Chin J Plant Ecol ›› 2022, Vol. 46 ›› Issue (5): 602-612.DOI: 10.17521/cjpe.2021.0391

• Research Articles • Previous Articles    

Hydraulic architecture and safety margin in ten afforestation species in a lower subtropical region

HUANG Dong-Liu1, XIANG Wei1, LI Zhong-Guo1,2, ZHU Shi-Dan1,*()   

  1. 1State Key Laboratory for Conservation and Utilization of Subtropical Agro-bioresources, Guangxi Key Laboratory of Forest Ecology and Conservation, College of Forestry, Guangxi University, Nanning 530004, China
    2Experimental Center of Tropical Forestry, Chinese Academy of Forestry, Pingxiang, Guangxi 532600, China
  • Received:2021-11-01 Accepted:2022-02-17 Online:2022-05-20 Published:2022-06-09
  • Contact: ZHU Shi-Dan
  • Supported by:
    National Natural Science Foundation of China(32060330);Bagui Young Scholarship of Guangxi Zhuang Autonomous Region.

Abstract:

Aims In the lower subtropical region of China, there are large areas of single-species plantations. These plantations have simple community structure and thus are sensitive to climate change. Under the background of regional climate drying, the eco-physiological strategies of these afforestation species and their response to seasonal drought should be investigated.

Methods We selected ten tree species that are commonly planted in this region including six native species and four exotic species. Based on measurements of the mean growth rate, hydraulic traits, and economics traits, we analyzed the trait-growth correlations within each species and compared the differences in hydraulic safety margin and stomatal safety margin among species.

Important findings (1) The growth rate was significantly and positively correlated with hydraulic conductivity, but not with the economic traits, such as wood density, specific leaf area, and hydraulic safety-related traits. (2) There was no significant trade-off between hydraulic efficiency and safety. Two of the exotic tree species, Acacia crassicarpa and Eucalyptus grandis × urophylla, showed both high hydraulic conductivity and great cavitation resistance. (3) There were significant differences in hydraulic safety margin and stomatal safety margin among the tested species. During the dry season, Acacia auriculiformis, Castanopsis hystrix, Mytilaria laosensis and Cinnamomum burmannii would suffer from higher risks of hydraulic failure than the other species. We suggest that tree hydraulic traits should be included into the index system of ecological monitoring of subtropical plantations, which can provide important references for sustainable management of these plantations.

Key words: hydraulic conductivity, cavitation resistance, growth rate, hydraulic safety, plantation management