Rising CO2 and warming reduce global canopy demand for nitrogen
© 2022 The Authors. New Phytologist © 2022 New Phytologist Foundation.
| Veröffentlicht in: | The New phytologist. - 1979. - 235(2022), 5 vom: 01. Sept., Seite 1692-1700 |
|---|---|
| 1. Verfasser: | |
| Weitere Verfasser: | , , , , , , |
| Format: | Online-Aufsatz |
| Sprache: | English |
| Veröffentlicht: |
2022
|
| Zugriff auf das übergeordnete Werk: | The New phytologist |
| Schlagworte: | Journal Article Research Support, Non-U.S. Gov't Research Support, U.S. Gov't, Non-P.H.S. CO2 fertilization acclimation coordination hypothesis leaf chlorophyll nitrogen cycle nitrogen demand photosynthetic capacity mehr... |
| Zusammenfassung: | © 2022 The Authors. New Phytologist © 2022 New Phytologist Foundation. Nitrogen (N) limitation has been considered as a constraint on terrestrial carbon uptake in response to rising CO2 and climate change. By extension, it has been suggested that declining carboxylation capacity (Vcmax ) and leaf N content in enhanced-CO2 experiments and satellite records signify increasing N limitation of primary production. We predicted Vcmax using the coordination hypothesis and estimated changes in leaf-level photosynthetic N for 1982-2016 assuming proportionality with leaf-level Vcmax at 25°C. The whole-canopy photosynthetic N was derived using satellite-based leaf area index (LAI) data and an empirical extinction coefficient for Vcmax , and converted to annual N demand using estimated leaf turnover times. The predicted spatial pattern of Vcmax shares key features with an independent reconstruction from remotely sensed leaf chlorophyll content. Predicted leaf photosynthetic N declined by 0.27% yr-1 , while observed leaf (total) N declined by 0.2-0.25% yr-1 . Predicted global canopy N (and N demand) declined from 1996 onwards, despite increasing LAI. Leaf-level responses to rising CO2 , and to a lesser extent temperature, may have reduced the canopy requirement for N by more than rising LAI has increased it. This finding provides an alternative explanation for declining leaf N that does not depend on increasing N limitation |
|---|---|
| Beschreibung: | Date Completed 03.08.2022 Date Revised 05.09.2024 published: Print-Electronic CommentIn: New Phytol. 2022 Sep;235(5):1683-1685. doi: 10.1111/nph.18354. - PMID 35841595 Citation Status MEDLINE |
| ISSN: | 1469-8137 |
| DOI: | 10.1111/nph.18076 |