Research

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15 pages, 4547 KiB

Open AccessArticle

Approach to Urban Environmental Justice Using Exploratory Spatial Data Analysis. The Case of Valencia’s Monumental Trees

by Alfonso Gallego-Valadés, Francisco Ródenas-Rigla and Jorge Garcés-Ferrer

Sustainability 2020, 12(18), 7760; https://0-doi-org.brum.beds.ac.uk/10.3390/su12187760 - 19 Sep 2020

Cited by 2 | Viewed by 2997

Abstract

Environmental justice has been a relevant object of analysis in recent decades. The generation of patterns in the spatial distribution of urban trees has been a widely addressed issue in the literature. However, the spatial distribution of monumental trees still constitutes an unknown [...] Read more.

Environmental justice has been a relevant object of analysis in recent decades. The generation of patterns in the spatial distribution of urban trees has been a widely addressed issue in the literature. However, the spatial distribution of monumental trees still constitutes an unknown object of study. The aim of this paper was to analyse the spatial distribution of the monumental-tree heritage in the city of Valencia, using Exploratory Spatial Data Analysis (ESDA) methods, in relation to different population groups and to discuss some implications in terms of environmental justice, from the public-policy perspective. The results show that monumental trees are spatially concentrated in high-income neighbourhoods, and this fact represents an indicator of environmental inequality. This diagnosis can provide support for decision-making on this matter. Full article

(This article belongs to the Special Issue Urban Forestry and Urban Green Management: Promoting Sustainable Urban Tree Populations)

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16 pages, 9782 KiB

Open AccessArticle

Standardized Green View Index and Quantification of Different Metrics of Urban Green Vegetation

by Yusuke Kumakoshi, Sau Yee Chan, Hideki Koizumi, Xiaojiang Li and Yuji Yoshimura

Sustainability 2020, 12(18), 7434; https://0-doi-org.brum.beds.ac.uk/10.3390/su12187434 - 10 Sep 2020

Cited by 33 | Viewed by 5737

Abstract

Urban greenery is considered an important factor in sustainable development and people’s quality of life in the city. To account for urban green vegetation, Green View Index (GVI), which captures the visibility of greenery at street level, has been used. However, as GVI [...] Read more.

Urban greenery is considered an important factor in sustainable development and people’s quality of life in the city. To account for urban green vegetation, Green View Index (GVI), which captures the visibility of greenery at street level, has been used. However, as GVI is point-based estimation, when aggregated at an area-level by mean or median, it is sensitive to the location of sampled sites, overweighing the values of densely located sites. To make estimation at area-level more robust, this study aims to (1) propose an improved indicator of greenery visibility (standardized GVI; sGVI), and (2) quantify the relation between sGVI and other green metrics. Experiment on an hypothetical setting confirmed that bias from site location can be mitigated by sGVI. Furthermore, comparing sGVI and Normalized Difference Vegetation Index (NDVI) at the city block level in Yokohama city, Japan, we found that sGVI captures the presence of vegetation better in the city center, whereas NDVI is better at capturing vegetation in parks and forests, principally due to the different viewpoints (eye-level perception and top-down eyesight). These tools provide a foundation for accessing the effect of vegetation in urban landscapes in a more robust matter, enabling comparison on any arbitrary geographical scale. Full article

(This article belongs to the Special Issue Urban Forestry and Urban Green Management: Promoting Sustainable Urban Tree Populations)

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21 pages, 2080 KiB

Open AccessArticle

Household Perceptions and Practices of Recycling Tree Debris from Residential Properties

by Mikaela L. Schmitt-Harsh and Eric Wiseman

Sustainability 2020, 12(16), 6476; https://0-doi-org.brum.beds.ac.uk/10.3390/su12166476 - 11 Aug 2020

Cited by 3 | Viewed by 2673

Abstract

Thousands of trees are lost in urbanizing areas of Virginia each year to land development, storms, and pests. As a result, large amounts of tree debris, much of which could be suitable for high-value wood products, are flowing from Virginia’s urban forests annually. [...] Read more.

