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

2002 ◽  
Vol 32 (11) ◽  
pp. 2043-2050 ◽  
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 mark–recapture 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.

Factors limiting the early survivorship of Thuja plicata on northern Vancouver Island, British Columbia

2003 ◽  
Vol 33 (5) ◽  
pp. 854-861 ◽  
Author(s):  
Adrian Weber ◽  
Benjamin Gilbert ◽  
JP (Hamish) Kimmins ◽  
C E Prescott
Keyword(s):  
Forest Floor ◽  
Seedling Survival ◽  
Forest Edge ◽  
Vancouver Island ◽  
Tsuga Heterophylla ◽  
Thuja Plicata ◽  
Local Soil ◽  
Early Seedling ◽  
Successional Species ◽  
Thuja Plicata Donn

Western redcedar (Thuja plicata Donn ex D. Don), a late successional species on northern Vancouver Island, has a low seedling survival in mature hemlock (Tsuga heterophylla (Raf.) Sarg.) – amabilis fir (Abies amabilis (Dougl. ex Loud.) Dougl. ex J. Forbes) (HA) stands. Shade, moss competition, and substrate were tested as causes of low cedar establishment. Cedar seeds were sown on reference and local soils isolated from surrounding soil, on nonisolated local soil, and on forest floor with moss removed. Western hemlock, amabilis fir, and cedar seeded on forest floor acted as controls. Treatments were implemented in the HA interior and the HA–clearcut edge, with soil treatments also implemented in clearcuts. Germinants and very young seedlings of cedar have a low leaf area of needle-like primary foliage. Cedar development of secondary foliage (the scale foliage normally associated with this species) was correlated with greater vigour and growth. Secondary foliage developed in the rankings forest edge and clearcut > forest interior, and reference isolated soil > local isolated soil > nonisolated local soil. Seedling survival rankings were edge > interior, and amabilis fir > hemlock > cedar on soil and with moss removed > cedar on forest floor. Cedar and amabilis fir showed a smaller growth response to light than hemlock. The results indicate that cedar, normally considered a late successional species, needs disturbance for early seedling establishment and survival and thus has some characteristics of an early seral species.

scholarly journals Height prediction equations using diameter and stand density measures

2000 ◽  
Vol 76 (2) ◽  
pp. 303-309 ◽  
Author(s):  
Christie Staudhammer ◽  
Valerie LeMay
Keyword(s):  
Weibull Distribution ◽  
Predictor Variable ◽  
Stand Density ◽  
Tsuga Heterophylla ◽  
Douglas Fir ◽  
Thuja Plicata ◽  
Red Cedar ◽  
Non Linear Equation ◽  
Height Prediction ◽  
Thuja Plicata Donn

Height equations for western hemlock (Tsuga heterophylla (Raf.) Sarg.), western red cedar (Thuja plicata Donn), Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco), and alder (Alnus rubra Bong. and Alnus tenuifolia Nutt.) were fitted using dbh as the predictor variable. A simple, non-linear equation gave very similar results to the Weibull distribution, except for hemlock, which was better modelled using the more flexible Weibull distribution function. Introducing stand density variables into the base equations resulted in increased accuracy for predicting heights of alder. Smaller improvements were found for Douglas-fir, cedar, and hemlock. Key words: estimating height, Coastal BC, Weibull estimation, stand density measures

Population dynamics of Glaucomys sabrinus and Tamiasciurus douglasii in old-growth and second-growth stands of coastal coniferous forest

2003 ◽  
Vol 33 (4) ◽  
pp. 587-596 ◽  
Author(s):  
Douglas B Ransome ◽  
Thomas P Sullivan
Keyword(s):  
Population Dynamics ◽  
Habitat Preferences ◽  
Coniferous Forest ◽  
Glaucomys Sabrinus ◽  
Old Growth ◽  
Flying Squirrels ◽  
Survival Percentage ◽  
Second Growth ◽  
Northern Flying Squirrels ◽  
Population Breeding

