Abstract
Europe, the second smallest of the world's continents with a total area of 106 km2 and a population of about 700 million, is one of the most densely populated continents with about 80% of its population living in or adjacent to metropolitan centers. These centers are located from Gibraltar in the south (lat. 36°N) to Norway in the north (≈lat. 71°N), and from the Ural mountain range in the east (long. 55°E) to Iceland in the west, (≈long. 24°W).
This computer program, delivered-on a CD-ROM disc, develops a list of tree species and cultivars suited for a specific planting site. It requires little previous computer experience or tree knowledge to operate. Using multiple choice questions, the program automatically brings the user through above ground and below ground site analysis. This includes all the considerations known to influence proper species section for a planting site. Using C++ programming and the NASA-developed expert system shell called CUPS, a list of facts is generated as the user answers the questions. At the press of a button, the program finds trees that match the attributes the expert system placed on the facts list. The list can be further modified by choosing among ornamental and other tree attributes that might be of interest to the user. The tree list can be printed in several seconds. A typical run through the expert system takes 2 to 4 minutes to answer about 20 to 25 questions. The program contains data on 681 trees, more than 1,800 color photographs, and a 4-page fact sheet including 3 line drawings for each tree totaling more than 2,000 pages. The program can also be used as a reference by paging through the tree records to find information about specific trees. Each tree record lists on the computer monitor a large variety of data for the tree, allows you to view text about the tree, displays a line drawing of the entire tree, and displays up to seven photographs of each tree. The program will be distributed nationwide as a tool to help landscape architects, horticulturists and others select the right tree for the right place.
Abstract
Only a few species are capable of colonizing extreme environments, whereas more moderate environments can support many more. The diversity of species in a habitat is thus controlled by the environment, whether by soil fertility, altitude or any other factor. This diversity reflects the number of species adapted to grow in a habitat, and the nature of this adaptation must be examined in light of the physiological effect of the environmental factors making up the habitat, and their variation in time and space (11).
Plant development, leaf morphology, leaf cuticular wax content, and leaf water relations were determined for seven tree species exposed to consecutive cycles of drought. The objective of the experiment was to identify plant taxa suitable for landscapes prone to drought. On the day drought treatments began, plant development traits and leaf morphology varied among species. Leaf cuticular wax content was different among species and ranged from 0.053 mg·cm–2 in California white oak (Quercus lobata Née), to 0.200 mg·cm–2 in Texas red oak (Quercus buckleyi Buckl.). Was content in Bur oak (Quercus macrocarpa Michx.) and Shumard oak (Quercus shumardii Buckl.) averaged 0.105 and 0.11 mg·cm–2, respectively. At harvest, Texas red oak plants treated with drought had the highest root-to-shoot dry weight ratio which averaged 3.1. In contrast, plants of Arizona ash (Fraxinus velutina Torr.) and California white oak that were frequently irrigated had the lowest root-to-shoot dry weight ratio. Drought did not affect stem elongation, total lamina area, leaf dry weight, and specific leaf weight. Abaxial leaf surfaces of Arizona ash were the most pubescent and averaged1836 trichomes/cm2. Drought-stressed plants of golden rain tree (Koelreuteria paniculata Laxm.) had the most negative midday leaf water potential, which averaged –2.5 MPa. Plants of Chinkapin oak (Quercus muehlenbergii Engelm.) that were irrigated frequently had the least negative predawn leaf water potentials. Predawn leaf water potentials tended to be more negative for Arizona ash and golden rain tree than for the oak species. These results suggest that some species of oak might perform well in landscapes prone to drought.
Two tree species, Acer rubrum `October Glory' (October Glory red maple) and Quercus phellos (willow oak) were planted in Columbus, GA and Mobile, AL. Variables evaluated were location (park vs residential) and tree size (1.5 vs 3.0 inch caliper). Greater shoot elongation occurred with 1.5 inch red maples and willow oaks than with 3.0 inch caliper trees. First year growth differences were not related to photosynthesis, night respiration, leaf water potential, or foliar nitrogen levels. Little height or caliper change occurred with either species. Red maple shoot elongation was greater in Mobile than into Columbus. Growth was not affected by location within either city.
It is estimated that 90% of trees that are established in the urban environment in the northeastern United States are produced in the nursery as a field-grown plant where they are dug, wrapped in burlap, and transported to the new planting site as a
TROPICAL URBAN TREES Urban trees are an increasingly important quality of life issue in tropical cities as economic growth swells increasingly affluent urban populations ( Nilsson, 2005 ). The understanding and management of urban trees in tropical
Trees are an important component of urban landscapes and mitigate temperature and local microclimate effects, improve air quality by removing pollutants, store carbon and reduce carbon dioxide emission, and lower energy use for heating and cooling
water needs of their choice. Knowledge of the water needs of landscape types can be a major strategy in urban water conservation ( Hurd et al., 2006 ). Traditionally, a landscape water budget has been defined as the amount of water required to maintain
identify and correct these defects before a failure. In an urban environment, trees require more care than those in natural settings due to the presence of targets, or the people and property that can be harmed by tree failure ( Matheny and Clark, 1994