title: Is nitrogen transfer among plants enhanced by contrasting nutrient-acquisition strategies?
abstract: Nitrogen (N) transfer among plants has been found where at least one plant can fix N2 . In nutrient-poor soils, where plants with contrasting nutrient-acquisition strategies (without N2 fixation) co-occur, it is unclear if N transfer exists and what promotes it. A novel multi-species microcosm pot experiment was conducted to quantify N transfer between arbuscular mycorrhizal (AM), ectomycorrhizal (EM), dual AM/EM, and non-mycorrhizal cluster-rooted plants in nutrient-poor soils with mycorrhizal mesh barriers. We foliar-fed plants with a K(15) NO3 solution to quantify one-way N transfer from 'donor' to 'receiver' plants. We also quantified mycorrhizal colonization and root intermingling. Transfer of N between plants with contrasting nutrient-acquisition strategies occurred at both low and high soil nutrient levels with or without root intermingling. The magnitude of N transfer was relatively high (representing 4% of donor plant N) given the lack of N2 fixation. Receiver plants forming ectomycorrhizas or cluster roots were more enriched compared with AM-only plants. We demonstrate N transfer between plants of contrasting nutrient-acquisition strategies, and a preferential enrichment of cluster-rooted and EM plants compared with AM plants. Nutrient exchanges among plants are potentially important in promoting plant coexistence in nutrient-poor soils.
authors.affiliation: School of Plant Biology, The University of Western Australia, 35 Stirling Highway, Crawley (Perth), Western Australia, 6009, Australia.
authors.forename: François P
authors.initials: FP
authors.lastname: Teste
authors.forename: Erik J
authors.initials: EJ
authors.lastname: Veneklaas
authors.forename: Kingsley W
authors.initials: KW
authors.lastname: Dixon
authors.forename: Hans
authors.initials: H
authors.lastname: Lambers
mesh_terms: D001692:Biological Transport; D018533:Biomass; D038821:Mycorrhizae / Q000502:physiology*; D009584:Nitrogen / Q000378:metabolism*; D009586:Nitrogen Fixation; D009587:Nitrogen Isotopes; D018517:Plant Roots / Q000378:metabolism / Q000382:microbiology; D018520:Plant Shoots / Q000378:metabolism / Q000382:microbiology; D010944:Plants / Q000378:metabolism* / Q000382:microbiology; D012987:Soil
chemical_list: D009587:Nitrogen Isotopes; D012987:Soil; D009584:Nitrogen
keywords: arbuscular mycorrhiza; biodiversity; cluster roots; ecological restoration; ectomycorrhiza; isotope 15N; mycorrhizal networks; plant coexistence