Distribution of leaf orientations in six conifer species

2001 ◽  
Vol 79 (4) ◽  
pp. 389-397 ◽  
Author(s):  
Hugh J Barclay
Keyword(s):  
Pseudotsuga Menziesii ◽  
Pinus Contorta ◽  
Goodness Of Fit ◽  
Tsuga Heterophylla ◽  
Picea Sitchensis ◽  
The Other ◽  
Thuja Plicata ◽  
Leaf Angle ◽  
Conifer Species ◽  
Abies Grandis

Leaf angle distributions are important in assessing both the flexibility of a plant's response to differing daily and seasonal sun angles and also the variability in the proportion of total leaf area visible in remotely sensed images. Leaf angle distributions are presented for six conifer species, Abies grandis (Dougl. ex D. Don) Lindl., Thuja plicata Donn. ex D. Don, Tsuga heterophylla (Raf.) Sarg., Pseudotsuga menziesii (Mirb.) Franco, Picea sitchensis (Bong.) Carr. and Pinus contorta Dougl. ex Loud. var. latifolia. The leaf angles were calculated by measuring four foliar quantities, and then the distributions of leaf angles are cast in three forms: distributions of (i) the angle of the long axis of the leaf from the vertical for the range 0–180°; (ii) the angle of the long axis of the leaf for the range 0–90°; and (iii) the angle of the plane of the leaf for the range 0–90°. Each of these are fit to the ellipsoidal distribution to test the hypothesis that leaf angles in conifers are sufficiently random to fit the ellipsoidal distribution. The fit was generally better for planar angles and for longitudinal angles between 0° and 90° than for longitudinal angles between 0° and 180°. The fit was also better for Tsuga heterophylla, Pseudotsuga menziesii, Picea sitchensis, and Pinus contorta than for Abies grandis and Thuja plicata. This is probably because Abies and Thuja are more shade tolerant than the other species, and so the leaves in Abies and Thuja are preferentially oriented near the horizontal and are much less random than for the other species. Comparisons of distributions on individual twigs, whole branches, entire trees, and groups of trees were done to test the hypothesis that angle distributions will depend on scale, and these comparisons indicated that the apparent randomness and goodness-of-fit increased on passing to each larger unit (twigs up to groups of trees).Key words: conifer, leaf angles, ellipsoidal distribution.

Hybrid biovars of Agrobacterium species isolated from conifer roots

1991 ◽  
Vol 37 (1) ◽  
pp. 34-41 ◽  
Author(s):  
C. R. Bell ◽  
W. D. Ramey
Keyword(s):  
Pseudotsuga Menziesii ◽  
Picea Glauca ◽  
Pinus Contorta ◽  
Heterotrophic Bacteria ◽  
Principal Component ◽  
Tsuga Heterophylla ◽  
Thuja Plicata ◽  
Discrete Groups ◽  
Red Cedar ◽  
Cluster 2

A total of 377 heterotrophic bacteria were isolated on nonselective medium from the rhizoplanes of five species of conifer. The species were western hemlock (Tsuga heterophylla), Douglas-fir (Pseudotsuga menziesii), lodgepole pine (Pinus contorta), white spruce (Picea glauca), and western red cedar (Thuja plicata). Twenty-eight strains from this population were identified as presumptive agrobacteria. All proved nontumourigenic. Principal-component analysis indicated that the strains, which had clustered into two discrete groups, had intermediate biovar characteristics. Cluster 1 was predominately biovar 3/2 in character, cluster 2 was predominately biovar 2/3. All the presumptive agrobacteria were distributed randomly with respect to the tree species. This study demonstrates that agrobacteria, although atypical, do occur in forest soils and attests to the ubiquity of the genus in soil. Key words: Agrobacterium, biovars, crown gall, conifers.

Interactive effects of light and stratification on the germination of some British Columbia conifers

1994 ◽  
Vol 72 (11) ◽  
pp. 1635-1646 ◽  
Author(s):  
X. J. Li ◽  
P. J. Burton ◽  
C. L. Leadem
Keyword(s):  
British Columbia ◽  
Seed Germination ◽  
Pseudotsuga Menziesii ◽  
Seed Weight ◽  
Pinus Contorta ◽  
Picea Sitchensis ◽  
Thuja Plicata ◽  
Pinus Monticola ◽  
Larix Occidentalis ◽  
Tree Seed

Pregermination stratification treatment was generally more important than the effects of light on seed germination by 14 conifer species and varieties native to British Columbia. Nevertheless, there were some strong species differences in the response of germination to light. Final germination percentage after 21 days (28 days for Abies spp.) for both stratified and unstratified seeds of Picea glauca, Picea sitchensis, and Tsuga heterophylla showed no response to light during germination. Seed germination by Abies grandis, Pinus contorta var. contorta, Pinus contorta var. latifolia, Pinus ponderosa, Pseudotsuga menziesii var. glauca, and Pseudotsuga menziesii var. menziesii responded positively to light if unstratified but was not significantly affected by light when stratified. For Thuja plicata seeds, germination responded positively to light regardless of stratification pretreatment. Light appeared to reduce germination of stratified seeds of Abies amabilis, Abies lasiocarpa, Larix occidentalis, and Pinus monticola, although stratification conditions for these species were suboptimal. The germination rate of stratified seeds of all species and unstratified seeds of most species was increased by light. Results showed no significant relationship between germination response to light and shade-tolerance ranking or mean seed weight of the species. In six seed lots of Pinus contorta var. latifolia, however, we detected a weak negative correlation between mean seed weight and unstratified light responsivity measured after 1 week but a significant positive correlation when measured after 3 weeks. Very low light levels in closed-canopy forests or in the forest floor may prolong tree seed germination but are unlikely to constrain final germination levels after most seeds have been naturally stratified by moist, cool winter conditions. The importance of differences in the rate and timing of tree seed germination under natural conditions remains to be demonstrated. Key words: conifer biology, forest regeneration, light response, lodgepole pine, Pinus contorta, seed germination, stratification.

A 14,000 year vegetation history of a hypermaritime island on the outer Pacific coast of Canada based on fossil pollen, spores and conifer stomata

2012 ◽  
Vol 78 (3) ◽  
pp. 572-582 ◽  
Author(s):  
Terri Lacourse ◽  
J. Michelle Delepine ◽  
Elizabeth H. Hoffman ◽  
Rolf W. Mathewes
Keyword(s):  
Pinus Contorta ◽  
Vegetation History ◽  
Tsuga Heterophylla ◽  
Picea Sitchensis ◽  
Thuja Plicata ◽  
North Coast ◽  
Pollen Record ◽  
The North ◽  
History Of ◽  
Local Species

AbstractPollen and conifer stomata analyses of lake sediments from Hippa Island on the north coast of British Columbia were used to reconstruct the vegetation history of this small hypermaritime island. Between 14,000 and 13,230 cal yr BP, the island supported diverse herb–shrub communities dominated by Cyperaceae, Artemisia and Salix. Pinus contorta and Picea sitchensis stomata indicate that these conifers were present among the herb–shrub communities, likely as scattered individuals. Transition to open P. contorta woodland by 13,000 cal yr BP was followed by increases in Alnus viridis, Alnus rubra and P. sitchensis. After 12,000 cal yr BP, Pinus-dominated communities were replaced by dense P. sitchensis and Tsuga heterophylla forest with Lysichiton americanus and fern understory. Thuja plicata stomata indicate that this species was present by 8700 cal yr BP, but the pollen record suggests that its populations did not expand to dominate regional rainforests, along with Tsuga and Picea, until after 6600 cal yr BP. Conifer stomata indicate that species may be locally present for hundreds to thousands of years before pollen exceed thresholds routinely used to infer local species arrival. When combined, pollen and conifer stomata can provide a more accurate record of paleovegetation than either when used alone.

