Urban Forestry Management Research Articles

Accuracy and precision of consumer-grade GPS positioning in an urban green space environment

The use of global positioning systems (GPS) has increased in recent years, including for urban forestry management, as a result of its wide range of applications, ease of use and direct use of GPS data in geographic information systems. This study was conducted in an urban green space to assess the accuracy and precision of two consumer-grade GPS receivers with regard to ground control point (GCP) coordinates. Eleven fixed GCPs with known positions were selected and their data collected on four days (two seasons) and three different daytime periods (08:00, 11:00 and 14:00) each day. For each treatment (season and daytime) five replications were recorded. The results showed that the best mean position accuracies were provided by the Colorado receiver in leaf-off period (4–5 m), and its corresponding position accuracies for summer ranged from 9 to 12 m. The results of the Rino receiver mean position error in summer (19–36 m) and winter (10–26 m) were higher than reported in literature. Point averaging had a positive effect on accuracy in both receivers for winter. In summer, three-point averaging was more efficient than five-point averaging. During the day, the Colorado receiver had the best positional accuracy at 08:00 in winter, but in summer there was a large variation in the results. For the Rino receiver there was no general trend; however, results taken at 11:00 and 14:00 were better than those at 08:00. Regarding precision, point averaging had a positive effect on the Colorado while the Rino precision indicated the contrary. The Colorado receiver had better precision than the Rino in both seasons, and was the best in summer. The Rino receiver had better precision in summer compared to winter, and in both recievers daytime had no significant effect on precision. The measured accuracies of Colorado are acceptable for many environment and urban forestry measurement applications and satisfy mapping requirements, but the Rino receiver showed poorer results.

Is Evidence-Based Conservation Applied in Urban Forestry? A Case Study from Toronto, Canada

Evidence-based conservation seeks to incorporate sound scientific information into environmental decision making. The application of this concept in urban forest management has tremendous potential, but to date has been little applied, largely because existing scientific studies emphasize the importance of urban forests in large-scale ecological and anthropogenic processes, but in practice, scientific evidence is ostensibly incorporated into North American urban forest management only when deciding the fate of individual trees. Even under these disjunctive conditions, the degree to which evidence influences tree-level decisions remains debatable. In analyzing preliminary data from a case study from Toronto, Canada, we sought to test if and how scientific evidence factored into the decision to remove or preserve 53 trees, located in close proximity to a provincially significant area of natural and scientific interest (ANSI). We found that by far the strongest tree-level correlate of the recommendation to remove or preserve trees was whether or not an individual tree was in conflict with proposed development. In comparison, species identity, tree condition, and suitability for conservation were statistically unrelated to the final recommendation. Our findings provide the basis to expand our analysis to multiple case studies across Canada, and internationally. Furthermore, when interpreted with available research and policy, our preliminary (and future) analysis highlights clear opportunities where scientific evidence can and should be readily incorporated into urban forestry management and policy.

Water Scarcity and Urban Forests: Science and Public Policy Lessons from a Decade of Drought in Adelaide, Australia

Drawing on the experience of greater metropolitan Adelaide, South Australia, Australia, the paper points to the links and gaps between science and public policy. The paper explores urban stormwater management lessons emerging from a ten-year, prolonged dry period that impacted the integrity of urban forests in the City of Adelaide. Among the questions addressed: will stormwater remain, as its historic and institutional settings suggest, a liability or can it become an asset? Who owns stormwater resources and to whom is its management vested? The paper examines these issues with consideration to the dangers of continuing to use urban forestry management practices that are not informed by science. The study concludes that a more integrated approach to urban water management can maintain the integrity of urban forests in ways that potentially enhance social amenities and economic efficiency.

