伊犁绢蒿荒漠草地春季放牧强度与放牧始期的研究

目的]以伊犁绢蒿荒漠草地为研究对象,探讨其放牧利用时的合理放牧强度及放牧始期.方法]采用随机区组试验设计,设置轻度放牧(LG)、中度放牧(MG)、重度放牧(HG)和极度放牧(EG)四个放牧强度,及4月1日、4月15日、5月1日、5月15日、6月1日5个放牧始期,利用常规测定方法对春季模拟放牧前后伊犁绢蒿种群的地上收获量、盖度、密度及高度进行测定与分析.结果]放牧前,不同放牧始期间伊犁绢蒿盖度、密度差异不显著(P＞0.05),仅在高度和地上收获量上存在差异;而不同放牧强度间仅地上收获量存在差异,盖度、密度、高度差异不显著(P＞0.05).恢复后,除极度放牧全部死亡外,伊犁绢蒿的再生高度以4月1日、4月15日恢复最好,盖度以4月15日恢复最快,而密度变化不显著;轻度放牧、中度放牧条件下伊犁绢蒿的恢复效果较重度放牧好.结论]春季4月15日前后及中等放牧条件下最有利于伊犁绢蒿荒漠草地的可持续利用.

Studies on Grazing Intensity and Beginning Period in Seri pidium transiliensis Desert Grassland in Spring

【Objective】The study of desert grassland of seripidium transiliensis was conducted to discuss the reasonable grazing intensity and grazing period of Seriphidium.【Method】Adopting randomized block design:four simulated grazing intensities,including light grazing(LG),middle grazing(MG),high grazing(HG) and extreme grazing(EG),and five beginning grazing-periods,including April 1st,April l5 th,May 1st,May 15 th and June 1st were established,the vegetation coverage,density,height and yield of S.transiliense were measured and analyed in spring by using routine method.【Result】Before grazing,there were no different significance in coverage and density of S.transiliense in different beginning grazing-period at the same grazing intensity(P>0.05),there was significant difference only among aboveground yield and height.Coverage,height and density of S.transiliense had no discrepancy among different grazing intensity at the same beginning grazing-period(P>0.05),and only aboveground yield had significant difference.After resuming,S.transiliense had all died at extreme grazing.Regrowth best of S.transiliense was between April 1st and April 15 th.Coverage of resuming was the quickest on April 15 th,density had no discrepancy(P>0.05).The resuming effect of S.transiliense at light grazing and moderate grazing area was better than that of heavy grazing area.【Conclusion】According to the routine analysis,it was the most advantageous time for sustainable utilization of desert grassland under middle grazing conditions before and after April 15 in spring.