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为探讨反枝苋(Amaranthus retroflexus)在入侵农田生态系统过程中的化感作用与资源竞争能力之间的关系,采用添加活性炭的方法,比较了在有无活性炭条件下,反枝苋与大豆(Glycine max)的生物量积累、生物量分配及不同器官含氮量随供氮水平的变化情况。结果表明,在低供氮水平时,化感作用在竞争中占有的比重较大,在高供氮水平时,化感作用所占的比重相对降低;在高供氮条件下,反枝苋增加了对根和叶的生物量分配,而在低供氮条件下,则增加对繁殖器官的生物量分配;在氮素营养贫瘠的条件下,添加活性炭的大豆含氮量要明显小于不添加活性炭时,随着供氮水平的上升,差异逐渐减小。说明在入侵过程中,反枝苋可以通过调节自身的化感作用和生物量分配来适应不同的氮素营养条件。
In order to explore the relationship between the allelopathy of Amaranthus retroflexus in the invasion of farmland ecosystem and the resource competitiveness, the method of adding activated carbon was used to compare the effects of Amaranthus retroflexus with soybean Glycine max) biomass accumulation, biomass allocation and nitrogen content of different organs with the level of nitrogen supply. The results showed that the allelopathy played a major role in competition at low nitrogen levels, and the proportion of allelopathy was relatively lower at high nitrogen levels. Under the conditions of high nitrogen supply, Amaranthus retroflexus increased The biomass allocation to roots and leaves was increased, while the biomass allocation to reproductive organs was increased under low nitrogen supply. Under the condition of poor nitrogen nutrition, the nitrogen content of soybean with activated carbon was obviously smaller than that without activated carbon When the level of nitrogen supply increased, the difference gradually decreased. This indicated that in the process of invasion, Amaranthus retroflexus could adapt to different nitrogen nutrition conditions by regulating its allelopathy and biomass allocation.