The effect of tree dimension on the diversity of bark microhabitat structures and bark use in Douglas-fir (Pseudotsuga menziesii var. menziesii)

2011 ◽  
Vol 41 (2) ◽  
pp. 300-308 ◽  
Author(s):  
Alexa K. Michel ◽  
Susanne Winter ◽  
Andreas Linde
Keyword(s):  
Pacific Northwest ◽  
Pseudotsuga Menziesii ◽  
Large Diameter ◽  
Structural Complexity ◽  
Douglas Fir ◽  
Forest Monitoring ◽  
Tree Bark ◽  
Bark Thickness ◽  
Tree Diameter ◽  
The Us

The focus of this study was to investigate the role of tree dimension and associated bark structures for high structural complexity and high natural biodiversity in forest ecosystems. Two-hundred and ninety-one Douglas-fir (Pseudotsuga menziesii var. menziesii (Mirbel) Franco) trees in two regions of the US Pacific Northwest were investigated for the relationship between tree diameter and bark thickness (measured as bark fissure depth) and the relationships of both to bark microhabitats and signs of bark use. Our results emphasize the habitat function of tree bark of large-diameter Douglas-fir trees. Many bark microhabitat types and their total abundance significantly increased with increasing tree diameter and bark thickness. These were bark pockets with and without decaying substrate, bowls in the bark, and signs of bark use, e.g., small holes from woodpecker drillings and large insects, large bark excavations from woodpeckers, spider funnel webs, natural cavities at the stem base without decay, and the occurrence of herb vegetation at the tree base. In forest monitoring, tree diameter may be a good indicator of the number of bark microhabitats and of bark thickness because it is strongly related to both of these variables. However, because of the high variability of bark thickness in large-diameter trees, we suggest monitoring bark fissure depth if an ecological evaluation of Douglas-fir forests is needed.

scholarly journals Soil texture and other site-level factors differentially affect growth of Scotch broom (Cytisus scoparius) and Douglas-fir (Pseudotsuga menziesii) seedlings in the western Pacific Northwest

2021 ◽  
Author(s):  
David Carter ◽  
Robert A. Slesak ◽  
Timothy B. Harrington ◽  
Anthony W. D’Amato
Keyword(s):  
Pacific Northwest ◽  
Pseudotsuga Menziesii ◽  
Height Growth ◽  
Douglas Fir ◽  
Western Pacific ◽  
Limiting Factor ◽  
Cytisus Scoparius ◽  
Invasive Shrub ◽  
Scotch Broom ◽  
The Western Pacific

The invasive shrub Scotch broom (Cytisus scoparius (L.) Link) is a pervasive threat to regenerating Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco var. menziesii) stands in the Pacific Northwest, USA. Field observations indicate that the susceptibility of areas to Scotch broom invasion and dominance can vary by site. We selected ten sites throughout the western Pacific Northwest that spanned a gradient of soil textures and other factors to test the site-specific susceptibility of Douglas-fir to overtopping by Scotch broom. We expected to find that the ability of Scotch broom to dominate a site was mediated by site-level factors, particularly those influencing soil water – the most limiting factor to growth in the region. We found Scotch broom and Douglas-fir were inversely affected by site-level factors. In general, Douglas-fir absolute height growth rates were more competitive with those of Scotch broom on fine-textured soils than on more coarsely textured soils. We also found Douglas-fir to have a more dramatic response to increasing down woody material than Scotch broom. Scotch broom height growth approached an asymptote at 3 m. Sites with fast-growing Douglas-fir were able to surpass this height six to seven years after planting and appear likely to avoid suppression by Scotch broom.

Bark Thickness and Bark Volume in Southwestern Oregon Douglas-Fir

1990 ◽  
Vol 5 (1) ◽  
pp. 5-8 ◽  
Author(s):  
Douglas A. Maguire ◽  
David W. Hann
Keyword(s):  
Pseudotsuga Menziesii ◽  
Douglas Fir ◽  
Bark Thickness ◽  
Breast Height ◽  
Taper Equation ◽  
Taper Equations ◽  
Height Predictions

Abstract A segmented polynomial taper equation for southwestern Oregon Douglas-fir (Pseudotsuga menziesii) predicts double bark thickness (dbt) at any point above breast height. Below breast height predictions assume conformity to a neiloid frustrum. The equations facilitate estimation of inside bark diameter (dib) given outside bark (dob) measurements. Bark volume and bark biomass can also be estimated when supplemented with existing dib taper equations developed for southwestern Oregon. West J. Appl. For. 5(1):5-8.

