Foliar plasticity of hybrid spruce in relation to crown position and stand age

2000 ◽  
Vol 78 (3) ◽  
pp. 305-317 ◽  
Author(s):  
A D Richardson ◽  
G P Berlyn ◽  
P MS Ashton ◽  
R Thadani ◽  
I R Cameron
Keyword(s):  
Picea Glauca ◽  
Picea Sitchensis ◽  
Stand Age ◽  
Putative Hybrid ◽  
Physiological Measures ◽  
Needle Anatomy ◽  
Crown Position ◽  
Resource Limited ◽  
Important Relationship ◽  
And Function

This study examined the foliar response of putative hybrid Engelmann × white × Sitka spruce (Picea engelmannii Parry × Picea glauca (Moench) Voss × Picea sitchensis (Bong.) Carr) needles in relation to crown position and across three stages of development (15, 55, and 145 years). We focused on the morphological and anatomical response, and used physiological measures (photosynthesis and stomatal conductance) to emphasize the important relationship between structure and function. We found that needles from the upper outer crown position were adaptated to reduce stress from evapotranspiration. Trees from the 15- and 55-year-old stands generally responded the most, and trees from the 145-year-old stand responded the least. As they mature, these spruce trees may have reduced ability to adapt to their environment. Some of our results contradict what the literature considers "typical" for sun-shade dimorphism in temperate forests. For example, in all stands, sun needles were broader than shade needles and, in the two younger stands, sun needles were larger in area, not smaller, than shade needles. Also, in the youngest stand, stomatal pores were longer on sun needles than on shade needles. There were no definite patterns in stomatal spacing with regard to crown position. Our results are indicative of the strategies adopted to increase competitiveness in a resource-limited environment. We suggest that, in the 15-year-old stand, neither water nor light is limiting; in the 55-year-old stand, both water and light are highly limiting; and in the 145-year-old stand, water is most limiting.Key words: drought, foliar plasticity, needle anatomy, photosynthesis, Picea, stand development, sun-shade.

Vascular Fluid Mechanics, the Arterial Wall, and Atherosclerosis

1992 ◽  
Vol 114 (3) ◽  
pp. 274-282 ◽  
Author(s):  
R. M. Nerem
Keyword(s):  
Cell Culture ◽  
Blood Flow ◽  
Fluid Mechanics ◽  
Arterial Wall ◽  
Disease Process ◽  
The United States ◽  
Structure And Function ◽  
Medium Size ◽  
Important Relationship ◽  
And Function

Atherosclerosis, a disease of large- and medium-size arteries, is the chief cause of death in the United States and in most of the western world. Severe atherosclerosis interferes with blood flow; however, even in the early stages of the disease, i.e. during atherogenesis, there is believed to be an important relationship between the disease processes and the characteristics of the blood flow in the arteries. Atherogenesis involves complex cascades of interactions among many factors. Included in this are fluid mechanical factors which are believed to be a cause of the highly focal nature of the disease. From in vivo studies, there is evidence of hemodynamic influences on the endothelium, on intimal thickening, and on monocyte recruitment. In addition, cell culture studies have demonstrated the important effect of a cell’s mechanical environment on structure and function. Most of this evidence is for the endothelial cell, which is believed to be a key mediator of any hemodynamic effect, and it is now well documented that cultured endothelial monolayers, in response to a fluid flow-imposed laminar shear stress, undergo a variety of changes in structure and function. In spite of the progress in recent years, there are many areas in which further work will provide important new information. One of these is in the engineering of the cell culture environment so as to make it more physiologic. Animal studies also are essential in our efforts to understand atherogenesis, and it is clear that we need better information on the pattern of the disease and its temporal development in humans and animal models, as well as the specific underlying biologic events. Complementary to this will be in vitro model studies of arterial fluid mechanics. In addition, one can foresee an increasing role for computer modelling in our efforts to understand the pathophysiology of the atherogenic process. This includes not only computational fluid mechanics, but also modelling the pathobiologic processes taking place within the arterial wall. A key to the atherogenic process may reside in understanding how hemodynamics influences not only intimal smooth muscle cell proliferation, but also the recruitment of the monocyte/macrophage and the formation of foam cells. Finally, it will be necessary to begin to integrate our knowledge of cellular phenomena into a description of the biologic processes within the arterial wall and then to integrate this into a picture of the disease process itself.

