Optimized greenery configuration to mitigate urban heat: A decade systematic review

Urban vegetation is a nature-based solution for cooling cities. Under global warming and urban population growth, it is essential to optimize urban vegetation configuration in the urban area to bring maximum cooling benefit. This paper reviews 85 optimized urban vegetation configuration studies published from 2010 to 2020 to provide an insight into the most effective vegetation configuration for urban heat mitigation. Patterns and preferences in methods and the optimized greenery configurations are comprehensively analyzed. The results indicate that size, quantity, and layout of urban green space and the physiological characteristics and spatial arrangement of urban vegetation significantly influence their cooling effect. Additionally, two other research gaps were identified. First, more research needs to be done in southern hemisphere cities experiencing rapid urbanization and severe impacts of extreme weather. Second, a comprehensive method for quantifying interactions and cumulative effects of natural and artificial factors in the urban environment is required. Future study needs a holistic understanding of the interactive effects of vegetation spatial distribution on urban environment and climate for a more accurate analysis of optimal cooling greening layouts in large urban areas at multi-scales

Quantifying Long-Term Urban Grassland Dynamics: Biotic Homogenization and Extinction Debts

Sustainable urban nature conservation calls for a rethinking of conventional approaches. Traditionally, conservationists have not incorporated the history of the landscape in management strategies. This study shows that extant vegetation patterns are correlated to past landscapes indicating potential extinction debts. We calculated urban landscape measures for seven time periods (1938–2019) and correlated it to three vegetation sampling events (1995, 2012, 2019) using GLM models. We also tested whether urban vegetation was homogenizing. Our results indicated that urban vegetation in our study area is not currently homogenizing but that indigenous forb species richness is declining significantly. Furthermore, long-term studies are essential as the time lags identified for different vegetation sampling periods changed as well as the drivers best predicting these changes. Understanding these dynamics are critical to ensuring sustainable conservation of urban vegetation for future citizens

The ‘Urbanforest’ and ‘Green space’ Classification Model in the Spatial Arrangement of Registro-SP, Brazil

The necessity of handling green areas relating to urban settings has become one of the vital environmental challenges in view of several accumulated environmental problems in the last few decades. In United States and Canada, many investments are being made for new techniques and instruments that are needed in environmental planning involving urban forest researches both in the local and national scale. However, there are few reports on urban forest classification connecting spatial characteristics, physical structures involving pattern and process. With the objective to classify urban green areas for integrated approach, this research have focused on urban pattern for an effective understanding of urban forest concept, green areas and urban vegetation types. The urban morphology in consistency with the urban forest Focus Chat (FC) recently designed has been applied to characterize spatial categories of urban vegetation involved in the urban arrangement of Registro-SP. Method has integrated zones, patterns and processes for technical analyses to contemplate the urban dynamics, occupation and land use. Categories of urban forest and vegetation types were derived for the urban planning and system management. The resulting pattern can be technically monitored in the use of suitable GIS (Geographical Information System) software for physical and environmental records.

Volunteer urban vegetation of Racine, Wisconsin

We have only meagre knowledge of the composition and the functions performed by vegetation in Wisconsin cities. The records of the U.S. Government Land Survey conducted in the 1830s provide information on the presettlement vegetation. Likewise, the notes and letters of settlers and early residents speak of the plants they found here, or brought with them. We know less about the vegetation now growing in our cities

Climate tolerances and trait choices shape continental patterns of urban tree biodiversity

