论文从植被的种丰富度和功能多样性两个方面研究不同沙漠化阶段科尔沁沙地植物种多样性与沙地草场地上生物量的关系。相关分析表明,在科尔沁沙地不同沙漠化阶段,植物种多样性和沙地草场地上生物量的关系与多样性指数计算的基本单位有关。研究结果显示:①依据一年生、多年生和灌木等生活型为划分标准的功能多样性,在固定沙丘、半流动沙丘和流动沙丘阶段与沙地草场地上生物量的关系最密切,关联系数分别为-0.534、-0.574和-0.431。以豆科植物、C₃植物和C₄植物为划分标准的功能多样性,在半固定沙丘阶段与沙地草场地上生物量的关系最密切,关联系数为0.722。②在不同的沙漠化阶段,生活型多样性与地上生物量的关系呈负相关。说明在不同沙漠化程度的草场中,植物生活型组成的不均匀,有利于提高沙地草场地上生物量。③从不同生活型在各个沙漠化阶段中的种丰富度特征来看,一年生植物最高,多年生植物次之,灌木最低,平均值分别为9(±6.0)、3(±2.6)和1.8(±1.0),说明一年生植物在沙地植被组成中占主导地位。同时,研究结果表明,在不同沙漠化阶段中,以豆科植物、C₃植物和C₄植物划分的功能类型组的平均重要值以C₄植物最高,C₃植物次之,豆科最低,分别为48(±12.3)、39.7(±3.6)和12.3(±14.3),说明C₄类植物在科尔沁沙地植

This paper mainly studied the relationship of the species biodiversity and the ground biomass at different desertification stages in Horqin sandy grassland in terms of species richness and function diversity.Correlative analysis suggested that the relationship of ground biomass and plant diversity was related to the basic unit of calculated biodiversity indices.Further research drew the following conclusions:(1)the function diversity,based on the life form classification of annuals,perennials and shrubs,had a close relationship with ground biomass at the fixed dune,semi-fixed dune and mobile dune stages.The correlative coefficients were-0.534,-0.574,and-0.431respectively.Functional diversity,based on the classification of legume,C₃ and C₄ plant species,had a good correlativity with the ground biomass at semi-fixed dune stage and the correlative coefficient was0.722.(2)The life form diversity had a negative relationship with ground biomass at the different desertification stages,which indicated that the lower evenness of life form composition of sandy land vegetation should increase ground biomass.(3)According to the species richness change traits of the different life form categories at the different desertification stages,the annuals had highest occupation frequency,perennials and shrubs in turn and the richness reached to9(±6.0),3(±2.6)and1.8(±1.0)respectively.Meanwhile,the average important values of life form showed that C₄ plant had the best fitness among C₄ ,C₃ and legume plant and the value were48(±12.3),39.7(±3.6)and12.3(±14.3)respectively.