All boreal forest successional stages needed to maintain the full suite of soil biodiversity, community composition, and function following wildfire

Abstract

Wildfire is a natural disturbance in boreal forest systems that has been predicted to increase in frequency, intensity, and extent due to climate change. Most studies tend to assess the recovery of one component of the community at a time but here we use DNA metabarcoding to simultaneously monitor soil bacteria, fungi, and arthropods along an 85-year chronosequence following wildfire in jack pine-dominated ecosites. We describe soil successional and community assembly processes to better inform sustainable forest management practices. Soil taxa showed different recovery trajectories following wildfire. Bacteria shared a large core community across stand development stages (~ 95–97% of their unique sequences) and appeared to recover relatively quickly by crown closure. By comparison fungi and arthropods shared smaller core communities (64–77% and 68–69%, respectively) and each stage appeared to support unique biodiversity. We show the importance of maintaining a mosaic ecosystem that represents each stand development stage to maintain the full suite of biodiversity in soils following wildfire, especially for fungi and arthropods. These results will provide a useful baseline for comparison when assessing the effects of human disturbance such as harvest or for assessing the effects of more frequent wildfire events due to climate change.

Microenvironment heterogeneity affected by anthropogenic wildfire-perturbed soil mediates bacterial community in Pinus tabulaeformis forests

“…Research by Yang et al alongside García-Carmona et al, highlights significant shifts in microbial community composition post-wildfire, with minimal management impacts and potential biocrust-mediated recovery, respectively ( Garcia-Carmona et al, 2022 ; Yang et al, 2024 ). Divergent microbial recovery trajectories in boreal forests as demonstrated by Porter et al and the critical interplay of soil carbon and nitrogen highlighted by Hopkins et al underscore the multifaceted nature of microbial responses to environmental disturbances ( Porter et al, 2023 ; Hopkins et al, 2024 ). Further, the combined effects of drought legacies and wildfires on microbial dynamics, as explored by Dai et al emphasize the importance of considering historical climatic conditions ( Dai et al, 2021 ).…”