Spatial variation in CO2 exchange at a northern aapa mire
Spatial variation in CO2 exchange at a northern aapa mire
复制标题
DOI：
10.1007/s10533-010-9505-7
复制
发表时间：
2011-07
期刊：
影响因子：
4
通讯作者：
Liisa Maanavilja;T. Riutta;M. Aurela;M. Pulkkinen;T. Laurila;E. Tuittila
中科院分区：
文献类型：
--
作者：
Liisa Maanavilja;T. Riutta;M. Aurela;M. Pulkkinen;T. Laurila;E. Tuittila
我们比较了芬兰北部卡马宁沼泽的强烈图案化 aapa 沼泽植物群落中的二氧化碳交换及其控制。基于系统的植被清查和排序分析，选择了四种植物群落类型进行研究：杜鹃花目-侧耳草串顶、桦木-泥炭藓串缘、毛毛藻草丛和苔草-蝎子湿串。我们采用密闭室技术测量了2007年生长季和2008年初夏的植物群落CO2交换。非线性回归模型用于模拟测量期间不同沼泽成分和整个沼泽的CO2交换。二氧化碳交换动力学区分了泥沼中的两种功能成分：膜营养成分（杜鹃花目-侧耳草串顶部）和矿营养成分（其他植物群落类型）。矿营养植物群落对环境控制的反应类似，其中最重要的是叶面积和需氧泥炭体积（水位）的变化。营养成分的动态更加模糊；霜冻和可能的泥炭水分发挥了作用。在模拟中，矿营养群落起到了有效的二氧化碳汇的作用，而微营养群落的净二氧化碳交换接近于零。反营养群落的净能效较小是由于单位叶面积的光合作用效率较低，加上需氧泥炭体积较大而导致的高生态系统呼吸作用。我们的研究表明，沼泽/沼泽功能二分法也可能存在于一个泥沼中。北部沼泽内潮湿的营养型群落可以充当有效的二氧化碳汇。
We compared the CO2exchange and its controls in the plant communities of a strongly patterned aapa mire, the Kaamanen fen in northern Finland. Based on a systematic vegetation inventory and an ordination analysis, four plant community types were chosen for the study: Ericales–Pleurozium string tops, Betula–Sphagnum string margins, Trichophorum tussock flarks and Carex–Scorpidium wet flarks. We measured plant community CO2exchange with a closed chamber technique during the growing season of 2007 and early summer of 2008. Nonlinear regression models were used for simulating the CO2exchange over the measurement period for different mire components and for the whole mire. The CO2exchange dynamics distinguished two functional components in the mire: an ombrotrophic component (Ericales–Pleurozium string tops) and a minerotrophic component (other plant community types). Minerotrophic plant communities responded similarly to environmental controls, the most important of these being variation in leaf area and aerobic peat volume (water level). The ombrotrophic component dynamics were more obscure; frost and possibly peat moisture played a role. The minerotrophic communities functioned as effective CO2sinks in the simulation, while the net CO2exchange of the ombrotrophic community was close to zero. The smaller NEE of the ombrotrophic community was due to less efficient photosynthesis per unit leaf area in combination with high ecosystem respiration resulting from a large aerobic peat volume. Our study shows that a fen/bog functional dichotomy can also exist within one mire. Wet minerotrophic communities within northern mires can act as effective CO2sinks.