Thousands of trees are lost in urbanizing areas of Virginia each year to land development, storms, and pests. As a result, large amounts of tree debris, much of which could be suitable for high-value wood products, are flowing from Virginia’s urban forests annually. Finding cost-effective, sustainable strategies for recycling this debris, particularly into durable wood products that keep carbon stored, could benefit the local economy and the local environment throughout the state. To inform outreach and technical assistance efforts of multiple groups across the state, a survey study was conducted in the City of Harrisonburg to determine household perceptions and practices of tree debris recycling. A random sample of owner-occupied, single-family dwellings was contacted using a mixed-mode survey approach to determine why and how trees were removed from the properties in the past and how the debris was disposed of or recycled. Survey responses were received from 189 households, with survey responses pointing toward a strong community sentiment for trees and their care. Nearly all respondents agreed that wood from street trees, park trees, and other neighborhood trees should be recycled into products rather than disposed of in a landfill; however, the majority of households do not currently recycle woody debris from trees removed on these properties. The three most important factors that would facilitate future participation in tree recycling include timely removal of the wood, free curbside pick-up of the wood, and knowledge of who to contact to handle the wood. Overall, these results point to household interest and willingness to participate in wood recycling programs given appropriate information to guide their decisions and local services to facilitate transfer of wood to the municipality or commercial woodworkers. This suggests a need for greater availability of neighborhood or municipal wood recycling programs, ideally coupled with greater education and outreach about the economic and environmental benefits of recovering and utilizing wood from felled trees. Full article

(This article belongs to the Special Issue Urban Forestry and Urban Green Management: Promoting Sustainable Urban Tree Populations)

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13 pages, 1928 KiB

Open AccessArticle

Effective Placement Methods of Vermicompost Application in Urban Tree Species: Implications for Sustainable Urban Afforestation

by Huong Thi Thuy Dao, Jeong Min Seo, Jonathan O. Hernandez, Si Ho Han, Woo Bin Youn, Ji Young An and Byung Bae Park

Sustainability 2020, 12(14), 5822; https://0-doi-org.brum.beds.ac.uk/10.3390/su12145822 - 20 Jul 2020

Cited by 5 | Viewed by 2349

Abstract

Knowledge on growth and nutrient uptake characteristics of urban trees and effective strategies to grow trees can help accomplish the goal of urban afforestation initiatives in a sustainable way. Thus, the study investigated the effects of different vermicompost (VC) application placements on the [...] Read more.

Knowledge on growth and nutrient uptake characteristics of urban trees and effective strategies to grow trees can help accomplish the goal of urban afforestation initiatives in a sustainable way. Thus, the study investigated the effects of different vermicompost (VC) application placements on the growth and nutrient uptake of three contrasting tree species (fast-growing Betula platyphylla and Larix kaempferi and slow-growing Chamaecyparis obtusa) to provide implications for growing tree stocks for sustainable urban afforestation programs. Five placement methods were used in the greenhouse trial: no fertilization (CON), surface placement (VC_s), subsurface placement at 6-cm depth (VC_c), bottom placement (35-cm depth (VC_b)), and mixed with soil (VC_m). We measured the growth parameters such as height, root collar diameter (RCD), and biomass and analyzed foliar nutrient concentrations in response to different placement treatments of VC. Relative height growth was the highest at VC_c (132% (B. platyphylla), 114% (L. kaempferi)) and VC_s ((57%) C. obtusa). Significant improvement in aboveground and belowground biomass growth of all species at VC_s and VC_c compared to the other treatments was also observed. Generally, VC treatments significantly increased N concentration compared to CON in all species. In conclusion, fertilizing the fast- and slow-growing urban tree species using VC_s and/or VC_c is relevant to growing high quality planting stocks for sustainable urban afforestation purposes. Full article

(This article belongs to the Special Issue Urban Forestry and Urban Green Management: Promoting Sustainable Urban Tree Populations)

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24 pages, 20126 KiB

Open AccessArticle

Assessment of Outdoor Air Temperature with Different Shaded Area within an Urban University Campus in Hot-Humid Climate

by Sheikh Ahmad Zaki, Siti Wan Syahidah, Mohd Fairuz Shahidan, Mardiana Idayu Ahmad, Fitri Yakub, Mohamad Zaki Hassan and Mohd Yusof Md Daud

Sustainability 2020, 12(14), 5741; https://0-doi-org.brum.beds.ac.uk/10.3390/su12145741 - 16 Jul 2020

Cited by 9 | Viewed by 2623

Abstract

This study investigated the variation of outdoor air temperature in the shaded area covered by buildings in an urban university campus in Malaysia. In-situ field measurements were conducted to measure the distribution of outdoor air temperature at eight different locations for seven days. [...] Read more.

