Wildfire exerts a long-term impact on soil multifunctionality by influencing soil environments and vegetation regeneration in a Chinese boreal forest.
Kong, J., Y. Yue, X. Xiang and J. Yang. 2022.
Abstract
Background and aims
Wildfires can trigger significant changes in soil functioning in boreal forests, and fire-caused changes in
soil environments and vegetation community can further affect soil functioning. However, the response
of multiple simultaneous soil functions (i.e. multifunctionality) to wildfire and postfire changes in soil
environments and regeneration vegetation remains unknown though soil multifunctionality (SMF) is
crucial to the biogeochemical cycling and plant growth.
Methods
We sampled 60 soils at unburned control, 1-year-postfire, and 11-year-postfire sites in a Chinese boreal
larch forest to explore the relationships between SMF and fire severity, bacterial diversity, soil
environments and regenerated vegetation.
Results
The SMF was lower at the two burned sites relative to the control, decreasing with increased fire severity
but increasing with soil bacterial diversity. Structural equation modeling analysis confirmed that fire
severity was the most important predictor of SMF at the 1-year-postfire site, while SMF at the 11-yearpostfire site was mainly mediated by soil moisture besides fire severity, regenerated tree density and
grass cover.
Conclusions
Wildfire exerts a long-term negative effect on SMF and this effect is closely related to fire severity and
bacterial diversity in the Great Xing's Mountains. The effects of wildfire on SMF might be directly
mediated by fire severity in the short term but indirectly by altering soil environments and vegetation
regeneration in the long term. We conclude that increasing fire severity of these forests can both directly
decrease SMF and trigger the degradation of their soil-plant ecosystems, which would further imperil the
maintenance of SMF.
Key Words
Disturbance, Fire severity, Ecosystem functions, Bacterial diversity, Fine root