Development of a GIS Application for Urban Forestry Management Planning

Green spaces are indispensable for the urban ecosystem. Benefits coming form trees, parks, urban and peri-urban woods can be the mitigation of temperature, pollution decreasing, protection from water run-off and soil erosion, aesthetics increasing and quality of places, providing a place for recreation, education and learning. Geographic Information Systems (GIS) helps cities manage forestry projects efficiently and reduce management costs. This paper presents the development of a GIS application for urban forestry management. For developing the GIS application, Geoserver, PostGIS/PostgreSQL, OpenLayers, GDAL, PROJ.4, and Entity Framework 5.0 were used. Further ASP.NET MVC4 was used for developing the web site of the application. The GIS application that was developed is an independent window application, which run in every modern computer with no need to be connected to any other software. Such a GIS application must do, this one supports the authorities to choose appropriate measures for urban forest management, protection and utilization by connecting attribute to spatial data. Conclusively this GIS application is an appropriate tool for Municipality Administration Services in cooperation with researchers and concerned citizens, for contribution to a better management of urban forests, providing urban population with better living conditions.

Leaf Area Density as an urban forestry planning and management tool

Many of the benefits that we derive from urban forests are directly or indirectly related to the leaf area of the forest. If we are to consider these multiple benefits at the level of the forest, the use of Leaf Area Density (LAD) provides some advantages over other often used measures. Since many factors in the urban landscape can limit leaf area, Potential Leaf Area Density (PLAD) can provide a measure of the upper limit to leaf area density. Using these two measures, urban forest planners and managers can integrate many of the issues associated with broader aspects of the structure and benefits of the forest under their jurisdiction. Some planning, policy, and educational applications of LAD and PLAD are discussed. Key words: urban forestry management and planning, leaf area density

Statutory measures for the protection and enhancement of the urban forest in Guangzhou City, China

Summary Urban-forestry management in China, due to its unique political and social environment, exists in a different legislative and administrative regime. An evaluation of the current statutory and quasistatutory administrative instruments can throw light on the status and prospects of the country’s urban-forestry programme. Guangzhou City, the largest municipality in South China, with a high green cover, was chosen for a case study. The assessment includes measures with a bearing on the planning, development, management and protection of urban trees and urban landscapes, at the national, provincial and municipal levels. Four national laws accompany a plethora of administrative documents to define an overall urban-forestry framework, and to demarcate the relevant authority and responsibility at different planes of the government hierarchy. The provincial measures play a secondary role in filling some gaps in the national legislation, with the main contributions being in allocating financial responsibilities and laying down punitive and compensatory legal procedures. Operations-related measures have been developed comprehensively at the municipal level with practical guidelines for their implementation. Special issues related to weaknesses, room for improvement, and general implications for Guangzhou and other cities are discussed. The lack of clearly defined enforcement agents and generally lax enforcement have weakened the otherwise quite comprehensive legislative measures. The widespread illegal use of urban parks for commercial and other activities by government departments has undermined statutory integrity. The continued destruction of trees due largely to government projects signifies that the relevant laws are widely disregarded and ignored by civil servants. The legal vacuum of liability related to hazardous trees needs to be promptly filled. The overwhelming domination of the government with negligible participation by citizens contrasts vividly with urban forestry in other countries and deprives the programme of the necessary popular support.

Industrial-Area Street Trees in Portland, Oregon

Industrial-area trees have, with few exceptions, been neglected by the research community as well as by urban forestry management programs. A recent project in Portland, Oregon, provides both some data and a program model that easily could be replicated in other communities. An inventory of the Northwest Industrial Neighborhood Association (NINA) district identified 966 street trees and 1,140 unplanted/potential street tree sites, for a stocking level of 46%. While this figure is low relative to most other segments of the urban forest, it was received optimistically because it was higher than had been expected for an industrial area and it demonstrated a great deal of potential for expanding the urban forest through additional plantings. Diversity data indicated only 17 genera were represented, identified two genera (Acer and Prunus) that were overplanted, and provided guidance on which genera could be added to increase diversity. NINA officials have formed a partnership with other local urban forestry interests and are using the data to undertake a 10- year planting program for the district.

