Transpiração pelo método de dissipação térmica em áreas de vegetação campina e campinarana da Amazônia Central

Abstract

Transpiration is one of the hydrological cycle processes of great importance for studies on plant physiology, and, in recent years, sap flow measurements have been used to determine canopy transpiration. In this sense, the present study aimed to estimate the transpiration of trees in two types of vegetation in Central Amazonia, Campina and Campinarana, using measurements of sap flow. To determine the sap flow, the thermal dissipation method was used, with data collected daily between March 2007 and March 2008. Through the daily average of sap flow obtained, it was found that the values transpired by Campina were about 82 .7% higher than the values issued by Campinarana. The sap flow values were also determined for each month, and the Campina vegetation had the lowest sap flow value in May, with 31.6 mm month-1, the highest sap flow occurred in November. , which refers to the rainy season in the region. The Campinarana vegetation, on the other hand, presented the highest values of sap flow, which occurred in March 2007 and March 2008, with 40.3 mm month-1 and 42.2 mm month-1, respectively. In the period of one year, the sap flow in the Campinarana vegetation was greater than in the Campina vegetation, such results can be justified by the fact that in the Campina vegetation there is a less homogeneous canopy cover, allowing the entry of wind and heat, increasing evaporation. of soil water and vegetation. We concluded that the transpiration values brought important information about the water use mechanisms of these vegetations, in addition, we observed that the two vegetations behaved differently in the face of environmental and physiological variables