摘 要 ：探讨了白桦树冠投影面积对林下日阴密度的影响 ,发现日阴密度随白桦树冠投影面积呈双峰型变化。海拔高度、坡向、坡度对于日阴随白桦树冠投影面积的变化也有一定程度的影响。白桦荫蔽度、日阴地上部生物量和土壤水分含量三者具有较为一致的格局规模 ,这表明白桦通过改变林下的光照和地表水分而影响了日阴的生长。日阴在中等尺度上与土壤有机质的格局规模一致。溪荪个体数量与土壤 p H值在大、中尺度上均显示一致的格局规模 ,说明溪荪受p H值的影响。
Abstract:To inverstigate the impacts of overstory dominant tree species on understory herbaceous plants,a field experiments was carried out in growing season in 1997.Mountane secondary Betula platyphylla forests in the territory of Erguna,Hulunbuir League of Inner Mongolia autonomous region of China were chosen for the experiment.The region happened to be within the forest steppe ecotone of Da Xingan Ling Mountains and within the climatically transitional zone from cold temperate to intermediate temperate belt...