内蒙古典型草原建群种羊草基因型多样性抑制群落物种多样性的生态功能

Genotypic diversity of a dominant species Leymus chinensis inhibited ecological function of species diversity in the Inner Mongolia Steppe

植物群落的物种多样性以及群落建群种的基因型多样性对群落生态功能是否存在交互影响已成为群落生态学研究的热点内容。以内蒙古典型草原群落内常见物种为研究对象,研究了群落物种多样性与建群种羊草(Leymus chinensis)基因型多样性及其交互作用对群落生物量生态功能特性的影响。结果表明:(1)羊草基因型多样性、物种多样性及其交互作用对群落地上、地下和总生物量无显著影响(P>0.05);(2)羊草基因型多样性、物种多样性及其交互作用对多样性效应(净多样性效应、互补效应和选择效应)有显著影响(P<0.05)。羊草基因型多样性抑制多样性净效应的发挥,且主要抑制互补效应;而物种多样性则促进多样性净效应的发挥,主要表现为选择效应对地上生物量的正效应;(3)互补效应对群落生物量多样性净效应起主要贡献。实验所得结果不仅为探讨多样性效应在物种水平以及群落水平上对群落生物量的影响因素提供了重要启示,而且为内蒙古草原种质资源的保护及合理利用,乃至生态系统的恢复和重建提供理论指导。

Community ecologists have focused on whether there exists an interactive effect between species diversity and genotypic diversity of dominant species on community ecological function in recent years. In the present study, we selected some common species in the Inner Mongolia Steppe as study objects, and examined how the genotypic diversity of the dominant species, the species diversity of common species and their interactions influenced the community biomass.(1) Genotypic diversity of Leymus chinensis, species diversity, and their interactions did not significantly influence the community aboveground, belowground, or total biomass (P > 0.05).(2) The genotypic diversity of L. chinensis, species diversity, and their interactions significantly influenced diversity effects (net diversity effect, complementarity effect, and selection effect) on community biomass (P < 0.05). The genotypic diversity of L. chinensis inhibited the net diversity effect, mainly complementarity effect. However, species diversity promoted the net diversity effect, in particular, selection effect on aboveground biomass.(3) The net diversity effect on ecological function of the community biomass was mainly due to complementarity effect. The above results provided not only an important message for exploring whether species diversity or genotypic diversity of dominant species plays a more important role in influencing the diversity effect on community biomass, but also proper guides for protection and rational utilization of seed resources, and moreover, for the ecosystem recovery and re-establishment in the Inner Mongolia Steppe.