水肥耦合对科尔沁羊草割草场植物群落多样性和生产力的影响

Effect of Water and Fertilizer on Plant Community Diversity and Productivity in Leymus chinensis Mowing Meadow in Horqin

采用随机区组设计,探讨了不同时间及水肥耦合用量对科尔沁羊草(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。结果表明:在5月30日和6月15日时,加水量15 mm加尿素150 kg/hm^2(15N)的水肥耦合组合群落高度、盖度、密度和地上生物量较对照显著增加,其中,地上生物量是对照的2倍多;水肥耦合降低了物种多样性指数,5月15日的15N处理使得群落Margalef丰富度指数、Shannon-wiener多样性指数和Simpson指数显著降低(P<0.05)。在科尔沁沙质羊草割草场进行草地改良,最佳的实施时间应该在5月30日以后,15N可作为优先水肥耦合组合来推荐。

An experiment of randomized block design was conducted to study the effects of different application time and amount of water and fertilizer on community characteristics, productivity and species diversity of Leymus chinensis mowing pasture in Horqin. The results showed that the community height,coverage, density and aboveground biomass significantly increased in the treatment of water 15 mm and urea 150 kg/hm^2（treatment 15N） on May 30 and June 15, and the aboveground biomass doubled that of control.Water and fertilizer coupling decreased plant species diversity, and the community Margalef diversity index,Shannon-wiener diversity index and Simpson dominance index significantly decreased in treatment 15N on May 15（P〈0.05）. In conclusion, the optimal improvement time is after May 30, and the best treatment is 15N.