乌兰布和沙漠沙蒿与油蒿群落的物种组成与数量特征

Quantitative characteristics and species composition of Artemisia sphaerocephala and A. ordosica communities in the Ulanbuh Desert

沙蒿与油蒿群落均是我国最典型的沙地植被类型,在沙漠地区发挥了重要的生态防护作用,掌握其分布、组成及其数量特征对沙漠化防治具有一定的指导作用。调查研究表明,沙蒿与油蒿群落是乌兰布和沙漠典型的沙地植被类型,其中沙蒿群落多分布于沙漠中东部、南部和东北部,而油蒿群落仅分布于沙漠东部、东北部和东南部;其群落类型可划分为沙蒿群落、油蒿群落、沙蒿+油蒿群落、沙蒿+沙竹群落、沙蒿+花棒+沙拐枣群落、油蒿+白刺群落、沙蒿伴生群落和油蒿伴生群落;群落的物种组成比较简单,其中沙蒿群落共有9科21属22种,油蒿群落共有10科35属37种。草本植物是沙蒿与油蒿群落的主体,所占总物种数的比例均超过70%;Simpson、Shannon多样性指数和Pielou均匀度指数高,反映了沙蒿与油蒿群落具有较高的物种多样性。与沙蒿群落相比,油蒿群落物种丰富度、单位面积个体数、盖度、Simpson和Shannon物种多样性指数均明显大于沙蒿群落,而群落相似性显著低于沙蒿,说明乌兰布和沙漠油蒿群落较沙蒿群落具有更丰富的物种组成、多样性和群落结构,更具保护和人工促进潜力。研究结果可为乌兰布和沙漠沙蒿、油蒿群落的保护及人工促进提供理论基础,对区域沙漠治理物种选择具有一定的指导意义。

Artemisia sphaerocephala and A. ordosica communities are all typical vegetation types which play an important ecological protection role in desert areas. Understanding their distribution, species composition and quantitative characteristics is conducive to desertification control. Research results showed that A. sphaerocephala and A. ordosica communities were typical desert vegetation widely distributed in the Ulanbuh Desert, A. sphaerocephala communities were mainly distributed in the central east, northeast and south of the Ulanbuh desert, while A. ordosica communities only distributed in the east, northeast and southeast of the Ulanbuh Desert. Both A. sphaerocephala and A. ordosica communities in the Ulanbuh Desert can be classified into eight types of communities： A. sphaerocephala, A. ordosica, A. sphaerocephala-A. ordosica, A. sphaerocephala-Psammochloa villosa, A. ordosica-Nitraria spp., A.sphaerocephala-Hedysarum scoparium-Calligonum mongolicunl, A. sphaerocephala and A. ordosica concomitant communities. Species composition of A. sphaerocephala and A. ordosica communities was relatively simple. A. sphaerocephala communities consist of 22 species belonging to 9 families of 21 genera; and A. ordosica communities comprise 37 species belonging to 10 families of 35 genera. A. sphaerocephala and A. ordosica communities mainly are dominated by herbs which accounted for more than 70% of total species number. The Simpson and Shannon diversity and Pielou eveness index of A. sphaerocephala and A. ordosica communities were large, which means larger species diversity. The species richness, individual number per unit area, coverage, the Simpson and Shannon diversity index of A. ordosica communities were obviously larger than those of A. sphaerocephala communities, while its community similarity was significantly lower than that of A. sphaerocephala, which indicated that A. ordosica communities had a more abundant species composition, diversity and community structure, and was worthy of protection and artificial construction. These findings may provide an important theoretical basis for the protection and artificial construction of A. sphaerocephala and A. ordosica communities, and help to the species selection in regional desert control.