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排序方式: 共有2313条查询结果,搜索用时 15 毫秒
1.
柚树间种短期经济作物在提高柚园经济效益的同时,还可提高土壤的有机质和N、P、K养分质量分数,改善柚园小区气候,增加有机肥来源。间种物残余体作为绿肥,可显著地提高柚果产量和质量。  相似文献   
2.
理解极端洪水事件活动特征及其与气候变化、人类活动的相互关系一直是全球变化研究的热点问题。现代器测数据较短对洪水事件变化规律预测存在不足,而利用历史文献记录研究百年-千年尺度洪水事件的发生规律则成为一个较好的选择。洪水灾害是长江流域最为严重的自然灾害之一。本文以官方现存历史记载为依据,构建了过去2000年长江干流上、中、下游洪水事件序列,并将其与气候和人类活动代理指标进行对比。结果表明,1350年之前,长江干流洪水事件受东亚季风(EASM)、西南季风(ISM)、厄尔尼诺-南方涛动(ENSO)、热带辐合带(ITCZ)移动等多种气候因素驱动,且气候驱动机制在同期不同区、同区不同期存在显著差异。此外,1350年之后人类活动的增强可能明显加剧了长江干流洪水事件的频率和强度。  相似文献   
3.
温室气体和空气污染物的协同治理是一种双赢的策略。自协同效应的概念提出以来,大量研究对温室气体和大气污染之间的协同减排技术、措施、潜力等方面进行了评估。本研究回顾了协同治理理论的发展历程、典型案例以及重要的政策实践,在此基础上讨论了当前研究与实践的特点,并对未来研究提出了建议。典型案例涉及能源、交通、工业和居民部门,政策实践讨论了温室气体和空气污染协同治理政策的主要类型及其实施情况。从损失评估、协同机理、高精度排放清单及模拟等角度对未来促进协同治理的研究提出了方向建议。  相似文献   
4.
Conservation programs often manage populations indirectly through the landscapes in which they live. Empirically, linking reproductive success with landscape structure and anthropogenic change is a first step in understanding and managing the spatial mechanisms that affect reproduction, but this link is not sufficiently informed by data. Hierarchical multistate occupancy models can forge these links by estimating spatial patterns of reproductive success across landscapes. To illustrate, we surveyed the occurrence of grizzly bears (Ursus arctos) in the Canadian Rocky Mountains Alberta, Canada. We deployed camera traps for 6 weeks at 54 surveys sites in different types of land cover. We used hierarchical multistate occupancy models to estimate probability of detection, grizzly bear occupancy, and probability of reproductive success at each site. Grizzly bear occupancy varied among cover types and was greater in herbaceous alpine ecotones than in low‐elevation wetlands or mid‐elevation conifer forests. The conditional probability of reproductive success given grizzly bear occupancy was 30% (SE = 0.14). Grizzly bears with cubs had a higher probability of detection than grizzly bears without cubs, but sites were correctly classified as being occupied by breeding females 49% of the time based on raw data and thus would have been underestimated by half. Repeated surveys and multistate modeling reduced the probability of misclassifying sites occupied by breeders as unoccupied to <2%. The probability of breeding grizzly bear occupancy varied across the landscape. Those patches with highest probabilities of breeding occupancy—herbaceous alpine ecotones—were small and highly dispersed and are projected to shrink as treelines advance due to climate warming. Understanding spatial correlates in breeding distribution is a key requirement for species conservation in the face of climate change and can help identify priorities for landscape management and protection. Patrones Espaciales del Éxito Reproductivo de Osos Pardos, Derivados de Modelos Jerárquicos Multi‐Estado  相似文献   
5.
