食细菌线虫对热或铜胁迫下土壤功能稳定性的影响

Effects of bacterial-feeding nematodes on soil functional stability under heat or copper stress

在室内模拟重金属铜的持续胁迫或者短期加热(18 h,40℃)的瞬时胁迫条件下,以大麦叶粉短期分解过程代表土壤功能,研究了土壤食细菌线虫对土壤生态功能稳定性(抗性和恢复力)的影响。结果表明,在未施加任何胁迫对照处理中和铜胁迫条件下,食细菌线虫在一定程度上有促进土壤微生物活性的趋势。在施加铜胁迫后第15天,接种食细菌线虫导致土壤基础呼吸显著增加,并且接种食细菌线虫处理的土壤功能抗性显著高于未接种线虫处理。而在热胁迫条件下,接种食细菌线虫对土壤基础呼吸和土壤微生物活性没有显著影响,且接种食细菌线虫处理的土壤功能抗性低于未接种线虫处理。在两种胁迫条件下,接种食细菌线虫反而降低了土壤功能的恢复力。

A microcosm experiment was conducted to study the effects of inoculating bacterial-feeding nematodes on the soil ecological functional stability under persistent Cu2＋ stress or transient heating stress （40 ℃ for 18 h）, with the shortterm decomposition of barley leaf power as the representative of soil function. In the treatments without any stress （blank control） and with Cu2＋ stress, soil bacterialfeeding nematodes could promote soil microbial activities to some extent. On the 15th day of Cu2＋ stress, the soil basal respiration in nematodesinoculated treatments increased significantly, and the soil functional resistance was significantly higher than that in the treatments without nematodes inoculated. However, under heating stress, inoculating bacterialfeeding nematodes had less effect on the soil basal respiration and microbial activities, and the soil functional resistance was lower than that in treatments without nematodes inoculation. It was suggested that under the two stresses, inoculating bacterial-feeding nematodes could decrease soil functional resilience.