Transient response of sap flow to wind speed
| Autor: | Cheng-I Hsieh, Shen Yuang Wu, Chia Ren Chu, Nathan Phillips |
|---|---|
| Rok vydání: | 2008 |
| Předmět: |
Daytime
Physiology Internal flow Flow (psychology) Water Plant Transpiration Wind Plant Science Atmospheric sciences Research Papers transient response Models Biological Wind speed sap flow Bombacaceae Botany Nocturnal transpiration Environmental science Transient (oscillation) Transient response wind speed Wind tunnel Transpiration |
| Zdroj: | Journal of Experimental Botany |
| ISSN: | 1460-2431 0022-0957 |
| DOI: | 10.1093/jxb/ern282 |
| Popis: | Transient responses of sap flow to step changes in wind speed were experimentally investigated in a wind tunnel. AGranier-type sap flow sensor was calibrated and tested in a cylindrical tube for analysis of its transient time response.Then the sensor was used to measure the transient response of a well-watered Pachira macrocarpa plant to windspeed variations. The transient response of sap flow was described using the resistance–capacitance model. Thesteady sap flow rate increased as the wind speed increased at low wind speeds. Once the wind speed exceeded8.0 m s 2 1 , the steady sap flow rate did not increase further. The transpiration rate, measured gravimetrically, showeda similar trend. The response of nocturnal sap flow to wind speed variation was also measured and compared withthe results in the daytime. Under the same wind speed, the steady sap flow rate was smaller than that in the daytime,indicating differences between diurnal and nocturnal hydraulic function, and incomplete stomatal closure at night. Inaddition, it was found that the temporal response of the Granier sensor is fast enough to resolve the transientbehaviour of water flux in plant tissue.Key words: Nocturnal transpiration, sap flow, transient response, wind speed. |
| Databáze: | OpenAIRE |
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