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1.
An invasive forest pathogen, Cronartium ribicola, white pine blister rust (WPBR), is believed to have arrived in the Sacramento Mountains of south-central New Mexico about 1970. Epidemiological and genetic evidence supports the hypothesis that introduction was the result of long-distance dispersal (LDD) by atmospheric transport from California. This study applies a method to identify the atmospheric conditions favorable for rust transport and infection. An upper level synoptic classification (ULSC) identifies patterns of upper-level flow favorable for the transport of rust spores from a source to a target. Transport data are coupled with data for surface conditions favorable for infection at a designated target. A resulting calendar lists likelihood classes for establishment by four-times-daily observations during a dispersal season from April through July in the years 1965 to 1974. The single most-favorable period for transport and infection at the New Mexico site was identified as 1-15 June 1969. Five additional sites in the western United States with susceptible white pine populations and known infestation status were then evaluated to verify the model. Only the infested sites exhibit an establishment likelihood of "high" or "very high." This suggests that the methodology correctly identifies locations with elevated establishment likelihood. Finally, likelihoods at nine additional points in the southwestern United States are determined and used to map regional patterns of transport, infection and establishment. The ULSC combined with appropriate surface meteorological data could be used to further investigate transport and infection, identify other areas at risk, assess the potential for gene flow of WPBR and evaluate long-distance dispersal of other pathogens.  相似文献   
2.
Tourism climate and thermal comfort in Sun Moon Lake,Taiwan   总被引:1,自引:0,他引:1  
Bioclimate conditions at Sun Moon Lake, one of Taiwan’s most popular tourist destinations, are presented. Existing tourism-related climate is typically based on mean monthly conditions of air temperature and precipitation and excludes the thermal perception of tourists. This study presents a relatively more detailed analysis of tourism climate by using a modified thermal comfort range for both Taiwan and Western/Middle European conditions, presented by frequency analysis of 10-day intervals. Furthermore, an integrated approach (climate tourism information scheme) is applied to present the frequencies of each facet under particular criteria for each 10-day interval, generating a time-series of climate data with temporal resolution for tourists and tourism authorities.  相似文献   
3.
Species range boundaries are determined by a variety of factors of which climate is one of the most influential. As a result, climate change is expected to have a profound effect on organisms and ecosystems. However, the impacts of weather and climate are frequently modified by multiple nonclimatic factors. Therefore, the role of these nonclimatic factors needs to be examined in order to understand and predict future change. Marine intertidal ecosystems are exposed to heat extremes during warm, sunny, midday low tides. Thus, the timing of low tide, a nonclimatic factor, determines the potential contact intertidal invertebrates and algae have with heat extremes. We developed a method that quantifies the daily risk of high temperature extremes in the marine intertidal using solar elevations and spatially continuous tidal predictions. The frequency of 'risky days' is variable over time and space along the Pacific Coast of North America. Results show that at some sites the percentage of risky days in June can vary by 30% across years. In order to do a detailed analysis, we selected San Francisco as a study site. In San Francisco, May is the month with the greatest frequency of risky days, even though September is the month with the greatest frequency of high air temperature, ≥30 °C. These results indicate that marine intertidal organisms can be protected from high temperature extremes due to the timing of tides and local weather patterns. In addition, annual fluctuations in tides influence the frequency of intertidal zone exposures to high temperature extremes. Peaks in risk for heat extremes in the intertidal zone occur every 18 years, the length of the tidal epoch. These results suggest that nonclimatic variables can complicate predictions of shifts in species ranges due to climate change, but that mechanistic approaches can be used to produce predictions that include these factors.  相似文献   
4.
This paper takes an air mass approach to investigating the influence of weather on pollen concentrations in the atmosphere in Sydney, Australia, by producing a synoptic classification of pollen concentrations measured in the Sydney Basin. This synoptic classification has been produced using multivariate statistical techniques including principal component analysis and cluster analysis, to assign days into meteorologically homogenous categories. Surface and upper air meteorological data for warm months (October-March) over a 10-year period were used as input into the statistical analyses. Eleven synoptic categories were found in Sydney during the warm months. Pollen concentrations for the total pollen load and five individual families measured over a 3.5-year period have been investigated for each of the synoptic categories. High pollen concentrations during the warm months in Sydney are found to be influenced by the presence of a region of low surface pressure located to the south of the continent, bringing fast dry westerly gradient winds to Sydney. It is envisaged that these results will be important from a pollen forecast and associated public health perspective.  相似文献   
5.
