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1.
Rainfall interception by Santa Monica's municipal urban forest   总被引:4,自引:2,他引:2  
Effects of urban forests on rainfall interception and runoff reduction have been conceptualized, but not well quantified. In this study rainfall interception by street and park trees in Santa Monica, California is simulated. A mass and energy balance rainfall interception model is used to simulate rainfall interception processes (e.g., gross precipitation, free throughfall, canopy drip, stemflow, and evaporation). Annual rainfall interception by the 29,299 street and park trees was 193,168 m3 (6.6 m3/tree), or 1.6% of total precipitation. The annual value of avoided stormwater treatment and flood control costs associated with reduced runoff was $110,890 ($3.60/tree). Interception rate varied with tree species and sizes. Rainfall interception ranged from 15.3% (0.8 m3/tree) for a small Jacaranda mimosifolia (3.5 cm diameter at breast height) to 66.5% (20.8 m3/tree) for a mature Tristania conferta (38.1 cm). In a 25-year storm, interception by all street and park trees was 12,139.5 m3 (0.4%), each tree yielding $0.60 (0.4 m3/tree) in avoided flood control costs. Rainfall interception varied seasonally, averaging 14.8% during a 21.7 mm winter storm and 79.5% during a 20.3 mm summer storm for a large, deciduous Platanus acerifolia tree. Effects of differences in temporal precipitation patterns, tree population traits, and pruning practices on interception in Santa Monica, Modesto, and Sacramento, California are described.  相似文献   
2.
Tree health is a critical parameter for evaluating urban ecosystem health and sustainability. Traditionally, this parameter has been derived from field surveys. We used multispectral remote sensing data and GIS techniques to determine tree health at the University of California, Davis. The study area (363 ha) contained 8,962 trees of 215 species. Tree health conditions were mapped for each physiognomic type at two scales: pixel and whole tree. At the pixel scale, each tree pixel within the tree crown was classified as either healthy or unhealthy based on vegetation index values. At the whole tree scale, raster based statistical analysis was used to calculate tree health index which is the ratio of healthy pixels to entire tree pixels within the tree crown. The tree was classified as healthy if the index was greater than 70%. Accuracy was checked against a random sample of 1,186 trees. At the whole tree level, 86% of campus trees were classified as healthy with 88% mapping accuracy. At the pixel level, 86% of the campus tree cover was classified as healthy. This tree health evaluation approach allows managers to identify the location of unhealthy trees for further diagnosis and treatment. It can be used to track the spread of disease and monitor seasonal or annual changes in tree health. Also, it provides tree health information that is fundamental to modeling and analysis of the environmental, social, and economic services produced by urban forests.  相似文献   
3.
A significant proportion of young people in Australia are currently not being engaged in school and other social systems. This article presents the results of a mixed-methods study of a pilot Family Wellbeing intervention designed to enhance the social and emotional wellbeing (SEWB) of young Aboriginal men and improve engagement in education, employment, and other social participation. A questionnaire incorporating the Kessler Psychological Distress Scale and respondent self-assessment SEWB questions was administered to program participants pre and post intervention (N = 30) and qualitative data were collected from program organisers (N = 6). The results suggest that the Family Wellbeing intervention has the capacity to make a marked contribution to the SEWB of young Aboriginal men; participants experienced strong improvement in capacity to manage relationships, engagement in education and employment, and mental and physical health. The factors that enabled the program to be adapted to the target group and setting are documented.  相似文献   
4.
Child and family practice is recognised as a field of social work that has become increasingly complex. While evidence is growing in relation to effective supervision, there has been little research about the attributes of an effective supervisor, or the components of effective supervision. This paper reports on research undertaken in Victoria, Australia, which explored practitioners’ and supervisors’ experiences of effective supervision in this field. Data collection involved in-depth interviews with experienced supervisors and supervisees in order to explore the concept of effective supervision from participants’ perspectives. The data were systematically interrogated using a thematic inductive process, designed to enhance the voice of participants in the research. The study findings confirmed the complexity and centrality of the supervisory relationship, with the experience of a safe supervisory relationship proving essential. The importance of contemporary knowledge, leadership skills, and an enabling organisational and community context were also highlighted.  相似文献   
5.
How best to support children and young people in foster care remains a challenge for child welfare. There has been little Australian research on the outcomes for children and young people placed in therapeutic foster care (TFC). This article aims to address this knowledge gap, presenting the evaluation of a state‐wide model of TFC known as the Circle Program operating in Victoria, Australia. Data sources for the study were case assessment analysis; surveys of foster carers, program workers and other stakeholders in the sector; and both focus groups and individual interviews with foster care workers. The evaluation found that the Circle Program lessened the number of unplanned exits of children from foster placements compared with generalist foster care. Another important finding was that the Circle Program positively influenced foster carers' decisions to stay in the carer role. Key components perceived as contributing to outcomes of the Circle Program included enhanced training of foster carers, intensive carer support, specialist therapeutic support to the child and carer, therapeutic service to family members and a network of services to provide support to the child.  相似文献   
6.
The current study assesses ageism and heterosexism relating to older adult sexual activity within long-term care facilities. To assess caregiver reactions, 153 residential care facility staff members read one of three vignettes. Each vignette described a scenario in which a staff member walks in on two residents (male/female, male/male, or female/female) engaging in sexual activity. Although no main effects were discovered for vignette type, exploratory analyses revealed that the facility where participants were employed was significantly related to their ratings of approval. Furthermore, an interaction effect between vignette and facility types was also discovered for caregivers’ approval of sexual activity among residents. Additionally, a strong overall approval rating of older adult sexuality was reported by staff members. The results of this study warrant that further research is necessary regarding older adults’ perception of caregiver bias, as well as further investigation of caregivers’ perceptions of older adults’ sexual activity.  相似文献   
7.
Child and family practice and child protection are extraordinarily complex. They require in-depth understanding of intra- and inter-personal skills and intricate service systems, and capacity to operate in a constantly changing policy environment. One way of meeting the needs of such practitioners is facilitating their access to experts working across direct practice, management and leadership and policy-making contexts. This article discusses the rationale for collaboratively delivered post-qualifying courses for child and family practitioners, and discusses a highly successful example of such courses delivered through La Trobe University. It outlines the unique developmental process and model of delivery adopted by the consortium responsible for the postgraduate programme. It concludes with reference to early evaluative findings indicating it as a promising pedagogical model.  相似文献   
8.
Randrup  T.B.  McPherson  E.G.  Costello  L.R. 《Urban Ecosystems》2001,5(3):209-225

