Evidence of Ash Tree (Fraxinus spp.) Specific Associations with Soil Bacterial Community Structure and Functional Capacity

Abstract

The spread of the invasive emerald ash borer (EAB) across North America has had enormous impacts on temperate forest ecosystems. The selective removal of ash trees (Fraxinus spp.) has resulted in abnormally large inputs of coarse woody debris and altered forest tree community composition, ultimately affecting a variety of ecosystem processes. The goal of this study was to determine if the presence of ash trees influences soil bacterial communities and/or functions to better understand the impacts of EAB on forest successional dynamics and biogeochemical cycling. Using 16S rRNA amplicon sequencing of soil DNA collected from ash and non-ash plots in central Ohio during the early stages of EAB infestation, we found that bacterial communities in plots with ash differed from those without ash. These differences were largely driven by Acidobacteria, which had a greater relative abundance in non-ash plots. Functional genes required for sulfur cycling, phosphorus cycling, and carbohydrate metabolism (specifically those which breakdown complex sugars to glucose) were estimated to be more abundant in non-ash plots, while nitrogen cycling gene abundance did not differ. This ash-soil microbiome association implies that EAB-induced ash decline may promote belowground successional shifts, altering carbon and nutrient cycling and changing soil properties beyond the effects of litter additions caused by ash mortality.

Spartina alterniflora raised soil sulfide content by regulating sulfur cycle-associated bacteria in the Jiuduansha Wetland of China

“…The seeds were soaked in 5% sodium chloride solution at 4°C to preserve the vigor of seeds (Vertucci and Roos 1990). The experiment was conducted in the phytotron of the School of Environmental and Chemical Engineering, Shanghai University, in 2019, and the temperature was controlled at 28℃ (day) / 20℃ (night) (Ricketts et al 2018), the relative humidity was 80%, and the daily light duration was 12 h. Twenty seeds of S. alterni ora and S. mariqueter were disinfected with 0.1% sodium hypochlorite solution and rinsed with distilled water. Then the seeds were placed in Petri dishes that were cleaned and disinfected in advance.…”

Spartina Alterniflora Raised Soil Sulfide Content by Regulating Sulfur Cycle-Associated Bacteria in the Jiuduansha Wetland of China

“…The seeds were soaked in 5% sodium chloride solution at 4°C to preserve the vigor of seeds (Vertucci and Roos 1990). The experiment was conducted in the phytotron of the School of Environmental and Chemical Engineering, Shanghai University, in 2019, and the temperature was controlled at 28℃ (day) / 20℃ (night) (Ricketts et al 2018), the relative humidity was 80%, and the daily light duration was 12 h. Twenty seeds of S. alterni ora and S. mariqueter were disinfected with 0.1% sodium hypochlorite solution and rinsed with distilled water. Then the seeds were placed in Petri dishes that were cleaned and disinfected in advance.…”

Ecological Impacts of Emerald Ash Borer in Forests at the Epicenter of the Invasion in North America

“…Widespread and relatively simultaneous mortality of ash has been predicted to have substantial direct and indirect ecological impacts on forest structure, function, and community composition via gap formation as trees die, as well as accumulation of coarse woody debris as dead trees fall [3,51]. This disturbance can alter soil microbial communities [52], hydrology [53,54], and carbon and nutrient cycling [22,52,54], ultimately leading to community-level effects on successional trajectories [55], facilitation of the establishment and spread of exotic plants [56], and impacts on native fauna [57,58]. Some effects of ash mortality will dissipate relatively quickly as canopy gaps close via regeneration in the understory and growth of dominant and subdominant trees [59,60].…”