近期和长远时段内北极生态系统结构受到的影响  

Effects on the Structure of Arctic Ecosystems in the Short-and Long-term Perspectives

作　　者：Terry V.Callaghan Lars Olof Bjrn Yuri Chernov Terry Chapin Torben R.Christensen Brian Huntley Rolf A.Ims Margareta Johansson Dyanna Jolly Sven Jonasson Nadya Matveyeva Nicolai Panikov Walter Oechel Gus Shaver Heikki Henttonen 李利平 

机构地区：[1]Abisko Scientific Research Station [2]Departnent of Cell and Organism Biology Lund University [3]A.N.Severtsov Institute of Evolutionary Morphology and Animal Ecology Russian Academy of Sciences [4]Institute of Arctic Biology University of Alaska [5]Department of Physical Geography and Ecosystem Analysis GeoBiosphere Science Centre Lund University [6]School of Biological and Biomedical Sciences University of Durham [7]Institute of Biology University of Troms [8]Centre for Maori and Indigenous Planning and Development Lincoln University [9]Physiological Ecology Group Botanical Institute University of Copenhagen [10]Komarov Botanical Institute Russian Academy of Sciences [11]Stevens Technical University [12]Global Change Research Group San Diego State University [13]The Ecosystems Center Marine Biological Laboratory [14]Finnish Forest Research Institute Vantaa Research Centre Vantaa Unit

出　　处：《AMBIO－人类环境杂志》2004年第B11期412-423,共12页

摘　　要：生物在物种水平上对全球气候变暖和紫外线B(UV-B)辐射增强的反应受到其群落内其他物种以及生态系统内养分循环的调节,所有的这些反应将会导致生态系统结构的变化。根据高纬度地区环境因子的可能变化而做的控制试验表明,由夏季变暖而引起苔原植被的变化要小于增加施肥而引起的变化,试验涉及的某些环境因子对北极生态系统的结构有非常强烈地影响,但是这些影响因地区而异,观测结果表明,处于最寒冷地区的植物群落和无脊椎动物群落对全球气候变暖和紫外线B辐射的增强反应最为强烈。尽管微生物量和养分储存量相对稳定,北极无脊椎动物群落还是很可能会对全球变暖产生迅速的反应。试验结果显示,加强紫外线B辐射会改变革兰氏阴性细菌和真菌的群落组成结构,但不会对植物群落的组成产生影响。由夏季气温升高而提高的植物生产力将会控制食物网的动态变化,以苔原植被和亚极地森林植物为基础的食物网中的营养流动会明显地影响到几种优势动物种群数量的周期性波动,在某些年分这些动物的种群数量会达到峰值。小型啮齿动物和食叶昆虫如秋毛虫种群数量的周期性变化则会影响苔原和森林苔原植物的组成结构和多样性,同时也会影响到一些专性捕食者和寄生虫的变化。在暖冬,雪表形成冰壳可能会减少旅鼠的植物食物来源,然而较深的雪也可以使它们免受雪地表面上捕食者对它们的捕食。在芬诺斯堪的亚地区,已有证据表明小型啮齿类动物群落结构和种群动态的显著变化会导致专门以小型啮齿类动物为食物的捕食者的数量减少。气候还可能改变昆虫在白桦森林生态系统中的作用,因为暖冬可以增加这些昆虫卵的成活率,并且扩大其分布范围。此外,在夏季困扰驯鹿的昆虫会由于夏季气候的变暖而扩大其分布范围、增加种群数量并�Species individualistic responses to warming and increased UV-B radiation are moderated by the responses of neighbors within communities,and trophic interactions within ecosystems.All of these responses lead to changes in ecosystem structure.Experimental manipulation of environmental factors expected to change at high latitudes showed that summer warming of tundra vegetation has generally led to smaller changes than fertilizer addition.Some of the factors manipulated have strong effects on the strueture of Arctic ecosystems but the effects vary regionally,with the greatest response of plant and invertebrate communities being observed at the coldest locations.Arctic invertebrate communities are very likely to respond rapidly to warming whereas microbial biomass and nutrient stocks are more stable.Experimentally enhanced UV-B radiation altered the community composition of gram-negative bacteria and fungi,but not that of plants.Increased plant productivity due to warmer summers may dominate foodweb dynamics.Trophic interactions of tundra and sub-Arctic forest plant-based food webs are centered on a few dominant animal species which often have cyclic population fluctuations that lead to extremely high peak abundances in some years.Population cycles of small rodents and insect defoliators such as the autumn moth affect the structure and diversity of tundra and forest-tundra vegetation and the viability of a number of specialist predators and parasites. Ice crusting in warmer winters is likely to reduce the accessibility of plant food to lemmings, while deep snow may protect them from snow-surface predators.In Fennoscandia,there is evidence already for a pronounced shift in small rodent community structure and dynamics that have resulted in a decline of predators that specialize in feeding on small rodents. Climate is also likely to alter the role of insect pests in the birch forest system:warmer winters may increase survival of eggs and expand the range of the insects.Insects that harass reindeer in the summer are als

关 键 词：生态系统结构 紫外线B辐射 气候变化 荒漠生态系统 北极 苔原 无脊椎动物群落 极地 全球气候变暖 

分 类 号：X171[环境科学与工程—环境科学] Q948.122.3[生物学—植物学]