Literature relevant to tree root and urban infrastructure conflicts is reviewed. Although tree roots can conflict with many infrastructure elements, sidewalk and curb conflicts are the focus of this review. Construction protocols, urban soils, root growth, and causal factors (soil conditions, limited planting space, tree size, variation in root architecture, management practices, and construction materials) are discussed. Because costs related to sidewalk and curb damage are substantial, a review of research addressing repair, mitigation, prevention, and litigation costs is included. Finally, future research needs are discussed.

Potential for conflicts between trees and sidewalks/curbs is high when one or more of these factors are present: tree species that are large at maturity, fast growing trees, trees planted in restricted soil volumes, shallow top soil (hard-pan underneath top-soil), shallow foundations underneath the sidewalk (limited or no base materials), shallow irrigation, distances between the tree and sidewalk of less than 2.0–3.0 m., trees greater than 15 to 20 years old.

The results of this survey indicate that cities are spending substantial sums of money to address conflicts between street tree roots and infrastructure. It can be inferred that most of these expenditures are spent dealing with problems that already exist. However, this raises the question: How much is being spent now to ensure that conflicts are minimized in the future?

Future research should concentrate on plant factors, site design, and construction of sidewalks and curbs. Also, more knowledge is needed about interactions between root growth and management techniques, such as pruning and irrigation. Finally, there is need for studies that will assist policy-makers to efficiently allocate funds among repair, mitigation, prevention, and legal remedies.

  相似文献   
9.
Theory Trimming     
This paper attempts to show that the “Theory Trimming” technique makes little contribution to theory in sociology. A brief history of the technique is given, and several key assertions of its proponents are abstracted. These assertions are shown to be highly questionable. The general alternative to Theory Trimming is shown, and the relationship between Theory Trimming and more general orientations to research is discussed.  相似文献   
10.
This paper is a review of research in Chicago that linked analyses of vegetation structure with forest functions and values. During 1991, the regions trees removed an estimated 5575 metric tons of air pollutants, providing air cleansing worth 9.2 million. Each year they sequester an estimated 315 800 metric tons of carbon. Increasing tree cover 10% or planting about three trees per building lot saves annual heating and cooling costs by an estimated 50 to 90 per dwelling unit because of increased shade, lower summertime air temperatures, and reduced neighborhood wind speeds once the trees mature. The net present value of the services trees provide is estimated as 402 per planted tree. The present value of long-term benefits is more than twice the present value of costs.  相似文献   
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