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G. V. Ponomarev 《Geography and Natural Resources》2014,35(1):48-54
The key aspects of reindeer ecology within the Konda river basin are considered. The study revealed the factors governing the characteristics of calving reindeer pastures determined by the structure of forest-bog landscapes of a different generalization level. A deficit of such pastures is regarded as the factor of differentiation of reindeer groups with respect to migrants and residents. It is shown that the individual geocomplexes have a multifunctional role. Of particular significance among them are the aufeis glades with outcrops of salt-saturated groundwater, and the dark-coniferous forests along river valleys rich in epiphytic lichens (beard lichens). 相似文献
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Global warming with the burgeoning anthropogenic greenhouse gas (GHG) emissions (400 parts per million from 280 ppm CO2 emissions of pre-industrial era) has altered climate, eroding the ecosystem productivity and sustenance of water, affecting the livelihood of people. The anthropogenic activities such as burning fossil fuel, power generation, agriculture, industry, polluting water bodies and urban activities are responsible for increasing GHG footprint of which 72% constitute CO2. GHG footprint needs to be in balance with sequestration of carbon to sustain ecosystem functions. Forests are the major carbon sinks (about 45%) that aid in mitigating global warming. The current research focusses on the carbon budgeting through quantification of emissions and sinks in the forest ecosystems and changes in climatic conditions of Western Ghats. This would help in evolving appropriate mitigation strategies toward sustainable management of forests and mitigate impacts of global warming. The land-use land-cover (LULC) dynamics are the prime driver of climate change due to the loss of carbon sequestration potential as well as emissions. The Western Ghats are one among 36 global biodiversity hotspots and forests in this region sequester atmospheric carbon, which aid in moderating the global climate and sustaining water to ensure water and food security in the peninsular India. Assessment of LULC dynamics using temporal remote sensing data shows the decline of evergreen forest by 5% with an increase in agriculture, plantations and built-up area. The interior or intact forests have declined by 10%, and they are now confined to protected areas. The simulation of likely changes indicates that the region will have only 10% evergreen cover and 17% agriculture, 40% plantations and 5% built-up. Quantification of carbon reveals that the WG forest ecosystem holds 1.23 MGg (million gigagrams or Gt) in vegetation and soils. The annual incremental carbon is about 37,507.3 Gg, (or 37.5 million tons, Mt) and the highest in the forests of Karnataka part of WG. Simulation of the likely changes in carbon content indicates the loss of 0.23 MGg (2018–2031) carbon sequestration potential under business as usual scenario. The conservation scenario depicts an increase in carbon sequestration potential of WG forests with the protection. Sequestered carbon in WG is about INR 100 billion ($1.4 billion) at carbon trading of INR 2142 ($30) per tonne. Large-scale land-cover changes leading to deforestation has contributed to an increase in mean temperature by 0.5°C and decline in rainy days, which necessitates evolving prudent landscape management strategies involving all stakeholders for conservation of ecologically fragile WG. This will enhance the ability of forests to sequester atmospheric carbon and climate moderation, with the sustenance of ecosystem goods and services.
相似文献4.
对气候变暖问题争议的分析 总被引：50，自引：8，他引：50
综合评述和分析了近年来关于全球气候变暖问题的研究。重点是有关气候变暖的一些争议。目前的结论是:(1)19世纪中期以来全球平均地表气温上升了0.4～0.8℃;(2)全球气候变暖的论断得到了海洋温度、大气温度、钻孔温度、陆地雪盖、海冰及冰川资料的支持;(3)1998年是近一个半世纪有观测资料以来最暖的一年,对1961～1990年平均的距平为0.55℃。20世纪变暖的趋势为0.066℃/10a;(4)1990′s是20世纪最暖的10年,平均气温距平0.35℃,也可能是500a或者甚至1000a来最暖的10年。所以,20世纪气候的变暖是无可怀疑的。人类活动影响很可能是20世纪气候变暖的主要原因,至少是主要原因之一。 相似文献
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西北地区气候暖干化对作物气候生态适应性的影响 总被引：12，自引：1，他引：11
在综述西北地区现代气候变化基本特征是暖干化的基础上,重点揭示了冬小麦、春小麦 (夏粮)、玉米、马铃薯、谷子、糜子（秋粮）和棉花、胡麻、冬油菜、酿酒葡萄（经济作物）等10种主要作物的热量指标、水分指标和生长发育状况等对现代气候暖干化的响应特征。气候变暖对作物热量生态适应性的影响非常显著,作物需要热量指标比变暖前有提高的趋势;气候变干对作物水分生态适应性的影响非常敏感,作物需要水分指标比变干前有增多的趋势。气候暖干化对作物气候生态适应性的影响总体来说是利弊并重。对灌溉区作物是利多弊少,建议要创建干旱区现代农业发展模式来应对;对旱作区作物是弊远大于利,建议要建立一整套旱作农业生产机制来适应气候暖干化。提出了作物气候生态适宜度是气候暖干化对作物产生重大影响的重要原因。 相似文献
