Postgraduate Program in Plant Production, Academic Unit of Serra Talhada, Federal Rural University of Pernambuco, Serra Talhada, Pernambuco, Brazil.
Department of Biodiversity, Institute of Biosciences, São Paulo State University-UNESP, Av. 24A, 1515, Rio Claro, 13506-900, São Paulo, Brazil.
J Environ Manage. 2024 Sep;367:121959. doi: 10.1016/j.jenvman.2024.121959. Epub 2024 Jul 28.
Changes to forests due to deforestation, or their replacement by agricultural areas, alter evapotranspiration and the partitioning of available energy. This study investigated seasonal variations in the energy balance and evapotranspiration in landscapes under different levels of anthropogenic intervention in the semi-arid region of Brazil. Micrometeorological data was obtained from September 2020 to October 2022 for three areas of the semi-arid region: preserved Caatinga (CAA, native vegetation), Caatinga under regeneration (REGE) and a deforested area (DEFA). Here, we use the Bowen ratio energy balance method. Measurements were taken of global solar radiation, air temperature, relative humidity, vapour pressure deficit, rainfall, net radiation, latent heat flux, sensible heat flux, soil heat flux, evapotranspiration, volumetric soil water content and Normalised Difference Vegetation Index. Sensible heat flux was the dominant flux in both areas with 66% for preserved Caatinga vegetation, 63% for Caatinga under regeneration and 62% deforested area. The latent heat flux was equivalent to 28% of the net radiation for preserved Caatinga vegetation, Caatinga under regeneration and deforested area. The evapotranspiration in turn responded as a function of water availability, being higher during the rainy seasons, with average values of 1.82 mm day for preserved Caatinga vegetation, 2.26 mm day for Caatinga under regeneration and 1.25 mm day for deforested area. The Bowen ratio presented values > 1 in deforested area, preserved Caatinga vegetation and Caatinga under regeneration. Thus, it can be concluded that the change in land use alters the energy balance components, promoting reductions in available energy and latent and sensible heat fluxes during the rainy-dry transition in the deforested area. In addition, the seasonality of energy fluxes depends on water availability in the environment.
由于森林砍伐或被农业区取代，森林的变化改变了蒸散和可用能量的分配。本研究调查了巴西半干旱地区不同人为干预水平下的景观能量平衡和蒸散的季节性变化。从 2020 年 9 月到 2022 年 10 月，在半干旱地区的三个区域获得了微气象数据：原生植被的保护卡廷加（CAA）、再生中的卡廷加（REGE）和砍伐森林的区域（DEFA）。在这里，我们使用波文比能量平衡法。测量了总太阳辐射、空气温度、相对湿度、水汽压亏缺、降雨量、净辐射、潜热通量、感热通量、土壤热通量、蒸散量、土壤体积含水量和归一化差异植被指数。在这两个区域中，感热通量都是主要的通量，分别占保护卡廷加植被的 66%、再生卡廷加的 63%和砍伐森林的 62%。潜热通量相当于保护卡廷加植被、再生卡廷加和砍伐森林净辐射的 28%。蒸散量反过来又作为水分可用性的函数而变化，在雨季更高，保护卡廷加植被的平均值为 1.82 毫米/天，再生卡廷加的为 2.26 毫米/天，砍伐森林的为 1.25 毫米/天。在砍伐森林的区域、保护卡廷加植被和再生卡廷加中，波文比的值>1。因此，可以得出结论，土地利用的变化改变了能量平衡的组成部分，在砍伐森林的区域从雨季到旱季的过渡期间减少了可用能量和潜热及感热通量。此外，能量通量的季节性取决于环境中的水分可用性。
