Vegetation composition on recent landslides in the Cascade Mountains of western Oregon

1986 ◽  
Vol 16 (4) ◽  
pp. 739-744 ◽  
Author(s):  
D. W. R. Miles ◽  
F. J. Swanson
Keyword(s):  
Pacific Northwest ◽  
Tree Species ◽  
Vegetation Cover ◽  
Cascade Mountains ◽  
Vegetation Disturbance ◽  
The Pacific ◽  
Below Ground ◽  
Steep Slopes ◽  
Herb Species ◽  
Common Tree

Shallow, rapid landslides are common events and significant causes of vegetation disturbance in the Pacific Northwest. Landslides remove surface soil and above- and below-ground biomass from steep slopes and deposit them downslope or in streams. Vegetation cover and frequency were sampled on 25 landslides aged 6–28 years in the Cascade Mountains of western Oregon. Landslides sampled were debris avalanches ranging in surface area from 36 to 1287 m2, in elevation from 460 to 1100 m, and in slope from 40 to 173%. The landslides originated in undisturbed forests, recently harvested tracts of timber, road cuts, and road fills. Substrates within landslide areas were separated into five types and the vegetation cover was estimated for each: bedrock, 19%; secondary erosion, 25%; primary scar, 51%; secondary deposition, 57%; primary deposition, 71%. Vegetation cover averaged 51% overall and cover ranged from 7 to 88% among landslide sites. No relation between landslide age and vegetation cover was established. Pseudotsugamenziesii (Mirb.) Franco was the most common tree species overall and dominated all substrates except bedrock, where no single tree species occurred on more than 20% of the plots. Rubusursinus Cham. & Schlecht. was the most common shrub species on all substrates. Anaphalismargaritacea (L.) B & H and Trientalislatifolia Hook, were the most common herb species on all substrates except bedrock, where annual Epilobium spp. were most common.

Decay rates of above- and below-ground coarse woody debris of common tree species in New Zealand’s natural forest

2019 ◽  
Vol 438 ◽  
pp. 96-102 ◽  
Author(s):  
Loretta G. Garrett ◽  
Mark O. Kimberley ◽  
Graeme R. Oliver ◽  
Mallory Parks ◽  
Stephen H. Pearce ◽  
...  
Keyword(s):  
Tree Species ◽  
Coarse Woody Debris ◽  
Woody Debris ◽  
Decay Rates ◽  
Natural Forest ◽  
Below Ground ◽  
Common Tree

A Tree Selection Survey of Tree City USA Designated Cities in the Pacific Northwest

2020 ◽  
Vol 46 (5) ◽  
pp. 371-384
Author(s):  
Joshua Petter ◽  
Paul Ries ◽  
Ashley D’Antonio ◽  
Ryan Contreras
Keyword(s):  
Pacific Northwest ◽  
Tree Species ◽  
Urban Areas ◽  
Urban Forest ◽  
Urban Trees ◽  
Species Selection ◽  
Invasive Pests ◽  
The Pacific ◽  
Canopy Volume ◽  
The Right

As urban areas expand, there are a greater number of urban trees; however, development often leads to a reduction in urban trees in many areas. A reduction in the canopy volume of trees results in a reduction in the number of benefits. Additionally, urban trees can have additional stressors and must be more actively managed to maintain those services. Selecting tree species for the right site can lead to greater benefits and longer-lived trees. Increasing diversity of urban trees can help to mitigate some of the threats facing urban forests, such as invasive pests and climate change. We surveyed Tree City USA designated cities across Oregon and Washington to explore how they are selecting tree species for their municipalities. Responses were recorded for 79 out of 151 municipalities for a 52.3% response rate. Both open-ended questions and descriptive statistics were used to triangulate how managers are selecting tree species. Emergent themes in open-ended responses indicate a variety of justifications for tree species selection and the challenges of balancing those criteria. There is evidence to suggest that these municipalities are actively diversifying the urban forest; however, there are still 10 municipalities that reported ash (Fraxinus spp.) in their top 5 most frequently planted species in 2016. Many municipalities are still planting large quantities of maple (Acer spp.). Overplanting certain genera and species can lead to an increase in susceptibility to pests and pathogens. We recommend an increase in consideration for the diversification of tree species in urban areas.

Fertility management in dryland conservation cropping systems of the Pacific Northwest

1996 ◽  
Vol 11 (2-3) ◽  
pp. 108-114 ◽  
Author(s):  
Paul E. Rasmussen
Keyword(s):  
Plant Growth ◽  
Pacific Northwest ◽  
Conservation Tillage ◽  
Cropping Systems ◽  
Conventional Tillage ◽  
Growth And Yield ◽  
Root Pruning ◽  
Soil Pathogens ◽  
The Pacific ◽  
Steep Slopes

The Pacific Northwest dryland region is moving toward conservation tillage to control excessive erosion on steep slopes, but progress has been slow because of adverse effects on plant growth and yield. Fertility relations in cereal grains with conventional tillage are well known, with deficiencies occurring for nitrogen, sulfur, and phosphorus, in declining order of frequency. N and S deficiencies are more severe in conservation tillage, although the pattern of crop response to nutrient application is the same as in conventional tillage. Placing nutrients in a subs urface band near the seed is more effective than broadcasting on the surface. Higher fertility is required near developing root systems to offset greater competition from grassy weeds and more intense pressure from root-pruning soil pathogens. Conservation tillage alters soil fertility and plant growth in different ways on different landscapes. These differences must be considered to ensure tha t conservation tillage will be effective over the entire field.

How Are Managers Making Tree Species Selection Decisions in the Pacific Northwest of the United States?

