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This content will become publicly available on May 6, 2024

Title: Peat loss collocates with a threshold in plant–mycorrhizal associations in drained peatlands encroached by trees

Drainage‐induced encroachment by trees may have major effects on the carbon balance of northern peatlands, and responses of microbial communities are likely to play a central mechanistic role.

We profiled the soil fungal community and estimated its genetic potential for the decay of lignin and phenolics (class II peroxidase potential) along peatland drainage gradients stretching from interior locations (undrained, open) to ditched locations (drained, forested).

Mycorrhizal fungi dominated the community across the gradients. When moving towards ditches, the dominant type of mycorrhizal association abruptly shifted from ericoid mycorrhiza to ectomycorrhiza atc.120 m from the ditches. This distance corresponded with increased peat loss, from which more than half may be attributed to oxidation. The ectomycorrhizal genusCortinariusdominated at the drained end of the gradients and its relatively higher genetic potential to produce class II peroxidases (together withMycena) was positively associated with peat humification and negatively with carbon‐to‐nitrogen ratio.

Our study is consistent with a plant–soil feedback mechanism, driven by a shift in the mycorrhizal type of vegetation, that potentially mediates changes in aerobic decomposition during postdrainage succession. Such feedback may have long‐term legacy effects upon postdrainage restoration efforts and implication for tree encroachment onto carbon‐rich soils globally.

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Award ID(s):
2031076 2031085
Publication Date:
Journal Name:
New Phytologist
Sponsoring Org:
National Science Foundation
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