scholarly journals Street Tree Density and Distribution: An International Analysis of Five Capital Cities

2020 ◽  
Vol 8 ◽  
Author(s):  
Nicholas Smart ◽  
Theodore S. Eisenman ◽  
Andrew Karvonen
Keyword(s):  
Urban Form ◽  
Tree Density ◽  
Washington Dc ◽  
Urban Greening ◽  
Street Trees ◽  
Climate Zones ◽  
Climate Zone ◽  
Capital Cities ◽  
Tree Distribution ◽  
Street Tree

Municipal leaders around the world are demonstrating significant interest in urban greening to realize a range of socioecological benefits. The urban greening toolkit often includes street trees, an essential component of urban design informed by historic legacies of both human and environmental factors. To date, there has been little comparative analysis of street tree density and distribution across international and intercontinental settings, and associated research has not been situated within the broader discussion of historical legacies. This study focuses on five capital cities (Ottawa, Stockholm, Buenos Aires, Paris, and Washington, DC) situated in two climate zones and it addresses two research questions: (1) What are the density and distribution of street trees across a given city and its street hierarchy? and (2) How do these metrics compare within and between cities by climate zone? The analysis draws upon up-to-date datasets from local authorities and includes geospatial analysis of street trees across hierarchical street classes within the central zones of each city. The results show clear differences in street tree density in cities within and between climate zones as well as differences in street tree distribution in cities within the same climate zone. Substantial differences within climate zones further suggest that cultural factors—including but not limited to urban form, aesthetic norms, and governance regimes—may play a pivotal role in the distribution and density of street trees. This illustrates the importance of place-specific cultural and environmental legacies as determinants of street tree density and distribution and supports further comparative research on the topic.

scholarly journals The Variation of Air Purification Benefit Provided by Street Tree Assemblages in Shenyang, China

2021 ◽  
Author(s):  
Jing Yao ◽  
Miao Liu ◽  
Nina Chen ◽  
Wei Chen ◽  
Xiaobo Wang ◽  
...  
Keyword(s):  
Ecosystem Services ◽  
Urban Form ◽  
Time Lag ◽  
Road Construction ◽  
Vegetation Management ◽  
Air Purification ◽  
Street Trees ◽  
Street Tree ◽  
Significant Difference ◽  
Tree Assemblages

Abstract Street tree assemblages are a widespread natural component in cities and provide a range of ecosystem services. The spatial distribution of street tree assemblages within cities, however, is not uniform. We assessed the air purification benefits provided by street trees in Shenyang, China, to examine how urban form, urban geography and drivers of vegetation management affect this ecosystem service. The i-Tree Street Model was utilized to evaluate air purification benefits provided by street trees. We analyzed the results using two indices, with values expressed in US dollars (USD, $): the per kilometer benefit (PKB) and average tree benefit (ATB). Neither index displayed a consistent trend across the human population density gradient or along the urban-suburban continuum. The district with the highest PKB and ATB is neither the oldest nor the newest one to develop, but rather the one that began to develop around 2002. We conclude that public policy is a main driver of vegetation management, especially for street trees, because street tree abundance is closely related to road construction, which, in turn, is closely tied to economic development in a region. We also discovered no significant difference in the benefit of street tree assemblages along the urban-suburban continuum. That's probably because all areas within the different beltways contain mature street trees, the time-lag effect for growth is inconsequential. We recommend that the dynamic variations of street tree assemblages over a certain time span be taken into consideration when examining the effects of urban sprawl on ecosystem services provided by street tree assemblages.

scholarly journals The Variation of Air Purification Benefit Provided by Street Tree Assemblages in Shenyang, China

2021 ◽  
Author(s):  
Jing Yao ◽  
Wei Chen ◽  
Miao Liu ◽  
Xiaobo Wang ◽  
Nina Chen ◽  
...  
Keyword(s):  
Ecosystem Services ◽  
Urban Form ◽  
Time Lag ◽  
Vegetation Management ◽  
Air Purification ◽  
Street Trees ◽  
Street Tree ◽  
Lag Effect ◽  
Wide Range ◽  
Main Driver

Abstract Background: Street trees assemblage is a widespread natural component in the cities and provides a wide range of ecosystem services to the cities. However, the distribution of street trees assemblage within a city is inequal. In this paper, we took air purification benefit provided by street trees for example to examine how urban form, urban geography and drivers of vegetation management affect the variation of ecosystem services provided by street trees in metropolitan Shenyang, Northeastern China. The i-Tree Street (2018) was utilizing to evaluate air purification benefit provided by street trees.Results: We analyze the results using 2 indices: per kilometer benefit and average tree benefit. The results showed us that (1) both indices didn’t vary along the population gradient. (2) The per kilometer benefit had a decreasing trend along the urban-suburban gradient. (3) The districts which had the highest per kilometer benefit and average tree benefit are neither the old ones nor the newest one, but the districts start to develop from around 2002 and 2003.Conclusions: We infer that the public policy is a main driver of vegetation management, especially for street trees, because street tree is closely related to road/street development which is closely related to economic development of a region. Besides, there could be a time lag effect for ecosystem services provided by trees.

