林下和撂荒地生境紫茎泽兰幼苗的生长特征及其种内竞争形态反应

Growth characteristics and morphological responses to intra-specific competition of Ageratina adenophora seedlings under forestry and in the wasteland habitats

比较研究了林下和撂荒地生境有无竞争条件下紫茎泽兰(Ageratina adenophora(Sprengel))幼苗的生长特征、生长速率、生物量和种内竞争的形态反应。结果表明:(1)2类生境条件下紫茎泽兰植株幼苗形态特征基本一致,无竞争条件下紫茎泽兰幼苗根长和叶片数明显高于在竞争条件下对应指标值;(2)同类生境中,在无竞争条件下紫茎泽兰幼苗的生长速率、生物量积累显著比在竞争条件下的高;(3)不同生境中,撂荒地生境紫茎泽兰幼苗生物量显著高于林下生境的值,在无竞争条件下,林下生境紫茎泽兰幼苗生长速率比撂荒地生境的高,而在竞争条件下反之;(4)林下和撂荒地生境紫茎泽兰幼苗植株竞争强度差异不显著,但在林下生境其地上部分的竞争强度显著大于其在撂荒地生境的值,而根的竞争强度相反。可见,紫茎泽兰幼苗在种群建立的过程中具有不同的生态适应性和形态反应,这可能是其能成功入侵不同生境的一种重要生理生态策略。

A comparative study on the growth characteristics, growth rate, biomass allocation and morphological response of Ageratina adenophora seedling under competition and without competition conditions in forestry and wasteland habitats was conducted in the suburbs of Kumming City, Yunnan province. The results showed that： （1） the morphological characteristics of A. adenophora seedling under forestry and in the wasteland habitats are basically the same, but the root length and leaf number of A. adenophora seedling in non-competitive conditions was significantly higher than the corresponding index value in competitive conditions; （2） at the same habitat, the seedling growth rate and biomass accumulation ofA. adenophora seedling in non-competitive conditions were significantly more than those in competitive conditions; （3） in different habitats, the biomass accumulation of A. adenophora seedling in the wasteland habitats was significantly higher than those under forestry, and the growth rate of A. adenophora seedling under forestry habitat in the no competition conditions was significantly higher than those in the wasteland habitat, while the contrary in the conditions of competition; （4） the competition intensity of A. adenophora seedling under forestry and in the wasteland habitats had no significantly differences, but the competition intensity of shoot ofA. adenophora seedling under forestry habitats was significantly greater than those in the wasteland habitat, while the competition intensity of root was completely contradict. In conclusion, the seedling ofA.a adenophora showed different ecological adaptability and morphological responses in the process of its population establishment, which may be an important physiological and ecological strategy for its successful invades to the different habitats.