Vertical and seasonal variation in canopy arthropod communities in an old-growth conifer forest in southwestern Washington, USA

1998 ◽  
Vol 88 (6) ◽  
pp. 633-640 ◽  
Author(s):  
T.D. Schowalter ◽  
L.M. Ganio
Keyword(s):  
Pacific Northwest ◽  
Pseudotsuga Menziesii ◽  
Tree Species ◽  
Community Organization ◽  
Tsuga Heterophylla ◽  
Thuja Plicata ◽  
Conifer Forest ◽  
Old Growth ◽  
Arthropod Species ◽  
Arthropod Fauna

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.

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.

Canopy disturbances over the five-century lifetime of an old-growth Douglas-fir stand in the Pacific Northwest

2002 ◽  
Vol 32 (6) ◽  
pp. 1057-1070 ◽  
Author(s):  
Linda E Winter ◽  
Linda B Brubaker ◽  
Jerry F Franklin ◽  
Eric A Miller ◽  
Donald Q DeWitt
Keyword(s):  
Pacific Northwest ◽  
Variable Density ◽  
Tsuga Heterophylla ◽  
Douglas Fir ◽  
Western Hemlock ◽  
Old Growth ◽  
The Pacific ◽  
History Of ◽  
Horizontal Heterogeneity ◽  
Restoration Strategies

The history of canopy disturbances over the lifetime of an old-growth Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco) stand in the western Cascade Range of southern Washington was reconstructed using tree-ring records of cross-dated samples from a 3.3-ha mapped plot. The reconstruction detected pulses in which many western hemlock (Tsuga heterophylla (Raf.) Sarg.) synchronously experienced abrupt and sustained increases in ringwidth, i.e., "growth-increases", and focused on medium-sized or larger ([Formula: see text]0.8 ha) events. The results show that the stand experienced at least three canopy disturbances that each thinned, but did not clear, the canopy over areas [Formula: see text]0.8 ha, occurring approximately in the late 1500s, the 1760s, and the 1930s. None of these promoted regeneration of the shade-intolerant Douglas-fir, all of which established 1500–1521. The disturbances may have promoted regeneration of western hemlock, but their strongest effect on tree dynamics was to elicit western hemlock growth-increases. Canopy disturbances are known to create patchiness, or horizontal heterogeneity, an important characteristic of old-growth forests. This reconstructed history provides one model for restoration strategies to create horizontal heterogeneity in young Douglas-fir stands, for example, by suggesting sizes of areas to thin in variable-density thinnings.

Hybrid biovars of Agrobacterium species isolated from conifer roots

1991 ◽  
Vol 37 (1) ◽  
pp. 34-41 ◽  
Author(s):  
C. R. Bell ◽  
W. D. Ramey
Keyword(s):  
Pseudotsuga Menziesii ◽  
Picea Glauca ◽  
Pinus Contorta ◽  
Heterotrophic Bacteria ◽  
Principal Component ◽  
Tsuga Heterophylla ◽  
Thuja Plicata ◽  
Discrete Groups ◽  
Red Cedar ◽  
Cluster 2

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.

Canopy openness and leaf area in chronosequences of coastal temperate rainforests

2000 ◽  
Vol 30 (2) ◽  
pp. 239-256 ◽  
Author(s):  
Gordon W Frazer ◽  
J A Trofymow ◽  
Kenneth P Lertzman
Keyword(s):  
Leaf Area ◽  
Tsuga Heterophylla ◽  
Thuja Plicata ◽  
Canopy Openness ◽  
East Side ◽  
The West ◽  
Old Growth ◽  
Regional Patterns ◽  
Forest Canopies ◽  
Old Growth Forest

We examined spatial and temporal differences in canopy openness and effective leaf area (Le) in a series of eight forest chronosequences located on southern Vancouver Island, British Columbia. Structural attributes were measured on the west and east side of the island in immature, mature, and old-growth stands using hemispherical photography and the LAI-2000 plant canopy analyzer (PCA). Old-growth forest canopies were distinct from those of younger stands: they were more open, more heterogeneous in their openness, and maintained a lower stand Le. Although the overall developmental trajectories of forests were similar across the study sites, site-to-site differences in the rate and magnitude of these temporal changes indicated that site-specific factors also play a significant role in determining the character of forest canopies and their development. The most significant changes in canopy structure did not emerge until the later stages of stand development (150-200 years). Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco) dominated east-side forests were, on average, more open, more heterogeneous, and had a lower stand Le than the stands dominated by western hemlock (Tsuga heterophylla (Raf.) Sarg.) and western redcedar (Thuja plicata Donn.) forming the west-side chronosequences. Shoot clumping, along with other evidence, suggested that species-related differences in leaf display and the geometry of branching structure might have contributed significantly to these regional patterns.

