摘要：Hydraulic conductivity and cavitation resistance are important in the investigation of drought damage to trees. The negative xylem pressure causing a 50 % loss of conductivity (P50) is usually used to assess cavitation resistance of the xylem conduits of trees. The hypothesis that greater safety due to cavitation comes at the cost of less efficient conductivity and less cavitation resistance change before and after water stress was tested in fourteen plant species. The resistance to cavitation of all sampled species was variable, however, a significant positive correlation was observed between P50 and Ks, resulting in a pronounced trade-off between efficiency and drought-induced cavitation. Following a drought-refilling cycle, most of the sampled species showed cavitation fatigue, and the species with more negative P50 were characterized by a large change in cavitation resistance, while the species with moderate P50 (usually above ± 2 MPa) could restore > 60 % of their original cavitation resistance. Diverse strategies must be developed by trees to adapt to increasing situations of water stress. These findings provide insight into the safety margins of trees in response to drought.
关键词：Hydraulic conductivity;cavitation;drought;subtropical woody tree
