INVESTIGADORES
BUCCI Sandra Janet
artículos
Título:
Size-dependent mortality in a Neotropical savanna tree: the role of height-related adjustments in hydraulic architecture and carbon allocation
Autor/es:
YONG-JIANG ZHANG, FREDERICK C. MEINZER, GUANG-YOU HAO FABIAN G. SCHOLZ, SANDRA J. BUCCI, AUGUSTO C. FRANCO, RANDOL VILLALOBOS-VEGA, JUAN P. GIRALDO, KUN-FANG CAO, WILLIAM A. HOFFMANN & GUILLERMO GOLDSTEIN
Revista:
Plant Cell and Environment
Editorial:
Blackwell
Referencias:
Año: 2009 p. 1 - 11
Resumen:
Size-related changes in hydraulic architecture, carbon
allocation and gas exchange of Sclerolobium paniculatumSclerolobium paniculatum
(Leguminosae), a dominant tree species in Neotropical
savannas of central Brazil (Cerrado), were investigated
to assess their potential role in the dieback of tall individuals.
Trees greater than ~6-m-tall exhibited more branch
damage, larger numbers of dead individuals, higher wood
density, greater leaf mass per area, lower leaf area to
sapwood area ratio (LA/SA), lower stomatal conductance
and lower net CO2 assimilation than small trees. Stemspecific
hydraulic conductivity decreased, while leaf-specific
hydraulic conductivity remained nearly constant, with
increasing tree size because of lower LA/SA in larger trees.
Leaves were substantially more vulnerable to embolism
than stems. Large trees had lower maximum leaf hydraulic
conductance (Kleaf) than small trees and all tree sizes exhibited
lower Kleaf at midday than at dawn. These size-related
adjustments in hydraulic architecture and carbon allocation
apparently incurred a large physiological cost: large trees
received a lower return in carbon gain from their investment
in stem and leaf biomass compared with small trees.
Additionally, large trees may experience more severe water
deficits in dry years due to lower capacity for buffering the
effects of hydraulic path-length and soil water deficits.2 assimilation than small trees. Stemspecific
hydraulic conductivity decreased, while leaf-specific
hydraulic conductivity remained nearly constant, with
increasing tree size because of lower LA/SA in larger trees.
Leaves were substantially more vulnerable to embolism
than stems. Large trees had lower maximum leaf hydraulic
conductance (Kleaf) than small trees and all tree sizes exhibited
lower Kleaf at midday than at dawn. These size-related
adjustments in hydraulic architecture and carbon allocation
apparently incurred a large physiological cost: large trees
received a lower return in carbon gain from their investment
in stem and leaf biomass compared with small trees.
Additionally, large trees may experience more severe water
deficits in dry years due to lower capacity for buffering the
effects of hydraulic path-length and soil water deficits.Kleaf) than small trees and all tree sizes exhibited
lower Kleaf at midday than at dawn. These size-related
adjustments in hydraulic architecture and carbon allocation
apparently incurred a large physiological cost: large trees
received a lower return in carbon gain from their investment
in stem and leaf biomass compared with small trees.
Additionally, large trees may experience more severe water
deficits in dry years due to lower capacity for buffering the
effects of hydraulic path-length and soil water deficits.Kleaf at midday than at dawn. These size-related
adjustments in hydraulic architecture and carbon allocation
apparently incurred a large physiological cost: large trees
received a lower return in carbon gain from their investment
in stem and leaf biomass compared with small trees.
Additionally, large trees may experience more severe water
deficits in dry years due to lower capacity for buffering the
effects of hydraulic path-length and soil water deficits.~6-m-tall exhibited more branch
damage, larger numbers of dead individuals, higher wood
density, greater leaf mass per area, lower leaf area to
sapwood area ratio (LA/SA), lower stomatal conductance
and lower net CO2 assimilation than small trees. Stemspecific
hydraulic conductivity decreased, while leaf-specific
hydraulic conductivity remained nearly constant, with
increasing tree size because of lower LA/SA in larger trees.
Leaves were substantially more vulnerable to embolism
than stems. Large trees had lower maximum leaf hydraulic
conductance (Kleaf) than small trees and all tree sizes exhibited
lower Kleaf at midday than at dawn. These size-related
adjustments in hydraulic architecture and carbon allocation
apparently incurred a large physiological cost: large trees
received a lower return in carbon gain from their investment
in stem and leaf biomass compared with small trees.
Additionally, large trees may experience more severe water
deficits in dry years due to lower capacity for buffering the
effects of hydraulic path-length and soil water deficits.2 assimilation than small trees. Stemspecific
hydraulic conductivity decreased, while leaf-specific
hydraulic conductivity remained nearly constant, with
increasing tree size because of lower LA/SA in larger trees.
Leaves were substantially more vulnerable to embolism
than stems. Large trees had lower maximum leaf hydraulic
conductance (Kleaf) than small trees and all tree sizes exhibited
lower Kleaf at midday than at dawn. These size-related
adjustments in hydraulic architecture and carbon allocation
apparently incurred a large physiological cost: large trees
received a lower return in carbon gain from their investment
in stem and leaf biomass compared with small trees.
Additionally, large trees may experience more severe water
deficits in dry years due to lower capacity for buffering the
effects of hydraulic path-length and soil water deficits.Kleaf) than small trees and all tree sizes exhibited
lower Kleaf at midday than at dawn. These size-related
adjustments in hydraulic architecture and carbon allocation
apparently incurred a large physiological cost: large trees
received a lower return in carbon gain from their investment
in stem and leaf biomass compared with small trees.
Additionally, large trees may experience more severe water
deficits in dry years due to lower capacity for buffering the
effects of hydraulic path-length and soil water deficits.Kleaf at midday than at dawn. These size-related
adjustments in hydraulic architecture and carbon allocation
apparently incurred a large physiological cost: large trees
received a lower return in carbon gain from their investment
in stem and leaf biomass compared with small trees.
Additionally, large trees may experience more severe water
deficits in dry years due to lower capacity for buffering the
effects of hydraulic path-length and soil water deficits.