Chin J Plant Ecol ›› 2024, Vol. 48 ›› Issue (7): 888-902.DOI: 10.17521/cjpe.2024.0016  cstr: 32100.14.cjpe.2024.0016

Special Issue: 植物功能性状

• Research Articles • Previous Articles     Next Articles

Relationship of embolism resistance with xylem anatomical structure and related traits of 12 tree species in tropical karst seasonal rainforests

MA Lin1, CHAO Lin1,2, HE Yu-Sha1, LI Zhong-Guo2, WANG Ai-Hua1, LIU Sheng-Yuan3, HU Bao-Qing1, LIU Yan-Yan1,*()()   

  1. 1Institute of Geography and Oceanography, Nanning Normal University, Key Laboratory of Environment Change and Resource Use in Beibu Gulf (Ministry of Education), Guangxi Key Laboratory of Earth Surface Process and Intelligent Simulation, Nanning 530001, China
    2Experimental Center of Tropical Forestry, Chinese Academy of Forestry, Guangxi Youyiguan Forest Ecosystem Research Station, Pingxiang, Guangxi 532600, China
    3Administration Ceter of Guangxi Nonggang National Nature Reserve, Longzhou, Guangxi 532400, China.
  • Received:2024-01-19 Accepted:2024-05-06 Online:2024-07-20 Published:2024-05-16
  • Contact: * LIU Yan-Yan(liuyanyan5000@163.com),ORCID: 0000-0003-0151-8509
  • Supported by:
    National Natural Science Foundation of China(31800333);National Natural Science Foundation of China(32160252);Project for Local Science and Technology Development in Central Government Guides(Guangxi Science Fund AD19245133);Project for Local Science and Technology Development in Central Government Guides(Guangxi Science Fund AD20238078);China Postdoctoral Science Foundation(2019M663870XB);Natural Science Foundation of Guangxi(2018GXNSFBA138009);Natural Science Foundation of Guangxi(2018GXNSFAA281277)

Abstract:

Aims In the context of global climate change, drought-induced xylem embolism is considered as the main factor driving tree death. Therefore, analyzing the intrinsic anatomical determinants of xylem embolism resistance (water potential at 50% loss of xylem conductivity, P50) is of great significance for understanding the mechanism between its structure and function, and provides a theoretical basis for the selection of tree species for vegetation restoration in the context of climate change.
Methods We measured the xylem vessel diameter, vessel grouping index, fractions of xylem tissues, pit morphology, pit membrane ultrastructure and water storage capacity (such as wood density and saturated water content), and explored the relationships between xylem embolism resistance and their anatomical structure and structural characteristics of 12 main evergreen tree species in Nonggang karst forest of Guangxi.
Important findings We found that: (1) P50 had no significant correlation with vessel diameter, density, vessel grouping index and fraction of xylem tissues; (2) The correlations between P50 and pit morphology, thickness of pit membrane and depth of pit chamber were not significant; (3) P50 was negatively correlated with wood density and marginally positively correlated with saturated water content. Tree species with high wood density and low saturated water content had strong embolism resistance. The results indicated that using a single anatomical structure trait could not give out comprehensive evaluation on drought-induced embolic resistance. In addition, there was a trade-off between xylem water capacity and embolism resistance. This result was of great ecological significance for deeply understanding the internal structural mechanism of drought tolerance and diversified water use strategies of karst plants.

Key words: wood density, saturated water content, xylem vessel, pit, pit membrane