ENSO effects on the transpiration of eastern Amazon trees
| Autor: | Heidi Asbjornsen, Gilson Sanchez, Rafael S. Oiveira, Mauro Brum, Jose Gutierrez Lopez, Thomas G. Pypker, Julian Licata |
|---|---|
| Jazyk: | angličtina |
| Rok vydání: | 2018 |
| Předmět: |
0106 biological sciences
010504 meteorology & atmospheric sciences Amazon rainforest Vapour Pressure Deficit Oscillation Articles Atmospheric sciences 01 natural sciences General Biochemistry Genetics and Molecular Biology El Niño Southern Oscillation Environmental science Precipitation General Agricultural and Biological Sciences 010606 plant biology & botany 0105 earth and related environmental sciences Transpiration Tree transpiration |
| Popis: | Tree transpiration is important in the recycling of precipitation in the Amazon and might be negatively affected by El Niño–Southern Oscillation (ENSO)–induced droughts. To investigate the relative importance of soil moisture deficits versus increasing atmospheric demand (VPD) and determine if these drivers exert different controls over tree transpiration during the wet season versus the dry season (DS), we conducted sap flow measurements in a primary lowland tropical forest in eastern Amazon during the most extreme ENSO-induced drought (2015/2016) recorded in the Amazon. We also assessed whether trees occupying different canopy strata contribute equally to the overall stand transpiration ( T stand ). Canopy trees were the primary source of T stand . However, subcanopy trees are still important as they transpired an amount similar to other biomes around the globe. Tree water use was higher during the DS, indicating that during extreme drought trees did not reduce transpiration in response to low soil moisture. Photosynthetically active radiation and VPD exerted an overriding effect on water use patterns relative to soil moisture during extreme drought, indicating that light and atmospheric constraints play a critical role in controlling ecosystem fluxes of water. Our study highlights the importance of canopy and subcanopy trees to the regional water balance and highlights the resilience to droughts that these trees show during an extreme ENSO event. This article is part of a discussion meeting issue ‘The impact of the 2015/2016 El Niño on the terrestrial tropical carbon cycle: patterns, mechanisms and implications’. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|