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971.
Amber J. Soja Herman H. Shugart Anatoly Sukhinin Susan Conard Paul W. Stackhouse Jr. 《Mitigation and Adaptation Strategies for Global Change》2006,11(1):75-96
Under current climate change scenarios, temperatures in Siberia are expected to increase, and consequently, fire is also expected
to increase. Potential climate-induced change is difficult to assess in Siberia because ground-based fire data are not complete.
This investigation introduces a method by which potential climate-induced change can be remotely evaluated. Mean fire return
intervals are established for 58 ecosystems across Siberia using eight years of satellite-based area burned data (1995 to
2002). Mean fire return intervals should decrease under current climate change scenarios, however the results do not currently
demonstrate consistent evidence of fire-induced change. The overall boreal forest mean fire return interval is lower than
the published mean, inferring increased fire. Most notably, using satellite data to calculate mean fire return intervals in
individual ecosystems for the entire population of fire is shown to be a viable method by which potential climate-induced
land cover change can be evaluated. 相似文献
972.
Introduction The nonpoint source P pollutants play a significant role in eutrophication processes in the southeast of China. Nonpoint sources pollution from agricultural regions account for more than half of the phosphorus load in many water bodies (Linke… 相似文献
973.
Because of concerns with the growing threat of global climate change from increasing emissions of greenhouse gases, the United States and other countries are implementing, by themselves or in cooperation with one or more other nations, climate change projects. These projects will reduce greenhouse gas (GHG) emissions or sequester carbon, and will also result in non-GHG benefits (i.e., environmental, economic, and social benefits). Monitoring, evaluating, reporting, and verifying (MERV) guidelines are needed for these projects to accurately determine their net GHG, and other, benefits. Implementation of MERV guidelines is also intended to: (1) increase the reliability of data for estimating GHG benefits; (2) provide real-time data so that mid-course corrections can be made; (3) introduce consistency and transparency across project types and reporters; and (4) enhance the credibility of the projects with stakeholders. In this paper, we review the issues involved in MERV activities. We identify several topics that future protocols and guidelines need to address, such as: (1) establishing a credible baseline; (2) accounting for impacts outside project boundaries through leakage; (3) net GHG reductions and other benefits; (4) precision of measurement; (5) MERV frequency and the persistence (sustainability) of savings, emissions reduction, and carbon sequestration; (6) reporting by multiple project participants; (7) verification of GHG reduction credits; (8) uncertainty and risk; (9) institutional capacity in conducting MERV; and (10) the cost of MERV. 相似文献
974.
Under the dry weather conditions in the typical steppe region of Inner Mongolia, the diurnal change curve of photosynthetic rate of Aneurolepidium chinense community is a curve of "double peaks" with midday depression. The photosynthetic rate in the morning is height than in the afternoon, which is related to the water condition at that time. The decrease range of community photosynthetic rate at noon is closely correlated with the low air relative humidity and soil moisture, the photosynthetic rate decreases less under better water condition.The instantaneous photosynthetic rate and diurnal net photosynthesis declined in dry condition, but they rised after irrigation or nitrogen-fertilization. Thus irrigation and fertilization is a effective way to improve grasslands and to raise grassland productivity. 相似文献
975.
Wu Kunjun Chen Yuping Li MinghuiInstitute of Zoology Chinese Academy of Sciences Beijing China 《环境科学学报(英文版)》1993,(2)
The cotton bollworm, Heliothis armigera (Hubner) is an important insect species at-tacking many crops. Their performances have been examined at temperatures from 15℃ to 35℃ and relative humidities (RH) between 22.5% and 100%, respectively, in order to assess possible effect of climate in future on its occurrence and infestation. Durations of all developmental stages of the insect shortened with increasing temperature. The temperature favoring population growth ranged from 25℃ to 30℃.Larval duration and adult longevity decreased as relative humidity increased, but development of other stages was independent of RH. At RH of over 64%, their survival rate, egg production and oviposition rate varied a little, and all the population parameters of the insect remained at a relative constant level. 相似文献
976.