Postglacial vegetation history of Mitkof Island, Alexander Archipelago, southeastern Alaska

2010 ◽  
Vol 73 (2) ◽  
pp. 259-268 ◽  
Author(s):  
Thomas A. Ager ◽  
Paul E. Carrara ◽  
Jane L. Smith ◽  
Victoria Anne ◽  
Joni Johnson
Keyword(s):  
Pinus Contorta ◽  
Vegetation History ◽  
Regional Climate ◽  
Sitka Spruce ◽  
Tsuga Heterophylla ◽  
Picea Sitchensis ◽  
Thuja Plicata ◽  
Pollen Record ◽  
Coastal Forests ◽  
History Of

An AMS radiocarbon-dated pollen record from a peat deposit on Mitkof Island, southeastern Alaska provides a vegetation history spanning ∼12,900 cal yr BP to the present. Late Wisconsin glaciers covered the entire island; deglaciation occurred > 15,400 cal yr BP. The earliest known vegetation to develop on the island (∼12,900 cal yr BP) was pine woodland (Pinus contorta) with alder (Alnus), sedges (Cyperaceae) and ferns (Polypodiaceae type). By ∼12,240 cal yr BP, Sitka spruce (Picea sitchensis) began to colonize the island while pine woodland declined. By ∼11,200 cal yr BP, mountain hemlock (Tsuga mertensiana) began to spread across the island. Sitka spruce-mountain hemlock forests dominated the lowland landscapes of the island until ∼10,180 cal yr BP, when western hemlock (Tsuga heterophylla) began to colonize, and soon became the dominant tree species. Rising percentages of pine, sedge, and sphagnum after ∼7100 cal yr BP may reflect an expansion of peat bog habitats as regional climate began to shift to cooler, wetter conditions. A decline in alders at that time suggests that coastal forests had spread into the island's uplands, replacing large areas of alder thickets. Cedars (Chamaecyparis nootkatensis, Thuja plicata) appeared on Mitkof Island during the late Holocene.

scholarly journals British Columbia Vegetation and Climate History with Focus on 6 ka BP

2007 ◽  
Vol 49 (1) ◽  
pp. 55-79 ◽  
Author(s):  
Richard J. Hebda
Keyword(s):  
British Columbia ◽  
Pinus Contorta ◽  
Tsuga Heterophylla ◽  
Picea Sitchensis ◽  
Early Holocene ◽  
Thuja Plicata ◽  
Quercus Garryana ◽  
Climate History ◽  
The North ◽  
Vegetation And Climate

ABSTRACT British Columbia Holocene vegetation and climate is reconstructed from pollen records. A coastal Pinus contorta paleobiome developed after glacier retreat under cool and probably dry climate. Cool moist forests involving Picea, Abies, Tsuga spp., and Pinus followed until the early Holocene. Pseudotsuga menziesii arrived and spread in the south 10 000-9000 BP, and Picea sitchensis - Tsuga heterophylla forests developed in the north. T. heterophylla increased 7500-7000 BP, and Cupressaceae expanded 5000-4000 BP. Bogs began to develop and expland. Modern vegetation arose 4000-2000 BP. There were early Holocene grass and Artemisia communities at mid-elevations and pine stands at high elevations in southern interior B.C. Forests expanded downslope and lakes formed 8500-7000 BP. Modern forests arose 4500-4000 BP while lower and upper tree lines declined. In northern B.C. non-arboreal communities preceded middle Holocene Picea forests. Abies, Pinus and Picea mariana predominated at various sites after 4000 BP. At 6000 BP Tsuga heterophylla (south) and Picea sitchensis (north) dominated the coast and islands and Quercus garryana and Pseudotsuga on southeast Vancouver Island, but Thuja plicata was infrequent. Southern Interior Plateau vegetation at 6000 BP was more open than today at middle to lower elevations, whereas forests covered the Northern Interior Plateau. Picea forests occurred in northern B.C. Holocene climate phases were: 1) warm dry "xerothermic" ca. 9500-7000 BP, 2) warm moist "mesothermic" ca. 7000-4500 BP, 3) moderate and moist 4500-0 BP, with increasing moisture 8500-6000 BP and cooling (?increased moisture) 4500-3000 BP. B.Cs Hypsithermal had dry and wet stages; 6000 BP occurred in the warm and wet mesothermic stage.

