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Title: Mycorrhizal fungal communities respond to experimental elevation of soil pH and P availability in temperate hardwood forests

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. Furthermore, our findings suggest that elevating pH increased soil P availability, which may partly underlie the mycorrhizal fungal responses we observed.
 [1] ;  [1] ;  [1] ;  [2] ;  [3] ;  [4] ;  [5] ;  [1]
  1. The Holden Arboretum, Kirtland, OH (United States); Case Western Reserve Univ., Cleveland, OH (United States)
  2. Case Western Reserve Univ., Cleveland, OH (United States)
  3. The Holden Arboretum, Kirtland, OH (United States)
  4. Ohio Univ., Athens, OH (United States)
  5. The Holden Arboretum, Kirtland, OH (United States); Kent State Univ., Kent, OH (United States)
Publication Date:
Grant/Contract Number:
Accepted Manuscript
Journal Name:
FEMS Microbiology Ecology (Online)
Additional Journal Information:
Journal Name: FEMS Microbiology Ecology (Online); Journal Volume: 92; Journal Issue: 3; Journal ID: ISSN 1574-6941
Federation of European Microbiological Societies
Research Org:
Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)
Sponsoring Org:
USDOE Laboratory Directed Research and Development (LDRD) Program
Country of Publication:
United States
59 BASIC BIOLOGICAL SCIENCES; acid deposition; arbuscular mycorrhizal fungi; ectomycorrhizal fungi; phosphorus; 454-sequencing; phosphatase
OSTI Identifier: