Restoration age affects microbial-herbaceous plant interactions in an
oak woodland
Abstract
In degraded ecosystems, soil microbial communities (SMCs) may influence
the outcomes of ecological restoration. Restoration practices can affect
SMCs, though it is unclear how variation in the onset of restoration
activities in woodlands affects SMCs, how those SMCs influence the
performance of hard-to-establish woodland forbs, and how different
woodland forbs shape SMCs. In this study, we quantified soil properties
and species abundances in an oak woodland restoration chronosequence
(young, intermediate, and old restorations). We measured growth of three
woodland forb species when inoculated with live whole-soil from young,
intermediate, or old restorations. We used DNA metabarcoding to
characterize SMCs of each inoculum treatment and the soil after
conditioning by each plant species. Our goals were to: 1) understand how
time since onset of restoration affected soil abiotic properties, plant
communities, and SMCs in a restoration chronosequence, 2) test
growth-responses of three forb species to whole-soil inoculum from
restoration sites, and 3) characterize changes in SMCs before and after
conditioning by each forb species. Younger restored woodlands had
greater fire-sensitive tree species and lower concentrations of soil
phosphorous than intermediate or older restored woodlands. Bacterial and
fungal soil communities varied significantly among sites. Forbs
exhibited greater growth in soil from the young restoration. Each forb
species developed unique soil microbial community. Our results highlight
how restoration practices affect SMCs, which can in turn affect growth
of hard-to-establish forb species. Our results also highlight that the
choice of forb species can have major effects on SMCs, with long-term
potential consequences for restoration success.