Abstract
Deforestation, followed by abandonment and forest regeneration, has become one of the dominant types of land cover changes in the tropics. This study applied the eddy covariance (EC) technique to quantify the energy budget and evapotranspiration in a regenerated secondary dry dipterocarp forest in Western Thailand. The mean annual net radiation was 126.69, 129.61, and 125.65 W m−2 day−1 in 2009, 2010, and 2011, respectively. On average, fluxes of this energy were disaggregated into latent heat (61%), sensible heat (27%), and soil heat flux (1%). While the number of energy exchanges was not significantly different between these years, there were distinct seasonal patterns within a year. In the wet season, more than 79% of energy fluxes were in the form of latent heat, while during the dry season, this was in the form of sensible heat. The energy closure in this forest ecosystem was 86% and 85% in 2010 and 2011, respectively, and varied between 84–87% in the dry season and 83–84% in the wet season. The seasonality of these energy fluxes and energy closure can be explained by rainfall, soil moisture, and water vapor deficit. The rates of evapotranspiration also significantly varied between the wet (average 6.40 mm day−1) and dry seasons (3.26 mm day−1).
Highlights
In tropical regions, deforestation has been the predominant mode of land use changes [1,2]
A general pattern of rainfall at the site is as follows: the dry period was between November–April when monthly rainfall was usually below 100 mm, and the rest of the time was the wet season with monthly rainfall exceeding 100 mm
During the dry months (November–April) and rain break, soil water content (SWC) decreased to below 10% volumetric water content (VWC), while during the rest of the year, it stayed above
Summary
Deforestation has been the predominant mode of land use changes [1,2]. It was estimated that deforestation in Southeast Asia resulted in a forest area loss of 43 × 106 ha between 1880 and 1980, equivalent to 28% of the initial area in 1880 [3]. In many cases clearing is coupled with subsequent abandonment [4] that has enabled the regeneration of forests [5]. This type of forest is known as a secondary forest and represents one of the dominant forest types in the tropics [6,7]. The International Tropical Timber Organization [8] and the Food and Agriculture Organization of the United Nations [9] estimated that 60% of tropical forest cover was degraded or secondary in 2002
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
