Growth of planted tree seedlings in response to ambient light levels in northwestern interior cedar-hemlock forests of British Columbia

1999 ◽  
Vol 29 (9) ◽  
pp. 1374-1382 ◽  
Author(s):  
K Dave Coates ◽  
Philip J Burton
Keyword(s):  
Growth Rates ◽  
Tree Species ◽  
Pinus Contorta ◽  
Picea Sitchensis ◽  
High Light ◽  
Thuja Plicata ◽  
Ambient Light ◽  
Growth Strategies ◽  
Light Levels ◽  
Whole Plant

Insights into field-planted conifer seedling growth were gained by fitting height and diameter growth to relative irradiance over the growing season using Michaelis-Menten functions. There was little difference among tree species (Abies lasiocarpa (Hook.) Nutt., Picea glauca (Moench) Voss × Picea sitchensis (Bong.) Carr., Pinus contorta Dougl. ex Loud., Thuja plicata Donn ex D. Don, Tsuga heterophylla (Raf.) Sarg.) in response to ambient light. No significant differences in whole-plant compensation points were observed among species but the ranking of species' compensation points was consistent with their shade-tolerance ranking. Five years after planting, total size and recent growth rates varied little among species from low to high light, implying an absence of trade-offs in low- and high-light growth strategies. Thuja plicata had the greatest response to increased light under deep shade (<20% relative irradiance). All species increased growth above 40% relative irradiance, with no clear whole-plant light saturation point evident under field conditions. Growth rates at high light were broadly overlapping and varied considerably within species. As expected,Pinus contorta growth exceeded that of other species above 70% relative irradiance, but it also exhibited high growth rates at low light. Greatest variability among species was at intermediate light levels (30-70% relative irradiance) where careful matching of tree species to light environment can maximize growth rates.

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.

scholarly journals Inferences on the Susceptibility of Wood of Different Tree Species to Heterobasidion annosum Sensu Lato (Fr.) Bref. Primary Infections and on the Range of Pathogen Spores Dispersal

Forests ◽  
2021 ◽  
Vol 12 (7) ◽  
pp. 854
Author(s):  
Lauma Brūna ◽  
Guglielmo Lione ◽  
Kristīne Kenigsvalde ◽  
Natālija Burņeviča ◽  
Astra Zaļuma ◽  
...  
Keyword(s):  
Tree Species ◽  
Pinus Contorta ◽  
Sharp Decrease ◽  
Picea Sitchensis ◽  
Heterobasidion Annosum ◽  
Forest Pathogens ◽  
Airborne Inoculum ◽  
Controlled Conditions ◽  
Airborne Infections ◽  
Norway Spruce Forest

Stumps play a pivotal role in the epidemiology of the fungal forest pathogens Heterobasidion spp. because they are the main courts of primary airborne infections. The aims of this study were (i) to determine the susceptibility of seven tree species (i.e., Larix sibirica, Picea abies, Picea sitchensis, Pinus contorta, Pinus strobus, Pinus sylvestris and Pseudotsuga menziesii) to primary infection by H. annosum and H. parviporum through comparative inoculation experiments of conidia on wood discs in controlled conditions; (ii) to compare the susceptibility of wood discs of the same tree species to natural airborne infections in two Latvian Norway spruce forest stands infested either by H. annosum or H. parviporum; (iii) to explore the rates of infection of wood discs at increasing distances from spore sources in these two forests to make inferences on the range of spores dispersal. Results obtained by spraying wood discs with conidial suspensions in controlled conditions are in agreement with those obtained by exposing wood discs to the natural airborne inoculum in the forests, as clearly supported by the significant correlation (r = 0.79; p < 0.05) between the two sets of data. Susceptibility was highest in Pinus species, followed by P. abies and P. sitchensis. Susceptibility was lowest for L. sibirica and P. menziesii. The area colonized by Heterobasidion spp. in the sapwood of wood discs was much greater than that colonized in the heartwood. A sharp decrease in the rate of infection of wood discs with distance from spore sources (i.e., fruiting bodies) was observed, further confirming the importance of local spore sources in the epidemiology of Heterobasidion spp. Taken together, these findings could help designing tactics to manage these fungal forest pathogens.

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.

