Because iso- and anisohydric species differ in stomatal regulation
of the rate and magnitude of fluctuations in shoot
water potential, they may be expected to show differences in
the plasticity of their shoot water relations components, but
explicit comparisons of this nature have rarely been made.
We subjected excised shoots...
Because iso- and anisohydric species differ in stomatal regulation
of the rate and magnitude of fluctuations in shoot
water potential, they may be expected to show differences in
the plasticity of their shoot water relations components, but
explicit comparisons of this nature have rarely been made.
We subjected excised shoots...
Stored non-structural carbohydrates (NSCs) could play an important role in tree survival in the face of a changing climate and
associated stress-related mortality. We explored the effects of the stomata-blocking and defoliating fungal disease called
Swiss needle cast on Douglas-fir carbohydrate reserves and growth to evaluate the extent to which...
Stored non-structural carbohydrates (NSCs) could play an important role in tree survival in the face of a changing climate and
associated stress-related mortality. We explored the effects of the stomata-blocking and defoliating fungal disease called
Swiss needle cast on Douglas-fir carbohydrate reserves and growth to evaluate the extent to which...
First-year tree seedlings represent a particularly vulnerable life stage and successful seedling establishment is crucial for forest
regeneration. We investigated the extent to which Pinus ponderosa P. & C. Lawson populations from different climate zones
exhibit differential expression of functional traits that may facilitate their establishment. Seeds from two populations...
First-year tree seedlings represent a particularly vulnerable life stage and successful seedling establishment is crucial for forest
regeneration. We investigated the extent to which Pinus ponderosa P. & C. Lawson populations from different climate zones
exhibit differential expression of functional traits that may facilitate their establishment. Seeds from two populations...
Recent work has suggested that plants differ in their relative
reliance on structural avoidance of embolism versus maintenance
of the xylem water column through dynamic traits such
as capacitance, but we still know little about how and why
species differ along this continuum. It is even less clear how
or...
Recent work has suggested that plants differ in their relative
reliance on structural avoidance of embolism versus maintenance
of the xylem water column through dynamic traits such
as capacitance, but we still know little about how and why
species differ along this continuum. It is even less clear how
or...
Non-structural carbohydrates (NSC) in plant tissue are frequently quantified to make inferences about plant responses to environmental conditions. Laboratories publishing estimates of NSC of woody plants use many different methods to evaluate NSC. We asked whether NSC estimates in the recent literature could be quantitatively compared among studies. We also...
First-year tree seedlings represent a particularly vulnerable life stage and successful seedling establishment is crucial for forest regeneration. We investigated the extent to which Pinus ponderosa P. & C. Lawson populations from different climate zones exhibit differential expression of functional traits that may facilitate their establishment. Seeds from two populations...
Leaf hydraulics, gas exchange and carbon storage in Pinus edulis and Juniperus monosperma, two tree species on opposite ends of the isohydry–anisohydry spectrum, were analyzed to examine relationships between hydraulic function and carbohydrate dynamics. Leaf hydraulic vulnerability, leaf water potential (Wl), leaf hydraulic conductance (Kleaf), photosynthesis (A), stomatal conductance (gs)...
Because iso- and anisohydric species differ in stomatal regulation
of the rate and magnitude of fluctuations in shoot
water potential, they may be expected to show differences in
the plasticity of their shoot water relations components, but
explicit comparisons of this nature have rarely been made.
We subjected excised shoots...
Stored non-structural carbohydrates (NSCs) could play an important role in tree survival in the face of a changing climate and associated stress-related mortality. We explored the effects of the stomata-blocking and defoliating fungal disease called Swiss needle cast on Douglas-fir carbohydrate reserves and growth to evaluate the extent to which...
Recent work has suggested that plants differ in their relative reliance on structural avoidance of embolism versus maintenance of the xylem water column through dynamic traits such as capacitance, but we still know little about how and why species differ along this continuum. It is even less clear how or...
Stomata control tree transpiration by sensing and integrating environmental signals originating in the atmosphere and soil, and co-occurring species may differ in inherent stomatal sensitivity to these above- and belowground signals and in the types of signals to which they respond. Stomatal responsiveness to environmental signals is likely to differ...
• Premise of the Study: Tropical liana abundance has been increasing over the past 40 yr, which has been associated with reduced
rainfall. The proposed mechanism allowing lianas to thrive in dry conditions is deeper root systems than co-occurring trees,
although we know very little about the fundamental hydraulic physiology...
Angiosperm and coniferous tree species utilize a continuum of hydraulic strategies. Hydraulic safety margins (defined as differences between naturally occurring xylem pressures and pressures that would cause hydraulic dysfunction, or differences between pressures resulting in loss of hydraulic function in adjacent organs (e.g., stems vs. leaves) tend to be much...
Hydraulic conductance of leaves (K[subscript leaf]) typically decreases with increasing water stress and recent studies have proposed different mechanisms responsible for decreasing K[subscript leaf]. We measured K[subscript leaf] concurrently with ultrasonic acoustic emissions (UAEs) in dehydrating leaves of several species to determine whether declining K[subscript leaf] was associated with xylem...
Plant hydraulic architecture (PHA) has been linked to water transport sufficiency, photosynthetic rates, growth form and attendant carbon allocation. Despite its influence on traits central to conferring an overall competitive advantage in a given environment, few studies have examined whether key aspects of PHA are indicative of successional stage, especially...
Given the fundamental importance of xylem safety and efficiency for plant survival and fitness, it is not surprising that these are among the most commonly studied features of hydraulic architecture. However, much remains to be learned about the nature and universality of conflicts between hydraulic safety and efficiency. Although selection...
In the Pacific north-west, the Cascade Mountain Range blocks much of the precipitation and maritime influence of the Pacific Ocean, resulting in distinct climates east and west of the mountains. The current study aimed to investigate relationships between water storage and transport properties in populations of Douglas-fir (Pseudotsuga menziesii) and...
This study investigated the mechanisms involved in the
regulation of stomatal closure in Douglas-fir and evaluated
the potential impact of compensatory adjustments in
response to increasing tree height upon these mechanisms.
In the laboratory, we measured leaf hydraulic conductance
(Kleaf) as leaf water potential (Yl) declined for comparison
with in...
1. The xylem pressure inducing 50% loss of hydraulic conductivity due to embolism
widely used for comparisons of xylem vulnerability among species and across aridity
However, despite its utility as an index of resistance to catastrophic xylem failure
drought, P5o may have no special physiological relevance in the context of...
Despite renewed interest in the nature of limitations on maximum tree height, the mechanisms governing ultimate and species-specific height limits are not yet understood, but likely involve water transport dynamics. Tall trees experience increased risk of xylem embolism from air-seeding because tension in their water column increases with height due...
The objectives of this study were (i) to provide further evidence of a positive correlation of stand density with early growth of coastal Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco var. menziesii); (ii) to determine when after planting the positive growth response occurs and how long it lasts; and (iii) to use...
My objectives were to investigate the correlation of height and diameter growth in young Douglas-fir (Pseudotsuga menziesii) plantations with stand density, and to determine the effects of stand density on the canopy boundary layer conductance (g[subscript]ac) and microclimate characteristics of young Douglas-fir plantations. I measured annual height (h) and diameter...
This dissertation investigated the impacts of tree height upon a range of physiological and structural characteristics of Douglas-fir foliage; relationships between structural and functional trends with height; and compensatory mechanisms that mitigate height-related growth constraints. Height-related trends in foliar physiological and anatomical characteristics were examined both within trees as well...