Drought-induced tree mortality in Scots pine mesocosms promotes changes in soil microbial communities and trophic groups
Open access
Date
2024-02Type
- Journal Article
Abstract
Increased tree mortality related to water limitation is documented for various species at different sites globally. Nevertheless, our understanding of tree mortality effects on soil microbial communities remains scarce. Therefore, we conducted a mesocosm experiment with young Scots pine saplings and natural forest soil with differing drought legacies to follow changes in soil microbial communities during tree mortality. Scots pine saplings were completely deprived of water during the experiment until they died. Shifts in soil microbial communities during tree mortality were assessed by metabarcoding in parallel with measurements of tree vitality and physicochemical soil properties. Drought history influenced the rate at which trees died, although high individual differences were observed. Tree death was accompanied by reduced stomatal conductance, discoloring of needles, increased defoliation, and shrinkage of the stem diameter. Soil NO3− concentrations increased after tree death, potentially through diminished plant uptake and increased microbial nitrification. Microbial abundance and community composition were affected by tree death and drought legacy. Copiotrophic bacterial taxa decreased during tree mortality, while oligotrophic taxa increased, probably slowing down soil carbon turnover. Fungal saprotrophs decreased, while symbiotrophs, such as ectomycorrhizal (ECM) fungi, increased in abundance, potentially through facultative saprothrophy and as a survival strategy of the trees in the initial phase of dying. Overall, our results indicate that drought-induced tree mortality promotes changes in soil prokaryotic and fungal communities, potentially affecting soil processes in forest ecosystems. Show more
Permanent link
https://doi.org/10.3929/ethz-b-000646227Publication status
publishedExternal links
Journal / series
Applied Soil EcologyVolume
Pages / Article No.
Publisher
ElsevierSubject
Soil microbiome; Scots pine; Tree mortality; Drought; Mesocosm experiment; DNA metabarcodingFunding
180030 - When trees die: Understanding how plants and microbes interact and influence soil biogeochemical processes (SNF)
More
Show all metadata