Non-structural carbon compounds in temperate forest trees
Non-structural carbon compounds in temperate forest trees
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DOI：
10.1046/j.0016-8025.2003.01032.x
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发表时间：
2003-07-01
影响因子：
7.3
通讯作者：
Körner, C
中科院分区：
文献类型：
--
作者：
Hoch, G;Richter, A;Körner, C
通过分析10种温带树种（6种落叶阔叶树、1种落叶针叶树和3种万年青针叶树）叶片、分支材和干边材非结构性碳水化合物（NSC）含量的季节变化，评价了温带森林树木的碳供应现状。此外，分析所有木质组织的脂质（酰基甘油）。主要的NSC级分是淀粉、蔗糖、葡萄糖和果糖，其他碳水化合物（例如棉子糖和水苏糖）和糖醇（环醇和山梨糖醇）仅起次要的定量作用。NSC的径向分布在整个干芯，在这里进行评估的第一次在一个直接的种间比较，揭示了物种之间的活性边材馏分的大小存在很大的差异，反映了特定的木材解剖结构（环孔与扩散孔木质部）。生长季节分支木材中的平均最小NSC浓度为最大值的55%，甚至在大量果实生产期间保持较高的NSC浓度。茎边材的NSC在整个季节变化很小（跨物种的平均值从未低于最大值的67%），观察到的小幅度减少对任何调查物种都不显着。虽然一些物种含有大量的脂质在木质组织（“脂肪树”，椴树，松，云杉，落叶松），脂质池没有显着变化，在整个生长季节的任何物种。平均而言，落叶树的碳储量将允许更换整个树叶树冠四次。这些数据意味着，通过不断增加大气中的二氧化碳浓度来进一步刺激增长的余地不大。传统的观点认为，落叶树木比万年青树木更依赖碳储量，似乎没有根据或失去了其理由，由于大气中的二氧化碳浓度在过去150年增加了30%以上。
The current carbon supply status of temperate forest trees was assessed by analysing the seasonal variation of non-structural carbohydrate (NSC) concentrations in leaves, branch wood and stem sapwood of 10 tree species (six deciduous broad-leafed, one deciduous conifer and three evergreen conifer trees) in a temperate forest that is approximately 100 years old. In addition, all woody tissue was analysed for lipids (acylglycerols). The major NSC fractions were starch, sucrose, glucose and fructose, with other carbohydrates (e.g. raffinose and stachyose) and sugar alcohols (cyclitols and sorbitol) playing only a minor quantitative role. The radial distribution of NSC within entire stem cores, assessed here for the first time in a direct interspecific comparison, revealed large differences in the size of the active sapwood fraction among the species, reflecting the specific wood anatomy (ring-porous versus diffuse-porous xylem). The mean minimum NSC concentrations in branch wood during the growing season was 55% of maximum, and even high NSC concentrations were maintained during times of extensive fruit production in masting Fagus sylvestris. The NSC in stem sapwood varied very little throughout the season (cross species mean never below 67% of maximum), and the small reductions observed were not significant for any of the investigated species. Although some species contained substantial quantities of lipids in woody tissues ('fat trees'; Tilia, Pinus, Picea, Larix), the lipid pools did not vary significantly across the growing season in any species. On average, the carbon stores of deciduous trees would permit to replace the whole leave canopy four times. These data imply that there is not a lot of leeway for a further stimulation of growth by ongoing atmospheric CO2 enrichment. The classical view that deciduous trees rely more on C-reserves than evergreen trees, seems unwarranted or has lost its justification due to the greater than 30% increase in atmospheric CO2 concentrations over the last 150 years.