Elevated CO2 and nitrogen availability have interactive effects on canopy carbon gain in rice
Elevated CO2 and nitrogen availability have interactive effects on canopy carbon gain in rice
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DOI：
10.1046/j.1469-8137.2003.00943.x
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发表时间：
2004-02-01
期刊：
影响因子：
9.4
通讯作者：
Kobayashi, K
中科院分区：
文献类型：
--
作者：
Anten, NPR;Hirose, T;Kobayashi, K
本文分析了CO2 （C-a）海拔和氮素有效性对水稻冠层结构、叶面积指数（LAI）和冠层光合作用的影响。利用自由空气CO2富集（FACE）和两种氮效度，在环境和提高c -a（比环境高200 μ mol mol(-1)）条件下种植水稻。测定叶片面积、叶面氮含量和叶片光合作用，计算净日冠层光合作用。当测量其自身生长CO2时，FACE植物具有比环境植物更高的光饱和光合速率（P-max）和表观量子产率。C-a高程降低了冠层总叶氮（N叶），但对LAI没有影响，平均叶氮含量（N叶/LAI）降低了8%。这种减少与我们的模型预测非常吻合。叶面积指数随氮有效性的增加而增加，这与我们的模型一致。计算的冠层光合作用在高氮条件下比在环境C-a条件下增加得更强烈。这表明在冠层碳增益中存在N × C-a交互效应。这种相互作用是由于LAI随N有效度的增加而增加，从而增强了C-a升高下高量子产率的正向效应。
Here we analysed the effects of CO2 (C-a) elevation and nitrogen availability on canopy structure, leaf area index (LAI) and canopy photosynthesis of rice (Oryza sativa).Rice was grown at ambient and elevated C-a (c. 200 mumol mol(-1) above ambient, using the free-air CO2 enrichment, FACE) and at two N availabilities. We measured leaf area, area-based leaf N contents and leaf photosynthesis, and calculated net daily canopy photosynthesis.FACE plants had higher light-saturated rates of photosynthesis (P-max) and apparent quantum yields than ambient plants, when measured at their own growth CO2. C-a elevation reduced the total leaf N in the canopy (N-leaf) but had no effect on LAI, and the average leaf N content (N-leaf/LAI) was therefore reduced by 8%. This reduction corresponded well with our model predictions. Leaf area index increased strongly with N availability, which was also consistent with our model.Calculated canopy photosynthesis increased more strongly with N-leaf under elevated than under ambient C-a. This indicates that there is an N x C-a interactive effect on canopy carbon gain. This interaction was caused by the increase in LAI with N availability, which enhanced the positive effect of the higher quantum yield under C-a elevation.