Abstract

ABSTRACT This study examined the linkage between xylem vulnerability, stomatal response to leaf water potential ( Ψ L ), and loss of leaf turgor in eight species of seasonally dry tropical forest trees. In order to maximize the potential variation in these traits species that exhibit a range of leaf habits and phenologies were selected. It was found that in all species stomatal conductance was responsive to Ψ L over a narrow range of water potentials, and that Ψ L inducing 50% stomatal closure was correlated with both the Ψ L inducing a 20% loss of xylem hydraulic conductivity and leaf water potential at turgor loss in all species. In contrast, there was no correlation between the water potential causing a 50% loss of conductivity in the stem xylem, and the water potential at stomatal closure ( Ψ SC ) amongst species. It was concluded that although both leaf and xylem characters are correlated with the response of stomata to Ψ L, there is considerable flexibility in this linkage. The range of responses is discussed in terms of the differing leaf‐loss strategies exhibited by these species.