摘要
本文总结了瑞典-俄罗斯94’苔原生态考察期间,在欧亚大陆北部一系列关于痕量气体实际与潜在的交换的研究中所获得的资料和结果。研究发现:①碳在有机苔原土壤中的长期累积速率,即大气CO_2的净吸收与简单的气候参数有关,例如7月份平均气温和年降水量等。②生态系统呼吸释放的碳受到气候条件的强烈影响;温度升高、含水量下降都对CO_2通量有促进作用;然而,土壤有机碳以CO_2形式的释放还受到其他因子的制约,如所贮存的有机化合物的低分解能力。③欧亚大陆北部甲烷在典型苔原生境中的释放稍低于北美地区类似的生境中的释放;这种差异可能与沿俄罗斯北极海岸的温度一般低于北美地区测点的温度有关。
This paper provides an overview of data and results obtained through a number of studies of actual and potential trace gas exchanges in northern Eurasia, made possible through the Swedish-Russian Tundra Ecology -94 expedition. It was found that: i) long-term accumulation rates of carbon in organic tundra soils, i.e. net uptake of atmospheric CO2, correlated with simple climatic parameters, such as mean July temperature and annual precipitation; ii) the release of carbon through ecosystem respiration is also strongly controlled by climate. Increased temperature and decrease of water-logging enhanced the CO2 flux. However, the release of organic soil carbon as CO2 is also constrained by other factors such as poor decomposability of the stored organic compounds; and Hi) methane emissions from typical tundra habitats in northern Eurasia were found to be slightly lower than from seemingly similar habitats in North America. This difference can probably be attributed to lower temperatures along the Russian arctic coast than at North American sites in general.
