title: Community structure of arbuscular mycorrhizal fungi at different soil depths in extensively and intensively managed agroecosystems.
abstract: The vertical distribution of spores of arbuscular mycorrhizal fungi (AMF) was investigated in soil profiles of extensively and intensively managed agroecosystems, including two permanent grasslands, a vineyard and two continuously mono-cropped maize fields. The number of AMF spores decreased with increasing soil depth--most drastically in the grasslands and the vineyard--but there was a large diversity of AMF species even in the deepest soil layers (50-70 cm). This was particularly striking in the maize fields where the highest species numbers were found below ploughing depth. Some species sporulated mainly, or exclusively, in the deep soil layers, others mainly in the top layers. Soil samples were used to inoculate trap cultures. Up to 18 months after inoculation, there was no conspicuous difference in the species composition among the trap cultures representing different soil depths, and only a weak match to the species composition determined by analysis of field samples. Our results indicate that the AMF communities in deep soil layers are surprisingly diverse and different from the topsoil. Thus, deep soil layers should be included in studies to get a complete picture of AMF diversity.
authors.affiliation: Institute of Botany, University of Basel, Hebelstrasse 1, CH-4056 Basel, Switzerland.
authors.forename: Fritz
authors.initials: F
authors.lastname: Oehl
authors.forename: Ewald
authors.initials: E
authors.lastname: Sieverding
authors.forename: Kurt
authors.initials: K
authors.lastname: Ineichen
authors.forename: Elisabeth-Anne
authors.initials: EA
authors.lastname: Ris
authors.forename: Thomas
authors.initials: T
authors.lastname: Boller
authors.forename: Andres
authors.initials: A
authors.lastname: Wiemken
mesh_terms: D017753:Ecosystem; D038821:Mycorrhizae / Q000502:physiology*; D010944:Plants / Q000382:microbiology; D011157:Population Dynamics; D012988:Soil Microbiology; D013172:Spores, Fungal