Stand growth responses after fertilization for thinned lodgepole pine, Douglas-fir, and spruce in forests of interior British Columbia, Canada

2019 ◽  
Vol 49 (11) ◽  
pp. 1471-1482
Author(s):  
Woongsoon Jang ◽  
Bianca N.I. Eskelson ◽  
Louise de Montigny ◽  
Catherine A. Bealle Statland ◽  
Derek F. Sattler ◽  
...  
Keyword(s):  
British Columbia ◽  
Picea Glauca ◽  
Lodgepole Pine ◽  
Basal Area ◽  
Stand Density ◽  
Site Index ◽  
Douglas Fir ◽  
Picea Sitchensis ◽  
Growth And Yield ◽  
Growth Responses

This study was conducted to quantify growth responses of three major commercial conifer species (lodgepole pine (Pinus contorta Douglas ex Loudon var. latifolia Engelm. ex S. Watson), interior Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco var. glauca (Beissn.) Franco), and spruce (white spruce (Picea glauca (Moench) Voss) and hybrid spruce (Picea engelmannii Parry ex. Engelm. × Picea glauca (Moench) Voss × Picea sitchensis (Bong.) Carrière))) to various fertilizer blends in interior British Columbia, Canada. Over 25 years, growth-response data were repeatedly collected across 46 installations. The fertilizer blends were classified into three groups: nitrogen only; nitrogen and sulfur combined; and nitrogen, sulfur, and boron combined. The growth responses for stand volume, basal area, and top height were calculated through absolute and relative growth rate ratios relative to a controlled group. Fertilizer blend, inverse years since fertilization, site index, stand density at fertilization, and their interactions with the fertilizer blend were used as explanatory variables. The magnitude and significance of volume and basal area growth responses to fertilization differed by species, fertilizer-blend groups, and stand-condition variables (i.e., site index and stand density). In contrast, the response in top height growth did not differ among fertilization blends, with the exception of the nitrogen and sulfur fertilizer subgroup for lodgepole pine. The models developed in this study will be incorporated into the current growth and yield fertilization module (i.e., Table Interpolation Program for Stand Yields (TIPSY)), thereby supporting guidance of fertilization applications in interior forests in British Columbia.

Sitka spruce (Picea sitchensis) in North America with special reference to its role in British forestry

1987 ◽  
Vol 93 (1-2) ◽  
pp. 1-12 ◽  
Author(s):  
L. Roche ◽  
P. G. Haddock
Keyword(s):  
Genetic Variation ◽  
North America ◽  
Special Reference ◽  
Picea Glauca ◽  
Natural Habitat ◽  
Sitka Spruce ◽  
Picea Sitchensis ◽  
Natural Distribution ◽  
Queen Charlotte Islands ◽  
Genetic Potential

SynopsisThe natural distribution of Sitka spruce is examined in relation to the species' role in British forestry. Particular attention is therefore given to a description of habitats on the Queen Charlotte Islands, and also on the adjacent mainland of British Columbia where Sitka spruce is sympatric with white spruce (Picea glauca) and hybridisation occurs. Examples of genetic variation are given and it is suggested that a knowledge of the genecologv of the species in its natural habitat would help to elucidate its full ecological and genetic potential in Britain.

Effects on understory biomass and forage 8–10 years after precommercial thinning of Sitka spruce – western hemlock stands in southeast Alaska

2020 ◽  
Vol 50 (2) ◽  
pp. 215-225
Author(s):  
Justin S. Crotteau ◽  
Annelise Z. Rue-Johns ◽  
Jeffrey C. Barnard
Keyword(s):  
Forest Type ◽  
Sitka Spruce ◽  
Picea Sitchensis ◽  
Wildlife Habitat ◽  
Western Hemlock ◽  
Stand Age ◽  
Southeast Alaska ◽  
Precommercial Thinning ◽  
Clear Cutting ◽  
Understory Biomass

In southeast Alaska, United States, multiple-use forest management objectives include both timber production and wildlife habitat. Following stand-replacing disturbances such as clear-cutting, Sitka spruce (Picea sitchensis (Bong.) Carrière) and western hemlock (Tsuga heterophylla (Raf.) Sarg.) naturally regenerate and competitively dominate resources, excluding understory biomass and biodiversity. Thinning may mitigate the effects of canopy closure and permit understory development, but evidence of the effect on understories 8–10 years after thinning is lacking. We report results 4–5 and 8–10 years after thinning experiments on the Tongass National Forest to demonstrate the effects of precommercial thinning (thinned versus control), stand age (15–25, 25–35, and 35–50 years), and weather on understory dynamics and Sitka black-tailed deer (Odocoileus hemionus sitkensis Merriam, 1898) forage availability. Stand density negatively affected understory biomass, whereas temperature and precipitation positively interacted to increase biomass. Thinning had an enduring effect on understories, with biomass at least twice as great in thinned versus unthinned stands through year 10. We identified compositional differences from thinning as stand age class increased. Deer forage responded similarly to biomass, but thinning-induced differences faded with increased winter snowfall scenarios, especially in older stands. This study aids the understanding of stand overstory and understory development following silvicultural treatments in the coastal temperate rain forest of Alaska and suggests management implications and applications for balancing objectives throughout the forest type.

