Phosphorus cycling in deciduous forest soil differs between stands dominated by ecto- and arbuscular mycorrhizal trees.
Although much is known about how trees and their associated microbes influence nitrogen cycling in temperate forest soils, less is known about biotic controls over phosphorus (P) cycling. Given that mycorrhizal fungi are instrumental for P acquisition and that the two dominant associations - arbuscular mycorrhizal (AM) and ectomycorrhizal (ECM) fungi - possess different strategies for acquiring P, we hypothesized that P cycling would differ in stands dominated by trees associated with AM vs ECM fungi. We quantified soil solution P, microbial biomass P, and sequentially extracted inorganic and organic P pools from May to November in plots dominated by trees forming either AM or ECM associations in south-central Indiana, USA. Overall, fungal communities in AM and ECM plots were functionally different and soils exhibited fundamental differences in P cycling. Organic forms of P were more available in ECM plots than in AM plots. Yet inorganic P decreased and organic P accumulated over the growing season in both ECM and AM plots, resulting in increasingly P-limited microbial biomass. Collectively, our results suggest that P cycling in hardwood forests is strongly influenced by biotic processes in soil and that these are driven by plant-associated fungal communities.
Department of Evolutionary Biology, EBC, Uppsala University, Uppsala, Sweden.
Anna
A
Rosling
Biology Department, Indiana University, Bloomington, IN, 47405, USA.
Meghan G
MG
Midgley
Biology Department, Indiana University, Bloomington, IN, 47405, USA.|Department of Forest Mycology and Plant Pathology, Swedish University of Agricultural Sciences, Uppsala, Sweden.
Tanya
T
Cheeke
Department of Evolutionary Biology, EBC, Uppsala University, Uppsala, Sweden.
Hector
H
Urbina
Department of Forest Mycology and Plant Pathology, Swedish University of Agricultural Sciences, Uppsala, Sweden.
Petra
P
Fransson
Biology Department, Indiana University, Bloomington, IN, 47405, USA.
Richard P
RP
Phillips
D018533:Biomass; D065928:Forests; D038821:Mycorrhizae / Q000502:physiology*; D010758:Phosphorus / Q000378:metabolism*; D025341:Principal Component Analysis; D012621:Seasons; D012987:Soil; D012988:Soil Microbiology
D012987:Soil; D010758:Phosphorus
deciduous forest; ectomycorrhizal (ECM) fungi; mycorrhiza; phosphorus (P) cycling; soil