Effects of seed source origin on bark thickness of Douglas-fir (Pseudotsuga menziesii) growing in southwestern Germany

2012 ◽  
Vol 42 (2) ◽  
pp. 382-399 ◽  
Author(s):  
Ulrich Kohnle ◽  
Sebastian Hein ◽  
Frank C. Sorensen ◽  
Aaron R. Weiskittel
Keyword(s):  
Pseudotsuga Menziesii ◽  
Douglas Fir ◽  
Seed Source ◽  
Bark Thickness

scholarly journals Ten-Year Growth Response of Young Douglas-Fir to Variable Density Varnishleaf Ceanothus and Herb Competition

1999 ◽  
Vol 14 (4) ◽  
pp. 208-213 ◽  
Author(s):  
V. J. Monleon ◽  
M. Newton ◽  
C. Hooper ◽  
J. C. Tappeiner
Keyword(s):  
Pseudotsuga Menziesii ◽  
Growth Response ◽  
Variable Density ◽  
Douglas Fir ◽  
The Other ◽  
Plantation Establishment ◽  
Single Application ◽  
Herbaceous Vegetation ◽  
Vegetation Control ◽  
Tree Diameter

Abstract The effect of different densities of varnishleaf ceanothus (Ceanothus velutinus var. laevigatus) and herbaceous vegetation control on stem diameter, height, and volume of plantation Douglas-fir (Pseudotsuga menziesii vat. menziesii) seedlings was examined during the 10 yr following planting. Initial densities of ceanothus ranged between 0 and 15,000 seedlings/ha and were obtained by interplanting ceanothus germinants or chemical thinning after clearcutting and broadcast-burning. Herbaceous vegetation control was achieved by a single application of glyphosate following planting, with shrub seedlings covered. Ceanothus density in the range of 0 to 6,750 plants/ha did not have an effect on Douglas-fir diameter, height, or volume at age 10; however, Douglas-fir growth was significantly decreased when ceanothus densities reached 15,000 plants/ha. Ten years after planting, Douglas-fir volume in the treatments with 6,750 ceanothus/ha or less was 1.7 times greater than that in the 15,000 ceanothus/ha treatment. On the other hand, removal of herbaceous vegetation after planting significantly increased tree diameter, height, and volume, regardless of ceanothus density. Even 10 yr after the application of the treatment, trees without early herb competition grew faster and had mean dbh, height, and volume that were 1.02 cm, 0.55 m, and 12.98 dm³/tree greater respectively than those with herbs. Thus, a treatment at plantation establishment to control herbaceous vegetation and to reduce ceanothus density to less than 7,000 plants/ha will ensure an increase in growth and stocking for at least 10 yr. West. J. Appl. For. 14(4):208-213.

Soil and Douglas-fir (Pseudotsuga menziesii) foliar nitrogen responses to variable logging-debris retention and competing vegetation control in the Pacific Northwest

2010 ◽  
Vol 40 (2) ◽  
pp. 254-264 ◽  
Author(s):  
Robert A. Slesak ◽  
Timothy B. Harrington ◽  
Stephen H. Schoenholtz
Keyword(s):  
Pacific Northwest ◽  
Pseudotsuga Menziesii ◽  
Douglas Fir ◽  
Soil N ◽  
Vegetation Control ◽  
Competing Vegetation ◽  
Total Soil ◽  
The Pacific ◽  
N Acquisition ◽  
Total Soil N

Experimental treatments of logging-debris retention (0%, 40%, or 80% surface coverage) and competing vegetation control (initial or annual applications) were installed at two sites in the Pacific Northwest following clearcutting Douglas-fir ( Pseudotsuga menziesii (Mirb.) Franco var. menziesii) stands to assess short-term effects on tree N acquisition, soil N supply, and total soil N. Vegetation control treatments began in the first year after harvest, and logging-debris manipulations were installed 2 years after harvest. Annual vegetation control increased foliar N concentration and content in most years at both sites, which was associated with higher available soil N and increased soil water content. Logging-debris retention treatments had no detectable effect on any of the foliar variables or soil available N at either site. There were no treatment effects on total soil N at the site with relatively high soil N, but total soil N increased with logging-debris retention when annual vegetation control was applied at the site with a low initial soil N pool. Competing vegetation control is an effective means to increase tree N acquisition in the initial years after planting while maintaining soil N pools critical to soil quality. The effect of logging-debris retention on tree N acquisition appears to be limited during early years of stand development, but increased soil N with heavy debris retention at certain sites may be beneficial to tree growth in later years.

scholarly journals Cooperative Second-Cycle Breeding and Testing of Coastal Douglas-fir in the US Pacific Northwest: Strategy, Implementation, and Operational Aspects

2020 ◽  
Vol 69 (1) ◽  
pp. 98-107
Author(s):  
KJS Jayawickrama ◽  
TZ Ye
Keyword(s):  
Pacific Northwest ◽  
Cooperative Breeding ◽  
First Generation ◽  
Acoustic Velocity ◽  
Douglas Fir ◽  
Strategy Implementation ◽  
Rating Score ◽  
The Us ◽  
Operational Aspects ◽  
Trial Series