Growth rates and age-size relationships of tropical wet forest trees in Costa Rica

1985 ◽  
Vol 1 (2) ◽  
pp. 97-109 ◽  
Author(s):  
Diana Lieberman ◽  
Milton Lieberman ◽  
Gary Hartshorn ◽  
Rodolfo Peralta
Keyword(s):  
Costa Rica ◽  
Growth Rates ◽  
Tree Species ◽  
Maximum Growth ◽  
Growth Behaviour ◽  
Carapa Guianensis ◽  
Light Levels ◽  
Tropical Wet Forest ◽  
Shade Tolerant Species ◽  
Zero Growth

ABSTRACTDiameter growth rates and age-size relationships are reported for 45 abundant tree species and one liana in tropical wet forest at La Selva, Costa Rica. Thirteen-year increments in each species were analysed using growth simulation, a stochastic technique which projects growth trajectories.Median growth rates ranged from 0.35 mm yr-1 (Anaxagorea crassipetala) to 13.41 mm yr-1) (Stryphnodendron excelsum). Maximum ranges ranged from 0.95 mm yr-1 (Quararibea brac-teolosa) to 14.62 mm yr-1 (Hernandia didymanthera). Minimum rates ranged from zero growth (Capparis pittieri, Colubrina spinosa, Doliocarpus spp.) to 7.45 mm yr-1 (Stryphno dendron excelsum).Projected lifespan (from 100 mm dbh to the maximum dbh for the species) varied from 52 years (Anaxagorea crassipetala, Guatteria inuncta) to 442 years (Carapa guianensis). The mean longevity among the 45 tree species studied is 190 years.Four main patterns of growth behaviour are recognized, based upon longevity and growth rates: (1) understorey species have slow maximum growth rates and short lifespans; (2) shade-tolerant subcanopy trees live around twice as long as understorey trees and grow at approxi-mately the same maximum rates; (3) canopy and subcanopy trees that are shade-tolerant but respond opportunistically to increased light levels have long lifespans and fast maximum growth rates; (4) shade-intolerant canopy and subcanopy species are short-lived and have fast maximum growth rates. Understorey species intergrade with shade-tolerant subcanopy species in terms of growth behaviour; shade-tolerant subcanopy species with opportunistic, shade-tolerant species; and opportunistic, shade-tolerant with shade-intolerant species.Intraspecific variation in growth rates is lower in short-lived trees (understorey species with uniformly slow growth and shade-intolerant species with uniformly rapid growth) than in the two long-lived groups. These patterns are discussed in the context of tree ecophysiology and forest light environments.

Matched filtering in the visual system of the fly : large monopolar cells of the lamina are optimized to detect moving edges and blobs

1990 ◽  
Vol 240 (1298) ◽  
pp. 279-293 ◽  
Keyword(s):  
Receptive Field ◽  
Receptive Fields ◽  
High Light ◽  
Vertical Stripe ◽  
Ambient Light ◽  
Low Light ◽  
Temporal Properties ◽  
Light Levels ◽  
Spatio Temporal ◽  
Temporal Inhibition

At high levels of ambient light, large monopolar cells (LMCS) display spatially antagonistic receptive fields and a biphasic response to a brief flash of light from an axially positioned point source. In low ambient light the response becomes monophasic everywhere within the receptive field. Using the theory of matched filters, we infer that the LMCS are optimal for the detection of moving edges at high light levels, and for ‘blobs’ in low ambient light. The spatio-temporal properties predicted by the theory are in agreement with experimental observation. At high light levels, the strong temporal inhibition, the weak, diffuse lateral inhibition, and the non-separability of the receptive field in space and time are all properties that promote the sensitivity to a moving edge. At low light levels, the lack of spatial or temporal antagonism enhances the sensitivity to a blob. Our hypothesis is reinforced by the observation that flies tend to walk toward the edges of a broad, dark vertical stripe at high light levels, but uniformly toward all regions within the stripe in low ambient light.

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.

scholarly journals Influence of elevation and site productivity on conifer distributions across Alaskan temperate rainforests

2016 ◽  
Vol 46 (2) ◽  
pp. 249-261 ◽  
Author(s):  
J.P. Caouette ◽  
E.A. Steel ◽  
P.E. Hennon ◽  
P.G. Cunningham ◽  
C.A. Pohl ◽  
...  
Keyword(s):  
Tree Species ◽  
Life Stage ◽  
Basal Area ◽  
Leading Edge ◽  
Picea Sitchensis ◽  
Thuja Plicata ◽  
Life Stages ◽  
Site Productivity ◽  
Mature Trees ◽  
Probability Of Occurrence

