短期休牧对昭苏草甸草原植被特征及多样性的影响

Influences of Short-term Grazing Exclusion on Vegetation Characteristics and Diversity of Zhaosu Meadow Steppe

【目的】研究秋季短期休牧对昭苏草原的影响,探讨适宜的休牧时间。【方法】采用控制放牧试验及野外常规取样技术,对不同时期(9月,10月)短期休牧(30 d)下昭苏草甸草原植被群落特征、多样性、主要种群特征进行测定。【结果】与对照比,休牧后草地植被群落高度、盖度、密度、生物量、Simpson指数、Shannonwiener多样性指数、Margalef物种丰富度指数均出现不同幅度的增加,且9月休牧仅在生物量上增加显著,而10月休牧均增加显著(P<0.05);休牧后黄花苜蓿、无芒雀麦、野草莓、委陵菜等适口性好的优良牧草重要值呈现增加,而当前主要优势种草原苔草、亚洲百里香重要值呈下降趋势。【结论】休牧有利于昭苏草甸草原植被的恢复,秋季休牧在10月进行效果较好。

[ Objective] In order to explore an appropriate grazing exclusion period in autumn, the influ- ences of short - term grazing exclusion on Zhaosu meadow steppe is studied. [ Method ] The vegetation commu- nity characteristics, diversity and the main population characteristic of Zhaosu meadow steppe under short - period grazing exclusion （30 d） at different period （September, October） was measured by grazing experi- ment plot method and conventional sampling techniqe in field. [ Result] Compare with CK, height, coverage, density, biomass, Simpson index, Shannon - wiener diversity index, Margalef species richness index of vege- tation community were increased to different degrees after short period grazing exclusion, and biomass was only significantly increased in September, but all the indices were significantly increased in October（P 〈0.05 ）. The important value of falcata, Bromus inermis, Fragaria vesca, Potentilla etc. were increased which showed fine patability, at the same time that of Carex liparocarpos and Thymus usiticus, the current do- iminat species, are declined after grazing exclusion. [ Conclusion] Grazing exclusion was beneficial for recove- ring of the vegetation on Zhaosu meadow steppe and October is the ideal period for grazing exclusion.