施肥对科尔沁羊草割草场植物群落多样性和生产力的影响

发布时间：2018-07-25 11:23

【摘要】：连续3年研究切根基础上的施肥对科尔沁羊草(Leymus chinensis)割草场植物群落特征、草地生产力和物种多样性的影响,设置4个肥料添加梯度,分别为CK(对照)、NP1(尿素75 kg/hm~2+磷酸二铵45 kg/hm~2)、NP2(尿素150 kg/hm~2+磷酸二铵90 kg/hm~2)和NP3(尿素225 kg/hm~2+磷酸二铵135 kg/hm~2)。结果表明,施肥当年(2014年),施肥促使群落高度、盖度和地上生物量增加,对群落密度和多样性指数无显著影响,其中NP3处理下的地上生物量为416.65 g/m2,是对照区的2.3倍;随着施肥量的增加,建群种羊草的重要值降低,而1年生植物狗尾草(Setaria viridis)的重要值大幅升高。施肥第2年(2015年),施肥处理显著增加了群落高度和地上生物量,对群落盖度、密度和群落多样性指数无显著影响,其中NP3处理下的地上生物量显著高于对照区,但是CK、NP1和NP2处理间无显著差异;随着施肥量的增加,建群种羊草的重要值有增加的趋势。施肥第3年(2016年),施肥对群落高度和盖度均无显著影响,但显著增加了群落密度,其中NP2、NP3处理下的群落密度分别为574.67、566.00株/hm~2,显著高于CK的293.00株/hm~2;NP1、NP2、NP3处理下的地上生物量分别高于对照区26.64%、18.26%、63.49%,但差异不显著;施肥处理的羊草重要值都升高至50%以上,最高达70.07%;群落的Margalef丰富度指数随着施肥量的增加而降低,且与CK差异显著,NP2和NP3处理下群落的Shannon-wiener多样性指数和Simpson指数降低,且与CK区差异性显著,Pielou均匀度指数在各处理间均无显著性差异。由此可见,物理改良切根和施肥相结合可以促进优势物种羊草的生长,有利于草地生产力的提高和草地的恢复。
[Abstract]:The effects of fertilization on the plant community characteristics, grassland productivity and species diversity in (Leymus chinensis) mowing field of Leymus chinensis were studied for 3 consecutive years. Four fertilizer gradients were set up. NP1 (urea 75 kg/hm~2 diammonium phosphate 45 kg/hm~2) NP2 (urea 150 kg/hm~2 diammonium phosphate 90 kg/hm~2) and NP3 (urea 225 kg/hm~2 diammonium phosphate 135 kg/hm~2) were used as CK (control). The results showed that in the year of fertilization (2014), fertilization increased the community height, coverage and aboveground biomass, but had no significant effect on the community density and diversity index. The aboveground biomass of NP3 treatment was 416.65 g / m ~ 2, which was 2.3 times of that of the control area. With the increase of fertilization amount, the important value of cultivated sheep grass decreased, while the important value of annual plant (Setaria viridis) increased significantly. In the second year of fertilization (2015), fertilization significantly increased community height and aboveground biomass, but had no significant effect on community coverage, density and community diversity index. The aboveground biomass of NP3 treatment was significantly higher than that of control area. However, there was no significant difference between CK NP1 and NP2 treatments. In the third year of fertilization (2016), fertilization had no significant effect on community height and coverage, but significantly increased community density. The community densities under NP2 + NP3 treatment were 574.67566.00 plants / hmc-2, respectively, which were significantly higher than that of CK (293.00 / hmc2NP1NP2NP3) treatment, respectively, and the aboveground biomass of NP2NP3 treatment was higher than that of the control area (26.64%), but the difference was not significant, and the important value of Leymus chinensis increased to more than 50% in fertilization treatment. The highest value was 70.07, the Margalef richness index of community decreased with the increase of fertilization, and the Shannon-wiener diversity index and Simpson index of community decreased under NP2 and NP3 treatments. There was no significant difference in Pielou evenness index between the treatments and CK. It can be seen that the combination of physical improvement root cutting and fertilization can promote the growth of dominant species Leymus chinensis and is beneficial to the improvement of grassland productivity and the restoration of grassland.
【作者单位】：中国科学院内蒙古草业研究中心;内蒙古自治区农牧业科学院;内蒙古通辽市畜牧兽医科学研究所;内蒙古民族大学;内蒙古自治区农牧业厅;
【基金】：公益性行业(农业)科研专项(编号:201303060)
【分类号】：S812.4

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