title: PIXE analysis to estimate the elemental composition of ectomycorrhizal rhizomorphs grown in contact with different minerals in forest soil.
abstract: The aim of this study was to investigate possible interactions between minerals and ectomycorrhizal (EM) mycelia. Fungal rhizomorphs growing in association with apatite and/or biotite were sampled both from a laboratory experimental system (Rhizopogon sp. and Pinus muricata) and from mesh bags buried in forest soil in the field. The elemental composition of the samples was analyzed with particle-induced X-ray emission (PIXE). Many EM rhizomorphs associated with apatite in laboratory systems and in mesh bags contained larger amounts of Ca (mean ranges between 12 and 31 mg Ca g(-1)) than similar rhizomorphs connected to acid-washed sand (range 0.3-3.5 mg Ca g(-1)). Ca originating from apatite was deposited as calcium oxalate crystals on the surface of the rhizomorphs. EM mycelium produced in mesh bags had a capacity to mobilize 0.6 mg P kg(-1) year(-1) from apatite-amended sand (which is 0.04% of the added apatite). A high concentration of K in some rhizomorphs (up to 11 mg K g(-1)) suggests that these fungi are good accumulators of K and may have a significant role in transporting K to trees.
authors.affiliation: Department of Microbial Ecology, Lund University, Ecology Building, 223 62 Lund, Sweden. hakan.wallander@mbioekol.lu.se
authors.forename: Håkan
authors.initials: H
authors.lastname: Wallander
authors.forename: Leif
authors.initials: L
authors.lastname: Johansson
authors.forename: Jan
authors.initials: J
authors.lastname: Pallon