Arboriculture & Urban Forestry 34(1): January 2008 Arboriculture & Urban Forestry 2008. 34(1):59–60. 59 ARBORICULTURAL ABSTRACTS TOOLS FOR MAPPING SOCIAL VALUES OF URBAN WOODLANDS AND OTHER GREEN AREAS Liisa Tyrvainen, Kirsi Makinen, and Jasper Schipperijn Since the social values of urban woodlands are not always suf- ficiently taken into account in decision-making on urban land- use and green space planning, new means of collecting the ex- perienced values of urban green areas and integrating this infor- mation into the planning processes are needed. The main aim of this study was to develop a simple method to describe the ex- perienced qualities of green areas for strategic green area plan- ning purposes. In a postal survey conducted in Helsinki, Finland, general attitudes towards and benefits felt to be derived from green areas as well as site specific information about the expe- rience values were gathered. Local residents were asked to iden- tify those areas on a map of the study area that had particular positive qualities, such as beautiful scenery, peace and quiet, and the feeling of being in a forest as well as those areas with nega- tive features. These results were compiled in map form using GIS software. The results highlight the most valued sites as well as problem areas within the study area. The most important features associated with favorite places were: tranquility, the feeling of being in a forest, and naturalness. The results suggest that the method is communicative and relatively easy to use in both collaborative green area planning and land-use planning. (Landscape and Urban Planning 2007. 79(1):5–19) GEOSPATIAL METHODS PROVIDE TIMELY AND COMPREHENSIVE URBAN FOREST INFORMATION Kathleen T. Ward and Gary R. Johnson Urban forests are unique and highly valued resources. However, trees in urban forests are often under greater stress than those in rural or undeveloped areas due to soil compaction, restricted growing spaces, high temperatures, and exposure to air and wa- ter pollution. In addition, conditions change more quickly in urban as opposed to rural and undeveloped settings. Subse- quently, proactive management of urban forests can be challeng- ing and requires the availability of current and comprehensive information. Geospatial tools, such as, geographic information systems (GIS), global positioning systems (GPS) and remote sensing work extremely well together for gathering, analyzing, and reporting information. Many urban forest management ques- tions could be quickly and effectively addressed using geospatial methods and tools. The geospatial tools can provide timely and extensive spatial data from which urban forest attributes can be derived, such as land cover, forest structure, species composition and condition, heat island effects, and carbon storage. Emerging geospatial tools that could be adapted for urban forest applica- tions include data fusion, virtual reality, three-dimensional visu- alization, Internet delivery, modeling, and emergency response. (Urban Forestry & Urban Greening 2007. 6:15–22) GROWTH OF BETULA PENDULA ROTH. THE FIRST SEASON AFTER TRANSPLANTING AT TWO PHENOLOGICAL STAGES Ingjerd Solfjeld and Per Anker Pedersen The root extension rate of Betula pendula, transplanted at two phenological stages, was studied in a Nordic climate. Landscape- size trees were transplanted from the field into root-study boxes (rhizotron) in early and late spring of 1999 and 2000. In early spring, 6 trees were transplanted when the leaves had just started to unfold; likewise, in late spring, six trees were transplanted when the leaves were fully unfolded and the shoot extension was in progress. Root growth was recorded during the first post- transplant season and the tree roots were finally excavated. Re- sults indicate that the root extension rate of B. pendula follows seasonal soil temperature. The mean root extension rates at ten day intervals varied from 4 to 11 mm/day with a total average for the growing season of 7 mm/day in 1999 and varied from 4 to 9 mm/day with a total average for the growing season of 4 mm/day for 2000. The average length of new roots was 89 cm and there was no significant difference in length, dry weight or number of new roots between the two transplant times. It appears, therefore, that the phenological stage at transplanting during the period from bud break to fully developed leaves has minor effect on landscape establishment of B. pendula, when an adequate amount of water is provided. (Urban Forestry & Urban Greening 2006. 5(2):101–106) URBAN VEGETATION MAPPING USING SUB-PIXEL ANALYSIS AND EXPERT SYSTEM RULES: A CRITICAL APPROACH S.W. Myint Since the traditional hard classifier can label each pixel only with one class, urban vegetation (e.g., trees) can only be recorded as either present or absent. The sub-pixel analysis that can provide the relative abundance of surface materials within a pixel may be a potential solution to effectively identifying urban vegetation distribution. This study examines the effectiveness of a sub-pixel classifier with the use of expert system rules to estimate varying distributions of different vegetation types in urban areas. The Spearman’s rank order correlation between the vegetation output and reference data for wild grass, man-made grass, riparian veg- etation, tree, and agriculture were 0.791, 0.869, 0.628, 0.743, and 0.840 respectively. Results from this study demonstrated that the expert system rule using NDVI threshold procedure is reliable and the sub-pixel processor picked the signatures relatively well. This study reports a checklist of the sources of limitation in the application of sub-pixel approaches. (International Journal of Remote Sensing 2006. 27(13):2645–2665) ©2008 International Society of Arboriculture
January 2008
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