scholarly journals Determinants of Electrical and Thermal Energy Consumption in Hospitals According to Climate Zones in Poland

Energies ◽  
2021 ◽  
Vol 14 (22) ◽  
pp. 7585
Author(s):  
Małgorzata Cygańska ◽  
Magdalena Kludacz-Alessandri
Keyword(s):  
Energy Consumption ◽  
Thermal Energy ◽  
Health Sector ◽  
Integrated Approach ◽  
Climatic Zone ◽  
Energy Costs ◽  
Work Intensity ◽  
Climate Zones ◽  
Climate Zone ◽  
Hospital Size

Energy use in hospitals is higher than in other public buildings, so improving energy efficiency in healthcare buildings is a significant challenge in this sector of engineering. For this, it is necessary to know the various determinants of energy consumption. Until now, the main factor affecting energy consumption in healthcare facilities studied in the literature was hospital capacity. However, the commonly used variables connected with hospital size and the number of beds do not take into account the medical activities carried out in these buildings. Assuming that energy consumption in hospitals is multiple and shaped by many factors that overlap, not only on an individual level but also on a higher scale level, this study devises a more integrated approach to its determinants. This study aims to investigate the determinants of electrical energy costs (EEC) and thermal energy costs (TEC) in Polish hospitals with regard to factors related to their size, work intensity and climate zones. The analysis was carried out using financial and resource data from all Polish hospitals for the years 2010–2019. The study used a multivariate backward stepwise regression analysis. In order to use climate as a moderating variable, a sample of Polish hospitals from 16 Polish NUTS 2 was divided into four climate zones. This article provides new empirical evidence on the determinants of electricity consumption in Polish hospitals related to their size and medical activity, taking into account climate zone as a moderating variable. The results of the analysis show that both electricity and heat consumption in hospitals are positively related to the number of doctors, beds and the number of medical operations performed. As expected, larger hospitals seem to use more energy. Moreover, there is regional heterogeneity in energy consumption in hospitals related to the climatic zone in which they operate. The conducted analysis shows that Polish hospitals located in the warmest climatic zone are characterized by higher energy consumption than hospitals in the coldest zone. It especially regards EEC in surgery hospitals. The warmer the climate zones, the higher intensity in terms of the number of surgeries, the higher EEC. In terms of nonsurgical hospitals, the influence of climate zone on EEC was not observed. Knowing the factors influencing energy consumption in hospitals can facilitate the correct adoption of an energy-saving strategy in the health sector, which is a reasonable response to climate change and supports a healthy and sustainable future.

scholarly journals The Legacy Effects of Colonial and Apartheid Imprints on Urban Greening in South Africa: Spaces, Species, and Suitability

2021 ◽  
Vol 8 ◽  
Author(s):  
Charlie M. Shackleton ◽  
N. Gwedla
Keyword(s):  
South Africa ◽  
Green Infrastructure ◽  
Tree Species ◽  
Urban Form ◽  
Green Spaces ◽  
Space Distribution ◽  
Legacy Effects ◽  
Urban Greening ◽  
Urban Nature ◽  
Urban Green

Colonialism is a significant legacy across most aspects of urban form, the nature and distribution of public green spaces, and tree species composition in many cities of the Global South. However, the legacy effects of colonialism on urban green infrastructure and the uses thereof have only recently come under scrutiny. Here we collate information from South Africa on urban greening and interpret it through a colonial and apartheid legacy lens in relation to the distribution and types of urban nature found and their resonance with contemporary needs as an African country. The analysis indicates marked inequalities in public green space distribution and quality between neighborhoods designated for different race groups during the colonial and apartheid periods, which continues to be reproduced by the post-colonial (and post-apartheid) state. Additionally, in the older, former colonial neighborhoods non-native tree species dominate in parks and streets, with most of the species having been introduced during the colonial period. Such colonial introductions have left a burdensome legacy of invasive species that costs billions of Rands annually to keep in check. Lastly, the forms of nature and activities provided in public urban green spaces remains reminiscent of the colonial norm, with little recognition of African worldviews, identity and needs. We conclude in emphasizing the necessity for urban authorities and planners to address these anachronistic legacies through adopting a more inclusive and co-design approach with respect to the extent, location and types of urban nature provided, as well as the types of cultural symbols and activities permitted and promoted.

