三峡消落带土壤古菌群落组成与代谢功能预测

Community Composition and Predicted Metabolic Function of Soil Archaea in Water Level Fluctuation Zone of the Three Gorges Reservoir

三峡消落带是受人为干扰影响而周期性水淹的一类特殊生境,微生物是消落带生态系统的重要组成部分。然而,消落带土壤中微生物群落组成与潜在代谢功能的相互联系还缺乏认识。本研究通过采集不同高程消落带土壤样品,结合古菌16S rRNA基因高通量测序和群落水平的代谢功能预测,分析消落带土壤古菌群落组成和代谢功能的变化特征与影响因子。结果表明,消落带古菌群落组成和代谢功能均表现出沿高程梯度的空间分异。其中古菌群落组成主要受土壤中氨氮、总氮和含水率的影响,而代谢功能的变化主要由含水率、有机质和总碳驱动,含水率是同时影响群落组成与代谢功能变化的关键因子。消落带各个高程淹水时间的不同可能是造成这种空间分异的主要因素,进一步导致三峡消落带土壤氮碳循环在不同高程上的功能分异。

The water level fluctuation zone(WLFZ)of the Three Gorges Reservior is a special ecosystem.It is af?fected by both water flooding and human disturbances,with microorganisms as its key component.However,knowledge about the interassociation of archaeal community composition and potential metabolic function in the WLFZ soil is limited.This study collected soil samples at different elevations,combined 16S rRNA gene highthroughput sequencing and community-level metabolic prediction to investigate the variation and influencing factors of soil archaeal community composition and predicted metabolic function,which showed spatial distribu?tion along the sampling elevations.Soil NH4+,total N and moisture were the most influential factors in archaeal community composition,whereas the variation of metabolic function was mainly driven by soil moisture,organic matter and total C.Soil moisture was considered as key factor that affected both variations of community compo?sitions and metabolic functions.This may be associated with the different flooding time at each elevation.The obvious spatial distinction of archaeal community and different functional potential would lead to spatial patterns of carbon and nitrogen cycles along the WLFZ of the Three Gorges Reservoir.