Atmospheric nitrogen enrichment changes nutrient stoichiometry and reduces fungal N supply to peatland ericoid mycorrhizal shrubs

Show full item record



Permalink

http://hdl.handle.net/10138/334173

Citation

Vesala , R , Kiheri , H , Hobbie , E A , van Dijk , N , Dise , N & Larmola , T 2021 , ' Atmospheric nitrogen enrichment changes nutrient stoichiometry and reduces fungal N supply to peatland ericoid mycorrhizal shrubs ' , The Science of the Total Environment , vol. 794 , 148737 . https://doi.org/10.1016/j.scitotenv.2021.148737

Title: Atmospheric nitrogen enrichment changes nutrient stoichiometry and reduces fungal N supply to peatland ericoid mycorrhizal shrubs
Author: Vesala, Risto; Kiheri, Heikki; Hobbie, Erik A.; van Dijk, Netty; Dise, Nancy; Larmola, Tuula
Contributor: University of Helsinki, Nat Resources Inst Finland Luke, Natural Resources Institute Finland (Luke), Milk Prod Solut, Green Technol
University of Helsinki, Department of Microbiology
Date: 2021-11-10
Language: eng
Number of pages: 10
Belongs to series: The Science of the Total Environment
ISSN: 0048-9697
URI: http://hdl.handle.net/10138/334173
Abstract: Peatlands store one third of global soil carbon (C) and up to 15% of global soil nitrogen (N) but often have low plant nutrient availability owing to slow organic matter decomposition under acidic and waterlogged conditions. In rainwater-fed ombrotrophic peatlands, elevated atmospheric N deposition has increased N availability with potential consequences to ecosystem nutrient cycling. Here, we studied how 14 years of continuous N addition with either nitrate or ammonium had affected ericoid mycorrhizal (ERM) shrubs at Whim Bog, Scotland. We examined whether enrichment has influenced foliar nutrient stoichiometry and assessed using N stable isotopes whether potential changes in plant nutrient constraints are linked with plant N uptake through ERM fungi versus direct plant uptake. High doses of ammonium alleviated N deficiency in Calluna vulgaris and Erica tetralix, whereas low doses of ammonium and nitrate improved plant phosphorus (P) nutrition, indicated by the lowered foliar N:P ratios. Root acid phosphatase activities correlated positively with foliar N:P ratios, suggesting enhanced P uptake as a result of improved N nutrition. Elevated foliar delta N-15 of fertilized shrubs suggested that ERM fungi were less important for N supply with N fertilization. Increases in N availability in peat porewater and in direct nonmycorrhizal N uptake likely have reduced plant nitrogen uptake via mycorrhizal pathways. As the mycorrhizal N uptake correlates with the reciprocal C supply from host plants to the soil, such reduction in ERM activity may affect peat microbial communities and even accelerate C loss via decreased ERM activity and enhanced saprotrophic activity. Our results thus introduce a previously unrecognized mechanism for how anthropogenic N pollution may affect nutrient and carbon cycling within peatland ecosystems. (C) 2021 The Authors. Published by Elsevier B.V.
Subject: Ombrotrophic bogs
Nitrogen deposition
Nitrate
Ammonium
Phosphorus
Stable isotopes
N-15 NATURAL-ABUNDANCE
ORGANIC NITROGEN
ECTOMYCORRHIZAL FUNGI
ARCTIC PLANTS
DEPOSITION
CARBON
PHOSPHORUS
SPHAGNUM
PATTERNS
FOREST
1172 Environmental sciences
Rights:


Files in this item

Total number of downloads: Loading...

Files Size Format View
1_s2.0_S0048969721038092_main.pdf 905.9Kb PDF View/Open

This item appears in the following Collection(s)

Show full item record