scholarly journals Can Field Crews Telecommute? Varied Data Quality from Citizen Science Tree Inventories Conducted Using Street-Level Imagery

Forests ◽  
2019 ◽  
Vol 10 (4) ◽  
pp. 349 ◽  
Author(s):  
Adam Berland ◽  
Lara A. Roman ◽  
Jess Vogt
Keyword(s):  
Data Quality ◽  
Survey Data ◽  
Field Data ◽  
Urban Forest ◽  
Street Trees ◽  
Diameter Class ◽  
Tree Diameter ◽  
Street Level ◽  
Street Tree ◽  
High Level

Street tree inventories are a critical component of urban forest management. However, inventories conducted in the field by trained professionals are expensive and time-consuming. Inventories relying on citizen scientists or virtual surveys conducted remotely using street-level photographs may greatly reduce the costs of street tree inventories, but there are fundamental uncertainties regarding the level of data quality that can be expected from these emerging approaches to data collection. We asked 16 volunteers to inventory street trees in suburban Chicago using Google Street ViewTM imagery, and we assessed data quality by comparing their virtual survey data to field data from the same locations. We also compared virtual survey data quality according to self-rated expertise by measuring agreement within expert, intermediate, and novice analyst groups. Analyst agreement was very good for the number of trees on each street segment, and agreement was markedly lower for tree diameter class and tree identification at the genus and species levels, respectively. Interrater agreement varied by expertise, such that experts agreed with one another more often than novices for all four variables assessed. Compared to the field data, we observed substantial variability in analyst performance for diameter class estimation and tree identification, and some intermediate analysts performed as well as experts. Our findings suggest that virtual surveys may be useful for documenting the locations of street trees within a city more efficiently than field crews and with a high level of accuracy. However, tree diameter and species identification data were less reliable across all expertise groups, and especially novice analysts. Based on this analysis, virtual street tree inventories are best suited to collecting very basic information such as tree locations, or updating existing inventories to determine where trees have been planted or removed. We conclude with evidence-based recommendations for effective implementation of this type of approach.

Modelling the impact of increased street tree cover on mean radiant temperature across Vancouver’s local climate zones

2019 ◽  
Vol 39 ◽  
pp. 9-17 ◽  
Author(s):  
Mehdi Aminipouri ◽  
Anders Jensen Knudby ◽  
E. Scott Krayenhoff ◽  
Kirsten Zickfeld ◽  
Ariane Middel
Keyword(s):  
Tree Cover ◽  
Mean Radiant Temperature ◽  
Climate Zones ◽  
Local Climate ◽  
Street Tree ◽  
Local Climate Zones ◽  
Radiant Temperature ◽  
The Impact

Town socio-economic status and road width determine street tree density and diversity in Karachi, Pakistan

2020 ◽  
Vol 47 ◽  
pp. 126473
Author(s):  
Zafar Iqbal Shams ◽  
Mubah Shahid ◽  
Zara Nadeem ◽  
Shafaq Naz ◽  
Dania Raheel ◽  
...  
Keyword(s):  
Economic Status ◽  
Tree Density ◽  
Socio Economic Status ◽  
Street Tree ◽  
Road Width

scholarly journals Tropospheric NO<sub>2</sub> concentrations over West Africa are influenced by climate zone and soil moisture variability

2017 ◽  
Author(s):  
Ajoke R. Onojeghuo ◽  
Heiko Balzter ◽  
Paul S. Monks
Keyword(s):  
Soil Moisture ◽  
West Africa ◽  
Linear Regression Models ◽  
Climate Zones ◽  
Climate Zone ◽  
Annual Cycles ◽  
Causality Tests ◽  
Arid Desert ◽  
Soil Moisture Variability ◽  
Moisture Variability

Abstract. The annual cycles of soil moisture and NO2 have been analysed across the climate zones of West Africa using two satellite data sets (OMI on AURA and ASCAT on MetOp-A). Exploring the sources and sinks for NO2 it is clear that the densely populated urban cities including Lagos and Abuja had the highest mean NO2 concentrations (> 1.8 × 1015 molecules cm−2) indicative of the anthropogenic urban emissions. The data analysis shows that rising soil moisture levels may influence the sink of NO2 concentrations after the biomass burning. The results also show significant soil moisture changes in areas of high humidity especially in the east equatorial monsoon climate zone where most of the Niger delta is located (4 %/yr.). A decline in NO2 (0.9 %/yr.) was also observed in this climate zone. Beyond seasonal linear regression models, climate based Granger’s causality tests show that tropospheric NO2 concentrations from soil emissions in the arid steppe (Sahel) and arid desert climate zones of West Africa are significantly affected by soil moisture variability (F > 10, p  0.8 %/yr). The results demonstrate the critical sensitivity of the West African emissions of NO2 on soil moisture and climate zone.

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