Effects of the experimental alteration of fine roots on stomatal conductance and photosynthesis: case study of devil maple (Acer diabolicum) in a cool temperate region
Effects of the experimental alteration of fine roots on stomatal conductance and photosynthesis: case study of devil maple (Acer diabolicum) in a cool temperate region
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细根实验改变对气孔导度和光合作用的影响：以冷温带魔鬼枫（Acer diabolicum）为例
DOI：
10.1016/j.envexpbot.2013.12.020
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发表时间：
2014
影响因子：
5.7
通讯作者：
Masaki Tateno
中科院分区：
文献类型：
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作者：
Daisuke Sugiura;Masaki Tateno
水分被细根吸收，并与必需物质一起运输，以在叶片中进行光合作用。为了确定需要多少细根才能吸收足够的水分并使光合作用最大化，使用理论模拟和实验室实验来评估减少细根生物量对气孔导度（GS）和光合速率（A）的影响。我们使用日本冷温带地区典型的木本树种魔鬼枫（Acer diabolicum）的树苗，在高光和低光环境下生长。A-GS关系和整株水力传导度（KW）被确定并用于模拟。在室内试验中，随着细根的逐步减少，KW、A和GS也逐渐变化。模型预测随着细根的减少，KW、GS和A适度降低。例如，当细根减少50%时，A仅减少12%。模型预测结果与实验室试验结果基本一致。总之，魔鬼枫树的树苗产生了细根，足以满足光合作用的水分需求。这些特点可能是有益的生存严重干旱和在中度水分胁迫条件下保持足够的水力传导。
Water is absorbed by fine roots and transported with essential substances to conduct photosynthesis in leaves. To determine how many fine roots are required to absorb adequate water and maximise photosynthesis, the effects of decreasing fine root biomass on stomatal conductance (GS) and photosynthetic rate (A) were evaluated using theoretical simulations and laboratory experiments. We used saplings of devil maple (Acer diabolicum), a typical woody species in the cool temperate regions of Japan, grown in high- and low-light environments.A–GSrelationships and whole-plant hydraulic conductance (KW) were determined and used for the simulations. Gradual changes inKW,A, andGSwere also evaluated with a stepwise decrease in fine roots in the laboratory experiments. The model predicted thatKW,GS, andAdecreased moderately with a decrease in fine roots. For example,Adecreased by only 12% when fine roots were decreased by 50%. The model predictions were nearly consistent with the results from laboratory experiments. In conclusion, saplings of devil maple produced fine roots that were more than sufficient in meeting the water demands of photosynthesis. These characteristics may be beneficial in surviving severe drought and in maintaining adequate hydraulic conductance under conditions of moderate water stress.