Understory conifer seedling response to a gradient of root and ectomycorrhizal fungal contact

2005 ◽  
Vol 83 (6) ◽  
pp. 638-646 ◽  
Author(s):  
J M Kranabetter
Keyword(s):  
Picea Glauca ◽  
Tsuga Heterophylla ◽  
Picea Sitchensis ◽  
Forest Understory ◽  
Western Hemlock ◽  
Scarce Resources ◽  
Full Contact ◽  
Mycorrhizal Network ◽  
Mycorrhizal Networks ◽  
Common Mycorrhizal Network

The possible benefit of common mycorrhizal network linkages to seedling growth was tested in a low light partial-cut forest understory. Naturally regenerated western hemlock (Tsuga heterophylla Raf.) and hybrid spruce (Picea glauca × Picea sitchensis [Moench] Voss) seedlings were transplanted directly into soil or within bags of different pore sizes to restrict the amounts of root and ectomycorrhizal contact. The 5-year study included "full contact" (no bag), "moderate contact" (250-µm openings), and "low contact" (4-µm openings) treatments. Height increment was lowest for full contact seedlings over most of the experiment, and highest for low contact seedlings by years 4 and 5. Full contact seedlings also had slightly lower foliar N content than moderate and low contact seedlings. There were no significant interactions in growth detected between tree species and treatments, despite the higher potential for common mycorrhizal network linkages between a western hemlock understory and canopy. Fifty-eight ectomycorrhizal fungal morphotypes were identified on the seedlings, including many with smooth mantles or with only sparse emanating hyphae, which likely reduced the potential for common mycorrhizal network linkages. These results would support the more traditional concepts of competition for scarce resources by isolated seedlings as the primary interaction for the understory of these mature forests.Key words: common mycorrhizal networks, facilitation, shade tolerance, competition.

Organization and distribution of a Sau3A tandem repeated DNA sequence in Picea (Pinaceae) species

Genome ◽  
1998 ◽  
Vol 41 (4) ◽  
pp. 560-565 ◽  
Author(s):  
Garth R Brown ◽  
Craig H Newton ◽  
John E Carlson
Keyword(s):  
In Situ Hybridization ◽  
Dna Sequence ◽  
Picea Glauca ◽  
Tandem Repeats ◽  
Picea Sitchensis ◽  
Repeated Dna ◽  
Metaphase Chromosomes ◽  
Genes Encoding ◽  
Repeated Dna Sequence

Repeated DNA families contribute to the large genomes of coniferous trees but are poorly characterized. We report the analysis of a 142 bp tandem repeated DNA sequence identified by the restriction enzyme Sau3A and found in approximately 20 000 copies in Picea glauca. Southern hybridization indicated that the repeated DNA family is specific to the genus, was amplified early in its evolution, and has undergone little structural alteration over evolutionary time. Fluorescence in situ hybridization localized arrays of the Sau3A repeating element to the centromeric regions of different subsets of the metaphase chromosomes of P. glauca and the closely related Picea sitchensis, suggesting that mechanisms leading to the intragenomic movement of arrays may be more active than those leading to mutation of the repeating elements themselves. Unambiguous identification of P. glauca and P. sitchensis chromosomes was made possible by co-localizing the Sau3A tandem repeats and the genes encoding the 5S and 18S-5.8S-26S ribosomal RNAs.Key words: Picea, repeated DNA, in situ hybridization, centromere.

