Response of Microbial Communities and Their Metabolic Functions to Drying–Rewetting Stress in a Temperate Forest Soil

Abstract

Global climate change is predicted to alter drought–precipitation patterns, which will likely affect soil microbial communities and their functions, ultimately shifting microbially-mediated biogeochemical cycles. The present study aims to investigate the simultaneous variation of microbial community compositions and functions in response to drought and following rewetting events, using a soil metaproteomics approach. For this, an established field experiment located in an Austrian forest with two levels (moderate and severe stress) of precipitation manipulation was evaluated. The results showed that fungi were more strongly influenced by drying and rewetting (DRW) than bacteria, and that there was a drastic shift in the fungal community towards a more Ascomycota-dominated community. In terms of functional responses, a larger number of proteins and a higher functional diversity were observed in both moderate and severe DRW treatments compared to the control. Furthermore, in both DRW treatments a rise in proteins assigned to “translation, ribosomal structure, and biogenesis” and “protein synthesis” suggests a boost in microbial cell growth after rewetting. We also found that the changes within intracellular functions were associated to specific phyla, indicating that responses of microbial communities to DRW primarily shifted microbial functions. Microbial communities seem to respond to different levels of DRW stress by changing their functional potential, which may feed back to biogeochemical cycles.

Higher tree diversity increases soil microbial resistance to drought

“…In the literature, the effects of DRW on DOC and TDN soil concentrations and their potential leaching from the ecosystem are not clear. Previous studies have found an increase in DOC and TDN with DRW cycles 15,46 , no effect 8,46 , or a short-term change but no net effect 47,48 . This discrepancy appears linked to soil type, habitat, and/or drought frequency 15,46 and intensity 44 .…”

“…Aerobic respiration seven days following rewetting was much higher than control values, but this was less pronounced in the second cycle. This, along with the stronger aerobic respiration decline following the second drought, could indicate the microbial mortality and/or a shift in the microbial community composition or physiological strategies 8 to stress-avoidance through declined activity during stress 9 . Since denitrification rates returned to pre-stress levels after rewetting, there was no indication of a loss in the denitrification taxa group during drought, instead the microorganisms appear tolerant to very low soil water potential through decreased activity or accumulation of protective molecules 7 .…”

“…In order to understand how increasing drought affects ecosystems, it is imperative to understand how soil microbial communities respond to climate change-induced shifts in soil moisture dynamics, due to their critical role in ecosystem functioning 5 , 6 . Although soil microbial communities are regularly exposed to drying-rewetting (DRW) cycles in most ecosystem types 7 , increasing drought duration and DRW cycle frequency may induce shifts in microbial community composition, biomass, and activity 8 – 10 , ultimately affecting biogeochemical cycling rates 7 , 11 . Changes in biogeochemical cycling have major impacts on soil carbon dynamics 12 , nutrient availability 5 , greenhouse gas fluxes between soils and the atmosphere 13 , and water soluble compounds leaching from the system 14 , 15 .…”

Bacterial Community Changes Associated with Land Use Type in the Forest Montane Region of Northeast China

“…The microbial communities of soils dominate biogeochemical cycling, while playing key roles in natural ecosystems [1][2][3][4]. Soil microorganisms provide the impetus for the transformation and recycling of soil resident organic matter and elemental nutrients, such as C and N [5,6].…”

Enhanced biotreatability of petroleum hydrocarbon–contaminated mining waste coupled with the attenuation of acid drainage production

“…To stimulate biodegradation at contaminated sites, N and P amounts required are typically estimated as C/N/P ratios. Additionally, the concentration of oxygen (Abbasian et al, 2015;CCME, 2010;Meckenstock et al, 2016;Widdel & Rabus, 2001) and the availability of water for microbial growth and metabolism (Engelhardt et al, 2018;Liu et al, 2019) have been identified as predominant factors influencing biodegradation rates of PHC in the environment. Although bioremediation is a common means of treating PHC-contaminated soils, this approach has not been well demonstrated in contaminated soils from mining sites that include mine wastes and residues, despite the fact that the use of diesel as a major energy source at mining sites generally results in PHC contamination via accidental release due to equipment malfunction, maintenance, leaks, or fuel transfer spills.…”