title: Sharing rotting wood in the shade: ectomycorrhizal communities of co-occurring birch and hemlock seedlings.
abstract: Coarse woody debris (CWD) is an important nursery environment for many tree species. Understanding the communities of ectomycorrhizal fungi (ECMF)and the effect of ECMF species on tree seedling condition in CWD will elucidate the potential for ECMF-mediated effects on seedling dynamics. In hemlock-dominated stands, we characterized ECMF communities associated with eastern hemlock (Tsuga canadensis (L.) Carr) and yellow birch (Betula alleghaniensis Britt) seedling pairs growing on CWD. Seedling foliage and CWD were analyzed chemically, and seedling growth, canopy cover, and canopy species determined. Thirteen fungal taxa, 12 associated with birch, and 6 with hemlock, were identified based on morphology and ITS sequencing. Five species were shared by co-occurring birch and hemlock, representing 75% of ectomycorrhizal root tips. Rarified ECMF taxon richness per seedling was higher on birch than hemlock. Nonmetric multidimensional scaling revealed significant correlations between ordination axes, the mutually exclusive ECMF Tomentella and Lactarius spp., foliar N and K, CWD pH, and exchangeable Ca and Mg. Seedlings colonized by Lactarius and T. sublilacina differed significantly in foliar K and N, and CWD differed in exchangeable Ca and Mg. CWD pH and nutrient concentrations were low but foliar macro-nutrient concentrations were not. We hypothesize that the dominant ECMF are adapted to low root carbohydrate availability typical in shaded environments but differ in their relative supply of different nutrients.
authors.affiliation: School of Forest Resources and Environmental Science, Michigan Technological University, 1400 Townsend Drive, Houghton, MI, 49931-1295, USA.
authors.forename: Sarah K
authors.initials: SK
authors.lastname: Poznanovic
authors.forename: Erik A
authors.initials: EA
authors.lastname: Lilleskov
authors.forename: Christopher R
authors.initials: CR
authors.lastname: Webster
mesh_terms: D029662:Betula / Q000254:growth & development / Q000382:microbiology*; D017753:Ecosystem; D005658:Fungi / Q000145:classification / Q000235:genetics / Q000254:growth & development / Q000302:isolation & purification; D038821:Mycorrhizae / Q000145:classification / Q000235:genetics / Q000254:growth & development / Q000302:isolation & purification*; D036226:Seedlings / Q000254:growth & development / Q000382:microbiology; D028225:Tsuga / Q000254:growth & development / Q000382:microbiology*; D014934:Wood / Q000382:microbiology*
references.citation: Mycorrhiza. 2009 Sep;19(7):493-500
references.pmid: 19421790
references.citation: Mycorrhiza. 2012 May;22(4):317-26
references.pmid: 21822679
references.citation: Environ Microbiol. 2008 May;10(5):1189-201
references.pmid: 18266759
references.citation: J Exp Bot. 2007;58(6):1473-83
references.pmid: 17350936
references.citation: Plant Cell Environ. 2009 Aug;32(8):992-1003
references.pmid: 19344334
references.citation: J Exp Bot. 2013 Apr;64(7):2081-92
references.pmid: 23630329
references.citation: Oecologia. 1994 Aug;98(3-4):419-428
references.pmid: 28313920
references.citation: Tree Physiol. 2003 Feb;23(3):157-67
references.pmid: 12566266
references.citation: Ecology. 2010 Aug;91(8):2294-302
references.pmid: 20836451
references.citation: Microb Ecol. 2011 Aug;62(2):460-73
references.pmid: 21475991
references.citation: Mycorrhiza. 2013 Nov;23(8):641-53
references.pmid: 23702643
references.citation: New Phytol. 2007;174(2):430-440
references.pmid: 17388905
references.citation: Trends Ecol Evol. 2006 Nov;21(11):621-8
references.pmid: 16843567
references.citation: New Phytol. 2007;174(2):250-256
references.pmid: 17388888
references.citation: Mol Ecol. 2001 Aug;10(8):1855-71
references.pmid: 11555231
references.citation: Appl Environ Microbiol. 2009 Dec;75(24):7639-48
references.pmid: 19854915