water Article Leaf Traits of Drought Tolerance for 37 Shrub Species Originating from a Moisture Gradient Gui-Qing Xu 1,2,3,* , Stefan K. Arndt 4 and Claire Farrell 4 1 State Key Lab of Desert and Oasis Ecology, Xinjiang Institute of Ecology and Geography, Chinese Academy of Sciences, Xinjiang 830011, China 2 Fukang Station of Desert Ecology, Chinese Academy of Sciences, Xinjiang 830011, China 3 University of Chinese Academy of Sciences, Beijing 100049, China 4 Department of Ecosystem and Forest Sciences, University of Melbourne, 500 Yarra Boulevard, Richmond, Victoria 3121, Australia;
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[email protected] (C.F.) * Correspondence:
[email protected]; Tel.: +86-991-7885414 Received: 29 April 2020; Accepted: 1 June 2020; Published: 6 June 2020 Abstract: Identifying the drought-tolerance traits of plant species originating from a moisture gradient will increase our understanding of the differences and similarities in plant drought tolerance. However, which traits can be used to evaluate drought tolerance remain an open question. Here, we conducted a common-garden experiment on 37 shrub species originating from desert to humid regions. The correlations between plant traits and the native environmental conditions were studied. Leaf sizes and Huber values were significantly correlated with most climate variables of the shrubs’ origins. The osmotic potentials at full turgor (π100), turgor loss point (YTLP), and midday leaf water potential (Ymid) were significantly correlated with most climate variables of their origins. We proposed using leaf sizes, Huber values, and YTLP as predictors of drought tolerance across shrub species and shrub biomes.