全文获取类型
收费全文 | 10917篇 |
免费 | 33篇 |
国内免费 | 9篇 |
专业分类
安全科学 | 58篇 |
废物处理 | 812篇 |
环保管理 | 1450篇 |
综合类 | 1085篇 |
基础理论 | 3486篇 |
环境理论 | 1篇 |
污染及防治 | 2025篇 |
评价与监测 | 1081篇 |
社会与环境 | 933篇 |
灾害及防治 | 28篇 |
出版年
2023年 | 10篇 |
2022年 | 15篇 |
2021年 | 15篇 |
2020年 | 21篇 |
2019年 | 20篇 |
2018年 | 1492篇 |
2017年 | 1401篇 |
2016年 | 1232篇 |
2015年 | 156篇 |
2014年 | 61篇 |
2013年 | 135篇 |
2012年 | 496篇 |
2011年 | 1387篇 |
2010年 | 733篇 |
2009年 | 644篇 |
2008年 | 931篇 |
2007年 | 1285篇 |
2006年 | 50篇 |
2005年 | 64篇 |
2004年 | 78篇 |
2003年 | 103篇 |
2002年 | 135篇 |
2001年 | 63篇 |
2000年 | 35篇 |
1999年 | 28篇 |
1998年 | 25篇 |
1997年 | 16篇 |
1996年 | 23篇 |
1995年 | 23篇 |
1994年 | 21篇 |
1993年 | 15篇 |
1992年 | 12篇 |
1991年 | 13篇 |
1990年 | 16篇 |
1989年 | 13篇 |
1988年 | 15篇 |
1987年 | 14篇 |
1986年 | 13篇 |
1985年 | 13篇 |
1984年 | 23篇 |
1983年 | 19篇 |
1982年 | 11篇 |
1981年 | 7篇 |
1980年 | 9篇 |
1979年 | 12篇 |
1978年 | 6篇 |
1977年 | 8篇 |
1973年 | 7篇 |
1972年 | 5篇 |
1969年 | 5篇 |
排序方式: 共有10000条查询结果,搜索用时 406 毫秒
991.
Roads function as prime habitats and corridors for invasive plant species. Yet despite the diversity of road types, there
is little research on the influence of these types on the spread of invaders. Common ragweed (Ambrosia artemisiifolia), a plant producing large amounts of allergenic pollen, was selected as a species model for examining the impact of road
type on the spread of invasive plants. We examined this relationship in an agricultural region of Quebec, Canada. We mapped
plant distribution along different road types, and constructed a model of species presence. Common ragweed was found in almost
all sampling sites located along regional (97%) and local paved (81%) roads. However, verges of unpaved local roads were rarely
(13%) colonized by the plant. A model (53% of variance explained), constructed with only four variables (paved regional roads,
paved local roads, recently mown road verges, forest cover), correctly predicted (success rate: 89%) the spatial distribution
of common ragweed. Results support the hypothesis that attributes associated with paved roads strongly favour the spread of
an opportunistic invasive plant species. Specifically, larger verges and greater disturbance associated with higher traffic
volume create propitious conditions for common ragweed. To date, emphasis has been placed on controlling the plant in agricultural
fields, even though roadsides are probably a much larger seed source. Strategies for controlling the weed along roads have
only focused on major highways, even though the considerable populations along local roads also contribute to the production
of pollen. Management prioritizations developed to control common ragweed are thus questionable. 相似文献
992.
Exploitation of certain resources within a protected area on a sustainable basis could contribute to higher living standards
of rural people, particularly those in poor countries, and decrease conflicts between these populations and park authorities.
This article presents data from a case study of Kopaonik National Park (NP), Serbia, which is a park with natural resources,
most notably bilberries, which have always been relied on by local people. Vaccinium myrtillus traditionally has been collected for decades in Kopaonik NP and used by local people. However, little is known about the
socioeconomic and ecological relations that affect the collection and use of this species. The aim of the present study was
to understand how local people collect bilberries in Kopaonik NP and what their attitudes toward the park are. Household questionnaire
data were used to examine how local people collect bilberries and how to improve the relations between local people and NP
authorities. The survey questionnaire included 52 households from 7 local communities, and we applied a purposive sampling
strategy. In addition, expert interviews were conducted, and from these data we obtained a broader understanding of the relation
between local people and NP authorities. The results indicate that in Kopaonik NP, there is a conflict between pickers and
NP authorities. Sustainable management should be directed toward the protection of bilberries. Education of local people is
a key element in the sustainable collection and protection of natural resources. 相似文献
993.
