Carbon and nitrogen depletion vary with temperature and elevated CO2 in ectomycorrhizal beech seedlings
Abstract
Beech seedlings (Fagus sylvatica L.) were grown in rhizotrons exposed to different temperature, at 17 seedlings per treatment: cold room (15-20°C) without cooling of roots (CR-) and with additional cooling of roots for 4-5°C (CR+), greenhouse (GH) with elevated temperatures and outside (OUT), and elevated CO2 concentrations in the cold room (700 ppm). Isotopic analyses of δ15N and δ13C were analysed with a Thermo-Finnegan Flash HT elemental analyzer at ZALF (Germany). Temperature and elevated concentrations of CO2 affected δ15N and δ13C values in leaves, stems and nonmycorrhizal roots. Plant tissues and mycorrhiza were more depleted of δ13C in the cooled chamber (-36.83‰ to -31.67‰) than in the greenhouse (-31.09‰ to -29.56‰) and in the outside treatment (-30.92‰ to -27.74‰). Leaves in the cooled chamber (-3.05‰ in CR+ and -3.51‰ in CR-) were 15N depleted compared to leaves in the greenhouse (-1.63‰) and outside (-0.46‰), while roots were 15N enriched (1.79‰ in CR+ and 1.34‰ in CR-) compared to roots in the greenhouse (-0.06‰) and outside treatments (0.33‰). No similar patterns were observed for stems and mycorrhizal roots. The δ13C analyses provide us with an insight into carbon circulation in the air-plant-fungal-soil system, while δ15N values reflect the soil structure and the form of nitrogen uptake of ectomycorrhizal fungi from soil. ACKNOWLEDGEMENTS: The study was financed by the Slovenian Research Agencyv through the research programme group P4-0107 and the PhD young researchers scheme (IŠ), and the projects EUFORINNO(7FW RegPot 315982) and LIFEGENMON (LIFE13ENV/SI/000148).
- Publication:
-
EGU General Assembly Conference Abstracts
- Pub Date:
- April 2018
- Bibcode:
- 2018EGUGA..2013025S