This study investigated the variation of outdoor air temperature in the shaded area covered by buildings in an urban university campus in Malaysia. In-situ field measurements were conducted to measure the distribution of outdoor air temperature at eight different locations for seven days. Meanwhile, the building-induced shadows were generated using the AutoCAD Revit software to investigate the air temperature change. The study used four urban morphological parameters namely building to greenery ratio, sky view factor (SVF), and height-to-street width (H/W) ratio. The relationship between building-induced shadow and outdoor air temperature (T_out) obtained from the in-situ measurement was investigated. The results showed that the building-induced shadows could lower air temperature. It can be noted that a high ratio of building to greenery resulted in a higher air temperature. In contrast, the area with a low SVF value due to the combination of prolonged shading by buildings and trees had a lower air temperature. Thus, the area with a high building ratio, low greenery ratio, higher SVF value, and low H/W ratio potentially has a higher outdoor air temperature. Conclusively, combination of building shading created by appropriate ratio of building morphology and sufficient greenery able to improve the microclimate of a campus area. Full article

(This article belongs to the Special Issue Urban Forestry and Urban Green Management: Promoting Sustainable Urban Tree Populations)

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16 pages, 916 KiB

Open AccessArticle

Communicating with the Public about Emerald Ash Borer: Militaristic and Fatalistic Framings in the News Media

by Mysha K. Clarke, Lara A. Roman and Tenley M. Conway

Sustainability 2020, 12(11), 4560; https://0-doi-org.brum.beds.ac.uk/10.3390/su12114560 - 03 Jun 2020

Cited by 10 | Viewed by 4058

Abstract

Invasive species can spread to new landscapes through various anthropogenic factors and negatively impact urban ecosystems, societies, and economies. Public awareness is considered central to mitigating the spread of invasive species. News media contributes to awareness although it is unclear what messages are [...] Read more.

Invasive species can spread to new landscapes through various anthropogenic factors and negatively impact urban ecosystems, societies, and economies. Public awareness is considered central to mitigating the spread of invasive species. News media contributes to awareness although it is unclear what messages are being communicated. We incorporated Frame Theory to investigate newspapers’ coverage of the emerald ash borer (EAB; Agrilus planipennis Fairmaire (Coleoptera: Buprestidae)), which has killed millions of ash trees in the continental United States. We conducted a content analysis of 924 news articles published between 2002 and 2017 to examine language framing (how a phenomenon like invasive species is constructed and communicated), information sources, management methods, recommended actions for the public and whether this communication changed overtime. Seventy-seven percent of articles used language evocative of distinctive risk framings, with the majority of these using negative attribute frames like invasion-militaristic and/or fatalistic language to describe EAB management. Few discussed positive impacts like galvanizing public support. Most articles used expert sources, primarily government agents. We recommend that public communications regarding invasive species be cautious about language evoking militarism and fatalism. Furthermore, invasive species communication requires a broader diversity and representation of voices because invasive species management requires community effort. Full article

(This article belongs to the Special Issue Urban Forestry and Urban Green Management: Promoting Sustainable Urban Tree Populations)

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17 pages, 13654 KiB

Open AccessArticle

Effects of Urban Morphology on Microclimate Parameters in an Urban University Campus

by Sheikh Ahmad Zaki, Nurnida Elmira Othman, Siti Wan Syahidah, Fitri Yakub, Firdaus Muhammad-Sukki, Jorge Alfredo Ardila-Rey, Mohd Fairuz Shahidan and Ahmad Shakir Mohd Saudi

Sustainability 2020, 12(7), 2962; https://0-doi-org.brum.beds.ac.uk/10.3390/su12072962 - 08 Apr 2020

Cited by 23 | Viewed by 4024

Abstract

This study investigated the effects of urban morphology on microclimate parameters in an urban university campus in Malaysia. Outdoor air temperatures (T_out) were recorded at eight different locations inside the campus for seven days. The study used three urban morphological [...] Read more.

This study investigated the effects of urban morphology on microclimate parameters in an urban university campus in Malaysia. Outdoor air temperatures (T_out) were recorded at eight different locations inside the campus for seven days. The study used three urban morphological parameters such as green cover ratio, height-to-width (H/W) ratio, and sky view factor (SVF). The relationship between urban morphological parameters and T_out obtained from in situ measurements was investigated. The results showed that, at a dense green cover ratio of 22% in a 7833 m² area where the H/W ratio was 0.2, T_out was reduced by about 1% due to a long building shadow cover (12 h) and a high range of SVF (from 0.61 to 0.68). The use of geographic information system (GIS) to generate the spatial data of Universiti Teknologi Malaysia Kuala Lumpur Campus (UTMKL), morphological features and in situ T_out distributions provided useful information of T_out variations, and proved the applicability of GIS as a useful tool in smart city urban planning. Full article

