부산대학교 도서관

Premise of research. Understanding the relationship between field-measured operating stomatal conductance (g op) and theoretical maximum stomatal conductance (g max), calculated from stomatal density and geometry, provides an important framework that can be used to infer leaf-level gas exchange of historical, herbarium, and fossil plants. To date, however, investigation of the nature of the relationship between g op and theoretical g max remains limited to a small number of experiments on relatively few taxa and is virtually undefined for plants in natural ecosystems. Methodology. We used the g op measurements of 74 species and 35 families across four biomes from a published contemporary data set of field-measured leaf-level stomatal conductance in woody angiosperms and calculated the theoretical g max from the same leaves to investigate the relationship between g op and g max across multiple species and biomes and determine whether such relationships are widely conserved. Pivotal results. We observed significant relationships between g op and g max, with consistency in the g op∶ g max ratio across biomes, growth habits (shrubs and trees), and habitats (open canopy and understory subcanopy). An overall mean g op ∶ g max ratio of 0.26 ± 0.11 (mean ± SD) was observed. The consistently observed g op ∶ g max ratio in this study strongly agrees with previous hypotheses that an ideal g op ∶ g max ratio exists. Conclusions. These results build substantially on previous studies by presenting a new reference for a consistent g op ∶ g max ratio across many levels and offer great potential to enhance paleoclimate proxies and vegetation-climate models alike. [ABSTRACT FROM AUTHOR]