Divergence of dominant factors on soil microbial communities and functions in forest ecosystems along a climatic gradient

Abstract

<p><strong>Abstract.</strong> Soil microorganisms play an important role in regulating nutrient cycling in terrestrial ecosystems. Most of the studies conducted thus far have been confined to a single forest biome or have focused on one or two controlling factors, and few have dealt with the integrated effects of climate, vegetation, and soil substrate availability on soil microbial communities and functions among different forests. In this study, we used phospholipid-derived fatty acid (PLFA) analysis to investigate soil microbial community structure, and extracellular enzymatic activities to evaluate the functional potential of soil microbes of different types of forests in three different climatic zones along the North-South transect in eastern China (NSTEC). In general, soil enzyme activities and microbial PLFAs were higher in primary forests than in secondary forests in temperate and warm temperate regions. In the subtropical region, soil enzyme activities were lower in the primary forests than in the secondary forests and microbial PLFAs did not differ significantly between primary and secondary forests. The microbial PLFAs and enzyme activities differed considerably between broadleaved and coniferous forests. Different species of coniferous trees may cause variations in soil microbial PLFAs and enzyme activities. Both climate and forest type had significant effects on soil enzyme activities and microbial communities with a considerable interactive effect. Litter nutrients made an important contribution to variations in the soil microbial communities and enzyme activities in temperate zones, while soil micro-climate and nutrients were the main controls on the soil microbial community structure and enzymatic activities in warm temperate and subtropical zones. Our results indicate that the main controls on soil microbes and functions vary across forest ecosystems in different climatic zones, and that the effects of soil moisture content, soil temperature, and the soil N/P ratio were considerable. This information will add value to modeling of microbial processes and will contribute to carbon cycling in large-scale carbon models.</p>

Analysis of spatiotemporal variations in the characteristics of soil microbial communities in Castanopsis fargesii forests

“…Studies have shown that these factors affect physicochemical properties and alter the microenvironment in which microorganisms live to modulate the activity, distribution, and community structures of microorganisms. Through these mechanisms, microbial PLFA content is altered (Hansson et al 2011;Hoogmoed et al 2014;Chen et al 2015a, b;Banerjee et al 2016;Deng et al 2016;Kang et al 2018;Xu et al 2018). Changes in 0.01-0.05 mm particle levels due to aeration and water retention also affected microbial community structure.…”