Natural regeneration after harvest and residue treatment in a mixed conifer forest of northwestern Montana

1999 ◽  
Vol 29 (2) ◽  
pp. 274-279
Author(s):  
Raymond C Shearer ◽  
Jack A Schmidt

In 1974, two clearcuts, two shelterwoods, and two sets of eight group selections (equally divided between two elevation zones) were harvested on the Coram Experimental Forest in northwestern Montana. Four levels of tree and residue utilization were compared. Moist fuels on approximately half of each area were poorly burned by prescribed fires in September 1975. Natural regeneration on these treatments was compared in 1979, 1987, and 1992. Regeneration of western larch (Larix occidentalis Nutt.) began in 1975 on soil exposed during yarding of logs and continued mostly in 1977 and 1979 on these scarified sites and other burned areas. Competing vegetation curtailed establishment of larch seedlings much past 1979 on these sites. Few Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco) regenerated before 1979 but aggressively established through 1992. Engelmann spruce (Picea engelmannii Parry) and subalpine fir (Abies lasiocarpa (Hook.) Nutt) regeneration began in 1979 and is increasing slowly throughout the area. Western hemlock (Tsuga heterophylla (Raf.) Sarg.) and western red cedar (Thuja plicata Donn.) also slowly regenerate moister areas of the lower elevation units.


1989 ◽  
Vol 4 (1) ◽  
pp. 10-13 ◽  
Author(s):  
Andrew C. Mason ◽  
David L. Adams

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.



1983 ◽  
Vol 20 (5) ◽  
pp. 873-885 ◽  
Author(s):  
Linda E. Heusser

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.



1991 ◽  
Vol 37 (1) ◽  
pp. 34-41 ◽  
Author(s):  
C. R. Bell ◽  
W. D. Ramey

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.



Author(s):  
D. N. Pegler

Abstract A description is provided for Inonotus weirii. Information is included on the disease caused by the organism, its transmission, geographical distribution, and hosts. HOSTS: On Abies amabilis, A. grandis, A. lasiocarpa, Chamaecyparis spp., Larix occidentalis, Picea engelmannii, P. sitchensis, Pinus contorta, P. monticola, P. ponderosa, Pseudotsuga menziesii, Thuja plicata, Tsuga heterophylla. DISEASE: Laminated butt rot and yellow ring rot of conifers. GEOGRAPHICAL DISTRIBUTION: North America (Western Canada, Oregon, Washington); Japan. TRANSMISSION: The disease is spread by root contact with infected material in the soil; there appears to be little spread of the fungus by growth through the soil. It is likely that infection of freshly exposed wounds takes place through airborne basidiospores.



2000 ◽  
Vol 76 (2) ◽  
pp. 303-309 ◽  
Author(s):  
Christie Staudhammer ◽  
Valerie LeMay

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



1998 ◽  
Vol 88 (6) ◽  
pp. 633-640 ◽  
Author(s):  
T.D. Schowalter ◽  
L.M. Ganio

AbstractVariation in canopy arthropod abundances and community structure were evaluated in an old-growth (500-year-old) forest at the Wind River Canopy Crane Research Facility in southwestern Washington, USA. Arthropods were sampled at three canopy levels and two seasons in each of four tree species (Pseudotsuga menziesii, Tsuga heterophylla, Abies grandis, and Thuja plicata). The four tree species had distinguishable arthropod species compositions and community organization. Thuja plicata (Cupressaceae) had a particularly distinctive canopy fauna dominated by several mite taxa which did not occur on the other tree species (all Pinaceae). Pseudotsuga menziesii hosted a relatively diverse arthropod fauna with greatest richness of taxa and functional groups. Distinct arthropod assemblages were not observed among canopy levels and sampling dates, but these factors significantly influenced abundances of 63% of the arthropod taxa, either individually or interactively with other factors. These data indicate that forests managed for fewer tree species eliminate important components of arthropod diversity in Pacific Northwest forests and that sampling for biodiversity assessment also should represent season and canopy level.



1996 ◽  
Vol 74 (10) ◽  
pp. 1626-1634 ◽  
Author(s):  
R. J. Keenan ◽  
C. E. Prescott ◽  
J. P. Kimmins ◽  
J. Pastor ◽  
B. Dewey

Litter decomposition and changes in N and organic chemicals were studied for 2 years in two forest types: old-growth western red cedar (Thuja plicata Donn) and western hemlock (Tsuga heterophylla (Raf.) Sarge) and 85-year-old stands of western hemlock and amabilis fir (Abies amabilis (Dougl.) Forbes) that developed after a major windstorm. We tested the hypothesis that lower rates of mass loss and different patterns of nutrient release in decomposing litter could explain lower nutrient availability in the cedar–hemlock type. Decomposition rate of a standard litter substrate, lodgepole pine needles, was almost identical in the two forest types indicating that each type had similar microenvironmental conditions for decomposers. Salal leaves had a lower lignin to N ratio and decomposed and released N more rapidly than the conifer litters. Among the conifers, cedar had poorer litter quality (higher lignin to N ratio), decomposed more slowly, and released considerably less N during the study. Cedar litter contributes to lower N availability in cedar–hemlock forests, but other factors, such as lower external N cycling and complexing of N with secondary carbon compounds during later stages of decomposition, are also likely to have a major influence on N availability. Keywords: Thuja plicata, Tsuga heterophylla, decomposition, litter quality, N cycling.



2018 ◽  
Vol 48 (9) ◽  
pp. 1073-1084 ◽  
Author(s):  
Kristina Kshatriya ◽  
Justin G.A. Whitehill ◽  
Lina Madilao ◽  
Hannah Henderson ◽  
Allison Kermode ◽  
...  

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.





1956 ◽  
Vol 88 (5) ◽  
pp. 197-202 ◽  
Author(s):  
J. Walters ◽  
L. H. McMullen

The Douglas-fir hylesinus, Pseudohylesinus nebulosus (Leconte), is a common bark beetle in western North America from British Columbia to Mexico. Although Douglas fir, Pseudotsuga menziesii (Mirb.) Franco, is the preferred host, the beetle has been collected also from western red cedar, Thuja plicata Donn, grand fir, Abies grandis (Dougl.) Lindl., amabilis fir, Abies amabilis (Dougl.) Forb., and western hemlock, Tsuga heterophylla (Raf.) Sarg., on the west coast of British Columbia, and from western hemlock and western yellow pine, Pinus ponderosa Laws., in the interior of the Province. Swaine (1918) describes Pseudohylesinus nebulosus (Lec.) as “a slender species, with strong colour-markings in dark and light reddish-brown; the male very densely clothed with stout scales; the epistomal lobe strongly developed; length, 2.8 mm.; width, 1.2 mm. The supposed female has interspace 9 on the declivity less strongly serrate, and the elytral scales decidedly elongate and becoming plumose towards the base.”



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