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东北地区植被分布全球气候变化区域响应 总被引：26，自引：8，他引：18
根据东北地区生态气候环境和生物地理规律对Holdridge生命地带分类系统进行修正,将东北地区植被分为寒温带湿润森林、寒温带潮湿森林、温带湿润森林、暖温带湿润森林、温带半湿润森林草甸草原、温带半湿润草甸草原、温带半干旱典型草原、暖温带半湿润草甸草原和暖温带半干旱典型草原等9 个生命地带并分析了其空间分布特征。运用大气环流模式分析东北地区由于温室气体增加导致的气候变化趋势。以此为基础评价东北地区植被分布的区域响应。全球气候变暖情景下,东北地区暖温带和温带范围明显扩大,而寒温带范围缩小甚至退出东北地区,植被分布界限显著北移;同时湿润区面积减少半湿润区和半干旱区扩大,导致森林面积缩小草原面积扩大。 相似文献
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Understanding the radial growth trends of trees and their response to recent warming along elevation gradients is crucial for assessing how forests will be impacted by future climate change. Here, we collected 242 tree-ring cores from five plots across the Qinghai spruce (Picea crassifolia Kom.) forest belt (2600-3350 m a.s.l.) in the central Qilian Mountains, Northwest China, to study trends in the radial growth of trees and their response to climate factors with variable elevation. All the sampled P. crassifolia chronologies showed an increasing trend in the radial growth of trees at higher altitudes (3000-3350 m), whereas the radial growth of trees at lower altitudes (2600-2800 m) has decreased in recent decades. The radial growth of trees was limited by precipitation at lower elevations (L, ML), but mainly by temperature at higher elevation sites (MH, H, TL). Climate warming has caused an unprecedented increase in the radial growth of P. crassifolia at higher elevations. Our results suggest that ongoing climate warming is beneficial to forest ecosystems at high elevations but restricts the growth of forest ecosystems at low elevations. 相似文献
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大九湖钻孔记录的神农架地区中更新世晚期以来的气候环境变化 总被引：2，自引：0，他引：2
运用孢粉浓缩物AMS 14C测年和氨基酸测年方法结合气候地层对比,建立神农架地区大九湖盆地DJH-2 孔的地层年代序列。依据孢粉分析结果并结合沉积环境,将大九湖盆地中更新世晚期以来的植被演替和古气候演化划分为六个阶段：① 275.0-188.0 ka,寒冷偏干,寒温带针叶林、高山草甸;② 245.0-188.0 ka,暖湿偏干,常绿、落叶阔叶混交林;③ 188.0-129.0 ka,冷干,寒温带针叶林为主,过渡为高山草甸为主;④ 129.0-71.8 ka,暖湿,暖温带落叶阔叶林;⑤71.8-15 ka,冷干,寒温带针叶林与高山草甸间隔发育,中间有喜暖种属增多的迹象;⑥ 15.0-1.0 ka,暖湿,亚热带常绿、落叶阔叶林。孢粉组合特征及单种属特征所显示的盆地气候变化反映了良好的全球冰期、间冰期气候旋回。孢粉浓度特征反映大九湖盆地气候变化受北半球高纬冰量与低纬太阳辐射的双重控制。 相似文献
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V. F. Loginov 《Geography and Natural Resources》2014,35(1):7-17
This paper is concerned with some debatable issues related to assessments of the role played by greenhouse gases and aerosols in the formation of seasonal patterns of temperature change in the northern and southern hemispheres as well as of air temperature across the territory of Belarus. It is shown that the periods of low aerosol pollution of the atmosphere coincide with high summer temperatures in the region. A warming period of the 1930s–early 1940s in the northern hemisphere (in the Arctic) was also observed during a warm season. In recent years when aerosol pollution has decreased, the growth rate of summer temperatures has increased; the temperature rise during a cold period became comparable to that observed during a warm period. In terms of the theory of greenhouse warming of the climate system, however, the temperature rise must be more pronounced in a cold season. Over the last 15–16 years, global temperature, remaining the highest for the period of instrumental observations, has not been increasing, whereas carbon dioxide content in the atmosphere has increased by more than 30%. A detailed study is made of the consequences of the forecasted climate warming in climate-dependent sectors of the economy. It is concluded that there is a need to work out multivariant adaptation measures in view of the uncertainty of existing knowledge regarding the causes for climate change, and because of the large spread in scenario-based assessments of future climate changes. 相似文献
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中国热带珊瑚礁的第四纪气候记录 总被引：1，自引：0，他引：1
珊瑚礁剖面的氧碳同位素、地球化学、造礁珊瑚生长带等分析结果表明,珊瑚礁记录了第四纪气候波动的基本轮廓.早更新世总体趋暖,但至少有4个旋回.中更新世总体趋冷,但至少有7个旋回.晚更新世气候剧烈波动,但总体变化为两个前暖后冷的旋回.全新世为回暖-升温-降温的波动.历史时期约1 700 a来有4个前冷后暖的旋回.近200 a的气候波动表现为前百年正距平,后百年以负距平为主,但总体趋暖. 相似文献
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1982-2006 年欧亚大陆植被生长季开始时间遥感监测分析 总被引：1，自引：0，他引：1
