Busca avançada
Ano de início
Entree
(Referência obtida automaticamente do Web of Science, por meio da informação sobre o financiamento pela FAPESP e o número do processo correspondente, incluída na publicação pelos autores.)

Environmental controls in the water use patterns of a tropical cloud forest tree species, Drimys brasiliensis (Winteraceae)

Texto completo
Autor(es):
Eller, Cleiton B. [1] ; Burgess, Stephen S. O. [2] ; Oliveira, Rafael S. [1, 2]
Número total de Autores: 3
Afiliação do(s) autor(es):
[1] Univ Campinas UNICAMP, Dept Plant Biol, Inst Biol, Campinas, SP - Brazil
[2] Univ Western Australia UWA, Sch Plant Biol, Perth, WA 6009 - Australia
Número total de Afiliações: 2
Tipo de documento: Artigo Científico
Fonte: TREE PHYSIOLOGY; v. 35, n. 4, SI, p. 387-399, APR 2015.
Citações Web of Science: 27
Resumo

Trees from tropical montane cloud forest (TMCF) display very dynamic patterns of water use. They are capable of downwards water transport towards the soil during leaf-wetting events, likely a consequence of foliar water uptake (FWU), as well as high rates of night-time transpiration (E-night) during drier nights. These two processes might represent important sources of water losses and gains to the plant, but little is known about the environmental factors controlling these water fluxes. We evaluated how contrasting atmospheric and soil water conditions control diurnal, nocturnal and seasonal dynamics of sap flow in Drimys brasiliensis (Miers), a common Neotropical cloud forest species. We monitored the seasonal variation of soil water content, micro-meteorological conditions and sap flow of D. brasiliensis trees in the field during wet and dry seasons. We also conducted a greenhouse experiment exposing D. brasiliensis saplings under contrasting soil water conditions to deuterium-labelled fog water. We found that during the night D. brasiliensis possesses heightened stomatal sensitivity to soil drought and vapour pressure deficit, which reduces night-time water loss. Leaf-wetting events had a strong suppressive effect on tree transpiration (E). Foliar water uptake increased in magnitude with drier soil and during longer leaf-wetting events. The difference between diurnal and nocturnal stomatal behaviour in D. brasiliensis could be attributed to an optimization of carbon gain when leaves are dry, as well as minimization of nocturnal water loss. The leaf-wetting events on the other hand seem important to D. brasiliensis water balance, especially during soil droughts, both by suppressing tree transpiration (E) and as a small additional water supply through FWU. Our results suggest that decreases in leaf-wetting events in TMCF might increase D. brasiliensis water loss and decrease its water gains, which could compromise its ecophysiological performance and survival during dry periods. (AU)

Processo FAPESP: 10/17204-0 - Mudanças climáticas em montanhas brasileiras: respostas funcionais de plantas nativas de campos rupestres e campos de altitude a secas extremas
Beneficiário:Rafael Silva Oliveira
Linha de fomento: Auxílio à Pesquisa - Regular
Processo FAPESP: 11/52072-0 - Interações entre solo-vegetação-atmosfera em uma paisagem tropical em transformação
Beneficiário:Rafael Silva Oliveira
Linha de fomento: Auxílio à Pesquisa - Parceria para Inovação Tecnológica - PITE
Processo FAPESP: 13/19555-2 - Dinâmica de uso de água e balanço de carbono de espécies lenhosas de matas nebulares
Beneficiário:Cleiton Breder Eller
Linha de fomento: Bolsas no Brasil - Doutorado