Canopy processing of N deposition increases short-term leaf N uptake and photosynthesis, but not long-term N retention for aspen seedlings
© 2020 The Authors New Phytologist © 2020 New Phytologist Foundation.
| Veröffentlicht in: | The New phytologist. - 1979. - 229(2021), 5 vom: 01. März, Seite 2601-2610 |
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| 1. Verfasser: | |
| Weitere Verfasser: | , , , , , , , , , |
| Format: | Online-Aufsatz |
| Sprache: | English |
| Veröffentlicht: |
2021
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| Zugriff auf das übergeordnete Werk: | The New phytologist |
| Schlagworte: | Journal Article Research Support, Non-U.S. Gov't 15N labeling canopy nitrogen uptake leaf photosynthesis nitrogen allocation nitrogen deposition soil nitrogen addition stable isotope Nitrogen |
| Zusammenfassung: | © 2020 The Authors New Phytologist © 2020 New Phytologist Foundation. Forest canopies can retain nitrogen (N) from atmospheric deposition. However, most empirical and modeling studies do not consider the processing of the N deposited in the canopy. To assess whether N deposition through canopy will alter the plant's N uptake and retention, we conducted a 3-yr mesocosm experiment by applying (15 NH4 )2 SO4 solution to aspen sapling canopies or directly to the soil. We found that 15 N-NH4+ applied to the canopy was directly taken up by leaves. Compared with the soil N application, the canopy N application resulted in higher photosynthesis but lower N retention of the plant-soil system in the first growing season. Plant biomass, N concentration, and leaf N resorption were not significantly different between the canopy and soil N applications. The partitioning of retained 15 N among plant components and soil layers was similar between the two treatments 3 yr after the N application. Our findings indicated that the canopy N processing could alter leaf N supply and photosynthesis in the short term but not N retention in the long term. Under natural conditions, the chronic N deposition could continuously refill the canopy N pool, causing a sustained increase in canopy carbon uptake. Canopy N processing needs to be considered for accurately predicting the impact of N deposition |
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| Beschreibung: | Date Completed 14.05.2021 Date Revised 14.05.2021 published: Print-Electronic Citation Status MEDLINE |
| ISSN: | 1469-8137 |
| DOI: | 10.1111/nph.17041 |