Plant Diversity ›› 2019, Vol. 41 ›› Issue (04): 258-265.DOI: 10.1016/j.pld.2019.06.003

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Stem and leaf traits as co-determinants of canopy water flux

Jianguo Gaoa,c,d, Kai Tianb   

  1. a Department of Ecology, College of Urban and Environmental Sciences, Key Laboratory for Earth Surface Processes of the Ministry of Education, Peking University, No.5 Yiheyuan Road Haidian District, Beijing, 100871, PR China;
    b School of Life Sciences, Nanjing University, Nanjing, 210023, PR China;
    c Coastal Ecosystems Research Station of the Yangtze River Estuary, Ministry of Education Key Laboratory for Biodiversity Science and Ecological Engineering, Institute of Biodiversity Science, Fudan University, Shanghai, 200438, PR China;
    d Key Laboratory of Vegetation Restoration and Management of Degraded Ecosystems, Chinese Academy of Sciences, South China Botanical Garden, Guangzhou, 510650
  • Received:2019-04-04 Revised:2019-06-10 Online:2019-08-25 Published:2019-09-17
  • Contact: Jianguo Gao,E-mail
  • Supported by:
    Many thanks go to Professor Ping Zhao and the graduate student Peiqiang Zhao of South China Botanical Garden (SCBG), CAS for their very early fieldwork. Hui Liu of SCBG provides critical insights into our experimental results. Sincere thanks go to two anonymous reviewers for their constructive comments and encouragements.

Abstract: Transpiration through stomata in tree canopies plays an important role in terrestrial water cycles. However, the empirical relationship between leaf stomata anatomy and canopy stomatal conductance (Gs) is surprisingly rare, thereby the underlying biological mechanisms of terrestrial water flux are not well elucidated. To gain further insight into these mechanisms, we reanalyzed the dataset of Gs previously reported by Gao et al. (2015) using a quantile regression model. The results indicated that the reference Gs (Gsref, Gs at 1 kPa) was negatively correlated with wood density at each quantile, which confirmed previous data; however, Gsref was significantly correlated with stomatal density at the 0.6 quantile, i.e., 450 stomata mm-2. This highlighted the potential of using stomatal density as a trait to predict canopy water flux. A conceptual model of co-determinants of xylem and stomatal morphology suggests that these traits and their coordination may play a critical role in determining tree growth, physiological homeostatic response to environmental variables, water use efficiency, and drought resistance.

Key words: Gsref, Quantile regression, Stomatal density, Water flux, Wood density