Urban Ecology最新文献

Differences in eastern gray squirrel (Sciurus carolinensis) abundance were studied in five types of habitat in Springfield, MA, from July 1974 to December 1976. These data were compared with selected habitat variables to determine whether differences in those variables could quantify differences in squirrel abundance. Squirrel abundance ranged from 0.15 squirrel per ha in areas of high urbanization to 1.08 squirrel per ha in parks, college campuses, and cemeteries. Their abundance was not significantly different in three urban habitats. Squirrel abundance was significantly correlated with basal area, tree density, and number of oaks per ha. Pavement, building cover, and the distance to woodlots appeared to have a negative influence on squirrel activity. Height of trees and lawn cover apparently had little or no influence on squirrel abundance. A six-variable stepwise regression model explains 74% of the squirrel variation throughout Springfield.

The reconstruction of the determinants of residential preferences represents a major problem of behavioural studies on intra-urban migration and mobility. In research on this topic, two approaches may be distinguished. One of these tries to deduce these determinants from the analysis of already realized decisions and the other employs the direct measurement of preferences by means of interviews. The determinants discussed mostly refer to variables related to distance, facilities of infrastructure, residential characteristics and facilities, social attributes of the neighbourhood, and aspects of the natural environment. A survey of the relevant literature shows that this last group of variables has been treated insufficiently so far although there do exist a lot of studies that stress the importance of attributes of the natural environment as one criterion of decision-making when assessing the qualities of alternative housing sites. After discussing various problems of methods and measurement, the paper presents some proposals which should help to avoid the shortcomings of several previous studies. Finally the paper reports on some preliminary results of an investigation on residential preferences in Salzburg, Austria, which was carried out according to the given proposals. The results confirm the postulated influence of the natural environment as an important determinant of residential preferences.

Health effects on subjects during a bus drive on an urban road were investigated in a real situation. Leukocyte count, adrenalin level in blood and urine, noradrenalin and dopamine in urine, diastolic blood pressure, and index of vascular resistance increased significantly on the drive day compared with the control day. A bus drive on an urban road induced enhanced sympathetic-adreno-medullary activity in real life as a result of the comprehensive effect of various factors. The concentrations of air pollutants were excessively high on the road, and correlated with traffic volume. It was concluded that the interactions between psychogenic, physical nonspecific and physical specific effects should be taken into consideration when evaluating human health effects of air pollution in the urban environment.

The spatial arrangement of woody vegetation in residential developments from 40 to 1000 ha is analyzed in terms of the “species-area curve” and other principles of island biogeography. These principles, which predict the number of wildlife species which will occur in an area as a function of the size, shape and distribution of vegetation patches in the area, promise to be a powerful tool in greenspace planning. Using birds as an example, we examine some of the trade-offs among wildlife, visual and recreational amenities which are associated with three different approaches to the arrangement of a given amount of greenspace. These three approaches are examined both at the scale of small and large subdivisions and at a micro-regional scale of 10 km².