Rooting depth, water relations and non-structural carbohydrate dynamics in three woody angiosperms differentially affected by an extreme summer drought

Autor: Nardini, Andrea, Casolo, Valentino, Dal Borgo, Anna, Savi, Tadeja, Stenni, Barbara, Bertoncin, Paolo, Zini, Luca, Mcdowell, Nathan G.
Přispěvatelé: Nardini, Andrea, Casolo, Valentino, Dal Borgo, Anna, Savi, Tadeja, Stenni, Barbara, Bertoncin, Paolo, Zini, Luca, Mcdowell, Nathan G.
Jazyk: angličtina
Rok vydání: 2016
Předmět:
Rainfall
Xylem hydraulic
Sucrose
TREE MORTALITY
Angiosperms
Physiology
Rain
Cave
Xylem hydraulics
Plant Science
Oxygen Isotopes
Plant Roots
CARBON STARVATION
Angiosperm
Isotopes
Soil
Xylem sap
Carbohydrates
Caves
Gases
Plant Leaves
Plant Stems
Starch
Temperature
Water
Wood
Xylem
Droughts
Seasons
PLANT HYDRAULICS
TROPICAL TREE
Isotope
Gase
EMBOLISM REPAIR
Plant Leave
HYDRAULIC FAILURE
VEGETATION MORTALITY
Carbohydrate
xylem hydraulics SHALLOW KARST SOILS
cave
isotopes
rainfall
soil
xylem sap
xylem hydraulics SHALLOW KARST SOILS
XYLEM CAVITATION
TREE MORTALITY
HYDRAULIC FAILURE
PLANT HYDRAULICS
EMBOLISM REPAIR
VEGETATION MORTALITY
CARBON STARVATION
USE STRATEGIES
TROPICAL TREE
Plant Stem
Magnoliopsida
Oxygen Isotope
Drought
Plant Root
XYLEM CAVITATION
USE STRATEGIES
Settore GEO/08 - Geochimica e Vulcanologia
Season
Popis: In 2012, an extreme summer drought induced species-specific die-back in woody species in Northeastern Italy. Quercus pubescens and Ostrya carpinifolia were heavily impacted, while Prunus mahaleb was largely unaffected. By comparing seasonal changes in isotopic composition of xylem sap, rainfall and deep soil samples, we show that P. mahaleb has a deeper root system than the other two species. This morphological trait allowed P mahaleb to maintain higher water potential (Ψ), gas exchange rates and non-structural carbohydrates content (NSC) throughout the summer, when compared with the other species. More favourable water and carbon states allowed relatively stable maintenance of stem hydraulic conductivity (k) throughout the growing season. In contrast, in Quercus pubescens and Ostrya carpinifolia, decreasing Ψ and NSC were associated with significant hydraulic failure, with spring-to-summer k loss averaging 60%. Our data support the hypothesis that drought-induced tree decline is a complex phenomenon that cannot be modelled on the basis of single predictors of tree status like hydraulic efficiency, vulnerability and carbohydrate content. Our data highlight the role of rooting depth in seasonal progression of water status, gas exchange and NSC, with possible consequences for energy-demanding mechanisms involved in the maintenance of vascular integrity.
Databáze: OpenAIRE
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