Habitat preferences and population dynamics of northern flying squirrels (Glaucomys sabrinus Shaw) and Douglas squirrels (Tamiasciurus douglasii Audubon and Bachman) were examined in old-growth and mature second-growth stands in British Columbia, Canada. Using mark–recapture techniques to estimate population dynamics, we tested the hypothesis that old-growth stands provided higher-quality habitat than second-growth stands for these species. Populations were monitored in two old-growth and two mature second-growth stands from August 1995 to May 1999. We were unable to detect major differences in movement, density, recruitment, mass of males, survival, percentage of the population breeding, and the duration that individuals remained on the study plots between stand types for G. sabrinus. Similarly, with the exception of recruitment, we were unable to detect major differences in these parameters between stand types for T. douglasii. Recruitment of T. douglasii was higher in second-growth than in old-growth stands. Old-growth stands were not higher-quality habitat than second-growth stands for either species for the period of enquiry and the parameters we measured. We also presented evidence of late fall – early winter breeding for G. sabrinus, as well as seasonal fluctuations in mass and trappability, larger movement by males than females, and the age of some squirrels exceeding 3.5 years.

Rates of non-suberized impervious tissue development after wounding at different times of the year in three conifer species

1976 ◽  
Vol 54 (9) ◽  
pp. 881-892 ◽  
Author(s):  
D. B. Mullick ◽  
G. D. Jensen
Keyword(s):  
Tsuga Heterophylla ◽  
Thuja Plicata ◽  
Conifer Species ◽  
Intraspecific Variations ◽  
Cyclical Pattern ◽  
Woolly Aphid ◽  
Periderm Formation ◽  
Thuja Plicata Donn ◽  
Season Variations ◽  
Host Component

Rates of development of a non-suberized impervious tissue (NIT), which is a prerequisite to necrophylactic periderm formation, vary on the same tree with the changing environment at different times of the year. In Abies amabilis (Dougl.) Forbes, rates varied from 14 days in June, slowing gradually to 35 days in fall, virtually ceasing in winter, and resuming slowly (70 days) in spring. This cyclical pattern in rates of NIT formation was also found in Tsuga heterophylla (Raf.) Sarg. and Thuja plicata Donn. Fluctuations in the environment occasioned by year-to-year within-season variations appear to affect the physiology of NIT formation; in July, NIT developed after 21 days in 1968 and after 16 days in 1969, on the same A. amabilis. Preliminary observations indicate presence of intraspecific variations in the rates. Rates were consistently faster on the resistant than on the susceptible A. amabilis heavily infested with balsam woolly aphid, Adelges piceae Ratz. Possible causes of these variations and implications of the findings, in relation to process of NIT formation as a basic physiological host component in pathogenic interactions of bark, are discussed.

Sphagnum invasion after clear-cutting and excavator mounding in a hypermaritime forest of British Columbia

2004 ◽  
Vol 34 (8) ◽  
pp. 1730-1746 ◽  
Author(s):  
Taro Asada ◽  
Barry G Warner ◽  
Allen Banner
Keyword(s):  
British Columbia ◽  
Tsuga Heterophylla ◽  
Thuja Plicata ◽  
North Coast ◽  
Clear Cut ◽  
Clear Cutting ◽  
Lower Productivity ◽  
Sphagnum Girgensohnii ◽  
Thuja Plicata Donn

Sphagnum invasion 8 years after an experimental clear-cut and mounding field trial was examined in a mesic western redcedar (Thuja plicata Donn ex D. Don) – western hemlock (Tsuga heterophylla (Raf.) Sarg.) forest on the outer north coast of British Columbia. Sphagnum invasion was prominent in wet hollows in the mounded blocks. Pioneer species, Sphagnum pacificum Flatb. and Sphagnum angustifolium (C. Jens. ex Russ.) C. Jens., were common despite being minor components in the precut forest. Sphagnum girgensohnii Russ., a species of forests, showed expanding colonies and contained some Sphagnum capillifolium (Ehrh.) Hedw. Comparisons of vertical growth and decomposition rates of Sphagnum in the experimental field site and in a nearby natural peatland suggest that peat accumulation potential in the Sphagnum colonies in the mounded blocks is similar to that in the natural peatland. These observations suggest that open peatland-type plant communities become established and paludification processes are beginning. Mounding may be an effective strategy for silvicultural management to improve tree growth in the short term but may initiate paludification and negatively impact forest productivity in the long term in hypermaritime lower productivity forests.

