Atmospheric nitrogen enrichment changes nutrient stoichiometry and reduces fungal N supply to peatland ericoid mycorrhizal shrubs
Vesala, Risto; Kiheri, Heikki; Hobbie, Erik A.; van Dijk, Netty; Dise, Nancy ORCID: https://orcid.org/0000-0003-0463-6885; Larmola, Tuula. 2021 Atmospheric nitrogen enrichment changes nutrient stoichiometry and reduces fungal N supply to peatland ericoid mycorrhizal shrubs. Science of the Total Environment, 794, 148737. 10, pp. 10.1016/j.scitotenv.2021.148737
Before downloading, please read NORA policies.Preview |
Text
N530704JA.pdf - Published Version Available under License Creative Commons Attribution 4.0. Download (929kB) | Preview |
Abstract/Summary
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 δ15N 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.
Item Type: | Publication - Article |
---|---|
Digital Object Identifier (DOI): | 10.1016/j.scitotenv.2021.148737 |
UKCEH and CEH Sections/Science Areas: | Atmospheric Chemistry and Effects (Science Area 2017-) UKCEH Fellows |
ISSN: | 0048-9697 |
Additional Information. Not used in RCUK Gateway to Research.: | Open Access paper - full text available via Official URL link. |
Additional Keywords: | ombrotrophic bogs, nitrogen deposition, nitrate, ammonium, phosphorus, stable isotopes |
NORA Subject Terms: | Ecology and Environment Agriculture and Soil Science |
Date made live: | 14 Jul 2021 15:32 +0 (UTC) |
URI: | https://nora.nerc.ac.uk/id/eprint/530704 |
Actions (login required)
View Item |
Document Downloads
Downloads for past 30 days
Downloads per month over past year