The Douglas-fir forests of Banff and Jasper National Parks, Canada

1970 ◽  
Vol 48 (10) ◽  
pp. 1703-1726 ◽  
Author(s):  
Paul W. Stringer ◽  
George H. La Roi
Keyword(s):  
National Parks ◽  
Populus Tremuloides ◽  
Picea Glauca ◽  
Pinus Contorta ◽  
Vegetation Change ◽  
Floristic Composition ◽  
Stand Age ◽  
Physical Habitat ◽  
Regression Equations ◽  
Habitat Differences

Twenty stands of uniform, mature, undisturbed Pseudotsuga menziesii var. glauca forest were selected in Banff and Jasper National Parks, using a combination of airphoto and ground surveys. Quantitative sampling methods were used to describe their floristic composition, vegetation structure, and physical habitats.Scattered trees of Pinus contorta, Picea glauca, and Populus tremuloides occurred in the Pseudotsuga forests. The poorly developed shrub strata contained Shepherdia canadensis, Rosa acicularis, Spiraea lucida, Juniperus communis. Major herb, dwarf shrub, bryophyte, and lichen species were Elymus innovatus, Calamagrostis rubescens, Fragaria virginiana, Astragalus decumbens, Aster conspicuus; Arctostaphylos uva-ursi, Linnaea borealis; Hylocomium splendens, Abietinella abietina, Tortula ruralis; Peltigera canina. A cyclical pattern of vegetation change is related to the death, replacement, and maturation of Pseudotsuga trees.Relations between vegetation and physical habitat were analyzed by simple correlation and multiple regression. Available potassium in soil, stand age, and slope exposure were most influential in regression equations for tree stratum development. Understory strata were primarily correlated with tree stratum development.A two-dimensional stand ordination based on the vegetational similarity of subordinate vascular strata showed a pronounced separation of Banff and Jasper Pseudotsuga forests, and prompted recognition of two new climax associations (sensu Daubenmire): Pseudotsuga / Elymus innovatus in Jasper; Pseudotsuga / Calamagrostis rubescens – Elymus innovatus in Banff. Habitat differences between the two associations include macroclimate, parent materials, and soil moisture.

Foliar plasticity of hybrid spruce in relation to crown position and stand age

2000 ◽  
Vol 78 (3) ◽  
pp. 305-317 ◽  
Author(s):  
A.D. Richardson ◽  
G.P. Berlyn ◽  
P.M.S. Ashton ◽  
R. Thadani ◽  
I.R. Cameron
Keyword(s):  
Stand Age ◽  
Crown Position ◽  
Hybrid Spruce

A set of microsatellite markers for use in Sitka spruce (Picea sitchensis) developed from Picea glauca ESTs

2004 ◽  
Vol 4 (4) ◽  
pp. 659-663 ◽  
Author(s):  
S. W. A'HARA ◽  
J. E. COTTRELL
Keyword(s):  
Microsatellite Markers ◽  
Picea Glauca ◽  
Sitka Spruce ◽  
Picea Sitchensis

Ectomycorrhizal community effects on hybrid spruce seedling growth and nutrition in clearcuts

2004 ◽  
Vol 82 (7) ◽  
pp. 983-991 ◽  
Author(s):  
J M Kranabetter
Keyword(s):  
Picea Glauca ◽  
Forest Ecosystems ◽  
Picea Sitchensis ◽  
Community Effects ◽  
Close Spacing ◽  
Growth And Nutrition ◽  
Nitrogen Concentrations ◽  
Ecm Fungi ◽  
Diverse Community ◽  
Hybrid Spruce

A diverse community of ectomycorrhizal (ECM) fungi is generally considered beneficial to forest ecosystems, but the function of ECM communities should be considered within an ecological context. The growth of hybrid spruce (Picea glauca (Moench) Voss × Picea sitchensis (Bong.) Carrière) seedlings was compared after transplanting into recent clearcuts, where soil moisture and nitrogen are typically readily available. The seedlings had either a "forest" ECM community (taken from forest gap edges) or a "pioneer" ECM community (taken from disturbed road edges) and were planted at wide and close spacing. After 3 years, morphotype distribution and abundance (64% community similarity between "forest" and "pioneer" seedlings) overlapped considerably, but height growth was 25% greater for the "pioneer" seedlings. There was a reduction in diameter at close spacing, with little difference in competition effects between ECM communities. There were no differences detected in foliar nitrogen concentrations and no evidence of nitrogen or phosphorus deficiencies. The advantage of fungi such as Amphinema byssoides, Thelephora terrestris, and Laccaria laccata might be the proliferation of fine roots that allows for the fullest utilization of abundant soil resources. The results suggest that the ECM communities arising after clearcut disturbances are well adapted to these initial soil conditions.Key words: ectomycorrhiza, disturbance, diversity, productivity, competition, Picea glauca.

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