2020 ◽  
Vol 46 (2) ◽  
pp. 148-161
Author(s):  
Joshua Petter ◽  
Paul Ries ◽  
Ashley D’Antonio ◽  
Ryan Contreras
Keyword(s):  
Forest Management ◽  
Pacific Northwest ◽  
Tree Species ◽  
Selection Criteria ◽  
Urban Forest ◽  
The United States ◽  
Species Selection ◽  
The Pacific ◽  
Educational Campaigns ◽  
Urban Forest Management

Trees provide an array of social, economic, and ecological benefits; furthermore, trees on public land are critical for providing those benefits to people who cannot afford their own trees. It is important to know how managers make trade-offs and prioritize different tree selection criteria in order to target educational campaigns at the state or regional level. Primary contacts for Tree City USA designated cities were surveyed across the Pacific Northwest. Of these municipalities, 79 out of 151 responded (52.3% response rate), with 6 municipalities providing responses from different departments for a total of 85 responses. Currently, there are primarily descriptive statistics in relation to tree species selection. This study provides a framework for future statistical analysis and greater exploration of how municipalities and managers are selecting tree species. Results were analyzed with a Mann-Whitney U test to compare International Society of Arboriculture (ISA) Certified Arborists® to those who are not certified across various tree species selection criteria. Another Mann-Whitney U test was used to compare small (≤ 50,000) and large (> 50,000) municipalities across the same criteria. ISA Certified Arborists® showed statistically significant differences from those who are not certified in a number of tree species selection criteria. ISA Certified Arborists® also differed in urban forest management on a city-wide scale, particularly in favoring greater tree species diversity. The differences in urban forest management between ISA Certified Arborists® and noncertified—and between municipality sizes—can help to influence future educational campaigns targeted toward increasing urban forest health and resiliency.

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.

scholarly journals First report of Armillaria cepistipes causing root disease on Populus trichocarpa (black cottonwood) in Oregon, USA.

Plant Disease ◽  
2021 ◽  
Author(s):  
Brandon Alveshere ◽  
Patrick Bennett ◽  
Mee-Sook Kim ◽  
Ned B. Klopfenstein ◽  
Jared M. LeBoldus
Keyword(s):  
North America ◽  
Pacific Northwest ◽  
North American ◽  
Tree Species ◽  
Populus Trichocarpa ◽  
Phylogenetic Study ◽  
Malt Extract ◽  
Black Cottonwood ◽  
The Pacific ◽  
Armillaria Cepistipes

Populus trichocarpa Torr. and Gray (black cottonwood) is an economically and ecologically important tree species native to western North America. It serves as a model tree species in biology and genetics due to its relatively small genome size, rapid growth, and early reproductive maturity (Jansson and Douglas 2007). Black cottonwood is susceptible to root rot caused by at least one species of Armillaria (Raabe 1962), a globally distributed genus that exhibits diverse ecological behaviors (Klopfenstein et al. 2017) and infects numerous woody plant species (Raabe 1962). However, several Armillaria spp. have been isolated from Populus spp. in North America (Mallet 1990), and the most recent report of Armillaria on P. trichocarpa used the now ambiguated name A. mellea (Vahl.) Quel. (see Raabe 1962). In April 2016, mycelial fans and rhizomorphs of an unknown Armillaria species (isolate WV-ARR-3) were collected from P. trichocarpa in a riparian hardwood stand ca. 5.5 km east of Springfield, Oregon, USA (44°3'21.133"N, 122°49'39.935"W). The host was dominant in the canopy, large in diameter (ca. 90-cm dbh) relative to neighboring trees, and exhibited minimal crown dieback (ca. < 5%). A mycelial fan was observed destroying living cambium beneath the inner bark, indicating pathogenicity. The isolate was cultured on malt extract medium (3% malt extract, 3% dextrose, 1% peptone, and 1.5 % agar) and identified as A.cepistipes on the basis of somatic pairing tests and translation elongation factor 1α (tef1) sequences (GenBank Accession No. MK172784). DNA extraction, PCR, and tef1 sequencing followed protocols of Elías-Román et al. (2018). From nine replications of somatic incompatibility tests (18 tester isolates representing six North American Armillaria spp.), the isolate showed high intraspecific compatibility (colorless antagonism) with three A. cepistipes tester isolates (78%), but low compatibility with the other Armillaria spp. (0 – 33%) that occur in the region. Isolate WV-ARR-3 yielded tef1 sequences with a 99% identity to A. cepistipes (GenBank Accession Nos. JF313115 and JF313121). A second isolate (WV-ARR-1; GenBank Accession No. MK172783) with a nearly identical sequence was collected from a maturing P. trichocarpa in a riparian stand ca. 8 km northeast of Monroe, Oregon (44°21’47.57”N, 123°13’14.415”W) along the Willamette River, downstream from the McKenzie river tributary where WV-ARR-3 was collected. Armillaria cepistipes has been reported on Alnus rubra (red alder) in Washington, USA (Banik et al. 1996) and on broad-leaved trees in British Columbia, Canada (Allen et al. 1996). It is generally considered to be a weak pathogen on broad-leaved trees in the Pacific Northwest, but it is also associated with pathogenicity on both coniferous and deciduous trees in Europe (e.g., Lygis et al. 2005). However, a recent phylogenetic study suggested that North American A. cepistipes is phylogenetically distinct from Eurasian A. cepistipes (Klopfenstein et al. 2017), butadditional studies are needed to determine the formal taxonomic status of North American A. cepistipes. To our knowledge, A. cepistipes has not been previously confirmed on P. trichocarpa in the U.S.A. or formally reported as a pathogen of any Populus species in North America. Continued studies are needed to determine the distribution, host range, and ecological role of A. cepistipes in riparian forests of the Pacific Northwest, while monitoring its populations under changing climates.

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