A simple framework to analyze water constraints on seasonal transpiration in rubber tree (Hevea brasiliensis) plantations

Frontiers in Plant Science

Frederic eGay¹  Philippe eThaler¹  Frederic C. Do²  Claude eHammecker²  Supat eIsarangkool Na Ayutthaya³  Charlchai eTanavud⁴  Jessada eSopharat⁴  Sayan eSdoodee⁴ 

[1] CIRAD;IRD;Khon Kaen University;Prince of Songkla University;

关键词: drought;    Canopy phenology;    Relative extractable soil water;    potential transpiration model;    high evaporative demand;   

DOI  :  10.3389/fpls.2014.00753

来源: DOAJ

【 摘 要 】

Climate change and fast extension in climatically suboptimal areas threaten the sustainability of rubber tree cultivation. A simple framework based on reduction factors of potential transpiration was tested to evaluate the water constraints on seasonal transpiration in tropical sub-humid climates, according pedoclimatic conditions. We selected a representative, mature stand in a drought-prone area. Tree transpiration, evaporative demand and soil water availability were measured every day over 15 months. The results showed that basic relationships with evaporative demand, leaf area index and soil water availability were globally supported. However the implementation of a regulation of transpiration at high evaporative demand whatever soil water availability was necessary to avoid large overestimates of transpiration. The details of regulation were confirmed by the analysis of canopy conductance response to vapour pressure deficit. The final objective of providing hierarchy between the main regulation factors of seasonal and annual transpiration was achieved. In the tested environmental conditions, the impact of atmospheric drought appeared larger importance than soil drought contrary to expectations. Our results support the interest in simple models to provide a first diagnosis of water constraints on transpiration with limited data, and to help decision making towards more sustainable rubber plantations.

【 授权许可】

Unknown