安图红松树轮稳定δ~(13)C、δ~(18)O序列记录的气候变化信息 总被引:1,自引:0,他引:1
测定了安图红松树轮稳定碳、氧同位素组成。选取与安图县毗邻的敦化市气象记录 ,分析了气象记录与树轮稳定碳、氧同位素的相关关系 ,发现红松树轮碳、氧同位素对气候变化均有显著的响应。合成了复合温湿指标 (TH) ,相关分析表明树轮碳、氧同位素对复合温湿指标的响应更加灵敏 ,而且碳同位素和氧同位素均对 5~ 8月的平均复合温湿指标有显著的响应。建立了碳、氧同位素对气候因子的响应函数 ,重建了安图地区近 2 0 0年来的气候变化。功率谱分析发现碳、氧同位素组成在 95 %的置信水平上存有准 2 0 0年、准 11年、准 4年和准 2年的变化周期。前两个周期变化基本上与太阳活动周期变化一致 ,后两个周期分别对应于“厄尔尼诺现象”和东亚夏季风的“准 2年振荡”。 相似文献
977.
Boreal forests represent a biome of the planet whose unique characteristics are changing rapidly under the influence of both
human and natural pressures. These forests hold the key to current and future supply of coniferous industrial wood and at
the same time play a significant role in regulating Earth's climatic system. Expected to be one of the most rapidly impacted
regions of the world by future climate change, the boreal biome has already been substantially affected by global change.
It is likely that if unabated, continued change will lead to impoverishment and degradation of boreal ecosystems, with consequent
loss of vital services upon which human society depends. An improved systems understanding of the functioning of circumpolar
boreal forests is a pressing challenge for boreal forest science and is needed in order to estimate their resilience to perturbations,
to predict likely responses to the changing environment, and to design mitigation strategies. With such understanding, coordinated
international efforts can be focused on developing anticipatory strategies for adaptation to, and mitigation of dangerous
consequences of global change for boreal resources. The International Boreal Forest Research Association (IBFRA) provides
a focus for international research on these issues and serves as a global window for boreal forest science and sustainable
forest management in the boreal region. 相似文献
978.
979.
TOMS/Al data with nearly 20 years are utilized in the paper to evaluate dust activities in North China. Combined with simultaneous NCEP reanalysis climate data, climate effects on dust activities are assessed. The results showed that the whole North China suffers impact by dust aerosols, with three centers standing out in TOMS/Al spring average map that are western three basins, which are characterized by lower annual precipitation and elevation. Gobi deserts in Mongolia Plateau do not attain higher TOMS/AI value due to cloud contamination and relative higher elevation. Spring is the season with the highest TOMS dust aerosol index; within the western three basins, high dust aerosol index appears in both spring and summer, especially in Tarim Basin. Wind speed in spring and precipitation in previous rainy season play important roles in controlling dust activities, higher wind speed and less precipitation than the normal are in favor of dust activities in spring. Temperature in spring and previous winter also affect dust activity to a certain extent, but with contrary spatial distribution. Temperature in winter exert effect principally in west part, contrarily, temperature effect in spring is mainly shown in east part. Both of them have negative correlation with dust activity. 相似文献
980.
Forest Fires and Climate Change in the 21ST Century 总被引:3,自引:0,他引:3
M. D. Flannigan B. D. Amiro K. A. Logan B. J. Stocks B. M. Wotton 《Mitigation and Adaptation Strategies for Global Change》2006,11(4):847-859
Fire is the major stand-renewing disturbance in the circumboreal forest. Weather and climate are the most important factors
influencing fire activity and these factors are changing due to human-caused climate change. This paper discusses and synthesises
the current state of fire and climate change research and the potential direction for future studies on fire and climate change.
In the future, under a warmer climate, we expect more severe fire weather, more area burned, more ignitions and a longer fire
season. Although there will be large spatial and temporal variation in the fire activity response to climate change. This
field of research allows us to better understand the interactions and feedbacks between fire, climate, vegetation and humans
and to identify vulnerable regions. Lastly, projections of fire activity for this century can be used to explore options for
mitigation and adaptation. 相似文献