Measurements of rubber tree transpiration in adult plantations

Verdier M., Roupsard Olivier, Thaler Philippe, Chantuma Arak, Siripornpakdeekul Pongpan, Kasemsap Poonpipope, Sangkhasila Kumut. 2006. Measurements of rubber tree transpiration in adult plantations. In : International Natural Rubber Conference, November 13-14, 2006, Ho Chi Minh, Vietnam : Preprints of papers. Mai Van Son, Nguyen Ngoc Bich, Tong Viet Thinh. Ho Chi Minh City : Rubber Research Institute of Vietnam, Résumé, 171. International Natural Rubber Conference, Ho Chi Minh, Viet Nam, 13 Novembre 2006/14 Novembre 2006.

Résumé : In order to assess water balance of rubber plantations at plot scale, accurate dynamic measurements of tree transpiration is required. Sapflow was measured in a 12 years old plantation (RRIM 600) in eastern Thailand, by heat dissipation method (Granier 1985, 1987) using home-made 20 mm-long radial probes, continuously heated (0.2 W), and connected to a data logger. The calibration of the homemade probes was checked in the laboratory with reference to the gravimetric method. We adjusted the experimental devices to rubber field conditions and evaluated the different sources of variability to design the appropriate monitoring process. Natural thermal gradient was not significant. Vertical variation along the trunk below canopy was low. Conversely a significant azimuthal variation was recorded, though without specific trend. Accordingly 2 probes (one on the North face, one on the South face), located above the tapping panel were used for monitoring. Radial distribution of sapflow was recorded, using a long probe, and our results showed significant variations of sapflow along the radius. A function was derived from these radial variations to estimate total tree sapflow from measurements within the outer 2 cm of sapwood. Finally to evaluate stand transpiration (mm h-1), trees were sampled according to trunk diameter. Such data will be used to partition evapotranspiration measured on the same plot by eddy-correlation between tree transpiration, T, and soil and understorey evaporation, E. (Texte intégral)

Mots-clés Agrovoc : Hevea brasiliensis, plantations, transpiration

Mots-clés géographiques Agrovoc : Thaïlande

Classification Agris : F62 - Physiologie végétale - Croissance et développement

Auteurs et affiliations

• Verdier M.
• Roupsard Olivier, CIRAD-FORET-UPR Ecosystèmes de plantations (VUT) ORCID: 0000-0002-1319-142X
• Thaler Philippe, CIRAD-FORET-UPR Ecosystèmes de plantations (THA) ORCID: 0000-0002-9924-4309
• Chantuma Arak
• Siripornpakdeekul Pongpan
• Kasemsap Poonpipope, Kasetsart University (THA)
• Sangkhasila Kumut

Source : Cirad - Agritrop (https://agritrop.cirad.fr/552382/)

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