中国两个气候过渡区森林土壤线虫群落的比较研究

Differences in Soil Nematode Community Structure between an Evergreen Broad-leaved Forest and a Deciduous Broad-leaved Forest of China

摘要:

为比较不同气候过渡区地带性森林土壤线虫群落结构和多样性,以南亚热带向中亚热带气候过渡区的石门台常绿阔叶林和北亚热带向暖温带气候过渡区的鸡公山落叶阔叶林为样地,探讨不同气候区土壤微食物网能流方式的差异。结果表明,石门台土壤线虫群落属数(S)、生物量(Biomass)、多样性指数(H')、丰富度指数(SR)、成熟度指数(MI)和结构指数(SI)在表层土壤(0~10 cm)均显著高于鸡公山。石门台的土壤线虫通路指数(NCR)均值高于0.5,而鸡公山的NCR均值小于0.5,说明前者土壤食物网可能偏向于细菌能流通道,而后者偏向于真菌能流通道,这也与食细菌线虫、食真菌线虫生物量的计算结果一致。可见线虫群落结构确实存在明显的南北差异,并较好地指示了土壤能流和养分循环状况。

Abstract:

Nematode abundance, diversity and functional indices were investigated at a subtropical evergreen broad-leaved forest in southern China and a temperate deciduous broad-leaved forest in central China to illustrate the effects of climate and vegetation on energy pathways and nematode diversity in soil food webs. The results showed that the biomass, indexes of MI, SI, PPI, H' and SR at 0-10 cm soil depth, and SI index at 10-20 cm soil depth in southern China were greater than those in central China. Besides, the NCR index was greater than 0.5 at a subtropical evergreen broad-leaved forest in southern China, but it was less than 0.5 at a temperate deciduous broad-leaved forest in central China, indicating that bacterial energy channel dominated in the former forest ecosystem and the fungal energy channel dominated in the latter. Overall, there was a difference in nematode community between two forest ecosystems, and nematodes could be used as bio-indicators for soil nutrient status and energy channel pathway.