Changes in stomatal sensitivity to leaf-to-air vapor pressure deficit under repeated drought-irrigation cycles.

*: P<0.05,
**: P<0.01,
ns: no significant difference.
The values of m (slope index) derived from the Eq 1 and Fig 7. The slope index indicates the stomatal sensitivity to leaf-to-air vapor pressure deficit (VPD). Parenthesized numbers indicate 1 standard error of mean. P-values indicate the significant differences among cycles in each species (one-way ANOVA, n = 4–5).