Alm J, Talanov Alexander, Saarnio Sanna, Silvola Jouko, Ikkonen Elena, Aaltonen Heikki, Nykänen Hannu, Martikainen Pertti J
Department of Biology, University of Joensuu, P.O. Box 111, FIN-80101 Joensuu, Finland, , , , , , FI.
Institute of Biology, Karelian Research Centre of Russian Academy of Sciences, Puskinskaja St. 11, SU-185610 Petrozavodsk, Russia, , , , , , RU.
Oecologia. 1997 Apr;110(3):423-431. doi: 10.1007/s004420050177.
Carbon dioxide (CO) exchange was studied at flark (minerotrophic hollow), lawn and hummock microsites in an oligotrophic boreal pine fen. Statistical response functions were constructed for the microsites in order to reconstruct the annual CO exchange balance from climate data. Carbon accumulation was estimated from the annual net CO exchange, methane (CH) emissions and leaching of carbon. Due to high water tables in the year 1993, the average carbon accumulation at the flark, Eriophorum lawn, Carex lawn and hummock microsites was high, 2.91, 6.08, 2.83 and 2.66 mol C m, respectively, and for the whole peatland it was 5.66 mol m year. During the maximum primary production period in midsummer, hummocks with low water tables emitted less methane than predicted from the average net ecosystem exchange (NEE), while the Carex lawns emitted slightly more. CH release during that period corresponded to 16% of the contemporary NEE. Annual C accumulation rate did not correlate with annual CH release in the microsites studied, but the total community CO release seemed to be related to CH emissions in the wet microsites, again excluding the hummocks. The dependence of CO exchange dynamics on weather events suggests that daily balances in C accumulation are labile and can change from net carbon uptake to net release, primarily in high hummocks on fens under warmer, drier climatic conditions.
在一个贫营养的北方松林湿地中，对浅洼地（矿质营养型洼地）、草坪和小丘微生境的二氧化碳（CO₂）交换进行了研究。为这些微生境构建了统计响应函数，以便根据气候数据重建年度CO₂交换平衡。根据年度净CO₂交换、甲烷（CH₄）排放和碳淋溶来估算碳积累。由于1993年地下水位较高，浅洼地、羊胡子草草坪、苔草草坪和小丘微生境的平均碳积累量较高，分别为2.91、6.08、2.83和2.66摩尔碳每平方米，整个泥炭地的碳积累量为5.66摩尔每平方米每年。在仲夏的最大初级生产期，地下水位较低的小丘排放的甲烷比根据平均净生态系统交换量（NEE）预测的要少，而苔草草坪排放的甲烷略多。该时期的CH₄释放量相当于当代NEE的16%。在所研究的微生境中，年度碳积累率与年度CH₄释放量没有相关性，但总群落CO₂释放似乎与潮湿微生境中的CH₄排放有关，同样不包括小丘。CO₂交换动态对天气事件的依赖性表明，碳积累的每日平衡是不稳定的，主要在温暖、干燥气候条件下的湿地高小丘中，碳积累可以从净碳吸收转变为净释放。
