刈割对四川嵩草（Kobresia setchwanensis）高寒草甸植物生物量和氮含量的影响

研究了生长季内刈割频次和时间对四川嵩草(Kobresia setchwanensis)草甸植物全年积累的生物量及其氮素特征的影响.结果表明,在生长季内刈割2次(6和7月份每月1次)或3次(6、7和8月份每月1次)比不刈割(仅在生长季末收获现存生物量)显著降低了植物地上和地下积累的生物量,但生长季内多次刈割能增加植物地上部分氮含量和贮量.与不刈割相比,生长季内不论在6、7或8月份刈割1次有利于获得较高的植物地上生物量和氮贮量,而且在8月份刈割1次是所有刈割处理中全年地上积累生物量及氮贮量最高的处理.除6月份刈割1次植物地下生物量及氮贮量显著小于不刈割外,7或8月份刈割1次与不刈割之间差异不显著.由此可见,生长季内多次刈割不利于四川嵩草草甸植物生物量及氮的积累,而在8月份进行1次刈割可获得全年最大的地上积累生物量及氮贮量.

Effects of Clipping on Biomass and Nitrogen of Kobresia setchwanensis Alpine Meadow

A study was conducted to investigate the responses of biomass and nitrogen of Kobresia setchwanensis alpine meadow to different clipping frequency and date in one growth season from June to August. Two or three clippings in growth season significantly decreased the above and below accumulated biomass of the whole year, but these two clipping treatment resulted in a considerable increase in the concentration and content of nitrogen in above biomass. One clipping in growth season, whether in June, July or August, was benefit to the accumulation of biomass and its nitrogen storage. Above accumulated biomass and nitrogen content was highest with one clipping in August among all of the clipping treatments. Below biomass and nitrogen content was significantly higher under one clipping in June compared to no clipping, but it was not significant different between one clipping in July or August and no clipping. Thus, several clippings in one growth season locked the accumulation of biomass and nitrogen of Kobresia setchwanensis alpine meadow. The most accumulated biomass and nitrogen content could be obtained with one clipping in August.