Data/hora: 01/06/2024 02:41:09

Biblioteca(s): | Embrapa Amazônia Oriental.
Data corrente: | 04/12/2023
Data da última atualização: | 04/12/2023
Autoria: | MENG, L.; CHAMBERS, J.; KOVEN, C.; PASTORELLO, G.; GIMENEZ, B.; JARDINE, K.; TANG, Y.; McDOWELL, N.; NEGRON-JUAREZ, R.; LONGO, M.; ARAUJO, A. C. de; TOMASELLA, J.; FONTES, C.; MOHAN, M.; HIGUCHI, N.
Afiliação: | LIN MENG, Lawrence Berkeley National Laboratory; JEFFREY CHAMBERS, Lawrence Berkeley National Laboratory / University of California Berkeley; CHARLES KOVEN, Lawrence Berkeley National Laboratory; GILBERTO PASTORELLO, Lawrence Berkeley National Laboratory; BRUNO GIMENEZ, INPA / Smithsonian Tropical Research Institute; KOLBY JARDINE, Lawrence Berkeley National Laboratory; YAO TANG, Lawrence Berkeley National Laboratory; NATE MCDOWELL, Pacific Northwest National Laboratory; ROBINSON NEGRON-JUAREZ, Lawrence Berkeley National Laboratory; MARCOS LONGO, Lawrence Berkeley National Laboratory; ALESSANDRO CARIOCA DE ARAUJO, CPATU; JAVIER TOMASELLA, Centro Nacional de Monitoramento e Alertas de Desastres Naturais—CEMADEN; CLARISSA FONTES, University of California; MIDHUN MOHAN, Lawrence Berkeley National Laboratory / University of California Berkeley; NIRO HIGUCHI, INPA.
Título: | Soil moisture thresholds explain a shift from light-limited to water-limited sap velocity in the Central Amazon during the 2015-16 El Niño drought.
Ano de publicação: | 2022
Fonte/Imprenta: | Environmental Research Letters, v. 17, n. 6, 064023, 2022.
DOI: | https://doi.org/10.1088/1748-9326/ac6f6d
Idioma: | Inglês
Conteúdo: | Transpiration is often considered to be light- but not water-limited in humid tropical rainforests due to abundant soil water, even during the dry seasons. The record-breaking 2015?16 El Niño drought provided a unique opportunity to examine whether transpiration is constrained by water under severe lack of rainfall. We measured sap velocity, soil water content, and meteorological variables in an old-growth upland forest in the Central Amazon throughout the 2015?16 drought. We found a rapid decline in sap velocity (-38 ± 21%, mean ± SD.) and in its temporal variability (-88%) during the drought compared to the wet season. Such changes were accompanied by a marked decline in soil moisture and an increase in temperature and vapor pressure deficit. Sap velocity was largely limited by net radiation during the wet and normal dry seasons; however, it shifted to be primarily limited by soil moisture during the drought. The threshold in which sap velocity became dominated by soil moisture was at 0.33 m3 m-3 (around -150 kPa in soil matric potential), below which sap velocity dropped steeply. Our study provides evidence for a soil water threshold on transpiration in a moist tropical forest, suggesting a shift from light limitation to water limitation under future climate characterized by increased temperature and an increased frequency, intensity, duration and extent of extreme drought events.
Palavras-Chave: | Ciclo da água; Soil moisture; Water cycle.
Thesagro: | Evapotranspiração; Floresta Tropical; Seca; Umidade do Solo.
Thesaurus Nal: | Drought; Evapotranspiration; Tropical forests.
Categoria do assunto: | P Recursos Naturais, Ciências Ambientais e da Terra
Registro original: | Embrapa Amazônia Oriental (CPATU)
Exemplares: | CPATU - (59196-1) - UPC - AP - DD -  -  -  - DIS