Large‐scale change in human values and associated behavior change is believed by some to be the ultimate solution to achieve global biodiversity conservation. Yet little is known about the dynamics of values. We contribute to this area of inquiry by examining the trajectory of values affecting views of wildlife in North America. Using data from a 19‐state study in the United States and global data from the Schwartz Value Survey, we explored questions of value persistence and change and the nature of attitudinal responses regarding wildlife conservation issues. We found support, based on subjects’ ancestry, for the supposition that domination is a prevalent American value orientation toward wildlife that has origins in European Judeo‐Christian traditions. Independent of that effect, we also found indications of change. Modernization is contributing to a shift from domination to mutualism value orientations, which is fostering attitudes less centered on human interests and seemingly more consistent with a biocentric philosophy. Our findings suggest that if value shift could be achieved in a purposeful way, then significant and widespread behavior change believed necessary for long‐term conservation success may indeed be possible. In particular, greater emphasis on mutualism values may help provide the context for more collaborative approaches to support future conservation efforts. However, given the societal forces at play, it is not at all clear that human‐engineered value shift is tenable. Instead of developing strategies aimed at altering values, it may be more productive to create strategies that recognize and work within the boundaries of existing values. Whereas values appear to be in a period of flux, it will be difficult to predict future trends without a better understanding of value formation and shift, particularly under conditions of rapid social‐ecological change.  相似文献   
6.
Agroforestry systems have substantial potential to conserve native biodiversity and provide ecosystem services. In particular, agroforestry systems have the potential to conserve native tree diversity and sequester carbon for climate change mitigation. However, little research has been conducted on the temporal stability of species diversity and aboveground carbon stocks in these systems or the relation between species diversity and aboveground carbon sequestration. We measured changes in shade‐tree diversity and shade‐tree carbon stocks in 14 plots of a 35‐ha coffee cooperative over 9 years and analyzed relations between species diversity and carbon sequestration. Carbon sequestration was positively correlated with initial species richness of shade trees. Species diversity of shade trees did not change significantly over the study period, but carbon stocks increased due to tree growth. Our results show a potential for carbon sequestration and long‐term biodiversity conservation in smallholder coffee agroforestry systems and illustrate the opportunity for synergies between biodiversity conservation and climate change mitigation. Interacciones entre el Secuestro de Carbono y la Diversidad de Árboles de Sombra en una Cooperativa de Café de Pequeños Agricultores en El Salvador  相似文献   
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8.
Red meat production has a range of negative environmental impacts. We sought to characterize the motivations, environmental attitudes and demographics of red meat-eaters, and examine the effect of message framing in reducing future meat consumption. Canadian adult meat-eaters (593) completed a survey and were randomly assigned to one of six message treatments that presented information on the environmental impacts of meat production using frames representing social norms and/or place identity constructs. Taste and quality were the most important motivators for eating meat, while moral/ethical factors were the least. Forty-nine percent of respondents indicated they would reduce red meat intake after exposure to an information only message, while the social norms frame was more effective than others (χ2). Awareness of the environmental effects increased significantly after messaging for all 13 impacts. These findings should assist communicators with designing more effective messaging aimed at encouraging pro-environmental behaviours associated with meat consumption.  相似文献   
9.
China is now facing huge pressure from both the domestic concern of energy security and the global community's call for emission reduction commitment. As one of the major energy consumers and greenhouse gas emitters, China's iron and steel industry has a huge clean development mechanism (CDM) potential. This article both quantitatively and qualitatively analyzes the current status of CDM project activities in the iron and steel industry in China, including characteristics of approved project types, applicable methodologies, and potential technology fields. From the perspective of project implementation, the article summarizes development barriers such as high investment risk, difficulty in project identification, strict requirements on PPDs, long registration waiting time, and etc. Policy suggestions are also put forwarded to help better promote the development of CDM projects in the iron and steel industry.  相似文献   
10.
气候变化问题、气候变化及其不利影响所导致的现实或潜在的大量气候移民已成为21世纪人类社会面临的严峻挑战,是现阶段人类社会普遍关注的核心问题之一。通过对社会发展进程中各种主客观因素叠加作用导致的渐变缓发性气候风险、极端突变灾害性气候风险等诸种气候变化现象所导致的气候移民问题的剖析,结合已有的研究文献对历史、现实条件下气候变化导致的气候移民产生的机理与逻辑展开分析,以把握其演变发展趋势。从而对气候移民进行概念上的辨析、梳理和界定,以揭示气候移民的实体内涵、本质特点与根本属性;并依据移民的迁移意愿、迁移时限长短、迁移的空间区域和距离远近、导致气候移民的不同致因对其进行类型上的划分与归类,以期加深我们对气候移民问题的深入理解与认知,更好把握气候移民问题产生的本质与演变发展规律。从而为有效破解各种气候变化现象导致的气候移民难题,化解气候移民面临的各种社会风险,促进社会的良性运行与协调发展做出初步探索。  相似文献   
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