三叶鬼针草生长特征对土壤氮素水平的响应

利用温室盆栽试验法,研究入侵植物三叶鬼针草生长特征对不同土壤氮素水平的响应。结果表明,氮素的增加能够促进三叶鬼针草叶片数、总叶面积、分枝数及生物量的增加,提高其相对生长速率。在物质分配方面,氮肥的施用能促进该植物向地上部分分配较多的物质,显著增加生殖器官（花）生物量的投入,降低向地下部分（根）的物质投入。同时,可塑性指数表明,三叶鬼针草在形态、生物量分配及生殖器官等方面对土壤氮素响应的表型可塑性较大。以上结果充分体现了三叶鬼针草具有较强的入侵性和对土壤氮素环境较高的适应性,预警人们对其预防和管理工作应加以重视。

Response of Growth Characteristics of Bidens piolsa L.to Soil Nitrogen Level

Soil nitrogen effects on the growth characteristics of alien invasive plant Bidens pilosa L.were studied by greenhouse pot experiment.The result indicated that added definite soil nitrogen were favorable to increase the number of leaf and branch,total leaf area(TLA),total biomass and relative growth rate(RGR)of B.pilosa.In the meantime,increased soil nitrogen could facilitate the weed assign more material to the organs on the ground,especially enhance the flower biomass rate significantly,and decrease the material assigned to the roots under ground.Phenotypic plasticity index indicated that in the case of morphological parameters,biomass allocation parameters and reproduction organ more phenotypic plasticity the weed presented on response to the soil nitrogen.All results above demonstrated that the weed B.pilosa had more grater invasion and adaptability to the soil nitrogen,which suggested that definite attention should be paid to the work of the weed prevention and management.