不同密度的羊草种群结构及其光照分布的研究

本文报道了耕翻后自然更新的羊草种群不同密度条件下垂直结构及其光照分布特征。结果表明，地上生物量和叶面积指数均以种群中部最大，向上或向下皆逐渐减小。在三种密度中，生物量，叶面积指数，株高，茎高和叶片含水量均随着密度的增大而升高。比叶重和单株绿叶数度增加而降低。

Study on the Population Structure of Leymus chinensis and Its Distribution of Illuminance under Its Different Density Conditions

In this paper,the vertical structure for naturally rejuvenating Leymus chinensis population after cultivated grassland and its distribution characteristic of illuminance are rcported under its different density conditions. It show that aerial biomass and leaf area at middle part of population are the highest,and they reduce gradually with upturning or downing of position. A comparison has been made between three densities,aerial biomass, leaf area index, plant height,stem height and leaf water content of L. chinensis increase with raising density of population,specific leaf weight and number of green leaves decrease with raising density. The leaf blade of L. chinensis are a erect type,more than all the angles of obliquity of superior leaves are the graeater. There are the distribution of uppermost expanded leaf at every levels from 10 cm above ground surface to top of community,and possessing proportion increases gradually with raising height. These characteristics advantage the photosynthetic production of L. chinensis population. The light intensity of L. chinensis population decreases with lowering height,but the decay rate at midd1e part is the greater,and at upper and lower part are smaller. The decay rate increases with rising population density. This is closely related to the distribution of leaf area of population.