Isotopic evidence for increased carbon and nitrogen exchanges between peatland plants and their symbiotic microbes with rising atmospheric CO2 concentrations since 15,000 cal. year BP
© 2022 John Wiley & Sons Ltd.
| Veröffentlicht in: | Global change biology. - 1999. - 29(2023), 7 vom: 31. Apr., Seite 1939-1950 |
|---|---|
| 1. Verfasser: | |
| Weitere Verfasser: | , , , , , , , |
| Format: | Online-Aufsatz |
| Sprache: | English |
| Veröffentlicht: |
2023
|
| Zugriff auf das übergeordnete Werk: | Global change biology |
| Schlagworte: | Journal Article Holocene Pleistocene Sphagnum moss elevated CO2 mycorrhizal fungi nitrogen fixation northern peatlands δ15N Nitrogen mehr... |
| Zusammenfassung: | © 2022 John Wiley & Sons Ltd. Whether nitrogen (N) availability will limit plant growth and removal of atmospheric CO2 by the terrestrial biosphere this century is controversial. Studies have suggested that N could progressively limit plant growth, as trees and soils accumulate N in slowly cycling biomass pools in response to increases in carbon sequestration. However, a question remains over whether longer-term (decadal to century) feedbacks between climate, CO2 and plant N uptake could emerge to reduce ecosystem-level N limitations. The symbioses between plants and microbes can help plants to acquire N from the soil or from the atmosphere via biological N2 fixation-the pathway through which N can be rapidly brought into ecosystems and thereby partially or completely alleviate N limitation on plant productivity. Here we present measurements of plant N isotope composition (δ15 N) in a peat core that dates to 15,000 cal. year BP to ascertain ecosystem-level N cycling responses to rising atmospheric CO2 concentrations. We find that pre-industrial increases in global atmospheric CO2 concentrations corresponded with a decrease in the δ15 N of both Sphagnum moss and Ericaceae when constrained for climatic factors. A modern experiment demonstrates that the δ15 N of Sphagnum decreases with increasing N2 -fixation rates. These findings suggest that plant-microbe symbioses that facilitate N acquisition are, over the long term, enhanced under rising atmospheric CO2 concentrations, highlighting an ecosystem-level feedback mechanism whereby N constraints on terrestrial carbon storage can be overcome |
|---|---|
| Beschreibung: | Date Completed 07.03.2023 Date Revised 26.05.2023 published: Print-Electronic Citation Status MEDLINE |
| ISSN: | 1365-2486 |
| DOI: | 10.1111/gcb.16578 |