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]Institute of Botany Academy of Sciences of the Czech Republic [15]Thule Institute University of Oulu [16]UNEP-WCMC
出 处：《AMBIO－人类环境杂志》2004年第B11期380-393,457,共14页
摘 要：生物个体是对气候变化和紫外线B(UV-B)辐射变化产生反应的基础,而且这种反应会在各种时间尺度上发生。北极地区的动物、植物以及微生物种类的多样性从表面上看是低的,而且从北方针叶林到极地荒漠逐渐减少,但其原始物种却很丰富。与这种物种多样性随纬向梯度减少的趋势相反,一些空间分布范围很广的单一优势物神的优势度则呈增长趋势。全球气候变暖可能会减少该地区的物种多样性,并限制到这些物种的分布范围,尤其是在该地区生物分布的北部边缘,一些极地特有的动物和植物种类会面临着灭绝的危险。最有可能侵入苔原地带的物种是那些目前生存在极地外缘的北方地区生物。许多植物都具有自身的特征使它们能够在以下环境中生存;短暂的无冰雪覆盖的生长季节,低的太阳高度角,永久冻结地带及低的土壤温度,贫乏的养分获取条件以及极少的物理扰动。以上这些特征有些可能会限制当地物种对气候变暖的反应,但其最主要的因素是这些物种与那些潜在的入侵物种相比缺乏竞争能力。北极地区陆生动物拥有许多适应特性,这使它们能够适应北极地区剧烈的温度变化。许多动物通过冬眠或迁移来逃避极地地区的恶劣天气和资源短缺。北极地区动物生存的生物环境则相对简单:几乎没有天敌、竞争者、疾病、寄生生物,但同时食物资源也很短缺。极地陆生动物可能对由气候变化带来的温暖而干旱的夏季非常不适应,这种变化将会影响到动物的迁移路线、途中栖息地,并会改变冬季积雪的状况和冻融的循环过程。气候变化还会改变动物繁殖和发育的季节,并会引来新的竞争者、捕食者、寄生生物以及疾病等。极地微生物也能很好地适应该地区的气候:一些微生物甚至在-39℃的低温下还能进行代谢活动。蓝藻细菌和藻类生物有着很广泛的适应策The individual of a species is the basic unit which responds to climate and UV-B changes, and it responds over a wide range of time scales.The diversity of animal,plant and microbial species appears to be low in the Arctic,and decreases from the boreal forests to the polar deserts of the extreme North but primitive species are particularly abundant.This latitudinal decline is associated with an increase in superdominant species that occupy a wide range of habitats.Climate warming is expected to reduce the abundance and restrict the ranges of such species and to affect species at their northern range boundaries more than in the South:some Arctic animal and plant specialists could face extinction.Species most likely to expand into tundra are boreal species that currently exist as outlier populations in the Arctic.Many plant species have characteristics that allow them to survive short snow-free growing seasons,low solar angles,permafrost and low soil temperatures,low nutrient availability and physical disturbance.Many of these characteristics are likely to limit speciesAf responses to climate warming,but mainly because of poor competitive ability compared with potential immigrant species.Terrestrial Arctic animals possess many adaptations that enable them to persist under a wide range of temperatures in the Arctic. Many escape unfavorable weather and resource shortage by winter dormancy or by migration.The biotic environment of Arctic animal species is relatively simple with few enemies,competitors,diseases,parasites and available food resources.Terrestrial Arctic animals are likely to be most vulnerable to warmer and drier summers,climatic changes that interfere with migration routes and staging areas,altered snow conditions and freezethaw cyclec in winter,climate-induced disruption of the seasonal timing of reproduction and development,and influx of new competitors,predators,parasites and diseases.Arctic microorganisms are also well adapted to the Arcticfs climate:some can metabolize at temperatures down to -39�
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