Drought Legacy Effects on the Composition of Soil Fungal and Prokaryote Communities

Abstract

It is increasingly acknowledged that climate change is influencing terrestrial ecosystems by increased drought and rainfall intensities. Soil microbes are key drivers of many processes in terrestrial systems and rely on water in soil pores to fulfill their life cycles and functions. However, little is known on how drought and rainfall fluctuations, which affect the composition and structure of microbial communities, persist once original moisture conditions have been restored. Here, we study how simulated short-term drying and re-wetting events shape the community composition of soil fungi and prokaryotes. In a mesocosm experiment, soil was exposed to an extreme drought, then re-wetted to optimal moisture (50% WHC, water holding capacity) or to saturation level (100% WHC). Composition, community structure and diversity of microbes were measured by sequencing ITS and 16S rRNA gene amplicons 3 weeks after original moisture content had been restored. Drying and extreme re-wetting decreased richness of microbial communities, but not evenness. Abundance changes were observed in only 8% of prokaryote OTUs, and 25% of fungal OTUs, whereas all other OTUs did not differ between drying and re-wetting treatments. Two specific legacy response groups (LRGs) were observed for both prokaryotes and fungi. OTUs belonging to the first LRG decreased in relative abundance in soil with a history of drought, whereas OTUs that increased in soil with a history of drought formed a second LRG. These microbial responses were spread among different phyla. Drought appeared to be more important for the microbial community composition than the following extreme re-wetting. 16S profiles were correlated with both inorganic N concentration and basal respiration and ITS profiles correlated with fungal biomass. We conclude that a drying and/or an extreme re-wetting history can persist in soil microbial communities via specific response groups composed of members with broad phylogenetic origins, with possible functional consequences on soil processes and plant species. As a large fraction of OTUs responding to drying and re-wetting belonged to the rare biosphere, our results suggest that low abundant microbial species are potentially important for ecosystem responses to extreme weather events.

Arabitol, mannitol, and glucose as tracers of primary biogenic organic aerosol: the influence of environmental factors on ambient air concentrations and spatial distribution over France

“…Alternatively, the vegetation leaves have also been suggested as sources of atmospheric SCs (Bozzetti et al, 2016;Golly et al, 2018;Jia et al, 2010;Myriokefalitakis et al, 2017;Pashynska et al, 2002;Sullivan et al, 2011;Verma et al, 2018;Wan et al, 2019). In fact, vascular plant leaf surfaces is an important habitat for endophytic and epiphytic microbial communities (Kembel and Mueller, 2014;Lindow and Brandl, 2003;Lymperopoulou et al, 2016;Mhuireach et al, 2016;Whipps et al, 2008). Our results are more in agreement with a dominant atmosphere entrance process closely linked to vegetation, which is more homogeneous than topsoil at the climatic regional scale.…”

“…These results highlight that ambient air temperature and humidity are key meteorological drivers of the annual variation cycles of polyol and glucose concentrations. Hot and dry ambient air conditions may decrease the metabolic activity of the microorganisms (e.g., microbial growth and sporulation) (Fang et al, 2018;Liang et al, 2013;Meisner et al, 2018). Finally, maximum ambient concentration levels for both SC and cellulose are observed in excellent temporal agreement with the harvest periods (late summer) at the OPE-ANDRA site (Fig.…”

“…The authors attributed such a spatial pattern to the differences in vegetation types and microbial diversity over distinct geographical regions. Accordingly, the vegetation struc-ture and composition have previously been shown to play essential roles on airborne microbial variabilities in nearby areas (Bowers et al, 2011;Laforest-Lapointe et al, 2017;Lymperopoulou et al, 2016;Mhuireach et al, 2016).…”

Drought and its legacy modulate the post‐fire recovery of soil functionality and microbial community structure in a Mediterranean shrubland

“…Previous studies in unburned soils also found legacy effects of short‐ or long‐lasting drought on microbial biomass, activity, and community structure (Evans & Wallenstein, : De Vries, Liiri, Bjørnlund, Bowker et al, ; De Vries, Liiri, Bjørnlund, Setälä et al, ; Martiny et al, ; Meisner, Jacquiod, Snoek, Hooven, & Putten, ; Legay et al, ). On the other hand, Rousk et al () reported no legacy effects of long‐term experimental summer drought on microbial community size, composition, growth rates, or respiration rates.…”

Reducing Emissions From Degraded Floodplain Wetlands

“…The relative abundance of these bacterial communities was still lower compared to during the wet phases of environmental watering ( Table 2). Re-wetting has been known to quickly alter microbial abundance in wetland soils (Meisner et al, 2018). However, environmental watering may have permanently altered the microbial community and carbon cycling within this ecosystem, as some community differences were still seen after 1 Month of watering.…”