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
Keyword(s):  
Natural Regeneration ◽  
Tsuga Heterophylla ◽  
Thuja Plicata ◽  
Abies Lasiocarpa ◽  
Conifer Forest ◽  
Larix Occidentalis ◽  
Burned Areas ◽  
Red Cedar ◽  
Northwestern Montana ◽  
Four Levels

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.

scholarly journals A lack of native congeners may limit colonization of introduced conifers by indigenous insects in Europe

2006 ◽  
Vol 36 (2) ◽  
pp. 299-313 ◽  
Author(s):  
Alain Roques ◽  
Marie-Anne Auger-Rozenberg ◽  
Solen Boivin
Keyword(s):  
Exotic Species ◽  
Pseudotsuga Menziesii ◽  
Natural Enemies ◽  
Douglas Fir ◽  
Feeding Habit ◽  
Plantation Forestry ◽  
Native Range ◽  
Arthropod Species ◽  
Arthropod Fauna ◽  
Arthropod Pests

We compared the recruitment of phytophagous arthropod pests onto exotic conifers introduced in Europe without any congeners with that of exotic conifers that have native congeners. In 130 years of extensive plantation forestry in Europe, Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco) recruited only 87 arthropod species, i.e., only 33.9% of the number of associated arthropod species in its native range (257 spp.). Exotic species of Cupressaceae without indigenous congeners also recruited only a portion (3.4% to 57.9%) of the arthropod fauna observed in their native range. In both cases, the majority of the recruited species were polyphagous, i.e., that they can feed on plants of different families of conifers and (or) angiosperms. In contrast, exotic conifers with native congeners recruited most of the insects colonizing the native congeneric conifers. Differences in arthropod recruitment were observed according to both guild and feeding habit, with the externally feeding herbivores being dominant. Typically, the damage caused by native insects that had been recruited by exotic conifers without congeners was limited, whereas the damage caused by native insects that had been recruited by exotic conifers with congeners often led to severe outbreaks at the time the shift between hosts occurred. However, when a highly specialized exotic insect was introduced along with the host, the invasive insect tended to occupy the entire niche, causing more damage than in the original range, in the absence of natural enemies and indigenous competitors.

Species richness, abundance, and composition of hypogeous and epigeous ectomycorrhizal fungal sporocarps in young, rotation-age, and old-growth stands of Douglas-fir (Pseudotsuga menziesii) in the Cascade Range of Oregon, U.S.A.

2002 ◽  
Vol 80 (2) ◽  
pp. 186-204 ◽  
Author(s):  
J E Smith ◽  
R Molina ◽  
M MP Huso ◽  
D L Luoma ◽  
D McKay ◽  
...  
Keyword(s):  
Pseudotsuga Menziesii ◽  
Ectomycorrhizal Fungi ◽  
Forest Succession ◽  
Fungal Species ◽  
Tsuga Heterophylla ◽  
Douglas Fir ◽  
Forest Age ◽  
Age Classes ◽  
Old Growth ◽  
Rotation Age

Knowledge of the community structure of ectomycorrhizal fungi among successional forest age-classes is critical for conserving fungal species diversity. Hypogeous and epigeous sporocarps were collected from three replicate stands in each of three forest age-classes (young, rotation-age, and old-growth) of Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco) dominated stands with mesic plant association groups. Over four fall and three spring seasons, 48 hypogeous and 215 epigeous species or species groups were collected from sample areas of 6300 and 43 700 m2, respectively. Cumulative richness of hypogeous and epigeous species was similar among age-classes but differed between seasons. Thirty-six percent of the species were unique to an age-class: 50 species to old-growth, 19 to rotation-age, and 25 to young stands. Seventeen species (eight hypogeous and nine epigeous) accounted for 79% of the total sporocarp biomass; two hypogeous species, Gautieria monticola Harkn., and Hysterangium crassirhachis Zeller and Dodge, accounted for 41%. Average sporocarp biomass in young and rotation-age stands compared with old-growth stands was about three times greater for hypogeous sporocarps and six times greater for epigeous sporocarps. Average hypogeous sporocarp biomass was about 2.4 times greater in spring compared with fall and for epigeous sporocarps about 146 times greater in fall compared with spring. Results demonstrated differences in ectomycorrhizal fungal sporocarp abundance and species composition among successional forest age-classes.Key words: ectomycorrhizal fungi, sporocarp production, forest succession, Pseudotsuga menziesii, Tsuga heterophylla zone, biodiversity.

Multi-decadal establishment for single-cohort Douglas-fir forests

2014 ◽  
Vol 44 (9) ◽  
pp. 1068-1078 ◽  
Author(s):  
James A. Freund ◽  
Jerry F. Franklin ◽  
Andrew J. Larson ◽  
James A. Lutz
Keyword(s):  
Pseudotsuga Menziesii ◽  
Temporal Patterns ◽  
Tsuga Heterophylla ◽  
Douglas Fir ◽  
Western Hemlock ◽  
Old Growth ◽  
Old Growth Forests ◽  
Western Washington ◽  
Century Development ◽  
Single Cohort

The rate at which trees regenerate following stand-replacing wildfire is an important but poorly understood process in the multi-century development of Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco) and western hemlock (Tsuga heterophylla (Raf.) Sarg.) forests. Temporal patterns of Douglas-fir establishment reconstructed from old-growth forests (>450 year) have generated contradictory models of either rapid (<25 year) or prolonged (>100 year) periods of establishment, while patterns of tree establishment in mid-aged (100 to 350 year) forests remains largely unknown. To determine temporal patterns of Douglas-fir establishment following stand-replacing fire, increment cores were obtained from 1455 trees in 18 mature and early old-growth forests in western Washington and northwestern Oregon, USA. Each of the stands showed continuous regeneration of Douglas-fir for many decades following initiating fire. The establishment period averaged 60 years (range: 32–99 years). These results contrast both with the view of rapid (one- to two-decade) regeneration of Douglas-fir promoted in the early forestry literature and with reports of establishment periods exceeding 100 years in older (>400 year) Douglas-fir–western hemlock stands. These results have important implications for management designed to create and promote early-seral forest characteristics.

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