Plant functional types define magnitude of drought response in peatland CO2 exchange
Plant functional types define magnitude of drought response in peatland CO2 exchange
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DOI：
10.1890/13-0270.1
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发表时间：
2014-01-01
期刊：
影响因子：
4.8
通讯作者：
Robroek, Bjorn J. M.
中科院分区：
文献类型：
--
作者：
Kuiper, Jan J.;Mooij, Wolf M.;Robroek, Bjorn J. M.
泥炭地是大气碳（C）的重要汇，但气候扰动下植物功能类型（PFT）对碳封存的作用仍不清楚。植物移除实验用于研究实验性干旱期间（即抵抗）和之后（即恢复）期间维管 PFT 对净生态系统 CO2 交换 (NEE) 的重要性。 PFT 的去除导致 NEE 下降，但微生境（即小丘和草坪）和 PFT 类型之间的比率有所不同。杜鹃花的去除对小丘中的NEE有很大影响，而禾本科植物在草坪中发挥了主要作用。 PFT的去除并不影响实验性干旱后的抗性或恢复。我们认为，泥炭藓（所有处理中唯一存在的 PFT）对干旱的反应优于共存的 PFT。然而，我们观察到干旱期间系统从碳汇转换为碳源的时间点是由维管 PFT 控制的。鉴于气候变化，物种组成的变化甚至某些 PFT 的丧失预计将强烈影响未来应对环境压力的碳动态。
Peatlands are important sinks for atmospheric carbon (C), yet the role of plant functional types (PFTs) for C sequestration under climatic perturbations is still unclear. A plant-removal experiment was used to study the importance of vascular PFTs for the net ecosystem CO2 exchange (NEE) during (i.e., resistance) and after (i.e., recovery) an experimental drought. The removal of PFTs caused a decrease of NEE, but the rate differed between microhabitats (i.e., hummocks and lawns) and the type of PFTs. Ericoid removal had a large effect on NEE in hummocks, while the graminoids played a major role in the lawns. The removal of PFTs did not affect the resistance or the recovery after the experimental drought. We argue that the response of Sphagnum mosses (the only PFT present in all treatments) to drought is dominant over that of coexisting PFTs. However, we observed that the moment in time when the system switched from C sink to C source during the drought was controlled by the vascular PFTs. In the light of climate change, the shifts in species composition or even the loss of certain PFTs are expected to strongly affect the future C dynamics in response to environmental stress.