A new approach to estimate fine root production, mortality, and decomposition using litter bag experiments and soil core techniques
A new approach to estimate fine root production, mortality, and decomposition using litter bag experiments and soil core techniques
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DOI：
10.1007/s11104-011-1090-6
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发表时间：
2012-06-01
期刊：
影响因子：
4.9
通讯作者：
Aizawa, Ryota
中科院分区：
文献类型：
--
作者：
Osawa, Akira;Aizawa, Ryota
提出了一种新的方法来估计陆地生态系统中同时发生的细根生产、死亡和分解，该方法使用顺序土芯采样或内生核心技术，计算假设从垃圾袋实验中获得给定时间段内死亡细根的分解速率。应用活细根有机质质量平衡模型，在细根死亡和分解的假设下，从可以量化的变量中估计分解的死细根。在日本中部一个约80年生的短叶松人工林中，将估计的细根动态与决策矩阵方法和三种新方法(正向估计、连续流入估计和向后估计)进行比较，结果表明，决策矩阵几乎总是通过突出向前估计的值来低估产量、死亡率和分解，这在理论上低估了真实值。用决策矩阵计算的细根产量和死亡率分别比连续入流量估计法低14%和38%。此外，连续流入估计法的估算值始终介于正向估计法和后向估计法之间。后者被认为高估了真实值。因此，我们认为，在比较的四种方法中，连续流入估计法提供了对细根产量、死亡率和分解的最好估计。
A new approach is proposed to estimate fine root production, mortality, and decomposition that occur simultaneously in terrestrial ecosystems utilizing sequential soil core sampling or ingrowth core techniques.The calculation assumes knowledge of the decomposition rate of dead fine roots during a given time period from a litter bag experiment. A mass balance model of organic matter derived from live fine roots is applied with an assumption about fine root mortality and decomposition to estimate decomposed dead fine roots from variables that can be quantified.Comparison of the estimated fine root dynamics with the decision matrix method and three new methods (forward estimate, continuous inflow estimate, and backward estimate) in a ca. 80-year-old Chamaecyparis obtusa plantation in central Japan showed that the decision matrix nearly always underestimated production, mortality, and decomposition by underscoring the values of the forward estimate, which theoretically underestimates the true value. The fine root production and mortality obtained by the decision matrix were on average 14% and 38% lower than those calculated by the continuous inflow estimate method. In addition, the values by the continuous inflow estimate method were always between those calculated by the forward estimate and backward estimate methods. The latter is known to overestimate the true value.Therefore, we consider that the continuous inflow estimate method provides the best estimates of fine root production, mortality, and decomposition among the four approaches compared.