In-depth analysis of N2O fluxes in tropical forest soils of the Congo Basin combining isotope and functional gene analysis
| Autor: | Simon Baumgartner, Joachim Mohn, Johan Six, Landry Cizungu Ntaboba, Matti Barthel, Engil Isadora Pujol Pereira, Isaac Ahanamungu Makelele, Pascal Boeckx, Elizabeth Verhoeven, Manon Longepierre, Marijn Bauters, John Kalume Mugula, Travis W. Drake, Nora Gallarotti |
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| Jazyk: | angličtina |
| Rok vydání: | 2021 |
| Předmět: |
N2O emissions
Denitrification Technology and Engineering 010504 meteorology & atmospheric sciences Soil test Evolution TIME-SERIES NITROUS-OXIDE EMISSIONS Rainforest Biology Structural basin Atmospheric sciences NITRIFICATION 01 natural sciences Microbiology Behavior and Systematics Abundance (ecology) Forest ecology AMAZON FOREST LOSSES Ecology Evolution Behavior and Systematics 0105 earth and related environmental sciences Ecology Biogeochemistry 04 agricultural and veterinary sciences RAIN-FOREST Congo Basin equipment and supplies NITRIFIER DENITRIFICATION Chemistry DENITRIFYING BACTERIA Earth and Environmental Sciences Soil water 040103 agronomy & agriculture 0401 agriculture forestry and fisheries RIBOSOMAL-RNA NOSZ GENES |
| Zdroj: | ISME JOURNAL The ISME Journal, 15 |
| ISSN: | 1751-7362 1751-7370 |
| Popis: | Primary tropical forests generally exhibit large gaseous nitrogen (N) losses, occurring as nitric oxide (NO), nitrous oxide (N2O) or elemental nitrogen (N2). The release of N2O is of particular concern due to its high global warming potential and destruction of stratospheric ozone. Tropical forest soils are predicted to be among the largest natural sources of N2O; however, despite being the world’s second-largest rainforest, measurements of gaseous N-losses from forest soils of the Congo Basin are scarce. In addition, long-term studies investigating N2O fluxes from different forest ecosystem types (lowland and montane forests) are scarce. In this study we show that fluxes measured in the Congo Basin were lower than fluxes measured in the Neotropics, and in the tropical forests of Australia and South East Asia. In addition, we show that despite different climatic conditions, average annual N2O fluxes in the Congo Basin’s lowland forests (0.97 ± 0.53 kg N ha−1 year−1) were comparable to those in its montane forest (0.88 ± 0.97 kg N ha−1 year−1). Measurements of soil pore air N2O isotope data at multiple depths suggests that a microbial reduction of N2O to N2 within the soil may account for the observed low surface N2O fluxes and low soil pore N2O concentrations. The potential for microbial reduction is corroborated by a significant abundance and expression of the gene nosZ in soil samples from both study sites. Although isotopic and functional gene analyses indicate an enzymatic potential for complete denitrification, combined gaseous N-losses (N2O, N2) are unlikely to account for the missing N-sink in these forests. Other N-losses such as NO, N2 via Feammox or hydrological particulate organic nitrogen export could play an important role in soils of the Congo Basin and should be the focus of future research. The ISME Journal, 15 ISSN:1751-7362 ISSN:1751-7370 |
| Databáze: | OpenAIRE |
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