Evidence for efficient nonevaporative leaf-to-air heat dissipation in a pine forest under drought conditions
© 2021 The Authors. New Phytologist © 2021 New Phytologist Foundation.
| Veröffentlicht in: | The New phytologist. - 1979. - 232(2021), 6 vom: 25. Dez., Seite 2254-2266 |
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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 air-cooling convector effect evaporative cooling infrared thermal sensing leaf temperature leaf-to-air temperature difference sensible heat flux |
| Zusammenfassung: | © 2021 The Authors. New Phytologist © 2021 New Phytologist Foundation. The drier climates predicted for many regions will result in reduced evaporative cooling, leading to leaf heat stress and enhanced mortality. The extent to which nonevaporative cooling can contribute to plant resilience under these increasingly stressful conditions is not well known at present. Using a novel, high accuracy infrared system for the continuous measurement of leaf temperature in mature trees under field conditions, we assessed leaf-to-air temperature differences (ΔTleaf-air ) of pine needles during drought. On mid-summer days, ΔTleaf-air remained < 3°C, both in trees exposed to summer drought and in those provided with supplemental irrigation, which had a more than 10-fold higher transpiration rate. The nonevaporative cooling in the drought-exposed trees must be facilitated by low resistance to heat transfer, generating a large sensible heat flux, H. ΔTleaf-air was weakly related to variations in the radiation load and mean wind speed in the lower part of the canopy, but was dependent on canopy structure and within-canopy turbulence that enhanced the H. Nonevaporative cooling is demonstrated as an effective cooling mechanism in needle-leaf trees which can be a critical factor in forest resistance to drying climates. The generation of a large H at the leaf scale provides a basis for the development of the previously identified canopy-scale 'convector effect' |
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| Beschreibung: | Date Completed 06.01.2022 Date Revised 06.01.2022 published: Print-Electronic Citation Status MEDLINE |
| ISSN: | 1469-8137 |
| DOI: | 10.1111/nph.17742 |