From functional to mechanistic: coordination between turgor loss point
and traits related to drought tolerance in herbaceous plants
Abstract
We addressed the recent plea for a use of traits with a direct
mechanistic link to drought tolerance to be considered in trait-based
and global change ecology. On 122 herbaceous species covering a broad
range of water availability conditions in temperate grasslands, we
demonstrated the feasibility of the use of turgor loss point
(πtlp), a key leaf drought tolerance trait that becomes
operational for large-scale studies via the novel osmometry method. We
investigated the coordination of this mechanistic trait with other
commonly used proxies of drought tolerance. πtlpwas not
or very weakly coordinated with the first two leading dimension of the
global spectrum of form and function, plant height and specific leaf
area. πtlp was tightly coordinated with intrinsic water
use efficiency and leaf dry matter content. We suggest that
stratification by plant functional types and/or accounting for species
phylogeny might help to identify trait relationships that may be
transferable among different systems.