Resistance of subarctic soil fungal and invertebrate communities to disruption of belowground carbon supply

• Main Authors: Parker, TC, Chomel, M, Clemmensen, KE, Friggens, NL, Hartley, IP, Johnson, D, Kater, I, Krab, EJ, Lindahl, BD, Street, LE, Subke, J, Wookey, PA
• Format: Article in Journal/Newspaper
• Language: English
• Published: Wiley / British Ecological Society 2022
• Subjects: Subarctic
• Online Access: http://hdl.handle.net/10871/131181; https://doi.org/10.1111/1365-2745.13994

This is the author accepted manuscript. The final version is available from Wiley via the DOI in this record Data Availability Statement: All sequence data is stored at NCBI-SRA at https://www.ncbi.nlm.nih.gov/bioproject/PRJNA846260/. ITS copy numbers and species hypothesis relative abundance data are available at https://doi.org/10.5285/d6c787ec-146c-461b-b8a2-e0251259036c. Flux, hyphae and root data are available at https://doi.org/10.5285/4418c631-c39c-467c-b3b8-c75142fcae0a, soil fauna data are available at https://doi.org/10.5285/d3c98f24-7a4d-40b8-989a-6cc340e91cac. The supply of recent photosynthate from plants to soils is thought to be a critical mechanism regulating the activity and diversity of soil biota. In the Arctic, large-scale vegetation transitions are underway in response to warming, and there is an urgent need to understand how these changes affect soil biodiversity and function. We investigated how abundance and diversity of soil fungi and invertebrates responded to a reduction in fresh belowground photosynthate supply in treeline birch and willow, achieved using stem girdling. We hypothesised that birch forest would support greater abundance of ectomycorrhizal fungal species and fauna than willow shrubs, and that girdling would result in a rapid switch from ectomycorrhizal fungi to saprotrophs as canopy-supply of C was cut, with a concomitant decline in soil fauna. Birch forest had greater fungal and faunal abundance with a large contribution of root-associated ascomycetes (ericoid mycorrhizal fungi and root endophytes) compared to willow shrub plots, which had a higher proportion of saprotrophs and, contrary to our expectations, ectomycorrhizal fungi. Broad-scale soil fungal and faunal functional group composition was not significantly changed by girdling, even in the third year of treatment. Within the ectomycorrhizal community, there were some changes, with genera that are believed to be particularly C-demanding declining in girdled plots. However, it was notable how most ...