Reproduction-related variation in carbon allocation to woody tissues in Fagus crenata using a natural 13C approach
Reproduction-related variation in carbon allocation to woody tissues in Fagus crenata using a natural 13C approach
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DOI：
10.1093/treephys/tpw074
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发表时间：
2016-11-28
期刊：
影响因子：
4
通讯作者：
Inagaki, Yoshiyuki
中科院分区：
文献类型：
--
作者：
Han, Qingmin;Kagawa, Akira;Inagaki, Yoshiyuki
新的光合同化物和储存的碳（C）对植物生长的贡献仍然知之甚少，特别是在繁殖过程中。为了阐明如何桅杆播种影响C分配到生殖和营养组织，我们测量了每个组织的生物量增加，分支淀粉浓度和稳定的C同位素组成（δ C-13）在散装叶，当年的枝条，3年的分支和树轮结果和非结果树2年，以及在水果。我们隔离的C分配营养生长繁殖的影响，通过比较C-13富集在木质组织中的结果和非结果标本。与2%的C-13富集在枝相对于叶从非结果树，结果减少了富集到1%，这种减少消失在第二年没有结果，表明新的光合同化物优先用于木质组织，即使与结果的负担。与此相反，水果有高达2.5%的C-13富集在仲夏，此后下降，表明水果生产依赖于C存储在生长季节早期，然后转移到当前的光同化物。在这个临界点，新梢和壳斗的生长基本完成，坚果进入第二个快速生长期。结果树枝短，但单位长度的生物量增量高于非结果树，这些结果表明，由于水果负担的C限制最小化的微调分配的旧C商店和新的光合同化物，沿着在各种组织的生长模式。此外，结果对3年生枝条的淀粉浓度没有显着影响，在叶和花冲洗期间淀粉完全耗尽，但很快得到补充。这些结果表明，繁殖影响C分配到分支，但不是它的来源或存储。这些复制相关的变化的命运的C评估森林生态系统的C循环在气候变化的影响。
The contribution of new photo-assimilates and stored carbon (C) to plant growth remains poorly understood, especially during reproduction. In order to elucidate how mast seeding affects C allocation to both reproductive and vegetative tissues, we measured biomass increase in each tissue, branch starch concentration and stable C isotope composition (delta C-13) in bulk leaves, current-year shoots, 3-year branches and tree rings in fruiting and non-fruiting trees for 2 years, as well as in fruits. We isolated the effect of reproduction on C allocation to vegetative growth by comparing C-13 enrichment in woody tissues in fruiting and non-fruiting specimens. Compared with 2% C-13 enrichment in shoots relative to leaves from non-fruiting trees, fruiting reduced the enrichment to 1% and this reduction disappeared in the following year with no fruiting, indicating that new photo-assimilates are preferentially used for woody tissues even with fruiting burden. In contrast, fruits had up to 2.5% C-13 enrichment at midsummer, which dropped thereafter, indicating that fruit production relies on C storage early in the growing season then shifts to current photo-assimilates. At this tipping point, growth of shoots and cupules had almost finished and nuts had a second rapid growth period thereafter. Together with shorter shoots but higher biomass increment per length in fruiting trees than non-fruiting trees, these results indicate that the C limitation due to fruit burden is minimized by fine-tuning of allocation of old C stores and new photo-assimilates, along with the growth pattern in various tissues. Furthermore, fruiting had no significant effect on starch concentration in 3-year-old branches, which became fully depleted during leaf and flower flushing but were quickly replenished. These results indicate that reproduction affects C allocation to branches but not its source or storage. These reproduction-related variations in the fate of C have implications for evaluating forest ecosystem C cycles during climate change.