施肥和杂草防除对三江源区人工草地群落特征的影响

针对三江源区多年生人工草地可持续利用问题,采用杂草防除与施肥相结合的方式,对5龄垂穗披碱草(Elymus nutans)人工草地进行改良试验,研究了不同防除剂浓度和不同施肥水平对高寒人工草地群落特征和生产能力影响,为老龄"黑土型"人工草地可持续性利用提供科学依据。结果表明:喷施苯磺隆可有效降低群落中杂类草盖度、生物量和多样性,在苯磺隆108 g·hm^-2浓度时杂类草的防除效果好。随施肥量增加,群落中禾草总盖度和生物量的变化均显著增加,而杂类草生物量差异不显著。喷施苯磺隆108 g·hm^-2、施尿素150 kg·hm^-2和氯化钾60 kg·hm^-2时,改良效果显著高于其他处理,是三江源区人工草地进行改良的适宜参考标准。

Effects of Fertilization and Herbicide on Plant Community of Artificial Grassland in the Three Rivers Area

To propose scientifically sustainable utilization theories of artificial grassland in Three Rivers area,improved experiments of 5 years Elymus nutans artificial grassland were conducted using combinations of fertilization and weeds control.Supplemental effects of different fertilization and herbicide quantities on plant community and productivity of artificial grassland were also studied.Results of two experimental years showed that the application of tribenuron-methly,with optimum concentration is 108 g·hm-2,reduced the coverage,biomass and diversity of forbs.Coverage and biomass of grass were increased significantly with increased fertilizer,whereas there are no significant differences in forbs.The control efficiency of the combination of 108 g·hm-2 tribenuron-methly,150 kg·hm-2 urea and 60 kg·hm-2 potassium chloride was significantly higher than other combinations.Therefore,it is a reference standard for artificial grassland maintaining in the original area of Three Rivers.