施用尿素当年对退化天然草地物种地上生物量和重要值的影响

Influence of urea application on aboveground biomass and important value of the species in the degraded grassland

试验采取不同施肥梯度对内蒙古太仆寺旗地区的退化天然草地进行改良,经研究发现,不同物种对施肥梯度的反应不同。羊草在施尿素50 kg/hm2时地上生物量最大,在群落中重要值的上升也最明显;糙苏对施肥75kg/hm2反应最为敏感,在群落中重要值基本呈直线上升;星毛委陵菜在施肥100 kg/hm2时地上生物量增产最大,在群落中的重要值下降也最慢。结果表明,不同的施肥梯度可以在一定程度上控制群落的物种结构。

When different amounts of urea were applied to improve the degraded grassland, different species responded differently to the different concentrations. Fifty kg/ha of urea was the best concentration for increasing productivity and importance of Leymus chinensis in the grassland community, while 75 kg/ha was optimum for Phlomis tuberosa and 100 kg/ha for Potentilla acaulis. This shows that different concentrations of urea may be used to give some limited control of the structure of the degraded grassland plant community.