Hasselquist, Niles
- Department of Forest Ecology and Management, Swedish University of Agricultural Sciences
To assess how nitrogen (N) availability affected ectomycorrhizal functioning and to test a theoretical model of ectomycorrhizal N-15 partitioning, we measured C/N and delta N-15 in soils and nine fungal taxa in two Swedish N addition experiments. Sporocarp C/N and soil C/N decreased with fertilization, implying that N uptake per unit fungal growth increased. The S horizon was more responsive than the F and H horizons to changes in N addition, with N turnover for these horizons of 24, 57, and 57 y, respectively. Fungal and soil delta N-15 patterns identified fungal N sources, with N acquisition primarily from the S, F, or H horizon for two, five, and two taxa, respectively. With increasing N availability, sporocarp N-15 enrichment increased in five taxa, in agreement with our model of fungal-plant N partitioning. However, it decreased in Lactarius rufus and Russula aeruginea, perhaps indicating shifts towards greater inorganic N uptake in these two taxa. This may relate to the generally lower sensitivity of these taxa to N deposition compared to the Cortinarius and Suillus taxa that fit our model of N-15 partitioning. (C) 2019 Elsevier Ltd and British Mycological Society. All rights reserved.
Suillus variegatus; Paxillus involutus; Nitrogen isotopes; Nitrogen fertilization; Recovery; Ectomycorrhizal fungi; Soil nitrogen; Sporocarp
Fungal Ecology
2019, volume: 39, pages: 267-275
Forest Science
https://res.slu.se/id/publ/99429