Irreconcilable differences: Fine-root life spans and soil carbon persistence
Irreconcilable differences: Fine-root life spans and soil carbon persistence
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DOI：
10.1126/science.1151382
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发表时间：
2008-01-25
期刊：
影响因子：
56.9
通讯作者：
Oren, Ram
中科院分区：
文献类型：
--
作者：
Strand, Allan E.;Pritchard, Seth G.;Oren, Ram
细根碳在土壤中的停留时间是全球碳循环中最不为人所知的方面之一，而细根动态是植物功能中最不为人所知的方面之一。最近对这些地下动力学的研究大多使用了两种方法策略中的一种。一种方法是基于碳同位素的分析，推断出碳的持久性；另一种方法是用相机直接观察根系，测量单个根系的寿命。我们表明，细根对全球碳循环的贡献被夸大了，因为对根系寿命的观察系统地高估了细根生物量的周转。另一方面，同位素技术系统地低估了单个根的周转。由于测量了不同的进程或池，这些差异是不可调和的。
The residence time of fine- root carbon in soil is one of the least understood aspects of the global carbon cycle, and fine- root dynamics are one of the least understood aspects of plant function. Most recent studies of these belowground dynamics have used one of two methodological strategies. In one approach, based on analysis of carbon isotopes, the persistence of carbon is inferred; in the other, based on direct observations of roots with cameras, the longevity of individual roots is measured. We show that the contribution of fine roots to the global carbon cycle has been overstated because observations of root lifetimes systematically overestimate the turnover of fine- root biomass. On the other hand, isotopic techniques systematically underestimate the turnover of individual roots. These differences, by virtue of the separate processes or pools measured, are irreconcilable.