Atmospheric nitrogen enrichment changes nutrient stoichiometry and reduces fungal N supply to peatland ericoid mycorrhizal shrubs
| Autor: | Nancy B. Dise, Risto Vesala, Erik A. Hobbie, Netty van Dijk, Heikki Kiheri, Tuula Larmola |
|---|---|
| Přispěvatelé: | Department of Microbiology |
| Jazyk: | angličtina |
| Rok vydání: | 2021 |
| Předmět: |
0106 biological sciences
Nutrient cycle Environmental Engineering Peat Nitrogen Ombrotrophic ARCTIC PLANTS Nitrogen deposition Nitrate 010603 evolutionary biology 01 natural sciences Erica tetralix Sphagnum Ecology and Environment CARBON Soil chemistry.chemical_compound Nutrient Mycorrhizae Environmental Chemistry N-15 NATURAL-ABUNDANCE Ammonium DEPOSITION Waste Management and Disposal Ecosystem 1172 Environmental sciences Ombrotrophic bogs Stable isotopes 2. Zero hunger biology ECTOMYCORRHIZAL FUNGI Chemistry food and beverages Phosphorus SPHAGNUM Nutrients Soil carbon 15. Life on land biology.organism_classification FOREST Pollution 6. Clean water ORGANIC NITROGEN Agronomy Agriculture and Soil Science 13. Climate action PATTERNS 010606 plant biology & botany |
| DOI: | 10.1016/j.scitotenv.2021.148737 |
| Popis: | 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. |
| Databáze: | OpenAIRE |
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