人工柠条灌丛林下草地植物群落特征研究

以宁夏固原上黄东山封育的人工柠条(Caragana korshinskii Kom.)灌丛林下草地为研究对象,并以设置在其周围的放牧地天然草地作为对照,采用样线法进行群落调查,分析二者群落数量特征和地上生物量变化,以期为退化草地植被恢复提供理论依据。结果表明:上黄东山封育后的人工柠条灌丛林下草地群落物种数较放牧地显著增加,封育区本氏针茅(Stipa bungeana Trin.)的优势地位明显加强,重要值远大于放牧地;人工灌丛林下草地与放牧地的相似性系数为0.585,表明二者的相似程度不高,人工种植的柠条对群落的结构影响较大,能够改善草地群落的小生境,为新物种出现提供良好的环境;物种丰富度指数和多样性指数(Shannon-winner指数)均表现为人工灌丛林下草地显著高于放牧地(P<0.05),而均匀度指数则相反(P<0.01);人工柠条灌丛林下草地地上生物量鲜重极显著高于放牧地(P<0.01)。

Community Characteristics of an Artificially Planted Caragana Korshinskii Kom.Grassland

The grassland community characteristics and aboveground biomass were analyzed using line transact method based on the sampling data from the enclosed Caragana korshinskii Kom.grassland of Huangdong Mountain vs.non-enclosed grazing grassland nearby in Guyuan,Ningxia Hui Autonomous Region.The results show that the enclosure resulted in a significant increase in species quantity and the dominant status of Stipa bungeana Trin.with a higher important value in comparison with the non-enclosed grazing grassland.The similarity index between the two communities was 0.585 indicating that artificial planted C.korshinskii had effects on the community structure,improved the microhabitat of grassland,and offered a fitting environment for recruit species.The richness index and the species diversity index(Shannon-winner index)of the enclosed C.korshinskii grassland were both higher than those of the non-enclosed grazing grassland(P<0.05),but the evenness index was reversed(P<0.01).The total green aboveground biomass of the enclosed C.korshinskii grassland was higher than the non-enclosed grazing grassland(P<0.01).