Chin J Plant Ecol ›› 2022, Vol. 46 ›› Issue (9): 1064-1076.

• Research Articles •

### Difference in adaptation strategy between Haloxylon ammodendron and Alhagi sparsifolia to drought

ZHOU Jie1, YANG Xiao-Dong1,2,3,*(), WANG Ya-Yun1, LONG Yan-Xin1, WANG Yan1, LI Bo-Rui1, SUN Qi-Xing1, SUN Nan2,3

1. 1College of Resources and Environment Science, Xinjiang University, Ürümqi 830046, China
2Institute of Geography and Tourism Culture, Ningbo University, Ningbo, Zhejiang 315211, China
3Institute of East China Sea, Ningbo University, Ningbo, Zhejiang 315211, China
• Received:2021-09-22 Accepted:2021-12-22 Online:2022-09-20 Published:2022-10-19
• Contact: YANG Xiao-Dong
• Supported by:
National Natural Science Foundation of China(31860111);National Natural Science Foundation of China(41871031)

Abstract:

Aims The plant mortality induced by drought has significant impact on forest ecosystems around the world. It thus has brought intensive research attention on the plant adaptive strategy to drought in the field of physiological ecology. This study aims to investigate the differences in adaptation strategies to drought between two dominant species in arid desert areas, i.e., Haloxylon ammodendron and Alhagi sparsifolia.

Methods Three types of functional traits (i.e., leaf, photosynthetic and hydraulic traits) of A. sparsifolia and H. ammodendron were measured in response to a natural drought gradient (mild, moderate and severe) in Ebinur Lake Nature Reserve in Xinjiang Province, China. The changes of functional traits with drought gradient, and the differences of functional traits and adaptation strategies to drought between the two species were analyzed.

Important findings The functional traits of A. sparsifolia and H. ammodendron changed differently across drought gradient. All the functional traits were significantly different between the two species except for leaf dry matter content. However, the differences in functional traits between the two species showed a decrease due to the synergetic influence of drought stress and species convergence. Pearson correlation among the traits for the two species indicated that only 10 pairs of functional traits are significantly correlated for A. sparsifolia, while 15 pairs were significantly correlated for H. ammodendron. Principal component analysis (PCA) showed that two typical trait combinations related to drought resistance can be obtained from 11 functional traits of H. ammodendron, namely drought resistance-carbon acquisition group and drought resistance group. However, the trait combinations in coping with drought were not identified for A. sparsifolia. The results suggested that A. sparsifolia,was a conservative species, having greater drought tolerance than H. ammodendron. The traits in A. sparsifolia was less associated than that in H. ammodendron. In contrast, H. ammodendron used the trade-offs and compensatory relationships among functional traits to reduce drought stress. This study provided insights into the relationship between functional traits and drought adaptation strategies of different plant life forms, which advanced the fundamental theories of plant physiological ecology, and provided implications and references for the protection and diversity maintenance of desert ecosystem.