植被物候是环境条件季节和年际变化最直观、最敏感的生物指示器,物候变化可以反映陆地生态系统对气候变化的快速响应.论文基于1982-2006 年连续25 年的GIMMS AVHRR NDVI数据,采用动态阈值法、延迟滑动平均法,双Logistic 和Savitzky-Golay 方法提取欧亚大陆植被的生长季开始时间,并对不同方法的提取结果进行比较和分析.然后以动态阈值法的物候提取结果,研究了1982-2006 年期间植被物候变化趋势以及物候对温度变化的响应情况.结果表明：动态阈值法在欧亚大陆地区生长季开始时间提取率高,在纬度上的变化趋势稳定;北方森林/针叶林和苔原地区的生长季开始时间提取结果最稳定,低纬度区域的变率最大.1982-2006 年,大部分植被类型的生长季开始时间表现出提早趋势,其中森林覆盖区域提早趋势明显,变化幅度为11.45~15.61 d/25a;除了郁闭式至开放式( > 15%) 灌木丛( < 5 m)植被类型外,植被物候和温度表现出负相关关系,变化幅度为1.32~3.47d/℃,这也验证了近几十年气候变暖的趋势. 相似文献
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The coral reef in China’s tropics can be divided into three regions, namely, the South China Sea Islands, Hainan Island and the Leizhou Peninsula as well as Taiwan Island. There are 34 islands of coral reef which are named in the South China Sea Islands … 相似文献
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The analysis results of oxygen isotopes, carbon isotopes, geochemistry and the growth belt of reef coral etc. for some profiles of coral reef show that the basic pattern of climatic fluctuation during the Quaternary period can be reflected by coral reef. The trend of climate change was from cooling to warming during the Early Pleistocene with at least four cycles, and from warming to cooling with at least seven cycles during the Middle Pleistocene. The late Pleistocene is a period of the Quaternary which shows the most frequent variation of climate but generally two main cycles of warming–cooling can be seen. During the Holocene the climate went through a process of warming-rise in temperature-drop in temperature. During the historical period there were four cycles of cooling-warming at 1700 a BP. During the last 200 years climate change is characterized by two stages; a positive deviation in the former 100 years, and a negative deviation in the latter 100 years with general warming trend. 相似文献
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Present climate warming strongly affects limnological and ecological properties of lakes and may cause regime shifts that alter structure and function in the water bodies. Such effects are especially pronounced in climatologically extreme areas, e.g. at high altitudes. We examined a sediment core from Lake Oberer Landschitzsee, Austrian Alps, which spans the period from the Little Ice Age (LIA) to present. We investigated whether post-LIA climate warming altered aquatic invertebrate communities and limnological status in this sensitive high Alpine lake. Fossil Cladocera (Crustacea) and Chironomidae (Diptera) and organic matter in the core were analyzed. Chironomids were used to assess the lake??s benthic quality (i.e. oxygen availability). An instrumental Alpine temperature record was used to assess whether changes in the biotic assemblages correspond to post-LIA temperature trends. The planktonic and macro- and microbenthic invertebrate communities exhibit almost complete and simultaneous species turnover after the LIA, from about AD 1850 onward, when Sergentia coracina-type replaced oxyphilous Micropsectra contracta-type as the dominant macrobenthic taxon, and phytophilous Acroperus harpae outcompeted Alona affinis and Alona quadrangularis in the microbenthos. These directional community shifts corresponded with a period of reduced benthic quality, higher sediment organic content, and progressive climate warming, superimposed on Alpine land-use changes, until the early twentieth century. Detected changes suggest increased productivity and lower benthic oxygen availability. Faunal shifts were even more pronounced during the late twentieth century, simultaneous with enhanced warming. A new planktonic Cladocera species, Bosmina longirostris, typically absent from high Alpine lakes, colonized the lake and gradually became dominant toward the core top. Results show that post-LIA climate warming, coupled with increasing benthic and planktonic production, substantially altered the limnological and ecological status of this remote Alpine lake. Observed faunal turnovers provide evidence that temperature-driven ecological thresholds, whether associated directly or indirectly with greater human activity, have been crossed. Species abundances and distributions have changed in response to post-LIA and late twentieth century climate warming. 相似文献
