Kennedy Andrew D
Brifish Antarctic Survey, Natural Environment Research Council, High Cross, Madingley Road, CB3 0ET, Cambridge, UK.
Oecologia. 1996 Jul;107(2):141-150. doi: 10.1007/BF00327897.
This paper explores the biological consequences of climate change by integrating the results of a tripartite investigation involving fumarole, field manipulation and laboratory incubation experiments. The geographical region for this research is the maritime Antarctic. Under contemporary climate conditions, the lithosols in this region support only a sparse cryptogamic flora of limited taxonomic diversity and low structural complexity. However, the existence in geothermal areas of temperate species (e.g. Campylopus introflexus, Marchantia polymorpha, Philonotis acicularis) growing outside their normal biogeographical range suggests that elevated temperature and humidity may alter the trajectory of community development towards Magellanic or Patagonian composition. Productivity is also likely to increase, as indicated by significantly greater vegetative biomass recorded beneath climate-ameliorating soil covers than in controls. Barren fellfield soil samples transplanted to the laboratory and incubated at temperatures of 2-25°C show rapid development of moss, algae and lichen propagules in the range 15-25°C. A variety of species develop that have not been recorded in the field. The presence of exotic taxa indicates the existence of a dormant propagule bank in maritime Antarctic soils and suggests that no significant delay is likely to occur between the onset of climate warming and community development: instead, rapid establishment of those species favoured by the new climate conditions will yield a distinct founder effect, with increasing above- and below-ground biomass stimulating biogeochemical cycling. It is argued that the combined results of this synthesis identify generic responses to climate change arising from the importance at high latitudes of low temperature and water availability as limiting factors: subject to other growth resources being non-limiting, a more consistent stimulatory response to climate change may be expected than in temperate or tropical regions. The tripartite approach, encompassing field, microcosm and laboratory methodologies, renders the conclusions more robust than any single study considered in isolation.
本文通过整合涉及喷气孔、野外操作和实验室培养实验的三方调查结果，探讨了气候变化的生物学后果。本研究的地理区域是南极海洋地区。在当代气候条件下，该地区的石质土仅支持分类多样性有限且结构复杂性低的稀疏隐花植物群落。然而，在其正常生物地理范围之外生长的温带物种（如内卷曲尾藓、多歧紫菜、针状泽藓）在地热区域的存在表明，温度和湿度的升高可能会改变群落发展轨迹，使其朝着麦哲伦或巴塔哥尼亚的组成方向发展。正如在气候改善土壤覆盖层下记录到的营养生物量显著高于对照组所表明的那样，生产力也可能会提高。移植到实验室并在2 - 25°C温度下培养的贫瘠荒地土壤样本显示，在15 - 25°C范围内苔藓、藻类和地衣繁殖体迅速发育。出现了多种在野外未记录到的物种。外来分类群的存在表明南极海洋土壤中存在休眠繁殖体库，并表明在气候变暖开始与群落发展之间不太可能出现显著延迟：相反，那些受新气候条件青睐的物种迅速建立将产生明显的奠基者效应，地上和地下生物量的增加会刺激生物地球化学循环。有人认为，这一综合研究的结果确定了对气候变化的一般反应，这种反应源于低温和水资源可利用性在高纬度地区作为限制因素的重要性：在其他生长资源非限制的情况下，预计对气候变化的刺激反应将比温带或热带地区更为一致。包含野外、微观世界和实验室方法的三方研究方法使结论比单独考虑的任何单项研究都更具说服力。
