Effects of Climate Change on Soil Microarthropod Diversity and Ecological Function, 2011

The arctic region is currently facing great environmental changes of greenhouse-gas warming, with likely strong consequences for structure of plant and animal communities and ecosystem processes. The rates of the biological processes are mediated by temperature, season length, temporal and spatial distribution of snow and water conditions, i.e. factors predicted to undergo strong changes. At the same time, decomposition processes are moderated by the organisms themselves. Microbes and soil fauna use litter and soil organic matter as energy, carbon and nutrient sources for biomass production and for their metabolic functions. Climatic changes may both directly and indirectly facilitate an increase in the mineralisation of soil organic matter by microbes and microarthropods, which again may lead to increased nutrient availability. It is essential to reveal the diversity of species, species and population densities, life cycles, population dynamics and turnover in microarthopod communities to understand the effects on the decomposition processes. Experimental sites for investigation of effects of environmental changes on biological and physiological processes have been set up at Zackenberg, Greenland, and Abisko, Sweden. Here, intensive investigations of biological and biogeochemical effects of changed environmental conditions have been carried out. The ability of soil organisms to adapt to a changing environment will determine their response to climatic manipulations. The proposed research will be complementary to the ongoing research, and the role of the microarthropods in the system will be elucidated. Sampling will take place in existing field plots, in addition to establishing new field experiments specifically designed for this project. The main effortwill be on functional aspects on ecosystem level of processes, and interactions at the level of the microarthropods, studied by experimental perturbations within the ecosystems, and by laboratory studies.

北极地区当前正面临温室气体增温（greenhouse-gas warming）引发的剧烈环境变化，这极有可能对动植物群落结构与生态系统过程产生显著影响。生物过程的速率受温度、季节时长、积雪与水文条件的时空分布等因素调控——而这些因素预计将发生剧烈改变。与此同时，分解过程也会受到生物自身的调节。微生物与土壤动物群以枯落物和土壤有机质（soil organic matter）作为能量、碳源与养分来源，用于生物量合成及各项代谢活动。气候变化可通过直接与间接途径，促进微生物与微节肢动物（microarthropods）对土壤有机质的矿化作用，进而提升养分有效性。若要阐明气候变化对分解过程的影响，亟需探明微节肢动物群落的物种多样性、物种与种群密度、生活史、种群动态及周转速率。目前已在格陵兰扎科恩贝（Zackenberg）与瑞典阿比斯库（Abisko）设立研究站点，用于探究环境变化对生物及生理过程的影响。上述站点已针对环境条件改变带来的生物与生物地球化学效应开展了深入研究。土壤生物适应变化环境的能力，将决定其对气候调控实验的响应模式。本项拟开展的研究将与现有研究形成互补，阐明微节肢动物在该生态系统中的功能角色。采样工作将在既有野外样地中进行，同时还将为本项目专门搭建新的野外实验装置。研究的核心着力点将聚焦于生态系统尺度下的过程功能层面，以及微节肢动物间的相互作用，具体将通过生态系统内的实验扰动（experimental perturbations）与实验室研究展开。