994.
Merle Sowman Maria Hauck Lance van Sittert Jackie Sunde 《Environmental management》2011,47(4):573-583
A historical perspective on MPA identification and governance in South Africa reflects the continued influence of a top-down
and natural science-based paradigm, that has hardly changed over the past half century, despite the wealth of literature,
and a growing consensus, that advocates the need to adopt a more integrated and human-centered approach. Based on extensive
research in two coastal fishing communities, the paper highlights impacts and conflicts arising from this conventional approach
to MPA identification, planning and management. It argues that failure to understand the particular fishery system in all
its complexity, in particular the human dimensions, and involve resource users in planning and decision-making processes,
undermines efforts to achieve conservation and fisheries management objectives. The customary rights of local resource users,
and their food and livelihood needs in relation to marine resources, need to be acknowledged, prioritized and integrated into
planning and decision-making processes. Convincing ecologists, fisheries scientists and managers, that MPA success depends
on addressing the root causes of resource decline and incorporating social factors into MPA identification, planning and management,
remains a huge challenge in South Africa. 相似文献
995.
The management of small-scale freshwater fisheries in Amazon has been based usually on surveys of urban markets, while fisheries
of rural villages have gone unnoticed. We compared the fishing characteristics (catch, effort and selectivity) between an
urban market and five small villages in the Lower Tocantins River (Brazilian Amazon), downstream from a large reservoir. We
recorded 86 and 601 fish landings in the urban market and villages, respectively, using the same methodology. The urban fishers
showed higher catch per unit of effort, higher amount of ice (related to a higher fishing effort, as ice is used to store
fish catches) and larger crew size per fishing trip, but village fishers had a higher estimated annual fish production. Conversely,
urban and village fishers used similar fishing gear (gillnets) and the main fish species caught were the same. However, village
fishers showed more diverse strategies regarding gear, habitats and fish caught. Therefore, although it underestimated the
total amount of fish caught in the Lower Tocantins River region, the data from the urban market could be a reliable indicator
of main fish species exploited and fishing gear used by village fishers. Monitoring and management should consider the differences
and similarities between urban and rural fisheries, in Amazon and in other tropical regions. 相似文献
996.
Stakeholder Opinions on the Assessment of MPA Effectiveness and Their Interests to Participate at Pacific Rim National Park Reserve,Canada 总被引:1,自引:1,他引:0
As the number of marine protected areas (MPAs) is globally increasing, information is needed on the effectiveness of existing
sites. Many protected area agencies however have limited resources and are unable to evaluate MPA effectiveness. An evaluation
conducted entirely by the managing agency may also lack credibility. Long-term monitoring and evaluation programs should ideally
offer opportunities for participation of diverse groups in the selection of evaluation indicators and their assessment. A
participatory approach has the potential to enhance evaluation capacity, to increase credibility and acceptance of results,
to strengthen relationships between managers and local stakeholders, and to address more locally relevant information. Using
a case study approach, this paper investigates diverse stakeholder groups’ opinions on the design of an evaluation and their
interest to participate in an assessment. Respondents were most interested in the assessment of MPA achievements and outcome
indicators. Most groups identified a range of government agencies and stakeholders that should participate in an assessment
but only half of all respondents were interested to participate in monitoring activities. Most frequently mentioned limitations
for more participation were a lack of time and money, but also governance shortcomings such as limited participation possibilities
and not paying enough credit to stakeholders’ input. Participation interest was also influenced by occupation, place of residency,
and familiarity with the marine environment. Differences exist among stakeholders about suitable evaluators and preferred
monitoring partners, which could affect the credibility of evaluation results and affect monitoring activities. 相似文献
997.
