Environmental Sensitivity of Soil Microbial Communities is Altered in Association with Plant Roots in Saltmarsh Ecosystems

Steven E. Travis^1,*, Matt R. Simon^1,2, and Gregory P. Zogg¹

¹School of Biological Sciences, University of New England, 11 Hills Beach Road, Biddeford, ME 04005. ²Current address - Science Program, Lakes Regions Community College, Laconia, NH 03246. *Corresponding author.

Northeastern Naturalist, Volume 31, Issue 2 (2024): 146–162

First published early online: 28 May 2024

Abstract
The intimate associations between plants and microbes that develop in rhizosphere soils may alter the sensitivity of bacterial communities to environmental filters during the process of community assembly. We compared the sensitivity of rhizosphere and bulk soil communities to ecological variables in several New England salt marshes dominated by Spartina alterniflora (Smooth Cordgrass), characterizing community variation based on linear combinations of 16S rDNA fragments representing bacterial taxonomic units. Rhizosphere microbes showed significantly greater sensitivity to plant biomass and pH, perhaps because of their relationships with the quality of plant exudates and availability of nutrients, respectively, while bulk microbes showed significantly greater sensitivity to elevation and redox potential, perhaps through waterlogging and an absence of plants oxygenating the soil.

Download Full-text pdf (Accessible only to subscribers. To subscribe click here.)