家庭牧场不同放牧方式对草甸草原植物群落的影响

草原家庭承包制的推广实施改变了传统放牧制度,变化的放牧方式对草原植被群落造成不同影响。本研究通过对比分析内蒙古陈巴尔虎旗草甸草原3种放牧方式草场植物群落组成及α多样性指数,探究不同放牧方式对植物群落结构及多样性的影响,为改进草原家庭承包制提供参考依据。研究结果表明:四季轮牧草场的植物种数最多,四季轮牧与两季轮牧草场的原生建群种重要值较大,定居放牧草场中出现了大针茅(Stipagrandis)、羊草(Leymus chinensis)及星毛委陵菜(Potentilla acaulis),且星毛委陵菜的重要值最大。四季轮牧草场植物的Shannon-wiener指数、Margalef指数、Simpson指数、Pielou指数均高于两季轮牧与定居放牧草场,且与定居放牧草场相比,Shannon-wiener指数与Margalef指数差异显著(P0.05),两季轮牧草场与定居放牧草场的4种α多样性指数均无显著差异。Shannon-wiener指数与Margalef指数、Simpson指数、Pielou指数的相关系数分别为0.9421,0.5825,0.8550(P0.01)。从群落结构及生物多样性角度考虑,四季轮牧更有利于草场群落复杂结构及生物多样性的保持。

Plant Communities Diversity of Meadow Steppe under Different Grazing Systems of Household Pasture

The promotion and implementation of Rangeland Household Contract System altered the traditional grazing system,thus,different grazing systems have various effect on plant communities diversity of grassland.In order to provide a reference for evaluating Rangeland Household Contract System,the presented research analyzed the structure of plant communities and α diversity of three different grazing systems in meadow steppe of Chenbaerhu Banner,Inner Mongolia Autonomous Region,and inquired into the influence of grazing systems on plant community structure and diversity.The result indicated that four season rotational grazing (FSRG) meadow had largest quantity of plant species,whereas the meadow of FSRG and two season rotational grazing (TSRG) enjoyed relatively big important value (ⅠⅤ) of primary dominant species.The Stipa grandis,Leymus chinensis and Potentilla acaulis occured on settled grazing (SG) meadow,in which the Potentilla acaulis had the largest important value.Shannon-wiener index,Margalef index,Simpson index and Pielou index of FSRG were all higher than that of TSRG and SG,and the difference of Shannon-wiener index and Margalef index between FSRG and SG was significant (P＜ 0.05),whereas four α-diversity indexes between TSRG and SG had no significant difference.The correlation coefficients between Shannon-wiener index and Margalef index,Simpson index,Pielou index were 0.9421,0.5825 and 0.8550,respectively.Meanwhile,Shannon-wiener index had significant positive correlation with Margalef index,Simpson index and Pielou index at the 0.01 level.In conclusion,considered from the angle of community structure and biodiversity,FSRG was a more efficient grazing system to sustain a complex plant community structure and maintain biodiversity.