: 1. to ignore them; 2. avoid them; or 3. specifically target actions towards them, first individually and then simultaneously to assess the impact of their inclusion in spatial prioritisations. We apply our approach to the eastern Democratic Republic of the Congo (DRC) and identify priority areas for conserving biodiversity and carbon sequestration services. We found that a strategy that avoids addressing threats of mining and armed conflict more often misses important opportunities for biodiversity conservation, compared to a strategy that targets action towards areas under threat (assuming a biodiversity benefit is possible). We found that considering mining and armed conflict threats to biodiversity independently rather than simultaneously results in 13 800–14 800 km2 and 15 700–25 100 km2 of potential missed conservation opportunities when undertaking threat-avoiding and threat-targeting management strategies, respectively. Our analysis emphasises the importance of considering all threats that can be mapped in spatial conservation prioritisation.Supplementary InformationThe online version contains supplementary material available at 10.1007/s13280-022-01724-0. 相似文献
49.
Ole Mertz Kenneth Grogan Dirk Pflugmacher Guillaume Lestrelin Jean-Christophe Castella Thoumthone Vongvisouk 《Journal of Land Use Science》2018,13(1-2):1-15
Forest reference levels (FRLs) provide a benchmark for assessing reduced emissions from deforestation and forest degradation (REDD+), and they are central to demonstrate additionality of REDD+. Attaining realistic FRLs, however, is challenging, especially in complex mosaic landscapes. We established FRLs in northern Laos for different reference periods and tested them against actual carbon stock changes. Annual time series of Landsat satellite images were used to capture the subtle changes in carbon stocks in complex landscapes characterized by shifting cultivation. We found that FRLs differ considerably depending on the reference period chosen. Abrupt land-use changes occurred when hybrid maize replaced traditional shifting cultivation and forests, and this invalidated carbon stock trends that would have been predicted had the FRL been projected into the future. We conclude that demonstrating additionality of REDD+ in fast developing areas is difficult and that payment systems rewarding potential emission reductions against hypothetical extrapolation of FRLs are unlikely to be a cost-effective strategy. 相似文献
50.
Socioeconomic indicators and the survival of the tropical rainforest of cross river state of Nigeria
An internal household survey of socioeconomic indicators in the Cross River State forest communities showed that basic infrastructural
facilities such as clean water supply, adequate waste disposal system, good roads and electricity are grossly inadequate.
There is a total absence of modern family planning practices in the communities, and population is projected to increase by
44.8% between 2000 and 2015 and 85.4% between 2000 and 2025. The study revealed that about 65% of the population of the rainforest
communities consists of subsistence farmers and power chain operators, and besides the 19% of the Cross River State Tropical
High Forestry (THF) already reported to have been lost to agriculture and plantation between 1972 and 1991, about 9% was lost
between 1991 and 2000. An additional 25% of the THF will be lost by 2025, leaving only 470600 hectares (4706 km2). With 84.1% of community members having an annual income less than $300, the survival potential of the Cross River State
rainforest in the next fifty years is very low, unless an effective forest management programme is encouraged by government
in partnership with all stakeholders. 相似文献