Canopy temperatures strongly overestimate leaf thermal safety margins of tropical trees
© 2024 The Author(s). New Phytologist © 2024 New Phytologist Foundation.
| Veröffentlicht in: | The New phytologist. - 1979. - 243(2024), 6 vom: 15. Aug., Seite 2115-2129 |
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| 1. Verfasser: | |
| Weitere Verfasser: | , , , , , , , , , , |
| Format: | Online-Aufsatz |
| Sprache: | English |
| Veröffentlicht: |
2024
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| Zugriff auf das übergeordnete Werk: | The New phytologist |
| Schlagworte: | Journal Article canopy temperature elevation gradient homeothermy leaf temperature stomatal conductance thermal safety margin thermoregulation tropical forest |
| Zusammenfassung: | © 2024 The Author(s). New Phytologist © 2024 New Phytologist Foundation. Current estimates of temperature effects on plants mostly rely on air temperature, although it can significantly deviate from leaf temperature (Tleaf). To address this, some studies have used canopy temperature (Tcan). However, Tcan fails to capture the fine-scale variation in Tleaf among leaves and species in diverse canopies. We used infrared radiometers to study Tleaf and Tcan and how they deviate from air temperature (ΔTleaf and ΔTcan) in multispecies tropical tree plantations at three sites along an elevation and temperature gradient in Rwanda. Our results showed high Tleaf (up to c. 50°C) and ΔTleaf (on average 8-10°C and up to c. 20°C) of sun-exposed leaves during 10:00 h-15:00 h, being close to or exceeding photosynthetic heat tolerance thresholds. These values greatly exceeded simultaneously measured values of Tcan and ΔTcan, respectively, leading to strongly overestimated leaf thermal safety margins if basing those on Tcan data. Stomatal conductance and leaf size affected Tleaf and Tcan in line with their expected influences on leaf energy balance. Our findings highlight the importance of leaf traits for leaf thermoregulation and show that monitoring Tcan is not enough to capture the peak temperatures and heat stress experienced by individual leaves of different species in tropical forest canopies |
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| Beschreibung: | Date Completed 22.08.2024 Date Revised 22.08.2024 published: Print-Electronic Citation Status MEDLINE |
| ISSN: | 1469-8137 |
| DOI: | 10.1111/nph.20013 |