Net ecosystem carbon exchange in two experimental grassland ecosystems
Net ecosystem carbon exchange in two experimental grassland ecosystems
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DOI：
10.1111/j.1529-8817.2003.00744.x
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发表时间：
2004-04
影响因子：
11.6
通讯作者：
P. Verburg;J. Arnone;D. Obrist;D. E. Schorran;R. Evans;Debbie Leroux‐swarthout;Dale W. Johnson;
中科院分区：
文献类型：
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作者：
P. Verburg;J. Arnone;D. Obrist;D. E. Schorran;R. Evans;Debbie Leroux‐swarthout;Dale W. Johnson;
净初级生产力（NPP）的增加可能不一定会导致碳固存的增加，因为吸收的增加可以被同时增加的生态系统通过呼吸过程的碳损失所抵消。连续测定了两种试验用雀麦（Bromus tectorum L.）大型动态通量室（EcoCELLs）中的生态系统表明，在两个生长周期内，生态系统向大气中的碳净损失超过300 g C m−2。即使在第二个生长季节施氮后生态系统净生产力（NEP）增加一倍，也不能弥补休耕期土壤碳的损失。施肥不仅增加了生物量的碳吸收，而且增加了通过土壤呼吸的碳损失，从287到469 g C m−2，主要是通过增加根际呼吸。施肥通过45 ~ 10 g C m−2的淋溶减少了溶解无机碳的损失。
Increases in net primary production (NPP) may not necessarily result in increased C sequestration since an increase in uptake can be negated by concurrent increases in ecosystem C losses via respiratory processes. Continuous measurements of net ecosystem C exchange between the atmosphere and two experimental cheatgrass (Bromus tectorum L.) ecosystems in large dynamic flux chambers (EcoCELLs) showed net ecosystem C losses to the atmosphere in excess of 300 g C m−2 over two growing cycles. Even a doubling of net ecosystem production (NEP) after N fertilization in the second growing season did not compensate for soil C losses incurred during the fallow period. Fertilization not only increased C uptake in biomass but also enhanced C losses through soil respiration from 287 to 469 g C m−2, mainly through an increase in rhizosphere respiration. Fertilization decreased dissolved inorganic C losses through leaching of from 45 to 10 g C m−2.