Histology of resin vesicles and oleoresin terpene composition of conifer seeds

2018 ◽  
Vol 48 (9) ◽  
pp. 1073-1084 ◽  
Author(s):  
Kristina Kshatriya ◽  
Justin G.A. Whitehill ◽  
Lina Madilao ◽  
Hannah Henderson ◽  
Allison Kermode ◽  
...  
Keyword(s):  
Abies Balsamea ◽  
Seed Storage ◽  
Tsuga Heterophylla ◽  
Thuja Plicata ◽  
Abies Lasiocarpa ◽  
Thuja Occidentalis ◽  
Future Studies ◽  
Conifer Seeds ◽  
Seed Coats ◽  
Thuja Plicata Donn

The seed coats of several conifers contain terpene-filled resin vesicles, which may be involved in the protection of the dormant embryo and the seed storage tissue against herbivores or pathogens. We analyzed the terpenoid composition of seeds from four Abies species (Abies amabilis Douglas ex J. Forbes, Abies balsamea (L.) Mill., Abies grandis (Douglas ex D. Don) Lindl., and Abies lasiocarpa (Hook.) Nutt.), two Thuja species (Thuja plicata Donn ex D. Don and Thuja occidentalis L.), and three Tsuga species (Tsuga canadensis (L.) Carrière, Tsuga mertensiana (Bong.) Carrière, and Tsuga heterophylla (Raf.) Sarg.) and examined histological features of resin vesicles in seeds from one species from each genus. Resin vesicle morphology was generally similar among the species analyzed. The composition of the seed terpenes varied largely between species. The described seed terpene profiles of the nine species will serve as a foundation for future studies into the function of seed terpenes and resin vesicles in the seed coat.

scholarly journals Physiological variation among western redcedar (Thuja plicata Donn ex D. Don) populations in response to short-term drought

2010 ◽  
Vol 67 (5) ◽  
pp. 506-506 ◽  
Author(s):  
Steven C. Grossnickle ◽  
John H. Russell
Keyword(s):  
Thuja Plicata ◽  
Short Term ◽  
Western Redcedar ◽  
Physiological Variation ◽  
Thuja Plicata Donn

scholarly journals Short-term effects of culling on the ecology and population dynamics of the yellow-legged gull

2000 ◽  
Vol 37 (2) ◽  
pp. 369-385 ◽  
Author(s):  
M. Bosch ◽  
D. Oro ◽  
F.J. Cantos ◽  
M. Zabala
Keyword(s):  
Population Dynamics ◽  
Short Term ◽  
Short Term Effects

New concepts and terminology of coniferous periderms: necrophylactic and exophylactic periderms

1973 ◽  
Vol 51 (8) ◽  
pp. 1459-1470 ◽  
Author(s):  
D. B. Mullick ◽  
G. D. Jensen
Keyword(s):  
External Environment ◽  
Tsuga Heterophylla ◽  
Thuja Plicata ◽  
Chemical Characteristics ◽  
Main Function ◽  
Field Observations ◽  
New Concepts ◽  
Living Tissues ◽  
Second Category ◽  
Thuja Plicata Donn

Field observations were made on wound and pathological periderms, regardless of the causal agent, and periderms formed at abscission zones, old resin blisters and rhytidomes in Abies amabilis (Dougl.) Forbes, Abies grandis (Dougl.) Lindl., Tsuga heterophylla (Raf.) Sarg., and Thuja plicata Donn. It was established that these periderms were of reddish-purple sequent periderm (rsp) type, rather than either the brown first periderm (bfp), or brown sequent periderm (bsp) types. These reddish-purple pigmented periderms, like the rsp (the usual sequent periderm) were found abutting necrotic tissues and were moreover identical with rsp in 15 newly demonstrated cryofixation and chemical characteristics. Because of this equivalence, it is proposed that all these reddish-purple periderms, including the usual sequent periderm (rsp), constitute one category, the necrophylactic periderms. These periderms arise whenever regeneration of a periderm after death of cells is required, and their main function seems to be protection of living tissues from the adverse effects associated with cell death. Because of the equivalence of bfp and bsp, they constitute another category, the exophylactic periderms. This second category of periderms has a common function of protecting living tissues against the external environment.

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