羊草基因型数目对地下动物及微生物群落的影响

Effects of genotypic diversity of Leymus chinensis population on soil macrofauna and microorganism community

群落建群种的基因型多样性是否具有与物种多样性类似的生态功能已经成为种群生态学非常关注的问题,研究结果能够为种群或群落的保护和恢复提供理论指导。基于已构建并施加不同强度干扰(无刈割、留茬10 cm和留茬5 cm)的不同基因型组合(1-、3-、6-基因型)的羊草种群,本研究采集其地下部土壤研究羊草基因型数目及干扰对地下动物群落和微生物群落的影响。结果表明:(1)羊草基因型数目和干扰强度的交互作用对土壤动物的种类、数量的影响显著(P<0.05)。(2)在留茬10 cm处理组中,土壤动物的数量与羊草种群基因型数目呈显著的正相关关系(P<0.05),符合"资源化假说"。(3)在无刈割处理组中,羊草的基因型数目对根际土壤中微生物群落的组成和结构具有显著的影响(P<0.05)。

Whether genotypic diversity within a dominant species plays a pronounced role in com- munity and ecosystem processes similar to species diversity is a hot research topic in population ecology. Such studies will benefit the conservation and restoration of population or community. We collected soils from the previously established Leymus chinensis populations of different genotype combinations （1-, 3-, 6-genotype） under different interference intensities （no mowing, lO-cm stubble and 5-cm stubble）, to study the effects of genotypic diversity of L. chinensis population and the interferences on community composition and structure of soil macrofauna and phospholi- pid fatty acid （PLFA） biomarkers of soil microorganisms. The results showed that the interaction of genotypic diversity and disturbance intensity significantly impacted the amounts of groups and individuals of soil animals （P〈0.05）. Under 10-cm stubble condition, there was a significant positive correlation between the amounts of soil animal individuals and the number of L. chinensis genotype （P〈0.05）, which supported partly the ＂resource specialization hypothesis＂. The effects of genotypic diversity on soil microbial community composition and structure were significant un- der no mowing condition （P〈0.05）.