title: Linking root traits to nutrient foraging in arbuscular mycorrhizal trees in a temperate forest.
abstract: The identification of plant functional traits that can be linked to ecosystem processes is of wide interest, especially for predicting vegetational responses to climate change. Root diameter of the finest absorptive roots may be one plant trait that has wide significance. Do species with relatively thick absorptive roots forage in nutrient-rich patches differently from species with relatively fine absorptive roots? We measured traits related to nutrient foraging (root morphology and architecture, root proliferation, and mycorrhizal colonization) across six coexisting arbuscular mycorrhizal (AM) temperate tree species with and without nutrient addition. Root traits such as root diameter and specific root length were highly correlated with root branching intensity, with thin-root species having higher branching intensity than thick-root species. In both fertilized and unfertilized soil, species with thin absorptive roots and high branching intensity showed much greater root length and mass proliferation but lower mycorrhizal colonization than species with thick absorptive roots. Across all species, fertilization led to increased root proliferation and reduced mycorrhizal colonization. These results suggest that thin-root species forage more by root proliferation, whereas thick-root species forage more by mycorrhizal fungi. In mineral nutrient-rich patches, AM trees seem to forage more by proliferating roots than by mycorrhizal fungi.
authors.affiliation: Intercollege Graduate Degree Program in Plant Biology, Penn State University, University Park, PA, 16802, USA.|Department of Ecosystem Science and Management, Penn State University, University Park, PA, 16802, USA.
authors.forename: David M
authors.initials: DM
authors.lastname: Eissenstat
authors.affiliation: Intercollege Graduate Degree Program in Plant Biology, Penn State University, University Park, PA, 16802, USA.
authors.forename: Joshua M
authors.initials: JM
authors.lastname: Kucharski
authors.affiliation: Intercollege Graduate Degree Program in Plant Biology, Penn State University, University Park, PA, 16802, USA.|Institute of Dendrology, Polish Academy of Sciences, Parkowa 5, 62-035, Kórnik, Poland.
authors.forename: Marcin
authors.initials: M
authors.lastname: Zadworny
authors.affiliation: Department of Ecosystem Science and Management, Penn State University, University Park, PA, 16802, USA.
authors.forename: Thomas S
authors.initials: TS
authors.lastname: Adams
authors.affiliation: Intercollege Graduate Degree Program in Plant Biology, Penn State University, University Park, PA, 16802, USA.|Department of Biology, Brigham Young University, Provo, UT, 84602, USA.
authors.forename: Roger T
authors.initials: RT
authors.lastname: Koide
mesh_terms: D002980:Climate; D057231:Climate Change; D005308:Fertilizers; D065928:Forests; D005658:Fungi; D019684:Magnoliopsida / Q000254:growth & development / Q000382:microbiology / Q000502:physiology; D038821:Mycorrhizae; D010641:Phenotype; D018517:Plant Roots / Q000033:anatomy & histology / Q000254:growth & development* / Q000382:microbiology; D012987:Soil / Q000737:chemistry*; D012988:Soil Microbiology; D014197:Trees / Q000254:growth & development / Q000382:microbiology / Q000502:physiology*
chemical_list: D005308:Fertilizers; D012987:Soil
keywords: arbuscular mycorrhizal (AM) colonization; localized fertilization; nutrient patches; root diameter; root proliferation; root traits; specific root length (SRL)