三叶鬼针草生物量分配与化感作用对大气温度升高的响应

全球气候变暖已经成为不容置疑的事实,同时外来入侵植物对入侵地的生态环境造成严重的危害,外来入侵植物可能对温度升高做出积极地响应。文章研究了不同温度（22、26和30℃）处理对入侵植物三叶鬼针草（Bidens pilosa L.）种子萌发、幼苗生物量分配及化感作用的影响,探讨三叶鬼针草对全球气候变暖的响应策略。结果表明;温度为22和26℃比30℃有利于三叶鬼针草种子的萌发。温度升高显著增加三叶鬼针草的株高、生物量和叶面积,三叶鬼针草幼苗增加对茎和叶的生物量投资。同时相同浓度的三叶鬼针草水浸提液对马唐（Digitaria sanguinalis（L.）Scop）和牛筋草（Eleusine indica（L.）Gaertn）的化感作用随着温度升高而增强。研究表明：温度升高促进了三叶鬼针草的生长,改变生物量分配模式同时增强了对受体植物的化感作用。温度升高可能是促进三叶鬼针草入侵的生态环境因子之一,未来全球气温变暖可能使其入侵加剧。

Responses of biomass allocation patterns and allelopathic potential of Bidens pilosa L.to elevated temperature

There is no doubt that global warming is occurring.The invasive alien plants have caused substantial damage to ecosys-tems and may make a positive response to the increasing temperature.In this study,the effects of elevated temperature on the seed germination,biomass allocation patterns and allelopathic potential of invasive alien plant Bidens pilosa L.were evaluated.The re-sults showed that the germination rate of B.pilosa at 22 ℃ and 26 ℃ was higher than that at 30 ℃.Elevated temperature signifi-cantly increased shoot height,biomass and leave area of B.pilosa.The plant increased its investment of biomass to the aboveground stem and leaf.The allelopathic potential of aqueous leachates of B.pilosa on seedling growth of Digitaria sanguinalis（L.） Scop and Eleusine indica（L.） Gaertn at the same concentration were increased under higher temperature.These results indicate that elevated temperature may accelerate the growth of B.pilosan,change the biomass allocation patterns and enhance the allelopathic potential of it,suggesting that elevated temperature may be an environmental factor facilitating biological invasion of B.pilosa and the weed would become more prevalent under global warming.