Instituto de Desenvolvimento Sustentável Mamirauá, Tefé, Amazonas, Brazil.
Instituto de Pesquisas Hidráulicas (IPH), Universidade Federal do Rio Grande do Sul (UFRGS), Porto Alegre, Brazil.
Nat Commun. 2023 Oct 20;14(1):6656. doi: 10.1038/s41467-023-42467-0.
Evapotranspiration (ET) is a key process linking surface and atmospheric energy budgets, yet its drivers and patterns across wetlandscapes are poorly understood worldwide. Here we assess the ET dynamics in 12 wetland complexes across South America, revealing major differences under temperate, tropical, and equatorial climates. While net radiation is a dominant driver of ET seasonality in most environments, flooding also contributes strongly to ET in tropical and equatorial wetlands, especially in meeting the evaporative demand. Moreover, significant water losses through wetlands and ET differences between wetlands and uplands occur in temperate, more water-limited environments and in highly flooded areas such as the Pantanal, where slow river flood propagation drives the ET dynamics. Finally, floodplain forests produce the greatest ET in all environments except the Amazon River floodplains, where upland forests sustain high rates year round. Our findings highlight the unique hydrological functioning and ecosystem services provided by wetlands on a continental scale.
蒸散作用（ET）是连接地表和大气能量收支的关键过程，但全球范围内对其在湿地景观中的驱动因素和模式仍了解甚少。本研究评估了南美洲 12 个湿地复合体的 ET 动态，揭示了在温带、热带和赤道气候下的主要差异。虽然净辐射是大多数环境中 ET 季节性的主要驱动因素，但洪水在热带和赤道湿地中对 ET 的贡献也很强，尤其是在满足蒸发需求方面。此外，在温带、水资源更为有限的环境中和潘塔纳尔等洪水泛滥地区，湿地会发生大量的水分流失，且湿地与高地之间的 ET 存在差异，在这些地区，缓慢的河流洪水传播驱动着 ET 动态。最后，除了亚马孙河泛滥平原外，在所有环境中，洪泛平原森林的 ET 最大，而高地森林在全年都维持着较高的速率。本研究结果强调了湿地在大陆尺度上提供的独特水文功能和生态系统服务。
