不同生境中紫茎泽兰幼苗的动态特征

为了研究入侵植物紫茎泽兰生长瓶颈阶段幼苗在不同生境中的适应性动态变化，在四川省德昌县比较研究了非农作的林区、农林交错带及撂荒地3种生境下紫茎泽兰幼苗适应各自不同环境的生长特征。结果表明：（1）幼苗的增长有2个高峰：第1个阶段为7月中旬到9月中旬，第2个阶段为翌年春季进入3月份以后，2个高峰之间为平缓增长期。（2）林区内幼苗的生物量增速均显著低于其余2个生境；而撂荒地和农林带生境增速在第2个生长高峰前相近，之后农林带的生物量增速显著高于撂荒地。（3）越冬生长1年后农林带幼苗密度显著高于其余2个生境。从而说明农林交错带是最适合紫茎泽兰幼苗生长的，也是最容易被入侵的生境。

Dynamic Characteristics of Eupatorium adenophorum Seedlings in Different Habitats

Abstract: Growth characteristics of Eupatorium adenophorum seedlings adapting to different environments are studied comparatively in 3 non-farming habitats, forest, ecotone of farmland and forestry and fallow land. The results show that: 1) After emergence density of seedlings reaching the maximum, the quantity in each habitat decreases rapidly. After overwinter growth for one year, the seedling density in ecotone of farmland and forestry is significantly higher than that in each of the other two habitats. 2) Rise in height, main root length or leaf area of seedlings has two peaks: the first period is from mid July to mid September, in which the seedling density decreases sharply; the second period is the next spring since early March; the period between two peaks is a slow growth phase. 3) Biomass rise in stem of seedlings is significantly higher than that in root or leaf; biomass rise rateof root, stem or leaf of seedlings in forest is significantly lower than that in each of the other two habitats; rise rate in fallow land and that in ecotone of farmland and forestry are close before the second growth peak, and afterwards biomass rise rate of root or leaf in ecotone of farmland and forestry is significantly higher than that in fallow land.