Pollen transport and representation in the Coast Mountains of British Columbia. I. Flowering phenology and aerial deposition

Two years of aerial pollen trapping at two lakes surrounded by coniferous forest are summarized. Most of the annual pollen and spore deposition occurs between February and May (86%), followed by 10% during the summer, and 4% during the fall – winter nonflowering period. Annual aerial influx is very similar at both Marion and Surprise lakes, ca. 5000 grains∙cm−2∙year−1. The annual frequency spectra are also equivalent, with a predominance of Cupressaceae (32%) and Alnus (35%), followed by Tsuga heterophylla (8 – 11%), grasses (8 – 10%), and pine (2 – 3%). Regional, rather than local or extralocal pollen, is estimated to account for about 90% of the annual aerial deposition at both lakes. The data also suggest that pollen transport is predominantly upslope in this mountainous area.

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Vertical and temporal distribution of insolation in gaps in an old-growth coniferous forest

Canadian Journal of Forest Research ◽

10.1139/x00-108 ◽

2000 ◽

Vol 30 (12) ◽

pp. 1953-1964 ◽

Cited By ~ 10

Author(s):

Stuart B Weiss

Keyword(s):

Coniferous Forest ◽

Temporal Distribution ◽

Tsuga Heterophylla ◽

Hemispherical Photography ◽

Area Index ◽

Direct Measurements ◽

Canopy Access ◽

Solar Angle ◽

Term Data

The combination of canopy access at the Wind River Canopy Crane Research Facility, hemispherical photography, and long-term insolation data provided estimates of vertical and temporal distributions of insolation in nine canopy gaps in a 65 m tall Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco) - western hemlock (Tsuga heterophylla (Raf.) Sarg.) forest. Yearly insolation (long-term data from Portland, Oreg.) exhibited a sigmoidal pattern with height, with a bright zone (>4200 MJ/m2) above 50 m, a transition zone from 45 to 30 m (2000 MJ/m2), and less rapid decrease from 30 to below 10 m (600 MJ/m2). Intergap variation peaked between 20 and 40 m. Interannual variation of yearly insolation (CV = SD/mean) was about 5% throughout the canopy. Seasonality of insolation was driven by solar angle and cloudiness. Diffuse insolation was 50% of annual above-canopy flux, increasing to nearly 70% at 1.5 m, and diffuse proportion was greater in winter and spring. Hourly simulations under clear and cloudy conditions provided an appropriate time scale for modeling photosynthesis. Estimated leaf area index peaked at 30-35 and 5-10 m but was underestimated (3.7 vs. 9.1 m2/m2 from direct measurements) because of foliage clumping. The methods documented highly variable distributions of insolation driven by forest structure, cloudiness, and seasonal changes in solar angle.

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Four Pleistocene formations in southwest British Columbia: their implications for patterns of sedimentation of possible Sangamonian to early Wisconsinan age

Canadian Journal of Earth Sciences ◽

10.1139/e83-110 ◽

1983 ◽

Vol 20 (8) ◽

pp. 1232-1247 ◽

Cited By ~ 19

Author(s):

Stephen R. Hicock ◽

John E. Armstrong

Keyword(s):

