Mori S, Hagihara A
Shikoku Research Center, Forestry and Forest Product Research Institute, 915 Asakura-Tei, Kochi 780, Japan.
Tree Physiol. 1991 Apr;8(3):217-25. doi: 10.1093/treephys/8.3.217.
We examined the respiration rate of root segments, which had a constant length in relation to their diameter, from three small and two large 26-year-old Chamaecyparis obtusa (Siebold & Zucc.) Endl. trees. The dependence of respiration rate on segment diameter was described by a power function with an exponent of about 1.5, except for the smallest sample tree, for which the exponent was 1.74. Unlike stem segments, root segments of similar diameter showed similar rates of respiration regardless of the tree from which the root segments had been taken. On the basis of the power function, we propose a new equation to estimate the total root respiration rate of a tree. The relationship between root respiration rate per tree and root weight can be expressed by a power function with an exponent of 1.11. The ratio of the specific respiration rate of stems to that of roots was 0.7 for the three smaller trees, and 1.1 to 1.3 for the two larger trees. In November, the stand respiration rate of roots was estimated to be 0.36 kg CO(2) ha(-1) h(-1) for a root biomass (dry weight) of 28 Mg ha(-1).
我们研究了取自3棵小树和2棵26年生的大钝叶扁柏（Chamaecyparis obtusa (Siebold & Zucc.) Endl.）的根段的呼吸速率，这些根段的长度与其直径之比恒定。除了最小的样本树（其指数为1.74）外，呼吸速率与根段直径的关系可用指数约为1.5的幂函数来描述。与茎段不同，直径相似的根段，无论取自哪棵树，其呼吸速率都相似。基于该幂函数，我们提出了一个新的方程来估算树木的总根呼吸速率。每棵树的根呼吸速率与根重量之间的关系可用指数为1.11的幂函数来表示。3棵较小树木的茎的比呼吸速率与根的比呼吸速率之比为0.7，2棵较大树木的该比值为1.1至1.3。11月，对于根生物量（干重）为28 Mg·ha⁻¹的情况，根的林分呼吸速率估计为0.36 kg CO₂·ha⁻¹·h⁻¹。
