Effects of Rhododendron removal on soil bacterial and fungal communities in southern Appalachian forests

FOREST ECOLOGY AND MANAGEMENT

卷:496

Article

Osburn, Ernest D.¹  Miniat, Chelcy F.^2,3  Elliott, Katherine J.²  Barrett, J. E.¹ 

[1] Virginia Polytech Inst & State Univ, Dept Biol Sci, Blacksburg, VA 24061 USA

[2] USDA, US Forest Serv, Coweeta Hydrol Lab, 3160 Coweeta Lab Rd, Otto, NC 28763 USA

[3] USDA, US Forest Serv, Rocky Mt Res Stn, Albuquerque, NM 87102 USA

关键词: Microbial community;    16S;    ITS;    Diversity;    Mycorrhizal fungi;    Sequencing;   

DOI  :  10.1016/j.foreco.2021.119398

来源: Elsevier

【 摘 要 】

Rhododendron maximum, a native ericaceous evergreen shrub, is expanding in forests of the southern Appalachian region following eastern hemlock (Tsuga canadensis) mortality due to hemlock woolly adelgid (Adelges tsugae) infestations. The goal of our study was to examine soil microbial community responses to experimental R. maximum removal treatments. The experiment was implemented as a 2 x 2 factorial design, including two R. maximum canopy removal levels (cut vs. not cut) combined with two forest floor removal levels (burned vs. not burned). These treatments were designed as potential management strategies to facilitate hardwood tree establishment in forests that have experienced T. canadensis declines. We sampled soils after removals and characterized bacterial and fungal communities using amplicon sequencing. Shrub removal did not affect bacterial or fungal alpha diversity but did affect both bacterial and fungal community composition. Relative abundances of bacterial phyla and fungal classes exhibited no differences among R. maximum removal treatments. However, specific bacterial and fungal taxa that were responsive to R. maximum removal (i.e., differentially abundant sequences) did exhibit clear patterns at high taxonomic levels. Specifically, taxa that responded negatively to R. maximum removal were found primarily in two bacterial phyla (Proteobacteria and Bacteroidetes) and one fungal class (Archaeorhizomycetes) while positive responders were clustered in several other bacterial phyla (e.g., Actinobacteria, Planctomycetes, Cyanobacteria). Fungal functional guilds also responded to R. maximum removal, including negative responses of ericoid mycorrhizae and positive responses of arbuscular mycorrhizae and wood saprotrophs. Effects of R. maximum removal on soil microbial communities were minor overall, but clear effects on some key functional groups were evident (i.e., mycorrhizal fungi), suggesting that microbial responses to R. maximum removal may influence recovery of forests in the southern Appalachian region.

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