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

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.

2020 ◽  
Vol 46 (5) ◽  
pp. 371-384
Author(s):  
Joshua Petter ◽  
Paul Ries ◽  
Ashley D’Antonio ◽  
Ryan Contreras

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.


2016 ◽  
Vol 24 (4) ◽  
pp. 471-483 ◽  
Author(s):  
Sophie A. Nitoslawski ◽  
Peter N. Duinker ◽  
Peter G. Bush

Tree diversity is crucial to urban forest management. More diverse urban forests provide habitat for a wider range of organisms, increase resilience to pests and disease and, in cases where native tree species are well represented, contribute to local biodiversity protection. Studies have shown that tree diversity can peak in the low- to mid-density neighbourhoods found in suburban and peri-urban areas, emphasizing the potential for biodiversity enhancement during and after subdivision development. Most studies quantifying tree species composition in suburban areas focus on one or two major drivers of tree diversity, such as land use, socioeconomics and demographics, or the presence of natural features like parks or greenways. Furthermore, relatively little attention has been paid to the drivers of diversity for the variety of land types that make up the entire urban forest, which represent differences in tree planting and establishment practices, ownership, and maintenance. This paper presents an overview of drivers of tree species composition based on the literature, as well as factors that require further study because they play a role in determining the structure of the (sub)urban forest. These factors are examined in the context of four land types: street, residential property, park, and remnant woodland, and are organized under the following major themes: biophysical characteristics, community design, historical paradigms and influences, municipal management, and demographics and cultures. Based on what is known so far, a research agenda is also presented outlining major gaps in research on urban tree diversity in North America (USA and Canada). The information presented in this paper can thus serve as a guideline to inform urban forest management practices and strategically enhance tree diversity.


2012 ◽  
Vol 88 (02) ◽  
pp. 118-123 ◽  
Author(s):  
E. John Barker ◽  
W. Andy Kenney

Urban forestry has emerged as an important and timely discipline in an urbanizing world. The practice of urban forestry has focused mainly on large urban centres but urban forests in small municipalities provide the same benefits to the residents within and around them. Small municipalities face many challenges similar to those in urban centres but a lack of resources may worsen the negative effects on small municipalities. Urban forestry in Ontario is undertaken by municipalities with little involvement from upper-level governments. Thus, the effectiveness of urban forestry in Ontario is inconsistent and sporadic, with many small municipalities unable to manage urban forests optimally. Ontario's legislative framework governing urban forestry is critiqued and compared to the system employed in the United States. Recommendations are provided for action toward a centralized urban forestry program in Ontario.


1999 ◽  
Vol 14 (1) ◽  
pp. 28-34 ◽  
Author(s):  
Bruce Shindler ◽  
Lori A. Cramer

Abstract Wicked problems typify many of the natural resource debates in the United States and certainly describe the management of forestlands in the Pacific Northwest. Wicked problems are interrelated ones of organized complexity that cannot be solved in isolation from one another, but also hinge on differing sociopolitical values that clash in the political arena. Forestry professionals frequently find themselves caught up in the dilemma of making decisions in this era of social change and much scrutiny. This paper examines what shifting social values mean for forest management and research by (1) providing a conceptual context for forest policy decisions, (2) examining relevant problems facing management and research institutions, and (3) characterizing the implication for public forest management given the nature of wicked problems. West. J. Appl. For. 14(1):28-34.


2016 ◽  
Vol 148 (5) ◽  
pp. 616-618 ◽  
Author(s):  
E.R. Echegaray ◽  
R.N. Stougaard ◽  
B. Bohannon

AbstractEuxestonotus error (Fitch) (Hymenoptera: Platygastridae) is considered part of the natural enemy complex of the wheat midge Sitodiplosis mosellana (Géhin) (Diptera: Cecidomyiidae). Although previously reported in the United States of America, there is no record for this species outside the state of New York since 1865. A survey conducted in the summer of 2015 revealed that E. error is present in northwestern Montana and is likely playing a role in the suppression of wheat midge populations.


Plant Disease ◽  
2009 ◽  
Vol 93 (8) ◽  
pp. 797-803 ◽  
Author(s):  
Renuka N. Attanayake ◽  
Dean A. Glawe ◽  
Frank M. Dugan ◽  
Weidong Chen

The taxonomy of the powdery mildew fungus infecting lentil in the Pacific Northwest (PNW) of the United States was investigated on the basis of morphology and rDNA internal transcribed spacer (ITS) sequences. Anamorphic characters were in close agreement with descriptions of Erysiphe trifolii. However, teleomorphs formed chasmothecial appendages with highly branched apices, whereas E. trifolii has been described as producing flexuous or sometimes loosely branched appendages. Branched appendages have been described in Erysiphe diffusa, a fungus reported from species of Lens, Glycine, and Sophora, raising the possibility that the PNW fungus could be E. diffusa. Examination of morphological characters of an authentic specimen of E. trifolii from Austria determined that it included chasmothecial appendages resembling those seen in PNW specimens. Furthermore, ITS sequences from five powdery mildew samples collected from lentils in PNW greenhouses and fields from 2006 to 2008 were identical to one another, and exhibited higher similarity to sequences of E. trifolii (99%) than to those of any other Erysiphe spp. available in GenBank. Parsimony analysis grouped the lentil powdery mildew into a clade with Erysiphe baeumleri, E. trifolii, and E. trifolii–like Oidium sp., but indicated a more distant relationship to E. diffusa. In greenhouse inoculation studies, the lentil powdery mildew fungus did not infect soybean genotypes known to be susceptible to E. diffusa. The pathogenicity of E. trifolii on lentil was confirmed using modified Koch's postulates. This is the first report of E. trifolii infecting lentil. E. diffusa and E. trifolii have different host ranges, so the discovery of E. trifolii on lentil has implications both for determining species of powdery mildews on cool-season grain legumes, and in disease management.


2021 ◽  
Author(s):  
Mingming Yang ◽  
Linda S Thomashow ◽  
David M Weller

Pseudomonas brassicacearum Q8r1-96 and other 2,4-diacetylphloroglucinol (DAPG)-producing pseudomonads of the Pseudomonas fluorescens complex possess both biocontrol and growth-promoting properties and play an important role in suppression of take-all of wheat in the Pacific Northwest (PNW) of the United States. However, P. brassicacearum can also reduce seed germination and cause root necrosis on some wheat cultivars. We evaluated the effect of Q8r1-96 and DAPG on the germination of 69 wheat cultivars that have been or currently are grown in the PNW. Cultivars varied widely in their ability to tolerate P. brassicacearum or DAPG. The frequency of germination of the cultivars ranged from 0 to 0.87 and from 0.47 to 0.90 when treated with Q8r1-96 and DAPG, respectively. There was a significant positive correlation between the frequency of germination of cultivars treated with Q8r1-96 in assays conducted in vitro and in the greenhouse. The correlation was greater for spring than for winter cultivars. In contrast, the effect of Q8r1-96 on seed germination was not correlated with that of DAPG alone, suggesting that DAPG is not the only factor responsible for the phytotoxicity of Q8r1-96. Three wheat cultivars with the greatest tolerance and three cultivars with the least tolerance to Q8r1-96 were tested for their ability to support root colonization by strain Q8r1-96. Cultivars with the greatest tolerance supported significantly greater populations of strain Q8r1-96 than those with the least tolerance to the bacteria. Our results show that wheat cultivars differ widely in their interaction with P. brassicacearum and the biocontrol antibiotic DAPG.


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