根际土壤湿度和叶幕微气候对葡萄叶片水分代谢影响的模拟分析

在盆栽条件下取得初级数据以后进行数学模拟和分析。结果表明：根际土壤湿度对葡萄叶片水分代谢过程影响显著。根际土壤湿度与叶片水势（ψ_(ＷＬ)）、气孔扩散阻力（Ｒ_s）、蒸腾速率（Ｔ_ｒ）的关系可用相应的Ｌｏｇｉｓｔｉｃ方程表示。方程的拐点被定义为根际土壤湿度阀值。根际土壤湿度对叶片水分代谢的进程也有影响。供水充足的植株，叶片蒸腾速率（Ｔ_ｒ）在一日内都维持较高水平，呈单峰曲线型。而水分亏缺植株，则表现出明显的“午休”现象，且一日内蒸腾作用很弱。叶幕微气候诸因子对葡萄叶片水分代谢的影响作用较为复杂，基本遵循多元线性相关关系。建立了Ｒ_ｓ、Ｔ_ｒ与叶幕微气候诸因子的关系模型。进一步分析了葡萄根际土壤湿度阀值漂移与叶幕微气候因子的关系，结果表明：随光照增强、温度升高、湿度下降，阀值增大。

Simulated Analysis of Effects of Soil Moisture and Canopy Microclimate on Leaf Water Metabolism in Grape

Methemetical simulated analysis were taken for studying the influence of soil moisture and canopy micro-climate on the leaf water potential in grape. The relationships between the soil moisture and the leaf waterpotential,stomatal resistance,transpiration may be expressed by a logistical equation. The curve of day tran-spiration rate revealed a single peak when the soil moisture content was high enough, but it revealed a bi- peak and remained low all day when the soil moisture content was low,The relationship between the cornershift and the microclimate are discussed.