Stream Flow ◽

Vancouver Island ◽

Tsuga Heterophylla ◽

Last Interglacial ◽

Strait Of Georgia ◽

Coast Mountains ◽

Arboreal Pollen ◽

Juan De Fuca ◽

Stratigraphic Position ◽

Juan De Fuca Strait

Semiahmoo and Dashwood drifts were deposited during the penultimate glaciation, and Highbury Sediments and Muir Point Formation during the last interglacial. These sediments are defined and described, and stratotypes are established for them.Based on arboreal pollen assemblages, lithologic similarity, and relative stratigraphic position, Semiahmoo Drift of the Fraser Lowland is tentatively correlated with Dashwood Drift of Vancouver Island. Stone provenance, till fabrics, glaciotectonic structures, cross-bedding, and stone imbrication indicate that regional ice and meltwater flowed out of major fiords in the Coast Mountains and into the ancestral Strait of Georgia during the penultimate glaciation. Ice flowed southeastward against the east coast of Vancouver Island, and down the axis of the strait. Pollen and molluscs in Semiahmoo and Dashwood fossiliferous muds give evidence of transition from glaciomarine to marine conditions at the close of the penultimate glaciation.Highbury Sediments of the Fraser Lowland perhaps correlate with the Muir Point Formation of Vancouver Island, based on lithologic similarity and relative stratigraphic position. Stone provenance and paleocurrent data indicate that stream flow during the last interglacial issued from nearby mountains and onto coastal floodplains that shelved into the ancestral Strait of Georgia and Juan de Fuca Strait. Abundant Pseudotsuga and Tsuga heterophylla pollen indicate that climate during that time was at least as warm as the present.

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Short-term population dynamics of Glaucomys sabrinus and Tamiasciurus douglasii in commercially thinned and unthinned stands of coastal coniferous forest

Canadian Journal of Forest Research ◽

10.1139/x02-126 ◽

2002 ◽

Vol 32 (11) ◽

pp. 2043-2050 ◽

Cited By ~ 15

Author(s):

Douglas B Ransome ◽

Thomas P Sullivan

Keyword(s):

Population Dynamics ◽

Coniferous Forest ◽

Tsuga Heterophylla ◽

Survival Duration ◽

Thuja Plicata ◽

Glaucomys Sabrinus ◽

Short Term ◽

Commercial Thinning ◽

Thuja Plicata Donn ◽

Short Term Effects

Population dynamics of Glaucomys sabrinus (Shaw) and Tamiasciurus douglasii (Audubon and Bachman) were examined in commercially thinned and unthinned stands in British Columbia, Canada. We tested the hypothesis that commercial thinning would have negative short-term effects on the population dynamics of these species. Populations were monitored using markrecapture techniques in two commercially thinned and two unthinned stands dominated by 60- to 70-year-old western hemlock (Tsuga heterophylla (Raf.) Sarg.) and western redcedar (Thuja plicata Donn. ex D. Don). Populations were sampled intensively from August 1995 to May 1999 at Chehalis Lake and from May 1997 to March 2000 in the Malcolm Knapp Research Forest (MKRF). There were no differences among stands thinned and unthinned in movement, abundance, recruitment, survival, duration individuals remained in stands, percentage of males breeding, and mass of males for G. sabrinus or T. douglasii. Mean density of G. sabrinus in thinned and unthinned stands were 0.65 and 0.89 individuals/ha, respectively, at Chehalis and 0.09 and 0.51 individuals/ha, respectively, at MKRF. Mean density of T. douglasii in thinned and unthinned stands were 1.18 and 0.87 individuals/ha, respectively, at Chehalis and 1.08 and 1.00 individuals/ha, respectively, at MKRF. We concluded that commercial thinning had no negative short-term effects on the population dynamics of these species.

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Spatial distribution and succession of epiphytes on Tsuga heterophylla (western hemlock) in an old-growth Douglas-fir forest

Canadian Journal of Botany ◽

10.1139/b00-064 ◽

2000 ◽

Vol 78 (7) ◽

pp. 957-968 ◽

Cited By ~ 14

Author(s):

Betsy Lyons ◽

Nalini M Nadkarni ◽

Malcolm P North

Keyword(s):

