To assess the micrometeorological consequences of rice variety choices in relation to rising CO₂ associated to climate change, we quantified the interplay between rice architecture, physiology, and microclimate in current (~385 μmol mol⁻¹) and future (~580 μmol mol⁻¹) CO₂ microenvironments. Two rice varieties contrasting in canopy structure and physiology were grown embedded in irrigated rice paddies, under elevated CO₂ (using a Free‐Air CO₂ Enrichment facility) and ambient CO₂ conditions. The high‐yielding indica variety Takanari is more photosynthetically active and characterized by a more open canopy than a commonly cultivated variety Koshihikari. Our results show a strong diurnal interplay between solar angle, canopy structure, plant physiology, and the overlying atmosphere. Plant architecture was identified as a strong determinant of the relation between plant physiology and microclimate that in turn affects the surface forcing to the overlying atmosphere. Takanari was able to maintain lower canopy temperature both in current and future CO₂ owing to the greater atmospheric mixing and stomatal conductance than Koshihikari. In the perspective of food security, a shift to such a higher‐yielding variety would have consequences on the regional surface energy balance, which subsequently might alter regional weather.

中文翻译：

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量化当前和未来CO2条件下水稻结构，生理和小气候之间的反馈

为了评估对CO的上升相对于水稻品种的选择微气象后果₂相关联的气候变化，我们量化大米架构，生理学和小气候之间的相互作用在当前的（〜385微摩尔摩尔^-1）和未来（〜580微摩尔摩尔^{- 1}）CO ₂微环境。在升高的CO ₂（使用Free-Air CO ₂浓缩设备）和周围CO _2的条件下，将两种在冠层结构和生理上不同的水稻品种种植在灌溉的稻田中。高产in品种高田成与普通栽培的越光品种相比，它具有更高的光合作用活性，并具有更加开放的冠层特征。我们的结果表明太阳角，冠层结构，植物生理与上覆大气之间存在强烈的昼夜相互作用。植物结构被确定为植物生理与微气候之间关系的重要决定因素，而微气候又反过来影响表面对上覆大气的强迫。Takanari能够在当前和将来的CO _2中保持较低的冠层温度由于大气混合和气孔导度比越光更大。从粮食安全的角度来看，转向此类高产品种将对区域表面能平衡产生影响，随后可能会改变区域天气。