Hydrostatic constraints on morphological exploitation of light in tall Sequoia sempervirens trees

  title={Hydrostatic constraints on morphological exploitation of light in tall Sequoia sempervirens trees},
  author={Hiroaki T. Ishii and Gregory M. Jennings and Stephen C. Sillett and George W. Koch},
We studied changes in morphological and physiological characteristics of leaves and shoots along a height gradient in Sequoia sempervirens, the tallest tree species on Earth, to investigate whether morphological and physiological acclimation to the vertical light gradient was constrained by hydrostatic limitation in the upper crown. Bulk leaf water potential (Ψ) decreased linearly and light availability increased exponentially with increasing height in the crown. During the wet season, Ψ was… 

Physiological consequences of height-related morphological variation in Sequoia sempervirens foliage.

Relationships between foliar morphology and gas exchange characteristics as they vary with height within and among crowns of Sequoia sempervirens D. Don trees are examined, suggesting a transition from light to water relations as the primary determinant of morphology with increasing height.

The hydrostatic gradient, not light availability, drives height-related variation in Sequoia sempervirens (Cupressaceae) leaf anatomy.

That variation in leaf structure may be caused more by gravity than by light calls into question use of the terms "sun" and "shade" to describe leaves at the tops and bottoms of tall tree crowns.

Physiological and morphological acclimation to height in cupressoid leaves of 100-year-old Chamaecyparis obtusa

It is inferred that transfusion tissue flanking the leaf vein, which was more developed in the treetop leaves, contributes to water-stress acclimation and maintenance of leaf hydraulic conductance by facilitating osmotic adjustment of leaf water potential and efficient water transport from xylem to mesophyll.

Leaf acclimation to light availability supports rapid growth in tall Picea sitchensis trees

Anatomical investigations spanning the height gradient in tall tree crowns build the understanding of mechanisms underlying among-species variation in growth rates, life spans, and potential responses to climate change.

Hydraulic constraints modify optimal photosynthetic profiles in giant sequoia trees

It is found that leaf N and photosynthesis capacity do not follow the vertical light gradient, supporting the hypothesis that increasing limitations on water transport capacity with height modify photosynthetic optimization in tall trees.

Vertical gradients in foliar physiology of tall Picea sitchensis trees.

The use of fog, dew, and rain deposits on leaves and shifts in leaf structure to conserve and possibly enhance photosynthetic capacity likely contribute to the rapid growth rates measured in P. sitchensis trees in northwestern California.

Pushing the limits to tree height: could foliar water storage compensate for hydraulic constraints in Sequoia sempervirens?

Evidence is shown of foliar water storage as a mechanism that could partially compensate for hydraulic constraints and sustain turgor for both photosynthesis and height growth in Sequoia sempervirens, the tallest species.

Coping with gravity: the foliar water relations of giant sequoia

A collection of foliar traits allows giant sequoia to routinely, but safely, operate close to its turgor loss point, and suggests that gravity plays a major role in the water relations of Earth's largest tree species.

Investigating within-canopy variation of functional traits and cellular structure of sugar maple (Acer saccharum) leaves

Investigating the response of leaf functional traits to light availability, height, and leaf water potential in an Acer saccharum forest to tease apart the influence of light and hydraulic limitations suggests leaves acclimate.

Effects of height on treetop transpiration and stomatal conductance in coast redwood (Sequoia sempervirens).

It is confirmed that increasing tree height reduces gas exchange of treetop foliage and thereby contributes to lower carbon assimilation and height growth rates as S. sempervirens approaches maximum height.



A test of the hydraulic limitation hypothesis in fast‐growing Eucalyptus saligna

The hydraulic limitation hypothesis failed to explain the sharp decline in net primary productivity after canopy closure in this study, but the combination of similar G T and lower δ 13 C for the 26 m trees suggests that total crown photosynthesis was lower for the 27 m trees, perhaps a result of the lower Ψ LEAF.

Light capture efficiency decreases with increasing tree age and size in the southern hemisphere gymnosperm Agathis australis

The results suggest that the age-dependent and/or size-dependent decreases in stand productivity may partly result from reduced light interception efficiency in larger mature relative to smaller and younger plants.

Does turgor limit growth in tall trees

In tall trees, the gravitational component of Y Y Y l is superimposed on phenologically driven changes in leaf water relations characteristics, imposing potential constraints on turgor that may be indistinguishable from those associated with soil water deficits.

Net photosynthetic response to light intensity of shoots from different crown positions and age in picea abies (L.) karst

The results suggest that the enhanced efficiency of “shade” shoots is caused by morphologic adaptation, i.e. the more sparsely packed photosynthesis apparatus in needles and shoots, and adaptational possibilities of Norway spruce photosynthetic apparatus, its ecological plasticity diminish during tree ontogenesis.

Shoot structure, light interception, and distribution of nitrogen in an Abies amabilis canopy.

The role of morphological shade acclimation in the determination of resource use efficiency is investigated and it is found that variation in shoot structure and needle morphology was not enough to produce proportionality between the amounts of nitrogen and intercepted PAR throughout the canopy.

Effects of light on shoot geometry and needle morphology in Abies amabilis.

The close correlation of needle thickness and leaf mass/area with openness suggests that either parameter could be used as an index of the distribution of light or light-driven processes in an A. amabilis canopy.

Stoichiometry of foliar carbon constituents varies along light gradients in temperate woody canopies: implications for foliage morphological plasticity.

It is demonstrated that water relations play a central role in determining foliar structure and composition along light gradients in the canopy and that species differences in lignification were partly responsible for the observed interspecific variability in morphological plasticity.

The hydraulic limitation hypothesis revisited.

It is concluded that hydraulic limitation of gas exchange with increasing tree size is common, but not universal, and any limit to height or height growth does not appear to be related to the so-called age-related decline in wood production of forests after canopy closure.

Shade-shoot structure, photosynthetic performance in the field, and photosynthetic capacity of evergreen conifers.

In field-grown shoots of all species examined, photosynthetic capacity was negatively related to R(max), and pines, which have a low R( max) and a low leaf area index (>/= 3.5), had low rates of photosynthesis in the lowest crown zone.

The limits to tree height

Redwoods are studied, including the tallest known tree on Earth, in wet temperate forests of northern California, to estimate a maximum tree height of 122–130 m barring mechanical damage, similar to the tallest recorded trees of the past.