An Urban Forestry Strategy For Ontario

An urban forestry strategy is presented for Ontario, in response to a growing need to manage for viable and healthy urban vegetation. Urban forestry is about planning and managing existing and/or new treed vegetation of all types and associated wildlife, to establish attractive urban habitats, using systematic forestry-like approaches and environmental principles, in combination with arboricultural and modified silvicultural techniques. Urban forestry managers, having various educational backgrounds, are increasingly becoming involved in managing our urban forest, our habitat.Currently, there is no educational institution that totally prepares students for a career in urban forestry. As a result, people entering this field do so on an ad hoc basis, having various educational backgrounds, which do not cover all aspects of urban forestry management. A second problem is the limited awareness of various levels of government that systematic urban forestry management for densely populated areas is a growing need.Factors contributing to the need for urban forestry management, as well as obstacles to establishing such programs, are discussed. The urban forest, its managers, the content of programs and experience in the USA are outlined. Proposed actions include:1 development of a provincial policy, through the enlargement of the private land forestry program to initiate and support urban forestry programs;2 evaluation of the feasibility of having conservation authorities include urban forestry in their mandate;3 establishment of an umbrella-type diploma course administered by an educational institution; and4 establishment of an urban forestry chair at a university with cross appointments in forestry, planning and/or landscape architecture. Key Words : Urban forestry programs, options and alternatives for Ontario communities.

An analysis of urban tree communities using Landsat Thematic Mapper data

Highly diverse tree communities of natural and planted forests are found in distinct microhabitats in urban settings. The purpose of this paper is to examine the possibility of locating and analyzing urban tree communities at a relatively low cost, using the new satellite imagery data collected from the U.S. Landsat Thematic Mapper (TM). Mobile, Alabama, is the study area. A multichannel TM data set of the study area is analyzed using the hierarchical clustering and minimum-distance classification procedures of the Earth Resources Laboratory Applications Software. The data analysis, at one detail level chosen for this study, reveals 23 spectral classes of trees. Ground checking has verified that the 23 spectral classes include 8 distinct tree communities of remnant natural forests and 15, of cultivated residential forests. These tree communities, developed naturally or planted, vary with species composition, age, density, crown closure, and vertical structure. The detailed analysis of urban forests using TM data assists foresters and planners in the modification or maintenance of urban trees suited to local site conditions. It provides a database for achieving a balanced forest structure and composition that will promote neighborhood planning and the health, safety, and welfare of urban residents. The study has also disclosed the potential of TM data in creating or updating economic geographic information systems of tree communities in metropolitan areas to hasten urban forestry management and comparative research.

Indicators of Urban Forest Condition in New Orleans

Urban trees constitute a valuable environmental resource in many cities. Designing a tree maintenance and management strategy depends upon an understanding of the environments of urban trees and stresses on tree health and condition. Using New Orleans, Louisiana as an example, environmental indicators of tree condition are identified using data from sample inventory of trees. Tree condition is related to the types of land covers in the zone of root growth under the tree canopy, the presence of wires in the tree canopy and associated land uses. The inventory also shows that the New Orleans urban forest is a mature forest, which suggests special care is needed in order to protect and replenish the resource, this information can be used to plan urban forestry management strategies in New Orleans.

Urban forest of Dayton, Ohio: A preliminary assessment

Preliminary measurement of the characteristics of Dayton's vegetation configuration is provided in a context of the city's neighborhoods and land uses. Results show that 58% of the city's land is not covered with artificial surfaces, and that 37% (almost 2500 ha) of the non-surfaced land is covered with tree crowns. The city has nearly 2 km 2 of exposed soil. Only single and two-family residential land use has more area with tree cover than grass cover, but this land use category also has the greatest available space for increasing tree cover. Wide variations in land cover characteristics exist throughout the city and across its land uses. Results indicate a great potential for increasing tree-related benefits through broadened urban forestry management.