We investigated the influence of landscape factors on the distribution and life stage stability of coastal tree species near the northern limit of their ranges. Using data from 1465 forest inventory plots, we estimated probability of occurrence and basal area of six common conifer species across three broad latitudinal regions of coastal Alaska. By also comparing models across life stages of each species (seedlings, saplings, mature trees, and dead trees), we explored trends in population stability at this leading edge of climate change. Elevation had a stronger influence on the probability of tree species occurrence than on basal area; site productivity impacted both estimated odds of presence and estimated basal area for most species in at least some regions. Interestingly, there were fairly dramatic differences across species in the degree to which the modeled probability of occurrence differed across the four life stages. Western redcedar (Thuja plicata Donn ex D. Don), for example, showed relatively stable distributions but other species appear to be in flux, e.g., yellow-cedar (Callitropsis nootkatensis (D. Don) D.P. Little), which has experienced widespread mortality at low elevations. Differential effects of elevation on live versus dead basal area suggest that mountain hemlock (Tsuga mertensiana (Bong.) Carrière) and yellow-cedar are shifting upslope in some regions and that Sitka spruce (Picea sitchensis (Bong.) Carrière) is shifting downslope in the Northwest region.

scholarly journals The mossBryum argenteumvar.muticumBrid. is well adapted to cope with high light in continental Antarctica

2012 ◽  
Vol 24 (3) ◽  
pp. 281-291 ◽  
Author(s):  
B. Schroeter ◽  
T.G.A. Green ◽  
Daniel Kulle ◽  
S. Pannewitz ◽  
M. Schlensog ◽  
...  
Keyword(s):  
High Light ◽  
Carotenoid Content ◽  
Ambient Light ◽  
Light Levels ◽  
Bryum Argenteum ◽  
Victoria Land ◽  
Continental Antarctica ◽  
Lower Light ◽  
Sun And Shade ◽  
Very High

AbstractThe net photosynthetic rate (NP), chlorophyll fluorescence, carotenoid content and chlorophyll content of the cosmopolitan mossBryum argenteumwere measured in the field at Botany Bay, southern Victoria Land, continental Antarctica (77°S). Comparisons were made between sun- and shade-adapted forms, and changes were followed as the moss emerged from under the snow and during exposure of shade and sun forms to ambient light. Shade forms had lower light compensation and saturation values for NP but little difference in maximal NP rates. Shade forms exposed to ambient light changed rapidly (within five days) towards the performance of the sun forms. Surprisingly, this change was not by acclimation of shoots but by the production of new shoots. Chlorophyll and carotenoid levels measured on a molar chlorophyll basis showed no difference between sun and shade forms and also little change during emergence. The constant molar relationship between carotenoids and chlorophyll plus the high levels of the xanthophyll cycle pigments suggest that protection of the chlorophyll antenna was constitutive. This is an adaptation to the very high light levels that occur when the plants are active in continental Antarctica and contrasts to the situation in more temperate areas where high light is normally avoided by desiccation.

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.

Tree seedling growth and survival over 6 years across different microsites in a temperate rain forest

2006 ◽  
Vol 36 (4) ◽  
pp. 910-918 ◽  
Author(s):  
P J Bellingham ◽  
S J Richardson
Keyword(s):  
Seedling Growth ◽  
Growth Rates ◽  
Mortality Rates ◽  
Tree Regeneration ◽  
High Light ◽  
Tree Seedling ◽  
Tree Fern ◽  
Foliar N ◽  
Light Levels ◽  
Tree Ferns

We investigated whether canopy tree seedlings have different growth and mortality rates on different microsites in montane rain forests of the western South Island, New Zealand. Seedling relative height growth rates of three species, Podocarpus hallii, Quintinia acutifolia, and Weinmannia racemosa, were very low (mean = 0.037 cm·cm–1·year–1). Seedling growth rates were higher on logs than on the ground at high light levels, but the probability of seedling death on logs was also greater at high light levels. Seedling foliar N and P concentrations were generally not different between logs and the ground. Growth rates and foliar N concentrations of Quintinia and Weinmannia were greater for seedlings on tree fern trunks than for seedlings on the ground. Mortality rates did not differ between seedlings on tree fern trunks and seedlings on the ground. Seedling densities of Quintinia and Weinmannia were greater on logs and tree ferns than on the ground. Podocarpus densities were not different between logs and the ground, and this species did not occur on tree ferns. Quintinia and Weinmannia benefit from establishment on elevated microsites but this is not clearly the case for Podocarpus. Tree regeneration niches for such slow-growing species can only be determined through long-term studies.

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