Método de Granier e transpiração do mogno africano

• Autor(a) principal: Sérvulo, Ana Cláudia Oliveira
• Data de Publicação: 2016
• Tipo de documento: Dissertação
• Idioma: por
• Título da fonte: Repositório Institucional da UFG
• Texto Completo: http://repositorio.bc.ufg.br/tede/handle/tede/6222
• topic: Khaya ivorensis A. Chev.; Fluxo de seiva; Necessidade hídrica; Sap flux; Water requirement; Vegetative growth; AGRONOMIA::CIENCIA DO SOLO

The African Mahogany’s commercial exploitation in the Brazilian Midwest lacks information to assist management strategies of the specie and natural resources, specially water. The transpiration and growth analysis are useful, not just for water management, but also to support physiological studies. The Granier method (thermal dissipation probe – TDP) uses sap flow measurements to estimate transpiration in woody species, however it requires validate for each new specie. This paper aimed to study the African Mahogany’s water consumption and growth in the Cerrado bioma. The main activities aimed to: a) Adjust the Granier’s sap flux method to African Mahogany; b) Quantify water consumption and vegetative growth on a 2.5 years old African Mahogany’s forest, under two water regimes; c) Establish relations between tree transpiration and atmospheric water demand. This research consisted of two experiments. The first one, happened in oct-nov/2014 and feb-may/2015, consisted of the Granier’s model adjustment with aid of the lysimetry, for use in African Mahogany’s transpiration measurements. The second experiment, happened between oct/2014 and oct/2015, on a commercial forest up to 2.5 years old, evaluated water consumption (transpiration by leaf area – T) using integrated sap flux measurements by TDP, and vegetative growth [leaf area (AF), diameter at breast height (DAP), tree height (Alt), trunk volume (VTR) and leaf dry biomass (BMF)], treatments were defined as: T1 – forest with irrigation interrupted at two years old; T2 – forest without irrigation. The adjusted sap flux model to African mahogany is F    k  AS 6 1,231 268,25 10 , and the original Granier’s model underestimates the transpiration in 39.1%. The average potential transpiration was between 2.1 and 34.8 L day-1. In field conditions, the growth benefits from the T1 are seen in highest values for AF, DAP and BMF. However, the Alt and VTR are not significant different. The monthly T under field conditions varied between 10.2 and 24.2 L m-2, except for jul-aug/2015, when T2 transpiration was higher. The combination of bigger leaf area and low soil water content led to T1’s water deficit scenario.