Table of Contents Lauren M. Garcia, Michael A. Arnold, Geoffrey C. Denny, Sean T. Carver, and Andrew R. King Differential Environments Influence Initial Transplant Establishment Among Tree Species Produced in Five Container Sizes ................................................................................................. 170 Abstract. Effects of two post-transplant environments were tested on trees grown in five nursery container sizes to determine differ- ences in initial post-transplant growth. Vitex agnus-castus L., Acer rubrum L. var. drummondii (Hook. & Arn. ex Nutt.) Sarg., and Taxodium distichum (L.) Rich. grown in 3.5 L (#1), 11.7 L (#3), 23.3 L (#7), 97.8 L (#25), and 175.0 L (#45) containers were transplanted in early sum- mer into field plots in College Station, Texas, and Starkville, Mississippi, U.S. Height, trunk diameter, and canopy width measurements were recorded aſter nursery production and the end of the first growing season to determine initial growth during landscape establishment. Growth of A. rubrum and T. distichum were significantly (P ≤ 0.05) affected by interactions among container sizes and environments, while V. agnus-castus did not demonstrate a difference between environments but were affected by container sizes. Across all species and locations, trees transplanted from smaller container sizes exhibited a greater percent change in growth than the larger container-size trees. Greater per- cent change in growth measures in the smaller container-size trees during the first growing season may indicate a more rapid establish- ment time compared to trees from larger containers. Where differential responses to environments occurred, predominantly the ben- eficial effects of smaller container sizes on post-transplant establishment were accentuated with more stressful establishment conditions. Key Words. Acer rubrum; Bald Cypress; Chaste Tree; College Station; Mississippi; Red Maple; Starkville; Taxodium distichum; Texas; Vitex agnus-castus. Adam G. Dale, Elsa Youngsteadt, and Steven D. Frank Forecasting the Effects of Heat and Pests on Urban Trees: Impervious Surface Thresholds and the 'Pace-to-Plant' Technique ................................................................................................ 181 Abstract. Trees provide ecosystem services that benefit humans and the environment. Unfortunately, urban trees often do not provide maximum services due to abiotic stress and arthropod herbivores and borers. These problems often originate from trees being planted in unsuitable conditions. Cities are warmer than natural areas because impervious surfaces absorb and reradiate heat. Higher temperatures can increase pest insect abundance and water stress, and reduce street tree condition relative to natural forests. For example, the gloomy scale insect [Melanaspsis tenebricosa Comstock (Hemiptera: Diaspididae)], a pest of red maple (Acer rubrum) street trees, is more abundant in warmer than cooler urban sites. Acer rubrum, at warmer urban sites with more M. tenebricosa, are typically in poor condition. Here, researchers demonstrate these relationships and illustrate how impervious surface cover can be used to predict the condition of A. rubrum street trees. impervious surface thresholds were then developed to define suitable planting sites that can be used by individuals with access to GIS software. Researchers present the pace-to-plant technique, which can be used by landscape professionals to quickly estimate imper- vious surface cover around a planting site. These thresholds predict future tree condition based on planting site impervious surface cover. The hope is that more informed planting will minimize pest infestations and maximize the future vigor and performance of street trees. Key Words. Acer rubrum; Gloomy Scale; Impervious Surface; Integrated Pest Management; Melanaspis tenebricosa; Red Maple; Street Tree; Urban Forestry. Alessio Fini, Ciro Degl’Innocenti, and Francesco Ferrini Effect of Mulching with Compost on Growth and Physiology of Ulmus ‘FL634’ Planted in an Urban Park ........................................................................................................................... 192 Abstract. The effects of mixed compost as mulching material on growth and physiology of newly planted elm trees were evaluated over a three-year period aſter planting in an urban park. Trees mulched with compost generally had greater height (+10% and +19% for 5 cm layer and 10 cm layer treatments, respectively, if compared to control), trunk diameter (+13% and +29%) and current-year shoot growth (+46% and +56%). Limited effects were found with regard to carbon assimilation when considered on a per unit-leaf-area basis (-0.1% and +0.3%), but whole tree carbon assimilation increased in mulched trees (+7% and +59% for 5 cm and 10 cm treatments, respec- tively, if compared to control) because of the larger total tree leaf area of mulched plants. Mulching also increased chlorophyll content (+4% and +7% for 5 cm and 10 cm treatments, respectively). The results obtained in this study show how mulching with compost increased growth, carbon storage, and improved water use efficiency of trees planted in an urban environment characterized by hot dry summers. Key Words. Carbon Assimilation; Chlorophyll; Elm; Florence; Italy; Mediterranean Climate; Mulch; Photosynthesis; Ulmus; Water Use Efficiency. ©2016 | International Society of Arboriculture | ISSN:1935-5297
May 2016
| 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