Forest Canopy ◽

Spatial Scales ◽

Coniferous Forest ◽

Tsuga Heterophylla ◽

Forest Understory ◽

Western Hemlock ◽

Old Growth ◽

Old Growth Forest ◽

Crown Structure ◽

Large Trees

We examined the distribution and abundance of nonvascular epiphytes on western hemlock trees in an old-growth coniferous forest focusing on patterns of epiphyte distribution at different spatial scales, epiphyte abundance amongst trees differing in size, and crown structures associated with epiphyte abundance. Total epiphyte cover was greatest in four canopy microhabitats: the upper canopy strata, crowns of large trees, lower crown branches, and inner branch plots. Epiphyte functional groups were stratified vertically within the stand and horizontally within branches. Alectorioid and "other" lichens were most abundant in the upper canopy and outer branch plots. Cyanolichens and Sphaerophorus globosus (Huds.) Vain. were most abundant in the lower to mid canopy. Although cyanolichens were most abundant in middle branch plots, Sphaerophorus was most abundant in inner branch plots. Bryophytes were most abundant in the lower canopy and inner branch plots. At the stand level, canopy height and tree size were the main influences on epiphytes. Within trees, plots closer to the tree trunk and lower in the crown had the greatest abundance of epiphytes. In this forest, understory trees were colonized first by bryophytes, not by alectorioid and "other" lichens as is common for small trees in young stands.Key words: epiphyte succession, lichens, western hemlock, old growth, forest canopy, crown structure.

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Postglacial wetland succession, carbon accumulation, and forest dynamics on the east coast of Vancouver Island, British Columbia, Canada

Quaternary Research ◽

10.1017/qua.2018.146 ◽

2019 ◽

Vol 92 (1) ◽

pp. 232-245 ◽

Cited By ~ 1

Author(s):

Terri Lacourse ◽

Kyle W. Beer ◽

Kira B. Craig ◽

Dante Canil

Keyword(s):

British Columbia ◽

Pinus Contorta ◽

Coniferous Forest ◽

Tsuga Heterophylla ◽

Carbon Accumulation ◽

Early Holocene ◽

Poor Fen ◽

Peatland Development ◽

The Pacific ◽

Ombrotrophic Bog

ABSTRACTPeatland development and carbon accumulation on the Pacific coast of Canada have received little attention in paleoecological studies, despite wetlands being common landscape features. Here, we present a multi–proxy paleoenvironmental study of an ombrotrophic bog in coastal British Columbia. Following decreases in relative sea level, the wetland was isolated from marine waters by 13,300 cal yr BP. Peat composition, non-pollen palynomorph, and C and N analyses demonstrate terrestrialization from an oligotrophic lake to a marsh by 11,600 cal yr BP, followed by development of a poor fen, and then a drier ombrotrophic bog by 8700 cal yr BP. Maximum carbon accumulation occurred during the early Holocene fen stage, when seasonal differences in insolation were amplified. This highlights the importance of seasonality in constraining peatland carbon sequestration by enhancing productivity during summer and reducing decomposition during winter. Pollen analysis shows that Pinus contorta dominated regional forests by 14,000 cal yr BP. Warm and relatively dry summers in the early Holocene allowed Pseudotsuga menziesii to dominate lowland forests 11,200–7000 cal yr BP. Tsuga heterophylla and P. menziesii formed coniferous forest in the mid- and late Holocene. Tephra matching the mid-Holocene Glacier Peak–Dusty Creek assemblage provides evidence of its most northwesterly occurrence to date.

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Efficacy and Safety of Regular Vitamin and Mineral Supplement Use in France: Results from the ECCA Study

International Journal for Vitamin and Nutrition Research ◽

10.1024/0300-9831.75.3.201 ◽

2005 ◽

Vol 75 (3) ◽

pp. 201-209 ◽

Cited By ~ 12

Author(s):

Touvier ◽

Boutron-Ruault ◽

Volatier ◽

Martin

Keyword(s):

