Chin J Plant Ecol ›› 2023, Vol. 47 ›› Issue (11): 1576-1584.DOI: 10.17521/cjpe.2022.0262

Special Issue: 全球变化与生态系统

• Research Articles • Previous Articles     Next Articles

Hydraulic vulnerability segmentation in woody plant species from tropical and subtropical karst forests

YU Jun-Rui, WAN Chun-Yan, ZHU Shi-Dan()   

  1. State Key Laboratory for Conservation and Utilization of Subtropical Agro-bioresources, College of Forestry, Guangxi University, Nanning 530004, China
  • Received:2022-06-22 Accepted:2023-02-15 Online:2023-11-20 Published:2023-03-01
  • Contact: ZHU Shi-Dan(
  • Supported by:
    National Natural Science Foundation of China(32060330)


Aims Vulnerability segmentation is one of physiological mechanisms underlying drought resistance for tree species. The aim of this study is to clarify the patterns of vulnerability segmentation and its physiological significance for woody species from drought-prone tropical and subtropical karst forests.

Methods A total of 57 typical woody species were selected from tropical and subtropical karst forests. We measured their leaf and stem vulnerability curves and minimum water potential to calculate vulnerability segmentation (P50leaf-stemis the difference in cavitation resistance between leaf and stem, with larger values indicating stronger vulnerability segmentation) and hydraulic safety margin. We compared the differences in P50leaf-stem between different plant taxa and explored the relationships between P50leaf-stem and hydraulic safety margin.

Important findings (1) The P50leaf-stem across the woody species ranged from -1.28 MPa to 4.63 MPa, with an average value of 1.32 MPa. Out of the 57 species, 49 species showed a positive P50leaf-stem. (2) Shrub species showed higher P50leaf-stem than tree species, and species from karst ridge showed higher P50leaf-stem than those from karst valley. However, there was no significant difference in P50leaf-stem between evergreen and deciduous species. (3) During the drought period, species with higher P50leaf-stem tended to have smaller leaf hydraulic safety margin but larger stem hydraulic safety margin, indicating that occurrence of cavitation in leaves can reduce hydraulic risks of stems. This study confirms that vulnerability segmentation is an important hydraulic strategy for most tropical and subtropical karst woody species to deal with drought stress.

Key words: cavitation, drought adaptation, hydraulic safety margin, minimum water potential, plant taxa