Title: Fungal Communities and Functional Guilds Shift Along an Elevational Gradient in the Southern Appalachian Mountains

Abstract

Nitrogen deposition alters forest ecosystems particularly in high elevation, montane habitats where nitrogen deposition is greatest and continues to increase. We collected soils across an elevational (788–1940 m) gradient, encompassing both abiotic (soil chemistry) and biotic (vegetation community) gradients, at eight locations in the southern Appalachian Mountains of southwestern North Carolina and eastern Tennessee. We measured soil chemistry (total N, C, extractable PO₄, soil pH, cation exchange capacity [ECEC], percent base saturation [% BS]) and dissected soil fungal communities using ITS2 metabarcode Illumina MiSeq sequencing. Total soil N, C, PO₄, % BS, and pH increased with elevation and plateaued at approximately 1400 m, whereas ECEC linearly increased and C/N decreased with elevation. Fungal communities differed among locations and were correlated with all chemical variables, except PO₄, whereas OTU richness increased with total N. Several ecological guilds (i.e., ectomycorrhizae, saprotrophs, plant pathogens) differed in abundance among locations; specifically, saprotroph abundance, primarily attributable to genus Mortierella, was positively correlated with elevation. Ectomycorrhizae declined with total N and soil pH and increased with total C and PO₄ where plant pathogens increased with total N and decreased with total C. Finally, our results demonstrate significant turnover in taxonomic and functional fungal groups across elevationalmore » gradients which facilitate future predictions on forest ecosystem change in the southern Appalachians as nitrogen deposition rates increase and regional temperature and precipitation regimes shift.« less

Authors:

Veach, Allison M.  ^[1];

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Stokes, C. Elizabeth ^[2]; Knoepp, Jennifer ^[3]; Jumpponen, Ari ^[4]; Baird, Richard ^[5]

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+ Show Author Affiliations

1. Kansas State Univ., Manhattan, KS (United States). Division of Biology; Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Biosciences Division
2. Mississippi State Univ., Mississippi State, MS (United States). Dept. of Forest Products; Mississippi State Univ., Mississippi State, MS (United States). Dept. of Biochemistry, Molecular Biology, Entomology, and Plant Pathology
3. US Dept. of Agriculture (USDA)., Otto, NC (United States). Forest Service, Southern Research Station, Center for Forest Watershed Research, Coweeta Hydrologic Lab.
4. Kansas State Univ., Manhattan, KS (United States). Division of Biology
5. Mississippi State Univ., Mississippi State, MS (United States). Dept. of Biochemistry, Molecular Biology, Entomology, and Plant Pathology

Publication Date:

2017-12-04

Research Org.:

Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

Sponsoring Org.:

USDOE

OSTI Identifier:

1460223

Grant/Contract Number:  

AC05-00OR22725; DEB0218001; DEB0823293

Resource Type:

Accepted Manuscript

Journal Name:

Microbial Ecology

Additional Journal Information:

Journal Volume: 76; Journal Issue: 1; Journal ID: ISSN 0095-3628

Publisher:

Springer

Country of Publication:

United States

Language:

English

Subject:

59 BASIC BIOLOGICAL SCIENCES; 54 ENVIRONMENTAL SCIENCES