Table of Contents Jessica Sanders, Jason Grabosky, and Paul Cowie Establishing Maximum Size Expectations for Urban Trees with Regard to Designed Space .......... 68 Abstract. One issue confronting the application of forest management principles to urban tree canopy management decisions is the lack of data correlating site, tree size, and tree age. Researchers tested whether terminal size (stem diameter) can be linked to site type for informed management and design decisions. Data were considered from eleven New Jersey, U.S. communities. Diam- eter breast height (DBH) distribution established regionalized service life expectancies of commonly planted species by site type and expected maximum DBH. The goal was to develop a method to identify trees approaching senescence within an inven- tory. Three common urban landscape site types were used: tree pit, planting strip, and unlimited soil. Thirty-one taxa were pres- ent in large enough populations to use in species-specific analysis. The species were classified into small, medium, and large size categories based on published growth expectations. The study authors developed DBH occurrence percentiles, and DBH within the ninety-fifth were described as a maximum size range. There was a significant difference in maximum sizes between plant- ing site types. Regardless of the size class of the tree, the data showed reduced planting space resulted in reduced maximum size. Key Words. Age Class; Canopy Management; New Jersey; Senescence; Site Type; Urban Forest; Urban Tree Growth. Lilian M. Pearce, James B. Kirkpatrick, and Aidan Davison Using Size Class Distributions of Species to Deduce the Dynamics of the Private Urban Forest ................................................................................................................................... 74 Abstract. Urban governance in Western societies is increasingly shaped by awareness of the importance of trees in maintaining the envi- ronmental function and social livability of cities. Records of change in urban forest composition on public land are generally good. How- ever, a great proportion of trees in western cities occur on private land, where such changes are poorly-documented. The study authors tri- aled the use of size class analysis, a technique widely used to deduce the dynamics of natural forests, to determine change in the private urban forest. From a sample of blocks in ten suburbs of the Australian cities of Melbourne and Hobart, in which most dwellings have front and back gardens, researchers assessed the implications of changes for the functionality of the urban forest. The height class dis- tributions of a large number of front garden tree taxa were classified. Although the factors affecting height class distributions differ between a natural and an urban forest, those distributions found for most species were so extreme that there was little doubt in interpre- tation. Tree species that can grow to a large height were under-represented in the smaller height classes, indicating their future decline in the private tree estate. Individuals of glossy-leaved small tree species were over-represented in the smaller height classes, indicating a recent increase in their popularity. The shiſt toward smaller, denser trees on private land has implications for the functions of the urban forest. A higher level of large tree protection on private land and compensation through planting on public land could mitigate impacts. Key Words. Garden Tree; Species Composition; Species Preference; Street Tree; Suburban Residents; Tree Management; Urban Forest; Urban Plants; Urban Vegetation. L.P. Werner and L.G. Jull Fertilizer Nitrogen Uptake and Partitioning in Young and Mature Common Hackberry (Celtis occidentalis) Trees ............................................................................................................... 85 Abstract. Twenty-one mature and thirty-six young common hackberry (Celtis occidentalis L.) trees received a single applica- tion of 15 m-2 of canopy coverage, respectively. Foliage, current season stem wood, stem wood, root, and fruit tissues were analyzed for N double isotope enriched ammonium-nitrate (NH4 NO3 total concentration [N] and nitrogen derived from fertilizer (NDFF). Growth phase and application rate did not consistently affect total % [N], particularly the N demanding foliage. Growth phase and application rate significantly affected the percent- age of NDFF. In every instance, NDFF was highest in the tissues of young trees and/or trees receiving the 1.47 kg N 100 m-2 applica- tion rate. Mature trees relied upon previously assimilated N to meet the annual demand for N to a greater extent than young trees. Key Words. ANSI A-300; Celtis occidentalis; Fertilization; Hackberry; Nitrogen; Remobilization. ) fertilizer. Application rates were 0, 0.49, and 1.47 kg N 100 ©2013 | International Society of Arboriculture | ISSN:1935-5297
March 2013
| 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
