植物的自毒作用是同种植物个体间的一种化学竞争机制。为了探索紫茎泽兰种内竞争关系及种群受到自然破坏后的更新途径。采用生物测定及野外调查法，研究了紫茎泽兰叶片水浸液对其幼苗生长的影响及冻害后种群自然更情况。紫茎泽兰叶片水浸液对其幼苗的生长有明显的促进作用，对苗高的促进作用表现为先增加后缓慢减弱，3%浓度时促进作用达到了峰值；在潮湿的秋季紫茎泽兰入侵地破土后种子易发芽，未破土的地带由于枯落物的覆盖，阻碍了种子的发芽，土壤种子库主要分布在0~10 cm的土层中；紫茎泽兰单优势种群在受到冻害后，以萌蘖的方式进行种群更新。紫茎泽兰是一种抗自毒作用极强的植物，在干旱的条件下紫茎泽兰以萌蘖的方式进行种群更新。

Autotoxicity was a chemical interaction mechanism among intra-specific plant individuals. The aim f this study was to explore the relationship between intraspecific competition and population regeneration pproach after destroyed. Population of Eupatorium adenophorum (Spreng.) natural regeneration after frost damage and the effects of aqueous leaf extracts on seedling growth was studied by bioassay and field nvestigate. The results showed that the aqueous leaf extracts of Eupatorium adenophorum (Spreng.) could bviously promote the growth of seedlings, the promoting effect on seedling height increased at first and then gradually weakened, when the concentration was 3% the promote effect reached the peak; The seeds of Eupatorium adenophorum (Spreng.) in the wet autumn was easily germination when the area invaded by upatorium adenophorum (Spreng.) was break, no broken zone due to the litter coverage, hindered the seed germination, soil seed bank mainly distributed in 0-10 cm soil layer; Species update by tiller regeneration method when the dominant species ofEupatorium adenophorum (Spreng.) was damaged after frost. The results of this paper showed thatEupatorium adenophorum (Spreng.) had strong resistance capacity to autotoxicity, and its species update was by tiller regeneration method under the arid conditions.