AbstractThe second cycle of cooperative breeding and testing of coastal Douglas-fir in western Oregon and Washington was started around 1992. By 2020 the bulk of testing is nearing completion, while the latest program in southern Oregon and NW California is scheduled to run through 2035. A total of 109 first-generation programs were consolidated into nine second- cycle breeding and testing cooperatives (with 15 testing zones); 136 tests are planned, of which 120 have already been established. Between five and eight tests are established per trial series. Trials established to date have contained from 50 to 283 full-sib crosses. In total, the Douglas-fir breeding effort will be comprised of over 2,900 crosses, of which 2,500 have already been established in the field. A total of about 349,000 test trees are to be planted, with over 310,000 already planted.Tests typically get three main measurements when the trees are 3 (or 4), 7 and 12 years old from seed. (1) Age-3 or 4: progression of budburst, on a 1 to 5 rating score, when roughly 50 % of the seedlings have broken bud, on one or two sites per trial series. (2) Age-7: height (height pole), dbh, stem sinuosity in the second internode from the top, number of incidences of stem forking, number of incidences of ramicorn branching and (3) Age-12: height (vertex), dbh, stem sinuosity in the second internode from the top, number of incidences of stem forking, number of incidences of ramicorn branching, second flushing yes\no in current year, and wood acoustic velocity (in some trial series).

scholarly journals Geographic variation in the seed mycobiome of Pseudotsuga menziesii var. menziesii across the Pacific Northwest, USA

2020 ◽  
Author(s):  
Gillian E. Bergmann ◽  
Posy E. Busby
Keyword(s):  
Abiotic Stress ◽  
Pacific Northwest ◽  
Pseudotsuga Menziesii ◽  
Tree Species ◽  
Host Plants ◽  
Douglas Fir ◽  
Plant Tissues ◽  
The Pacific ◽  
Functional Consequences ◽  
Seedling Germination

ABSTRACTFungal symbionts occur in all plant tissues, and many aid their host plants with critical functions, including nutrient acquisition, defense against pathogens, and tolerance of abiotic stress. “Core” taxa in the plant mycobiome, defined as fungi present across individuals, populations, or time, may be particularly crucial to plant survival during the challenging seedling stage. However, studies on core seed fungi are limited to individual sampling sites, raising the question of whether core taxa exist across large geographic scales. We addressed this question using both culture-based and culture-free techniques to identify the fungi found in individual seeds collected from nine provenances across the range of Coastal Douglas-fir (Pseudotsuga menziesii var. menziesii), a foundation tree species in the Pacific Northwest and a globally important timber crop that is propagated commercially by seed. Two key findings emerged: 1) Seed mycobiome composition differed among seed provenances. 2) Despite spatial variation in the seed mycobiome, we detected four core members, none of which is a known pathogen of Douglas-fir: Trichoderma spp., Hormonema macrosporum, Mucor plumbeus and Talaromyces rugulosus. Our results support the concept of a core seed microbiome, yet additional work is needed to determine the functional consequences of core taxa for seedling germination, growth, survival and competition.

Characterization and classification of mycorrhizae of Douglas fir. II. Pseudotsuga menziesii + Rhizopogon vinicolor

1971 ◽  
Vol 49 (7) ◽  
pp. 1079-1084 ◽  
Author(s):  
B. Zak
Keyword(s):  
Pacific Northwest ◽  
Pseudotsuga Menziesii ◽  
Phytophthora Cinnamomi ◽  
Pythium Ultimum ◽  
Douglas Fir ◽  
Root Pathogens ◽  
The Pacific ◽  
Pythium Sylvaticum ◽  
Thin Walled

A common tuberculate ectomycorrhiza of Douglas fir in the Pacific Northwest, described earlier by Trappe, is further examined and defined. Tubercles consist of an outer rind of aseptate, amber, thick-walled hyphae encasing tightly packed inner elements mantled with septate, hyaline, thin-walled hyphae. Reported as a Phycomycete and a Basidiomycete, respectively, the two hyphal forms actually belong to a single fungus, Rhizopogon vinicolor A. H. Smith; cultural characteristics of this fungus are described. Pure culture mycorrhiza syntheses with both mycorrhizal and sporocarpic isolates and Douglas-fir seedlings are reported. Antagonism tests revealed the following inhibition of root pathogens by R. vinicolor: strong—Phytophthora cinnamomi Rands, Pythium debaryanum Heese, and Pythium sylvaticum Campbell & Hendrix; moderate—Fomes annosus (Fr.) Cke. and Poria weirii Murr.; and weak or none— Fusarium oxysporum f. pini (Hartig) Snyd. & Hans., Pythium ultimum Trow, Rhizoctonia solani Kuehn, and Macrophomina phaseoli (Maubl.) Ashby.

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