Assessment of Above-Ground Carbon Storage by Urban Trees Using LiDAR Data: The Case of a University Campus

The biomass represented by urban trees is important for urban decision-makers, green space planners, and managers seeking to optimize urban ecosystem services. Carbon storage by urban trees is one of these services. Suitable methods for assessing carbon storage by urban trees are being explored. The latest technologies in remote sensing and data analyses can reduce data collection costs while improving accuracy. This paper introduces an assessment approach that combines ground measurements with unmanned aerial vehicle-based light detection and ranging (LiDAR) data to estimate carbon storage by urban trees. Methods underpinning the approach were tested for the case of the Vancouver campus of the University of British Columbia (UBC), Canada. The study objectives were (1) to test five automated individual tree detection (AITD) algorithms and select one on the basis of the highest segmentation accuracy, (2) to develop a model to estimate the diameter at breast height (DBH), and (3) to estimate and map carbon storage over the UBC campus using LiDAR heights, estimated DBHs, and an existing tree-level above-ground carbon estimation model. Of the segmentation algorithms tested, the Dalponte AITD had the highest F score of 0.83. Of the five CW thresholds (th) tested in the DBH estimation model, we chose one resulting in the lowest Akaike’s information criterion, the highest log-likelihood, and the lowest root-mean-squared error (19.55 cm). Above-ground carbon was estimated for each tree in the study area and subsequently summarized, resulting in an estimated 5.27 kg C·m−2 over the main campus of UBC, Vancouver. The approach could be used in other urban jurisdictions to obtain essential information on urban carbon storage in support of urban landscape governance, planning, and management.Forestry, Faculty ofNon UBCForest Resources Management, Department ofReviewedFacult

Introducing a Method for Social-ecological Assessment of Small Urban Parks

Small parks in cities are important to support overall urban biodiversity and ecological network. The aim of this paper is to introduce a method of identifying and assessing the ecological characteristics and anthropogenic factors of small urban parks. We developed a framework that combined structured observation and field measurement. The method suggests an integrative assessment that is practical and understandable to the park planners and managers to enhance small parks to support overall urban biodiversity and ecosystem services. High biodiversity can provide opportunities for humans to experience nature and wildlife in cities, thus contributing to the quality of life of urban dwellers

From borders to ecotones - Private-public co-management of urban woodland edges bordering private housing

This paper conceptualises and evaluates so-called co-management zones as an approach for user participation in urban forestry, specifically in the management of public woodland edges bordering residential areas. Co-management zones can metaphorically be viewed as ‘ecotone-like’ spaces, i.e. zones where overlapping interest – in this case residents’ and municipal authorities’ – can be used to create richness and meetings rather than boundaries. Building on the perspectives of ecotone thinking and governance arrangements, co-management zones in the Danish residential area of Sletten in Holstebro were evaluated. The presented case study combined interviews with residents and interviews with three key green space professionals who had led the planning, design, establishment and management of the woodland and the implementation of co-management. The resident participation in the co-management zone was also assessed and photo documented in a field survey, categorising individual households according to type and degree of physical signs of participation. Findings illustrate the potential of co-management zones to initiate collaboration between residents and public woodland managers in creating recreationally valuable and varied meetings between private gardens and urban woodlands. Challenges with establishing co-management zones were also highlighted, especially the need for clear guidelines and continuous communication between residents and the municipality. Perspectives and implications related to residents, managers and green space quality are discussed

Planning and design considerations for birds and butterflies diversity of small urban parks: A case of Petaling Jaya, Malaysia

While most previous research has been conducted in large urban parks, the potential of small parks as urban habitats remains largely unexplored, particularly in tropical regions. The purpose of this paper is to provide landscape architects, planners, park managers and municipalities with recommendations for planning, design and management with the aim to enhance small urban parks’ biodiversity. Physical characteristics, vegetation and human factors are the important features that were highlighted using empirical data from nine small urban parks in Petaling Jaya, Malaysia sized between 0.5-3.5 hectares. Birds and butterflies are used as ecological indicators because they are relatively easy to identify and show clear responses to environmental change. Pearson’s correlations and multiple regressions, followed by an analysis of the Akaike’s Information Criterion were conducted to study the relationships between the measured variables, and to identify which of the variables have a significant effect on bird and butterfly species richness and abundance. The results demonstrate that the percentage of canopy cover, park size and native vegetation are the best predictors of bird species richness and abundance. Meanwhile, the butterfly species richness and abundance can be best predicted by the percentage of canopy cover, shrub species and native vegetation. Based on these results and the identification of key features for bird and butterfly richness and abundance, nine recommendations are provided to improve biodiversity of small urban parks: (1) set minimum areas for a small urban park; 2) inclusion of water elements to support a wider range of species; (3) the application of internal patch-corridor-matrix features; (4) attention to the aspect of cleanliness and appearance of small parks; (5) the proportion of open and shaded areas; (6) the planting composition of trees, palms and shrubs should be designed not only with aesthetic functions, but also for biodiversity; (7) the vertical and horizontal layers of vegetation structures; (8) providing natural buffers for wildlife protection; and (9) creating unmanaged patches in sunny areas by using wildflowers