【摘要】 通过不同密度和施氮肥水平创造不同群体叶层结构,运用ROSS分析方法,对群体叶层结构的形成、特征、特性、功能、动态变化等问题进行了探讨。结果证明:叶倾角在生育过程中有一定变化,一般在群体LAI最高峰的四分体期最趋向直立。叶面积在群体水平层中非均匀分布,行间与行内的LAI有显著差异。群体中叶面积垂直分布在生育进程的不同时段不同,四分体期群体叶面积密度的垂直分布呈双峰型。上层峰在株高3/5处,为“功能叶面积”;下层峰在株高1/4处,为“非功能叶面积”。更多还原

【Abstract】 The experiments were conducted with winter wheat ( Triticium aestivum L. ) of Beijing IS under two fastors: density ( three levels) and nitrogen fertilization ( two levels ) .with Ross’s method, the vertical distribution of foliage area, the foliage inclination angle and the orientation angle were studied.The rediation distributions in stands were also measured.The leaves of the wheat Beijing 18 are nearly vertical, the foliage area inclination index is about - 0.5.The values have some variations at different time.The most vertical foliage is at the time when stand has the LAImax. Treatments have significant effect on the foliage inclination angle. The higher the density, the lower the xlvalue; nitrogen fertilization makes foliage more vertical under high density,but more horizontal under low density.The foliage orientation distributions are nearly uniform, but the foliage distributions in horizontal layers are not uniform, especialy under low density treament.This is very important for the calculation of stand, because most stand models suppose horizontal distribution of foliage be uniform.更多还原