(This article belongs to the Special Issue Urban Forestry and Urban Green Management: Promoting Sustainable Urban Tree Populations)

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23 pages, 8742 KiB

Open AccessArticle

Effects of Roadside Trees and Road Orientation on Thermal Environment in a Tropical City

by Sheikh Ahmad Zaki, Hai Jian Toh, Fitri Yakub, Ahmad Shakir Mohd Saudi, Jorge Alfredo Ardila-Rey and Firdaus Muhammad-Sukki

Sustainability 2020, 12(3), 1053; https://0-doi-org.brum.beds.ac.uk/10.3390/su12031053 - 02 Feb 2020

Cited by 31 | Viewed by 5551

Abstract

Emerging tropical cities are experiencing rapid population growth and development, which can greatly affect the thermal environments. The effects of roadside trees and road orientation on the outdoor thermal environment were investigated on four different roads in Kuala Lumpur, Malaysia. Field measurements were [...] Read more.

Emerging tropical cities are experiencing rapid population growth and development, which can greatly affect the thermal environments. The effects of roadside trees and road orientation on the outdoor thermal environment were investigated on four different roads in Kuala Lumpur, Malaysia. Field measurements were conducted to assess outdoor thermal environments, where the selection of sites was based on different roadside tree morphological features and road orientations. Outdoor air temperature (T_a), relative humidity (RH), globe temperature (T_g), wind speed (WS), and wind direction (WD) were measured. Absolute humidity (AH) was estimated based on relative humidity and air temperature. Planting dense canopy trees with an average sky view factor (SVF) of 0.07 reduced the mean radiant temperature (T_mrt) by 35% and the physiological equivalent temperature (PET) by 25%. East–West (E–W) and Northwest–Southeast (NW–SE) oriented roads had high PET values of 41 °C and 43 °C, respectively. North–South (N–S) and Northeast–Southwest (NE–SW) orientated roads had lower PET values (37 °C), providing improved outdoor microclimate. Roadside trees provided greater cooling potential in E–W and NW–SE oriented roads. The findings are useful for urban road design in tropical cities in order to improve the outdoor thermal environment and pedestrian comfort. Full article

(This article belongs to the Special Issue Urban Forestry and Urban Green Management: Promoting Sustainable Urban Tree Populations)

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Review

Jump to: Research

15 pages, 789 KiB

Open AccessReview

Long-Term Validation and Governance Role in Contemporary Urban Tree Monitoring: A Review

by Blaz Klobucar, Johan Östberg, Märit Jansson and Thomas Barfoed Randrup

Sustainability 2020, 12(14), 5589; https://0-doi-org.brum.beds.ac.uk/10.3390/su12145589 - 11 Jul 2020

Cited by 14 | Viewed by 3159

Abstract

Urban trees provide important ecosystem services, across ownership and governance structures, and tree inventories are an important tool enabling urban foresters and green space managers to monitor and perform the sustainable management of urban trees. For optimal management of urban trees, a better [...] Read more.

Urban trees provide important ecosystem services, across ownership and governance structures, and tree inventories are an important tool enabling urban foresters and green space managers to monitor and perform the sustainable management of urban trees. For optimal management of urban trees, a better understanding is needed concerning how urban tree inventories can provide long-term monitoring overviews across administrative borders, and how inventory protocols should be adapted to address specific practitioner issues. In this review, 98 articles on urban tree inventories were examined, the primary focus being sampling design. A governance arrangement approach was applied to identify the policy-making arrangements behind the inventories. Stratification is commonly used in the sampling design, despite being problematic for long-term representativeness. Only 10% of the stratification sampling designs identified were considered as having long-term validity. The studies frequently relied on an individual sampling design aimed at a particular issue, as opposed to using an existing longitudinal sampling network. Although private trees can constitute over 50% of the urban tree population, 41% of the studies reviewed did not include private trees at all. Urban tree inventories focused primarily on tree data on a local scale. Users or private tree owners are commonly not included in these studies, and limited attention is paid to economic, cultural or social factors. A long-term validation of sampling methods in urban areas, and a multi-lateral approach to tree inventories, are needed to maintain long-term operational value for local managers in securing ecosystem service provisions for entire urban forests. Full article

(This article belongs to the Special Issue Urban Forestry and Urban Green Management: Promoting Sustainable Urban Tree Populations)

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