【摘要】 用量子传感器对桃、梨和苹果树冠层的透光率作了测量。两年的观测结果表明 :晴天树冠透光率 τ的日变化曲线呈 U字形 ,日平均透光率 τd 与树种和树龄的关系不大。在正常年份 ,展叶后符合关系式τd=7.85 N-0 .88,N为从 4月 1日起算的天数。而物候期变化对τd 的影响 ,可通过对该式作简单的物候期订正来解决更多还原

【Abstract】 Light (0.4～0.7μm) Penetration through individual peach, pear and apple tree crowns was measured with quantum sensors. Results from the 2-year experiment showed that for all the 3 fruit tree species and for normal years light penetration,τ d, can be expressed with an empirical formula, τ d= 7.85N -0.88, where N is the days counted from April 1. Varieties and ages of the trees have little impact on τ d. The effect of phenological stages on τ d can be removed by simply adjusting the formula according to phenological stages.更多还原