How adaptable is the hydraulic system of European beech in the face of climate change-related precipitation reduction?
Language
en
Article de revue
This item was published in
New Phytologist. 2016, vol. 210, n° 2, p. 443-458
Wiley
English Abstract
Climate warming will increase the drought exposure of many forests world-wide. It is not well understood how trees adapt their hydraulic architecture to a long-term decrease in water availability. We examined 23 traits ...Read more >
Climate warming will increase the drought exposure of many forests world-wide. It is not well understood how trees adapt their hydraulic architecture to a long-term decrease in water availability. We examined 23 traits characterizing the hydraulic architecture and growth rate of branches and the dependent foliage of mature European beech (Fagus sylvatica) trees along a precipitation gradient (855–594 mm yr−1) on uniform soil. A main goal was to identify traits that are associated with xylem efficiency, safety and growth. Our data demonstrate for the first time a linear increase in embolism resistance with climatic aridity (by 10%) across populations within a species. Simultaneously, vessel diameter declined by 7% and pit membrane thickness (Tm) increased by 15%. Although specific conductivity did not change, leaf-specific conductivity declined by 40% with decreasing precipitation. Of eight plant traits commonly associated with embolism resistance, only vessel density in combination with pathway redundancy and Tm were related. We did not confirm the widely assumed trade-off between xylem safety and efficiency but obtained evidence in support of a positive relationship between hydraulic efficiency and growth. We conclude that the branch hydraulic system of beech has a distinct adaptive potential to respond to a precipitation reduction as a result of the environmental control of embolism resistance.Read less <
Origin
Hal imported