Data for: Phenotypic variation of hydraulic traits for woody species

Hydraulic traits are major determinants of plant fitness, thus exerting
control over vegetation structure, function and distribution. Yet it
remains unclear whether and how hydraulic traits respond to environmental
stimuli (i.e., phenotypic variation of hydraulic traits; PVHT), and if the
coordination between different hydraulic traits and the trait-climate
relationship are affected by PVHT. Here, we synthesized data of PVHT
(maximum hydraulic conductivity and water potential inducing 50% loss of
hydraulic conductivity) as well as potentially related morphological and
anatomical traits (e.g. sapwood density, branch Huber value, mean and
hydraulic weighted conduit diameter). We analyzed the magnitude, direction
and source of variation of the plastic response, as well as the influence
of environmental factors on trait coordination. Additionally, we compared
the intra- and inter- specific variation between key hydraulic traits and
climate metrics (mean annual precipitation and mean annual temperature) at
the site of growth, as well as across the population range. PVHT was
highly variable in both magnitude and direction, which was contingent on
the environmental factor. The variation in PVHT mainly occurred at high
taxonomic levels (i.e., family and genus), whereas phenology explained
little variation for PVHT. Despite the high variability, trait correlation
remained robust in the presence of environmental stimuli. Moreover,
trait-climate relationships differed at inter-specific and intra-specific
levels. The intra-specific variation of hydraulic traits in most species
showed no correlation with climate metrics compared with the high
correlation of hydraulic traits with climate metrics across species. Our
findings suggest that the high variability of PVHT does not affect the
trait correlation which may be valuable in predicting vegetation dynamics
under varying environments. The distinct trait-climate relationships
highlight the need to unravel the driving force of PVHT, as well as the
adaptive strategy across populations.