Sanjiang National Nature Reserve (NNR) is a state-owned natural wetland in China that has suffered severe degradation due
to cultivation and wetland reclamation by farmers. As a consequence, the conversion of cultivated land to wetlands (CCW) was
proposed by the government of Heilongjiang province and the United Nations Development Programme/Global Environment Facility
(UNDP/GEF) project team in 2007. We suggest that voluntary participation in the CCW could be an important tool for accomplishing
the integrated objectives of wetland conservation and local development. The purpose of this study was to examine the main
factors that influence farmers’ willingness to participate in the CCW through a field investigation and a questionnaire. Based
on the data from our questionnaire, which provided an effective sample of 310 households in 11 villages, the influencing factors
of farmers’ willingness to participate were analyzed through binary logistic regression analyses. It was concluded that age,
education, the amount of cultivated land, geographical location, and the perceived benefits and risks were important factors
for participation. Furthermore, suggestions for improving the wetland compensation system and providing alternative livelihoods
are proposed to strengthen participation. 相似文献
998.
Approaches to Evaluating Climate Change Impacts on Species: A Guide to Initiating the Adaptation Planning Process 总被引:1,自引:1,他引:0
Assessing the impact of climate change on species and associated management objectives is a critical initial step for engaging
in the adaptation planning process. Multiple approaches are available. While all possess limitations to their application
associated with the uncertainties inherent in the data and models that inform their results, conducting and incorporating
impact assessments into the adaptation planning process at least provides some basis for making resource management decisions
that are becoming inevitable in the face of rapidly changing climate. Here we provide a non-exhaustive review of long-standing
(e.g., species distribution models) and newly developed (e.g., vulnerability indices) methods used to anticipate the response
to climate change of individual species as a guide for managers grappling with how to begin the climate change adaptation
process. We address the limitations (e.g., uncertainties in climate change projections) associated with these methods, and
other considerations for matching appropriate assessment approaches with the management questions and goals. Thorough consideration
of the objectives, scope, scale, time frame and available resources for a climate impact assessment allows for informed method
selection. With many data sets and tools available on-line, the capacity to undertake and/or benefit from existing species
impact assessments is accessible to those engaged in resource management. With some understanding of potential impacts, even
if limited, adaptation planning begins to move toward the development of management strategies and targeted actions that may
help to sustain functioning ecosystems and their associated services into the future. 相似文献
999.
South Korea’s Civilian Control Zone (CCZ), a relatively untouched area due to tight military oversight since the end of Korean
War, has received considerable attention nationally and internationally for its rich biodiversity. However, the exclusion
of local communities from the process of defining problems and goals and of setting priorities for biodiversity conservation
has halted a series of biodiversity conservation efforts. Through qualitative research, we explored CCZ farmers’ views of
key problems and issues and also the sources of their opposition to the government-initiated conservation approaches. Key
findings include the farmers’ concerns about the impact of conservation restrictions on their access to necessary resources
needed to farm, wildlife impacts on the value of rice and other agricultural goods they produce, and farmers’ strong distrust
of government, the military, and planners, based on their experiences with past conservation processes. The findings regarding
farmers’ perceptions should prove useful for the design of future participatory planning processes for biodiversity conservation
in the CCZ. This case highlights how conservative measures, perceived to be imposed from above—however scientifically valuable—can
be undermined and suggests the value that must be placed on communication among planners and stakeholders. 相似文献
1000.
People receive information about visiting places from a variety of sources, and it is important to understand how information
affects recreation experiences. This study examines how different information treatments describing a recreation place influence
perceived crowding and encounter norms. The study location was the Jungmoeri area of Mudeungsan Provincial Park (MPP) in Korea.
Data were collected from 50 college students utilizing a series of simulated moving pictures in a laboratory setting. Respondents
were given information describing three different types of conditions and experiences (nature preserve, transition/buffer,
and developed area), plus a no information control. Results showed that information influenced perceived crowding and encounter
norms. For the range of encounter numbers depicted in the photos, the nature preserve treatment produced higher crowding ratings
and lower tolerances for encounters, the developed area treatment produced lower crowding ratings and higher tolerances, and
the transition/buffer and the control were in between. Information treatments also influence the perceived importance of encounter
numbers, and importance was highest for the nature preserve. Management implications are discussed. 相似文献