半干旱生态条件下春小麦群体生态场的空间分布

THE SPATIAL DISTRIBUTION OF THE ECOLOGICAL FIELD IN SPRING WHEAT COLONY UNDER SEMI-ARID ECOLOGICAL CONDITIONS

在冠幅半径只有株距一半的三叶期，群体生态场呈以每株立地点为峰顶的相对独立的小凸起。随着个体生长，拔节期群体的生态场成为一个稍见起伏的大凸峰。将行距加倍后，场强在行间出现明显的低谷；株距也加倍后，在株间出现同样的低谷。群体的相对密度对其场强分布趋势起重要作用。由于边行效应使群体在发育后期边行的场强增高从而使群体场强分布呈近似平顶凸起状。

he distrbution of the ecological field in the spring wheat colonies was revealed by ana-lyzing the synthetical ecological effect of individuals under semi-arid ecological conditions.The ecological field figure shows same small convexe peaks which coincide with individuals .when crown diameter of wheat is half of the spacing in the rows at the trileaf stage. The eco-logical field figure assumess a large convexe peak with slight rise and fall at the jointing stage. A deep in valley in field intensity would appear between the rows if the row spacing was dou-bled. The same velley would appear among individuals if the spacing in individual plants was also doubled.As a rule,the trend of spatial distribution depends on the relative density of the colony. The field intensity of the marginal rows has been increased to the level of the insiderows because of the marginal effect,so that the field intensity of the whole colony appear alarge convexe with an approximate flat top.