summary In this paper, we have reviewed how the hydraulic design of trees influences movement water from roots to leaves. The architecture can limit their relations, gas exchange throughout crown trees, distribution over different habitats and, perhaps, even maximum height that a particular species achieve. Parameters importance include: (1) vulnerability stems drought‐induced cavitation events because reduces conductance stems, (2) leaf specific conductivity‐of it determines pressure...

Abstract Possible mechanical and hydraulic costs to increased cavitation resistance were examined among six co-occurring species of chaparral shrubs in southern California. We measured (xylem pressure at 50% loss conductivity), seasonal low potential (P min), xylem conductive efficiency (specific strength stems (modulus elasticity modulus rupture), density. At the cellular level, we vessel fiber wall thickness lumen diameter, transverse total area, estimated implosion using (t/b)h 2, where t...

• Here, hypotheses about stem and root xylem structure function were assessed by analyzing in nine chaparral Rhamnaceae species. Traits characterizing transport efficiency safety, mechanical strength storage analyzed using linear regression, principal components analysis phylogenetic independent contrasts (PICs). Stems showed a strong, positive correlation between (xylem density modulus of rupture) safety (resistance to cavitation estimated vessel implosion resistance), this was supported...

SUMMARY The relationship between conduit (vessel and tracheid) diameter water‐stress‐induced air embolism was examined using a double staining technique. Comparisons were made irrigated control plants at water potentials of −13 MPa stressed about −8 MPa. Water stress induced either by natural drought conditions or laboratory drying shoots from previously shrubs. Stem segments perfused with 0.1 % basic fuchsin to mark the initially conductive conduits, and, following high pressure perfusion...

Resistance to xylem cavitation depends on the size of pit membrane pores and strength vessels resist collapse or, in case freezing-induced cavitation, conduit diameter. Altering these traits may impact plant biomechanics or water transport efficiency. The evergreen sclerophyllous shrub species, collectively referred as chaparral, which dominate much mediterranean-type climate region southern California, have been shown display high resistance (pressure potential at 50% loss hydraulic...

Coniferous trees, dicotyledonous and lianas (woody vines) form interesting morphological contrasts in their xylem structure function. Lianas have among the largest (up to 8 metres or more) widest 500 µ m) vessels plant kingdom. In conifers water transport occurs through tracheids, which are relatively inefficient transport. We can compare disparate growth forms terms of leaf-specific. conductivity (LSC), is hydraulic per surface area leaves supplied by a stem. LSC inversely proportional...

Progressive diebacks of outer canopy branchlets Ceanothus crassifolius were repeatedly observed after rainless periods up to 9 mo in duration the Santa Monica Mountains southern California. Mean xylem pressures near end drought as low -11.2 MPa (N = 22) with a mean about 60 dead per shrub. Inoculation 15) three species fungi previously isolated from same population C. did not promote dieback, suggesting that decline was fungal induced, had been proposed. Further, at least 50%...

Summary Climate change in South Africa may threaten the sclerophyllous evergreen shrubs of this region. Available data suggest that they are not as tolerant water stress chaparral occurring climatically similar California, USA. Seventeen species from nine angiosperm families, including both fynbos and succulent karoo species, were studied at a field site Western Cape Province, Africa. Minimum seasonal pressure potential ( P min ), xylem specific conductivity K s stem strength against...

ABSTRACT The mechanism of water‐stress‐induced embolism xylem was investigated in Malosma laurina and Heteromeles arbutifolia , two chaparral shrub species southern California. We tested the hypothesis that primary cause dysfunction these during dehydration pulling air through pores cell walls vessels (pores pit membranes) as a result high tensions on water. First, we constructed vulnerability‐to‐embolism curves for (i) excised branches were increasingly dehydrated laboratory (ii) hydrated...

Vessels are the chief conduit for long-distance water transport in majority of flowering plants. Vessel length is a key trait that determines plant hydraulic efficiency and safety, yet relatively little known about this xylem feature. •We used previously published studies to generate new global data set vessel woody These were examine how evolutionary history, habit, environment, growth ring porosity influenced length. We also examined relationship between mean diameter maximum •Data on...

Results were compared between the latex paint and compressed air methods for determining total vessel lengths, sectioning maceration diameters. The minimum, mean, median, maximum diameters less with method than technique. Vessel diameter distributions always nonnormal had roughly similar patterns two techniques, but statistically different from one another. In all six species where length compared, both showed a skewed distribution, many short vessels few long ones. Although there was no...

ABSTRACT Vulnerability to water stress‐induced cavitation was measured on 27 woody shrub species from three arid plant communities including chaparral, coastal sage and Mojave Desert scrub. Dry season native embolism pre‐dawn potential, both wet dry xylem specific hydraulic conductivity ( K s ) were measured. Cavitation resistance, estimated as potential at 50% loss in Ψ 50 ), all during the a subset of season. resistance varied with sampling season, 8 13 sampled displaying significant...

Journal Article Water relations of a tropical vine-like bamboo (Rhipidocladum racemiflorum): root pressures, vulnerability to cavitation and seasonal changes in embolism Get access H. Cochard, Cochard 1INRA, Unité d'Écophysiologie ForestièreF-54280 Champenoux, France Search for other works by this author on: Oxford Academic PubMed Google Scholar F.W. Ewers, Ewers 2Department Botany Plant Pathology, Michigan State UniversityEast Lansing, MI 48824, USA M.T. Tyree 5 3Aiken Forestry Science...

ABSTRACT Pressure probe measurements have been interpreted as showing that xylem pressures below c. –0.4 MPa do not exist and pressure chamber of lower negative are invalid. We present new evidence supporting the technique existence well MPa. deduced in water‐stressed stem from following experiment: (1) loss hydraulic conductivity hydrated (xylem = atmospheric pressure) was induced by forcing compressed air into intact conduits; (2) cavitation embolism dehydrating stems measured, (3)...

Plant adaptations to the environment are limited, and therefore plants in similar environments may display functional physiological traits, a pattern termed convergence. Evidence was examined for convergence among 28 evergreen woody shrubs from three plant communities of semi-arid winter rainfall region southern California. Both leaf water relations traits were examined, including seasonal stomatal conductance (gs), specific area (SLA), conductivity (Kl), potential (Psi w), stem cavitation...

The notion that most xylem transport in stems of ring-porous trees occurs the outermost growth ring requires experimental support. Significance this is challenged by workers who find tracer dyes appearing 4 to 8 rings rather than only increment. We test hypothesis overriding significance fluid through Ulmus , a tree. Fluid flow was quantified removing ring, calculating gravity rates (hydraulic conductivity at 10.13 kPa m -1 ), and tracing pathway control stem segments. From measurements...

Hydraulic conductivity through the outermost growth ring of Ulmus americana was quantified to determine significance this single increment fluid flow in xylem a ring‐porous tree. Gravity rates trunks deprived dropped 8% rate achieved control whose cross section intact. However, colored dye, fed stem segments, appeared up 4‐yr old wood, corroborating earlier reports that flows more than just trees. Finally, pathway older rings shown consist narrow latewood elements while wider and...

Leaf specific conductivities (LSCs, hydraulic conductivity per gram dry weight of supplied leaves), Huber values (transverse xylem area (hydraulic unit transverse area), and tracheid diameters were measured throughout the trunk erown 9- to 96-year-old trees Tsuga canadensis (L.) Carr. By definition, LSC = value × conductivity. Specific is controlled by wood anatomical features, especially diameter. LSCs, which indicate relative water supply different plant parts, decrease acropetally but are...