Pantothenic Acid ◽

Assessment Tools ◽

Mineral Supplement ◽

Mineral Supplements ◽

Supplement Use ◽

Micronutrient Intake ◽

Frequency Of Use ◽

Retail Outlets ◽

Annual Frequency ◽

Excessive Intake

This study investigated the prevalence of inadequate micronutrient intake and the proportion of subjects who exceed Tolerable Upper Intake Levels a) with food only, and b) with food+supplements, in a population of French regular supplement users (n = 259). Assessment tools were seven-day records for supplements, three-day records for food intake, and a questionnaire about supplement use. Most subjects were recruited in retail outlets that sold supplements. They were recent users of vitamin/mineral supplements, aged over 15 years, and normo-energy reporters. The prevalence (%) of inadequate intake decreased with the inclusion of mean annual supplements, from 68.0 to 54.8 for magnesium, 55.9 to 40.7 for vitamin C, 53.4 to 43.9 for folic acid, 37.5 to 27.5 for iron, and 40.1 to 29.7 for pantothenic acid. Few subjects exceeded upper intake levels when mean annual intake of supplements was considered. When supplement consumption was considered during the studied week only, the proportion of subjects who were in excess of the upper intake levels was higher (maximum: 9.6% for magnesium). Supplement use brought a nutritional benefit for some targeted nutrients. It was not associated with excessive intake in this study, but could become hazardous if the annual frequency of use were to increase.

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Heart Rate Variability, Emotions, and Music

Journal of Psychophysiology ◽

10.1027/0269-8803/a000021 ◽

2010 ◽

Vol 24 (2) ◽

pp. 112-119 ◽

Cited By ~ 9

Author(s):

F. Riganello ◽

A. Candelieri ◽

M. Quintieri ◽

G. Dolce

Keyword(s):

Data Mining ◽

Heart Rate ◽

Heart Rate Variability ◽

Vegetative State ◽

Low Frequency ◽

Emotional Reactions ◽

Heart Beat ◽

Healthy Controls ◽

Frequency Spectra ◽

Emotional Value

The purpose of the study was to identify significant changes in heart rate variability (an emerging descriptor of emotional conditions; HRV) concomitant to complex auditory stimuli with emotional value (music). In healthy controls, traumatic brain injured (TBI) patients, and subjects in the vegetative state (VS) the heart beat was continuously recorded while the subjects were passively listening to each of four music samples of different authorship. The heart rate (parametric and nonparametric) frequency spectra were computed and the spectra descriptors were processed by data-mining procedures. Data-mining sorted the nu_lf (normalized parameter unit of the spectrum low frequency range) as the significant descriptor by which the healthy controls, TBI patients, and VS subjects’ HRV responses to music could be clustered in classes matching those defined by the controls and TBI patients’ subjective reports. These findings promote the potential for HRV to reflect complex emotional stimuli and suggest that residual emotional reactions continue to occur in VS. HRV descriptors and data-mining appear applicable in brain function research in the absence of consciousness.

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Right-Hemisphere Specialization for Contour Grouping

Experimental Psychology (formerly Zeitschrift für Experimentelle Psychologie) ◽

10.1027/1618-3169/a000252 ◽

2014 ◽

Vol 61 (5) ◽

pp. 331-339 ◽

Cited By ~ 1

Author(s):

Gregor Volberg

Keyword(s):

Right Hemisphere ◽

Contour Detection ◽

Global Processing ◽

Detection Accuracy ◽

Frequency Spectra ◽

Visual Hemifield ◽

Spatial Frequencies ◽

A Chain ◽

The Right ◽

Hemisphere Specialization

Previous studies often revealed a right-hemisphere specialization for processing the global level of compound visual stimuli. Here we explore whether a similar specialization exists for the detection of intersected contours defined by a chain of local elements. Subjects were presented with arrays of randomly oriented Gabor patches that could contain a global path of collinearly arranged elements in the left or in the right visual hemifield. As expected, the detection accuracy was higher for contours presented to the left visual field/right hemisphere. This difference was absent in two control conditions where the smoothness of the contour was decreased. The results demonstrate that the contour detection, often considered to be driven by lateral coactivation in primary visual cortex, relies on higher-level visual representations that differ between the hemispheres. Furthermore, because contour and non-contour stimuli had the same spatial frequency spectra, the results challenge the view that the right-hemisphere advantage in global processing depends on a specialization for processing low spatial frequencies.

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