Conversion of total to projected leaf area index in conifers

2000 ◽  
Vol 78 (4) ◽  
pp. 447-454 ◽  
Author(s):  
Hugh J Barclay ◽  
Doug Goodman
Keyword(s):  
Leaf Area Index ◽  
Leaf Area ◽  
Pinus Contorta ◽  
Tsuga Heterophylla ◽  
Picea Sitchensis ◽  
Thuja Plicata ◽  
Area Index ◽  
Conversion Factors ◽  
Horizontal Orientation ◽  
Thuja Plicata Donn

Several definitions of leaf area index (LAI) presently exist in the literature but the relationships among them are not clear. To compare the results of various studies, there is a need to convert from one definition to another. Factors for converting among four definitions of LAI are presented for six conifer species: Abies grandis (Dougl. ex D. Don) Lindl., Thuja plicata Donn ex D. Don., Tsuga heterophylla (Raf.) Sarg., Picea sitchensis (Bong.) Carr.), Pinus contorta Dougl., and Pseudotsuga menziesii (Mirb) Franco). Among the four definitions of LAI, the two extremes involve (i) the total area of the leaf and (ii) the projected area of nonhorizontal leaves, as they occur on the tree. If leaves are randomly oriented in space, then the conversion factor between definitions i and ii should be 0.25. Four of the six species have conversion factors very close to this value, and three of these four are relatively shade-intolerant,. The remaining two species, A. grandis and Thuja plicata, have conversion factors of approximately 0.35, owing to the approximately horizontal orientation of their leaves. These two species are both relatively shade-tolerant, and the trend toward horizontal leaves might be an adaptation to assist in shade tolerance. A sensitivity analysis indicated that the foliage of most of the species maximized the amount of light gathered when the light was coming from almost straight overhead, as is the case with many shaded forest trees.Key words: leaf area index, conifers, leaf area index conversion.

Black Bear Damage to Thinned Timber Stands in Northwest Montana

1989 ◽  
Vol 4 (1) ◽  
pp. 10-13 ◽  
Author(s):  
Andrew C. Mason ◽  
David L. Adams
Keyword(s):  
Pinus Contorta ◽  
Black Bear ◽  
Tsuga Heterophylla ◽  
Thuja Plicata ◽  
Abies Lasiocarpa ◽  
Pinus Monticola ◽  
Larix Occidentalis ◽  
Western Larch ◽  
Engelmann Spruce ◽  
Northwest Montana

Abstract Bear damage was at least five times higher in thinned blocks than in adjacent unthinned blocks of western larch (Larix occidentalis), lodgepole pine (Pinus contorta), and Engelmann spruce (Picea engelmannii) on the Kootenai National Forest in northwest Montana. Western larch suffered the greatest damage (63% of all trees damaged and 92% of the trees killed). Damaged larch ranged from 4 to 13 in. dbh; the 4 to 8-in. dbh class accounted for 85% of the damage. Douglas-fir (Pseudotsuga menziesii), western redcedar (Thuja plicata), subalpine fir (Abies lasiocarpa), western white pine (Pinus monticola), and western hemlock (Tsuga heterophylla) were not damaged. Stand projections showed up to a 17% reduction in board-foot yield from bear damage, after 50 years, compared with hypothetical undamaged stands. West. J. Appl. For. 4(1):10-13, January 1989.

Susceptibility of Western Conifers to Laminated Root Rot (Phellinus weirii) in Oregon and British Columbia Field Tests

1993 ◽  
Vol 8 (2) ◽  
pp. 67-70 ◽  
Author(s):  
E. E. Nelson ◽  
Rona N. Sturrock
Keyword(s):  
British Columbia ◽  
Pinus Ponderosa ◽  
Ponderosa Pine ◽  
Root Rot ◽  
Field Tests ◽  
Tsuga Heterophylla ◽  
Picea Sitchensis ◽  
Thuja Plicata ◽  
Giant Sequoia ◽  
Phellinus Weirii

