Dissolved and gaseous nitrogen losses in forests controlled by soil nutrient stoichiometry

0543408 - ÚVGZ 2022 RIV GB eng J - Journal Article
Oulehle, Filip - Goodale, C. L. - Evans, C. D. - Chuman, T. - Hruška, Jakub - Krám, Pavel - Navrátil, Tomáš - Tesař, Miroslav - Ač, Alexander - Urban, Otmar - Tahovská, K.
Dissolved and gaseous nitrogen losses in forests controlled by soil nutrient stoichiometry.
Environmental Research Letters. Roč. 16, č. 6 (2021), č. článku 064025. ISSN 1748-9326. E-ISSN 1748-9326
R&D Projects: GA ČR(CZ) GA18-17295S; GA MŠMT(CZ) LM2015055; GA MŠMT(CZ) EF16_019/0000797
Research Infrastructure: CzeCOS III - 90123
Institutional support: RVO:86652079 ; RVO:67985831 ; RVO:67985874
Keywords : n-15 natural-abundance * organic-matter * isotope fractionation * diffusion technique * global patterns * n fixation * deposition * denitrification * terrestrial * nitrate * nitrogen * catchment * isotope * mass balance * denitrification * carbon * sequestration
OECD category: Environmental sciences (social aspects to be 5.7); Hydrology (GLU-S); Hydrology (UH-J)
Impact factor: 6.947, year: 2021
Method of publishing: Open access
https://iopscience.iop.org/article/10.1088/1748-9326/ac007b

Global chronic nitrogen (N) deposition to forests can alleviate ecosystem N limitation, with potentially wide ranging consequences for biodiversity, carbon sequestration, soil and surface water quality, and greenhouse gas emissions. However, the ability to predict these consequences requires improved quantification of hard-to-measure N fluxes, particularly N gas loss and soil N retention. Here we combine a unique set of long-term catchment N budgets in the central Europe with ecosystem N-15 data to reveal fundamental controls over dissolved and gaseous N fluxes in temperate forests. Stream leaching losses of dissolved N corresponded with nutrient stoichiometry of the forest floor, with stream N losses increasing as ecosystems progress towards phosphorus limitation, while soil N storage increased with oxalate extractable iron and aluminium content. Our estimates of soil gaseous losses based on N-15 stocks averaged 2.5 +/- 2.2 kg N ha(-1) yr(-1) and comprised 20% +/- 14% of total N deposition. Gaseous N losses increased with forest floor N:P ratio and with dissolved N losses. Our relationship between gaseous and dissolved N losses was also able to explain previous N-15-based N loss rates measured in tropical and subtropical catchments, suggesting a generalisable response driven by nitrate (NO3 (-)) abundance and in which the relative importance of dissolved N over gaseous N losses tended to increase with increasing NO3 (-) export. Applying this relationship globally, we extrapolated current gaseous N loss flux from forests to be 8.9 Tg N yr(-1), which represent 39% of current N deposition to forests worldwide.
Permanent Link: http://hdl.handle.net/11104/0320623