Table of Contents Andrew Koeser, Richard Hauer, Jeff Edgar, and David Kleinhuizen Impacts of Wire Basket Retention and Removal on Planting Time, Root-Ball Condition, and Early Growth of Acer platanoides and Gleditsia triacanthos var. inermis ............................... 18 Abstract. The use of wire baskets to maintain root-ball integrity has greatly increased the efficiency of balled-and-burlapped har- vesting practices. Despite the advantages offered by these products, there is notable disagreement among green industry groups and practitioners regarding the effects of wire basket retention or removal at the time of planting. For this experiment, 30 Norway maple (Acer platanoides) and 30 honeylocust (Gleditsia triacanthos var. inermis ‘Skycole’) shade trees were evenly planted at two sites in the midwestern U.S. aſter random assignment of a wire-basket removal treatment (i.e., no removal/intact, partial removal, and full removal). Planting time and initial root-ball condition were assessed at the time of installation. Short-term growth and plant stress were assessed each season as trees became established in the research plots. Results indicate that treatment impacted both planting time (P < 0.0001; both sites) and root-ball condition (P = 0.0360 or P = 0.0049; depending on site). In contrast, treatment had limited impact on tree caliper, twig elongation, or chlorophyll fluorescence in the first two to three years aſter planting. Key Words. Acer platanoides; Burlap; Gleditsia triacanthos; honeylocust; Midwest; Minnesota; Norway maple; Planting Survival; Transplanting; Tree Stability; Wire Basket; Wisconsin. Jennifer Vander Vecht and Tenley M. Conway Comparing Species Composition and Planting Trends: Exploring Pest Vulnerability in Toronto’s Urban Forest ................................................................................................................................... 26 Abstract. Urban forests represent a valuable resource for cities but are not without costs. These costs can include time, money, and the loss of beneficial services as results of pest infestations. Knowledge of an urban forest’s tree species composition and vulnerability to pests is needed to help managers enhance services delivered, while minimizing expenses over the long-term. Recent research has explored the impacts of individual pests on urban forests, but less attention has been given to the overall pest vulnerability. In this research, tree gen- era currently prevalent and commonly planted in Toronto, Ontario, Canada, were analyzed using a pest vulnerability matrix to explore how the city’s urban forest species composition and pest vulnerability may be changing. Current tree species composition was derived from exist- ing inventory data, while the planting trends of a variety of local actors were determined through surveys and interviews. Results indicate there is somewhat limited diversity in current street and non-street tree populations, as well as a number of common tree species that have severe pest vulnerabilities. While new plantings replicate some current composition and pest vulnerability issues, several less common species are also being planted. As a result, overall pest vulnerability should decrease in the future, while some ongoing management concerns remain. Key Words. Canada; Ontario; Pest Vulnerability; Pest Vulnerability Matrix; Planting Trends; Species Diversity; Survey; Toronto; Tree Pests; Urban Forests. Jason E.E. Dampier, Richard W. Harper, Lora Schwartzberg, and R. Harvey Lemelin A Comparison of Arborists’ and Horticulturists’ Preferences of Tsuga chinensis to T. canadensis in the Urban Landscape. ...................................................................................... 41 Abstract. Recent research describing host resistance of hemlocks to the lethal, invasive insect hemlock woolly adelgid has suggested that Chinese hemlock (Tsuga chinensis) may be a suitable pest-resistant urban landscape replacement for eastern hemlock (T. canadensis). Presented here are the research findings of an in situ field questionnaire survey and participant observations. The study’s objective was to collect and evaluate arborists’ and other horticulturists’ perceptions and purchase preferences between eastern and Chinese hemlock to assess whether Chinese hemlock has potential to be accepted as an alternative landscape replacement for eastern hemlock. Fiſty-five participants visually inspected both hemlock specimens and responded to questions about which one they would prefer to purchase, what their preferences would be in light of potential insect resistance, and the likelihood of fewer insecticide applications being required. Multiple cross-tabulations indicated that there was no statistical association (Fisher’s Exact Test, P > 0.05) between participant background (i.e., arborists versus others) and questions related to general purchase pref- erence, and purchase preference if a specimen exhibited natural pest pant Perceptions; Survey; Tsuga canadensis; Tsuga chinensis. resistance or required less pesticides. Over three-quar- ters of participants were more inclined to purchase the specimen that possessed resistance to a serious pest. These findings sug- gest that Chinese hemlock may potentially serve as a hemlock woolly adelgid-resistant alternative to eastern hemlock in the landscape. Key Words. Adelges tsugae; Arborist; Chinese Hemlock; Eastern Hemlock; Hemlock Woolly Adelgid; Horticulturist; Invasive Species; Partici- ©2015 | International Society of Arboriculture | ISSN:1935-5297
January 2015
| Title Name |
Pages |
Delete |
Url |
| Empty |
Search Text Block
Page #page_num
#doc_title
Hi $receivername|$receiveremail,
$sendername|$senderemail wrote these comments for you:
$message
$sendername|$senderemail would like for you to view the following digital edition.
Please click on the page below to be directed to the digital edition:
$thumbnail$pagenum
$link$pagenum
Your form submission was a success. You will be contacted by Washington Gas with follow-up information regarding your request.
This process might take longer please wait