Abstract Several species of conifers were outplanted around infected stumps in Oregon and British Columbia to measure their susceptibility to laminated root rot caused by Phellinus weirii. Grand fir (Abies grandis) experienced nearly 30% mortality caused by P. weirii. Douglas-fir (Pseudotsuga menziesii) mortality exceeded 20%. Noble fir (A. procera), Sitka spruce (Picea sitchensis), giant sequoia (Sequoiadendron giganteum), western hemlock (Tsuga heterophylla), and ponderosa pine (Pinus ponderosa) mortality averaged less than 10%. Western white pine (P. monticola) and lodgepole pine (P. contorta) mortality was less than 1%. Phellinus weirii did not cause mortality of western redcedar (Thuja plicata) or redwood (Sequoia sempervirens). Apparent susceptibility, based on mortality over 17-20 growing seasons, was similar to that recorded in past field observations. West. J. Appl. For. 8(2):67-70.

scholarly journals Dichotomous Keys for Scaling and Grading Merchantable Quality Sawlogs

2003 ◽  
Vol 18 (4) ◽  
pp. 250-258
Author(s):  
Steve Bowers
Keyword(s):  
Pseudotsuga Menziesii ◽  
Tsuga Heterophylla ◽  
Picea Sitchensis ◽  
Advisory Group ◽  
Time Scaling ◽  
Dichotomous Key ◽  
Second Growth ◽  
Group A ◽  
Length Scaling ◽  
Log Scaling

Abstract This study documented and field-tested a simplified version of the Westside Grading Guidelines as published in the Official Rules Handbook by the Northwest Log Rules Advisory Group. A four-step dichotomous key was documented and field-tested to determine merchantable vs. nonmerchantable logs. The study also documented and field-tested an individual seven-step dichotomous log grading key for evaluating second-growth Douglas-fir (Pseudotsuga menziesii), Sitka spruce (Picea sitchensis), western hemlock (Tsuga heterophylla), and grand fir (Abies grandis) as derived from the Rules For Grading Logs section of the Official Rules Handbook. Results were compared with certified scalers employed by Yamhill Log Scaling & Grading Bureau and Columbia River Log Scaling & Grading Bureau. Eighty-four individuals measured the length, scaling diameter, determined merchantability versus nonmerchantability and assigned log grade for 440 logs. Results showed participants in the study correctly measuring log length 99% of time, scaling diameters were recorded correctly at an 89% rate, and merchantability and log grade at 98 and 97%, respectively. West. J. Appl. For. 18(4):250–258.

Palynology and paleoecology of postglacial sediments in an anoxic basin, Saanich Inlet, British Columbia

1983 ◽  
Vol 20 (5) ◽  
pp. 873-885 ◽  
Author(s):  
Linda E. Heusser
Keyword(s):  
British Columbia ◽  
Pinus Contorta ◽  
Tsuga Heterophylla ◽  
Douglas Fir ◽  
Western Hemlock ◽  
Thuja Plicata ◽  
Alnus Rubra ◽  
Red Cedar ◽  
Saanich Inlet ◽  
Anoxic Basin

Varved, black clayey silts deposited in the marine waters of Saanich Inlet yield unusually abundant and diverse pollen assemblages derived from the coastal Douglas-fir (Pseudotsuga) and western hemlock (Tsuga heterophylla) forests of southwestern British Columbia. The 12 000 year palynological record chronicles the development of vegetation since ice left Saanich Inlet: the succession of pine (Pinus contorta) and alder (Alnus rubra) woodlands by forests characterized by Douglas-fir and oak (Quercus) and later by western hemlock and red cedar (Thuja plicata). Rapid deposition of annual layers of pollen, charcoal, and other terrigenous particles provides detailed evidence of changes in land use during the past few hundred years: settlement, logging, farming, and urbanization. Vegetational and climatic changes inferred from pollen spectra in the marine sediments of Saanich Inlet compare favorably with changes inferred from correlative pollen assemblages previously described from adjacent parts of Vancouver Island and the Fraser River valley.

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