Multiple Climate Change Factors Interact to Alter Soil Microbial Community Structure in an Old‐Field Ecosystem

Abstract

Climate change hai the potential to alter both the composition and function of a soil's microbial communit), and interactions among climate change factors may alter soil communities in ways that are not possible to predict from experiments based on a single factor. This study evaluated the direct and interactive effects ot three climate change factors-elevated CO,, altered amounts of precipitation, and elevated air temperature-on soil microbial communities from an old-field climate change experiment being conducted at Oak Ridge, TN. Soil microbial community composition and biomass were determined by phospholipid fatty acid (PLFA) and neutral lipid fatty acid compsition.We found that the interactive effects of precipitation and temperature treatments, as well as the interactive effects ot precipitation and COj treatments, had significant impacts on microbial community compsition. We found that total soil PLFA concentration, a measure of microbial biomass, was greater in the low-precipitadon treatments, especially when low precipitation was combined with ambient COj concentrations or ambient temperature. Ordination analysis indicated that temperature was the most significant predictor of shifts in the soil microbial communit)' composition, explaining approximately 12% of the variance in relative abundance of PLFA biomarkers. The elevated-tempetature treatment increa.sed the abundance of Firmkutes (low-guanine-cytosine Gram positive) and decreased the abundance of Gram-negative bacteria. Elevated temperature also reduced the abundance of the arbusctilar mycorrhizal limgi PLFA biomarker 16:15)5c and saprophytic fungal PLFA biomarker 18:2Sé,9. Overall, our data indicate diat the interactions among climate change faaors alter the composition ofsoil microbial communities in old-field ecosystems, suggesting potential for changes in microbial community function under predicted future climate conditions.

Plant genetic effects on soils under climate change

“…Soil biota across a diversity of ecosystems are often sensitive to global change factors including changes in temperature, precipitation and elevated atmospheric CO 2 concentrations (e.g., Antoninka et al 2009;Castro et al 2010;Gray et al 2011). Recent evidence indicates that tolerance or acclimation is possible for soil bacteria and widespread groups of fungi in response to changes in temperature and soil moisture (Evans and Wallenstein 2012;Crowther and Bradford 2013).…”

Tallgrass prairie soil fungal communities are resilient to climate change

“…Variability in soil moisture may shift biomass or ratios of fungi and bacteria within a growing season (Clark et al 2009;Gray et al 2011;Cregger et al 2012;Baldrian et al 2013), in response to pulse events Zeglin et al 2013), or in response to experimental manipulations of soil moisture (Nazih et al 2001;Cregger et al 2012;Zeglin et al 2013). Some recent studies have suggested that soil fungal communities are highly responsive to changes in soil moisture within and across years (Hawkes et al 2011).…”

PLFA Profiling of Microbial Community Structure Influencing Ecosystem Restoration in Chronosequence Iron Mine Overburden Spoil

“…Soil moisture content exhibited positive correlation with F:B ratio (r = 0.784, p  0.001), which can account 61.48% of the variability in F:B ratio across the sites (Figure 3b). The changes in moisture content can alter microbial community composition and function due to differences in drought tolerance among taxonomic and functional groups of soil microorganisms [98][99]. Further, principal component analysis was performed in order to discriminate seven different age series iron mine overburden spoil and nearby NF soil based on the relative distribution of 75 PLFAs across the sites ( Figure 5) [100].…”