Warming threatens the microbial communities in middle-high latitude peatland: Evidence from testate amoebae

Abstract

Testate amoebae contribute significantly to belowground ecological processes like nutrient cycling, but a decline in their nutrient cycling functions in peatlands is expected due to global climate warming. We studied the dynamics of testate amoebae communities in relation to soil environmental variables in a permafrost peatland that experienced in situ experimental warming for a 7-yr period. Experimental warming reduced testate amoebae biomass by 41%. Redundancy analyses showed that testate amoebae community structure was correlated with water table depth and soil temperature (these explained 10% of the variance in community structure) and dissolved organic carbon (which explained 2.2% of the variance). Our results demonstrated that warming-induced changes to the water table depth affected the testate amoebae community in peatland, which could have consequences for the stability of the microbial food web and carbon cycling in peatland ecosystems.