In:
Forests, MDPI AG, Vol. 10, No. 5 ( 2019-05-10), p. 407-
Kurzfassung:
Stable hydraulic conductivity in forest trees maintains healthy tree crowns and contributes to productivity in forest ecosystems. Drought conditions break down this relationship, but the mechanisms are poorly known and may depend on drought severity. To increase the understanding of changes in hydraulic conductivity during drought, we determined hydraulic parameters in Populus euphratica Oliv. (P. euphratica) in naturally arid conditions and in a simulated severe drought using a high-pressure flow meter. The results showed that leaf-specific hydraulic conductance (LSC) of leaf blades was less variable in mild drought, and increased significantly in severe drought. Plants attempted to maintain stability in leaf blade LSC under moderate water stress. In extreme drought, LSC was enhanced by increasing hydraulic conductance in plant parts with less hydraulic limitation, decreasing it in other parts, and decreasing leaf area; this mechanism protected the integrity of water transport in portions of tree crowns, and induced scorched branches and partial mortality in other parts of crowns. We conclude that limitation in water supply and elastic regulation of hydraulic characteristics may drive the mortality of tree branches as a result of severe drought. Evaluation of adaptive water transport capacity in riparian plants in arid areas provides a scientific basis for riparian forest restoration.
Materialart:
Online-Ressource
ISSN:
1999-4907
Sprache:
Englisch
Verlag:
MDPI AG
Publikationsdatum:
2019
ZDB Id:
2527081-3
