Temporal photosynthetic carbon isotope signatures revealed in a tree ring through 13CO2 pulse-labelling
Temporal photosynthetic carbon isotope signatures revealed in a tree ring through 13CO2 pulse-labelling
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DOI：
10.1111/j.1365-3040.2005.01343.x
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发表时间：
2005-07-01
影响因子：
7.3
通讯作者：
Abe, H
中科院分区：
文献类型：
--
作者：
Kagawa, A;Sugimoto, A;Abe, H
采用脉冲标记树木和分析详细的C-13示踪剂在树轮内的分布相结合的方法，我们研究了如何在一个给定的一天，然后在树轮中分配的光合同化物。在2001年5月29日和2001年9月18日两次用非放射性（CO2）-C-13对生长于日本筑波的4年生日本柳杉D.Don树的分支进行脉冲标记。2002年3月4日，从树干上切下两个圆盘，一个在树枝下面，另一个在树枝下面0.5米处，并进行高分辨率δ C-13分析。δ C-13峰在早材和晚材的有关树木年轮，对应于每个脉冲标记日期。早材峰宽于晚材峰，可能反映了木材发育带宽度的季节变化。半宽度的峰值进行了测量，并作为指标的潜在的时间分辨率的树轮同位素分析。峰的半宽度表明，在早材和晚材的时间分辨率分别不超过8.7-28和33-42 d。综纤维素提取仅产生δ C-13峰形状的轻微变化。C-13示踪脉冲标记在5月和9月达到切向不同的位置在较低的光盘，这表明碳水化合物的途径的季节性变化。春季同化物的本地消耗和秋季同化物的远距离向下输送也被提出。
Using a combined method of pulse-labelling trees and analysing detailed distribution of C-13 tracer within tree rings, we studied how photo-assimilates incorporated on a given day are then distributed in a tree ring. A branch of a 4-year-old Cryptomeria japonica D.Don tree growing in Tsukuba, Japan was pulse-labelled with non-radioactive (CO2)-C-13 on two occasions: 29 May 2001 and 18 September 2001. Two discs were cut from the stem on 4 March 2002, one immediately under and the other 0.5 m below the branch and put through high-resolution delta C-13 analysis. delta C-13 peaks were observed in both the earlywood and latewood of the concerned tree ring, corresponding to each pulse-labelling date. The earlywood peaks was broader than the latewood peaks, possibly reflecting seasonal variation of the width of wood developing zone. Half-widths of the peaks were measured and used as indicators for the potential time resolution of tree-ring isotope analysis. The half-widths of the peaks indicated a time resolution no finer than 8.7-28 and 33-42 d in the early and latewood, respectively. Holocellulose extraction yielded only a slight change to the shape of the delta C-13 peaks. C-13 tracer pulse-labelled in May and September reached tangentially different locations in the lower disc, suggesting a seasonal change in the pathway of carbohydrates. Local consumption of spring assimilates and long-distance downward transport of autumn assimilates were also suggested.