玛曲退化草地主要植被特征对不同施肥处理的响应

Response of the degraded grassland vegetation characteristics to different fertilizer treatments at Maqu County

为探索甘肃玛曲县退化草地的科学恢复途径,通过小区施肥试验,研究不同施肥处理对玛曲高寒退化草地植被性状的影响.结果表明,施氮磷肥可以显著提高退化草地植被的平均高度,是最佳的施肥处理;施有机肥加氮磷肥可以显著提高莎草类植被的高度,施氮磷肥可以显著提高禾草类和豆科类植物的高度,施肥对杂类草高度无显著影响.施氮磷肥可以显著提高退化草地的地上生物量,是最佳的施肥处理;而施有机肥加磷肥可以显著提高莎草类和豆科类地上生物量,施氮磷肥可以显著提高禾草类植物的地上生物量,施肥对杂类草地上生物量无显著影响.单施氮肥或有机肥可以增加退化草地的多样性指数,单施有机肥的草地物种多样性指数最高,施有机肥加氮肥的草地物种多样性指数最低.

To explore the scientific restoration way of degraded grassland, the effect of fertilizer on vegetation characters of degraded alpine grassland at Maqu County, Gansu Province, was researched. The results showed that 1） mixed application of nitrogen with phosphorus fertilizer significantly improved the vegetation average height of degraded grassland, and regarded as the best treatment. Organic manure added with nitrogen and phosphorus fertilizer significantly increased the height of cypress-grass vegetation. Mixed application of nitrogen with phosphorus fertilizer significantly improved the height of both grass vegetation and leguminous plants. However, fertilizer had no significant effects on the height of weeds. 2）Mixed application of nitrogen with phosphorus fertilizer, as the best treatment, significantly improved the aboveground biomass of the grassland. Organic manure added with phosphorus fertilizer significantly improved the aboveground biomass of both cypress-grass vegetation and leguminous plants. Mixed application of nitrogen with phosphorus fertilizer signilicantly improved the aboveground biomass of grasses.However, fertilizer had no significant effects on the aboveground biomass of weeds. 3） Single application of nitrogen fertilizer or organic manure increased the species diversity indexes of degraded grassland, the maximum species diversity index of grassland occurred in case of applying organic manure, and the minimum species diversity index was obtained in those sample plots applied organic manure added with nitrogen fertilizer.