DOI: 10.5061/dryad.1hf2q
title: Data from: Divergence in strategies for coping with winter embolism among co-occurring temperate tree species: the role of positive xylem pressure, wood type and tree stature

description: 1. In temperate ecosystems, freeze-thaw events are an important
 environmental stress that can induce severe xylem embolism (i.e. clogging
 of conduits by air bubbles) in overwintering organs of trees. However, no
 comparative studies of different adaptive strategies among sympatric tree
 species for coping with winter embolism have examined the potential role
 of the presence or absence of embolism refilling by positive xylem
 pressure. 2. We evaluated the degree of winter embolism and hydraulic
 architecture traits in 22 deciduous angiosperm tree species typical of
 temperate forest sites in NE China. Co-occurring trees growing in a local
 botanical garden were used to minimize variation caused by differences in
 proximal environmental conditions and to ensure that interspecific
 variation reflected genetic differences between species. 3. Four
 functional groups with potentially different strategies for coping with
 winter embolism were compared: positive xylem pressure generating species
 (PXP) that are all diffuse-porous, except a semi-ring-porous species,
 large (LDP) and small (SDP) statured diffuse-porous tree species that are
 unable to generate positive xylem pressure, and ring-porous species (RP).
 4. The PXP group exhibited nearly full recovery from winter embolism in
 contrast to the other three groups, which showed persistent and relatively
 high degrees of hydraulic dysfunction during the subsequent growing
 season. The absence of a functional trade-off between hydraulic efficiency
 and safety against freeze-thaw induced embolism in the PXP group and the
 presence of a trade-off in the other three groups, suggests that the
 ability to generate root or stem pressure for embolism refilling may
 partially free some temperate tree species from adaptive constraints
 imposed by winter embolism formation. 5. Efficient winter embolism
 reversal by positive pressure in PXP species did not distinguish them from
 their non-xylem pressure-generating LDP counterparts in terms of various
 measures of xylem hydraulic efficiency during the growing season.
 Divergence in the ability to refill winter embolism through generation of
 positive xylem pressure implies a series of functional trade-offs that may
 partially explain the co-existence of these two types of temperate tree
 species.
description: Plant functional Stem
 hydraulic related traits of the 22 studied speciesThe file contains a
 single sheet. Data are the stem hydraulic related functional traits of the
 22 tree species studied. Values are mean ± 1SE (n = 4-6). These 22 species
 belong to four functional groups: PXP, species capable of generating
 positive xylem pressure; LDP, large-statured diffuse-porous species
 without positive xylem pressure; SDP, small-statured species without
 positive xylem pressure; RP, ring-porous species. In the column of “wood
 type”, D, R and SR represent diffuse-, ring- and semi-ring-porous wood
 type, respectively. The first row contains the abbreviations of 14
 functional traits used in the paper. Ks, sapwood specific conductivity;
 Ksmax, maximum sapwood specific hydraulic conductivity; Kw, wood specific
 hydraulic conductivity; Kwmax, maximum wood specific hydraulic
 conductivity; Kl, leaf specific hydraulic conductivity; PLCw, PLCs,
 percent loss of hydraulic conductivity in winter (December, 2014) and
 summer (July, 2015); PCW, proportion of conductive wood area; HV, Huber
 value; Dv, mean vessel diameter; Dh, hydraulically weighted vessel
 diameter; VD, vessel density; ρ_wood, wood density; LMA, leaf mass per
 area.winter
 embolism and adaptation of temperate
 trees.xlsx