石佛寺水库对周围环境的影响裴铁,范世香,韩绍文,迟振文(中国科学院沈阳应用生态研究所,110015)王鉴成(辽宁省水利电力厅,沈阳110003)ImpactsofShifosiReservoironItsAdjacentEcologicalEnvir...  相似文献   
6.
Although there is high potential for conservation of species outside protected areas, it is often neglected in researches and conservation programs. Protected species are legally protected even outside the protected areas and can be flagships for conservation in these areas, but their conservation aspects in these areas are poorly studied. We studied conservation aspects of a poorly known species, Yellow Monitor (Varanus flavescens), which is protected in most of its range countries, outside the protected areas in the Far-western lowlands of Nepal. We studied people's relationship, attitudes and threats to the species through questionnaire survey with adults and children in Parasan Village Development Committee of Kanchanpur District. We found that most of the adults were unaware about the protected status and importance of the species, and both adults as well as children killed the species. The study revealed that most of the killing occurred in agricultural land and children were more responsible for the killing than the adults. We found that monsoon vacation in schools increased the threat to the species. Our study revealed that fear from the species was the main reason and use of the species as food, medicine and hide were other reasons for killing of the species by adults. Low awareness was the major reason behind the killing by children as most of the killing was not related to any good reasons. We estimated that 87 individuals of the species could have been killed in the area in that year. Based on available evidences, we recommend further studies to predict the vulnerability of the species. Our study suggests that raising awareness among locals about its legal status and importance is the simple and efficient measure for the conservation of the species as well as for conserving other protected species outside the protected areas.  相似文献   
7.
基于大尺度因子的小麦白粉病长期预测模型   总被引:1,自引:0,他引:1  
根据1971—2008年全国小麦白粉病发生面积资料、1970—2008年大气环流特征量逐月资料及1970—2008年太平洋海温逐月资料,通过因子膨化、空间拓扑分析组合大气环流、海温因子,采用最优化处理、相关分析、相关稳定性检验、因子独立性检验等方法,筛选对小麦白粉病影响稳定、显著、独立的大气、海温因子,分别构建基于大气环流及太平洋海温的全国小麦白粉病发生面积率预报预测模型。利用2009—2010年资料对模型进行预测检验,经回代及预测检验,大气环流模型回代检验等级正确率为81.6%,2009、2010年等级预测正确率为100%,模型总体评价正确率为82.5%。太平洋海温模型回代检验等级正确率为78.95%,2009、2010年预测检验正确率为100%,模型总体评价正确率为80%。大气环流模型较太平洋海温模型总体评价准确率略高。  相似文献   
8.
 A synoptic climatological approach is used to investigate linkages between air mass types (weather situations), the daily mean particulate matter with a size of 10 μm or less (PM10) concentrations and all respiratory hospital admissions for the Birmingham area, UK. Study results show distinct differential responses of respiratory admission rates to the six winter air mass types identified. Two of the three air masses associated with above average admission rates (continental anticyclonic gloom and continental anticyclonic fine and cold) also favour high PM10 levels. This association is suggestive of a possible linkage between weather, air quality and health. The remaining admissions-sensitive air mass type (cool moist maritime) does not favour high PM10 levels. This is considered to be indicative of a direct weather-health relationship. A sensitising mechanism is proposed to account for the linkages between air mass type, PM10 concentrations and respiratory response. Received: 4 August 1997 / Received after revision: 8 January 1999 / Accepted: 20 January 1999  相似文献   
9.
10.
西双版纳是保存有大面积热带森林的地区,倍受海内外的关注.从本世纪30~40年代到90年代的研究表明西双版纳处于热带亚热带过渡地带的特殊性,其生态环境和生物成分不仅在生物演化中意义显要而且也是发展地方经济的重要资源.西双版纳为多民族聚居区,居住着傣族、爱尼族约20个民族或未定族群.各民族有其特殊的土地和自然资源利用传统.随着人口增加和经济发展,特别是橡胶种植的扩大,严重地损坏了西双版纳的热带森林及其生态环境,也使优秀传统文化在丧失.保护生态环境和优秀传统文化成了西双版纳可持续发展的关键.  相似文献   
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