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The alpine treeline ecotone is defined as a forest-grassland or forest-tundra transition boundary either between subalpine forest and treeless grassland, or between subalpine forest and treeless tundra. The alpine treeline ecotone serves irreplaceable ecological functions and provides various ecosystem services. There are three lines associated with the alpine treeline ecotone, the tree species line (i.e., the highest elevational limit of individual tree establishment and growth), the treeline (i.e., the transition line between tree islands and isolated individual trees) and the timber line (i.e., the upper boundary of the closed subalpine forest). The alpine treeline ecotone is the belt region between the tree species line and the timber line of the closed forest. The treeline is very sensitive to climate change and is often used as an indicator for the response of vegetation to global warming. However, there is currently no comprehensive review in the field of alpine treeline advance under global warming. Therefore, this review summarizes the literature and discusses the theoretical bases and challenges in the study of alpine treeline dynamics from the following four aspects: (1) Ecological functions and issues of treeline dynamics; (2) Methodology for monitoring treeline dynamics; (3) Treeline shifts in different climate zones; (4) Driving factors for treeline upward shifting. 相似文献
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Soil microbes play important roles in terrestrial ecosystem carbon and nitrogen cycling. Climatic warming and elevated CO2 are two aspects of climatic change. In this study, we used a meta-analysis approach to synthesise observations related to the effects of warming and elevated CO2 on soil microbial biomass and community structure. Ecosystem types were mainly grouped into forests and grasslands. Warming methods included open top chambers and infrared radiators. Experimental settings included all-day warming, daytime warming and nighttime warming. Warming increased soil actinomycetes and saprotrophic fungi, while elevated CO2 decreased soil gram-positive bacteria (G+). Mean annual temperature and mean annual precipitation were negatively correlated with warming effects on gram-negative bacteria (G-) and total phospholipid fatty acid (PLFA), respectively. Elevation was positively correlated with the warming effect on total PLFA, bacteria, G+ and G-. Grassland exhibited a positive response of total PLFA and actinomycetes to warming, while forest exhibited a positive response in the ratio of soil fungi to bacteria (F/B ratio) to warming. The open top chamber method increased G-, while the infrared radiator method decreased the F/B ratio. Daytime warming rather than all-day warming increased G-. Our findings indicated that the effects of warming on soil microbes differed with ecosystem types, warming methods, warming times, elevation and local climate conditions. 相似文献
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The seasonal frozen soil on the Qinghai-Tibet Plateau has strong response to climate change, and its freezing-thawing process
also affects East Asia climate. In this paper, the freezing soil maximum depth of 46 stations covering 1961–1999 on the plateau
is analyzed by rotated experience orthogonal function (REOF). The results show that there are four main frozen anomaly regions
on the plateau, i.e., the northeastern, southeastern and southern parts of the plateau and Qaidam Basin. The freezing soil
depths of the annual anomaly regions in the above representative stations show that there are different changing trends. The
main trend, except for the Qaidam Basin, has been decreasing since the 1980s, a sign of the climate warming. Compared with
the 1980s, on the average, the maximum soil depth decreased by about 0.02 m, 0.05 m and 0.14 m in the northeastern, southeastern
and southern parts of the plateau, but increased by about 0.57 m in the Qaidam Basin during the 1990s. It means there are
different responses to climate system in the above areas. The spectrum analysis reveals different change cycles: in higher
frequency there is an about 2-year long cycle in Qaidam Basin and southern part of the plateau in the four representative
areas whereas in lower frequency there is an about 14-year long cycle in all the four representative areas due to the combined
influence of different soil textures and solutes in four areas. 相似文献