Abstract:

The influences of different enclosure years on the grassland community characteristics, species diversity and pasture mass index of Seriphidium transiliense desert grassland were studied. The results showed that the total coverage, density and biomass of S.transiliense desert grassland presented the fluctuation of down-up-down with the increase of enclosure period, and reached the highest values after being enclosed for six years. Fenced enclosure was conducive to S.transiliense, Kochia prostrate growth and recovery, and the biomasses of both respectively increased by 158.63%~221.44%, 100% compared with the control area. The important values of S.transiliense returned to the top. The species diversity index of community increased first and then decreased and further increased with the increase of enclosure time compared with the control area. The analyses indicated that the desert grassland of S.transiliense did not yet returned to the state of original top after enclosure for 9 years. It was preliminarily speculated that the five years of enclosure was the best time for the S.transiliense desert grassland considering the productivity and economic benefit of grassland in this region.

Key words: Seriphidium transiliense desert, Important values, Species diversity index, Pasture mass index

摘要：

以伊犁绢蒿(Seriphidium transiliense)荒漠草地为对象,研究不同封育年限对伊犁绢蒿荒漠草地植被群落特征、物种多样性及草场质量指数的影响.结果表明:伊犁绢蒿荒漠草地总盖度、密度及生物量,随封育时间的增加呈先降后升再降的波动变化,且以封育6年达到最高;围栏封育有利于伊犁绢蒿、木地肤(Kochia prostrata)的生长与恢复,生物量较对照区分别提高了158.63%~221.44%,100%,且封育9年时伊犁绢蒿重要值恢复到首位;封育后群落的物种多样性指数较对照区均有增加,且随封育年限的增加呈现先增后减再增趋势;通过群落物种多样性分析认为,封育9年后伊犁绢蒿荒漠草地尚未恢复到原始顶级状态;以草地的生产力与经济效益来考虑,初步推测封育5年为该区域伊犁绢蒿荒漠草地的最佳围栏时间.

关键词: 伊犁绢蒿荒漠, 重要值, 物种多样性, 草场质量指数