title: Mycorrhizal fungal communities respond to experimental elevation of soil pH and P availability in temperate hardwood forests.
abstract: Many forests are affected by chronic acid deposition, which can lower soil pH and limit the availability of nutrients such as phosphorus (P), but the response of mycorrhizal fungi to changes in soil pH and P availability and how this affects tree acquisition of nutrients is not well understood. Here, we describe an ecosystem-level manipulation in 72 plots, which increased pH and/or P availability across six forests in Ohio, USA. Two years after treatment initiation, mycorrhizal fungi on roots were examined with molecular techniques, including 454-pyrosequencing. Elevating pH significantly increased arbuscular mycorrhizal (AM) fungal colonization and total fungal biomass, and affected community structure of AM and ectomycorrhizal (EcM) fungi, suggesting that raising soil pH altered both mycorrhizal fungal communities and fungal growth. AM fungal taxa were generally negatively correlated with recalcitrant P pools and soil enzyme activity, whereas EcM fungal taxa displayed variable responses, suggesting that these groups respond differently to P availability. Additionally, the production of extracellular phosphatase enzymes in soil decreased under elevated pH, suggesting a shift in functional activity of soil microbes with pH alteration. Thus, our findings suggest that elevating pH increased soil P availability, which may partly underlie the mycorrhizal fungal responses we observed.
authors: Research Department, The Holden Arboretum, Kirtland, OH 44094, USA Department of Biology, Case Western Reserve University, Cleveland, OH 44106, USA.
authors: Sarah R
authors: SR
authors: Carrino-Kyker
authors: Research Department, The Holden Arboretum, Kirtland, OH 44094, USA Department of Biology, Case Western Reserve University, Cleveland, OH 44106, USA.
authors: Laurel A
authors: LA
authors: Kluber
authors: Research Department, The Holden Arboretum, Kirtland, OH 44094, USA Department of Biology, Case Western Reserve University, Cleveland, OH 44106, USA.
authors: Sheryl M
authors: SM
authors: Petersen
authors: Department of Biology, Case Western Reserve University, Cleveland, OH 44106, USA.
authors: Kaitlin P
authors: KP
authors: Coyle
authors: Research Department, The Holden Arboretum, Kirtland, OH 44094, USA.
authors: Charlotte R
authors: CR
authors: Hewins
authors: Department of Environmental and Plant Biology, Ohio University, Athens, OH 45701, USA.
authors: Jared L
authors: JL
authors: DeForest
authors: Research Department, The Holden Arboretum, Kirtland, OH 44094, USA Department of Biological Sciences, Kent State University, Kent, OH 44240, USA.
authors: Kurt A
authors: KA
authors: Smemo
authors: Research Department, The Holden Arboretum, Kirtland, OH 44094, USA Department of Biology, Case Western Reserve University, Cleveland, OH 44106, USA dburke@holdenarb.org.
authors: David J
authors: DJ
authors: Burke
mesh_terms: D018533:Biomass; D017753:Ecosystem; D065928:Forests; D005658:Fungi / Q000235:genetics / Q000254:growth & development* / Q000302:isolation & purification / Q000378:metabolism; D006863:Hydrogen-Ion Concentration; D038821:Mycorrhizae / Q000235:genetics / Q000254:growth & development* / Q000302:isolation & purification / Q000378:metabolism; D010758:Phosphorus / Q000032:analysis* / Q000378:metabolism; D018517:Plant Roots / Q000382:microbiology; D012987:Soil / Q000737:chemistry; D012988:Soil Microbiology; D014197:Trees / Q000254:growth & development / Q000382:microbiology*
chemical_list: D012987:Soil; D010758:Phosphorus
keywords: 454-sequencing; acid deposition; arbuscular mycorrhizal fungi; ectomycorrhizal fungi; phosphatase; phosphorus