Aim: We propose and test a climate tolerance and trait choice hypothesis of urban macroecological variation in which strong filtering associated with low winter temperatures restricts urban biodiversity while weak filtering associated with warmer temperatures and irrigation allows dispersal of species from a global source pool, thereby increasing urban biodiversity. Location: Twenty cities across the USA and Canada. Methods: We examined variation in tree community taxonomic diversity, origins and production of an aesthetic ecosystem service trait in a cross-section of urban field surveys. We correlated urban tree community composition indicators with a key climate restriction, namely mean minimum winter temperature, and evaluated alternative possible drivers: precipitation, summer maximum temperature, population size and the percentage of adults with a college education. Results: Species accumulation curves differed substantially among cities, with observed richness varying from 22 to 122 species. Similarities in tree communities decreased exponentially with increases in climatic differences. Ordination of tree communities showed strong separation among cities with component axes correlated with minimum winter temperature and annual precipitation. Variation among urban tree communities in richness, origins and the provisioning of an aesthetic ecosystem service were all correlated with minimum winter temperature. Main conclusions: The urban climate tolerance and trait choice hypothesis provides a coherent mechanism to explain the large variation among urban tree communities resulting from an interacting environment, species and human decisions. Reconciling the feedbacks between human decision making and biophysical limitations provides a foundation for an urban ecological theory that can better understand and predict the dynamics of other linked biotic communities, associated ecosystem dynamics and resulting services provided to urban residents

Role of Vegetation as a Mitigating Factor in the Urban Context

It is known that the urban environment amplifies the effects of climate change, sometimes with disastrous consequences that put people at risk. These aspects can be affected by urban vegetation and planting design but, while there are thousands of papers related to the effects of climate change, a relatively limited number of them are directly aimed at investigating the role of vegetation as a mitigating factor in the urban context. This paper focuses on reviewing the research on the role of urban vegetation in alleviating the adverse conditions of the urban environment in order to provide some practical guidelines to be applied by city planners. Through an analysis of the documents found in Scopus, Web of Science, and Google Scholar using urban vegetation and climate change-related keywords we selected five major issues related to the urban environment: (1) particulate matter, (2) gaseous pollution, (3) noise pollution, (4) water runoff, (5) urban heat island effect. The analysis of existing knowledge reported here indicates that the roles of urban vegetation on the adverse effect of climate change could not be simply deemed positive or negative, because the role of urban green is also strongly linked to the structure, composition, and distribution of vegetation, as well as to the criteria used for management. Therefore, it could help to better understand the roles of urban green as a complex system and provide the foundation for future studie

Urban vegetation and the environmental health of sixteen global cities

Vegetation plays an important role in regulating the health of urban ecosystems (Sanders, 2004; Jim, 2004). Riparian zones, parks, nature reserves, and other forms of urban vegetation help minimize atmospheric and hydrologic pollution and reduce the urban heat island effect (Weng, 2003). In this study I used satellite imagery to classify and quantify vegetative cover for sixteen of the most populated cities on Earth. It was found that London England had the greatest percentage of urban vegetation with 53% while Karachi Pakistan had the least at 3.06%. The highest correlating physical variables with urban vegetation were year of origin (r² = -.602), population density (r²=.531) and latitude (r²=.215). Satellite imagery collected from NASA was analyzed to determine the percentage of vegetation cover in each of sixteen sample cities. The amount of vegetation recorded within the urban environments was dependent upon multiple variables. Climatic variables play a large role as habitat dictates vegetation cover. Physical independent variables including latitude, temperature, average annual rainfall, and elevation were tested for correlations with the dependent variable of urban vegetation. Further methods and analysis in this study include basic statistics, t-tests, and multiple step regression. Geographic Information Systems (GIS) were utilized in this thesis to objectively measure vegetative and geographic variables within major global cities. Outside of physical variables, vegetation within the urban environment is largely determined by human decisions and behavior. Public planning, non-profit organizations, and private owners may have had more influence on the percentage of vegetation within urban environments than the restrictions of climatic variables. Further, the examination of physical and sociological variables in relation to urban vegetation is included in the discussion. The purpose of this thesis is to contribute to the academic field of geography specific to vegetation and environmental services in urban environments. Results may be a reference or guide to scholars, planners, developers, and residents of urban environments

Tree collections of Auckland : biodiversity and management : a thesis presented in partial fulfilment of the requirements for the degree of Master of Applied Science in Landscape Management at Massey University, Palmerston North, New Zealand

Appendix 1: Personal Communications Contact List. Page 182 has been removed. Please consult the print copy held in the Library.Recent developments in New Zealand environmental legislation and government policies are based on an economic world-view where landscape is portrayed as a 'natural' resource. This paradigm largely ignores the human-made urban landscape where the highest proportion of population live. Our national legislation pays little attention to urban vegetation in general and exotic tree collections in particular. Research therefore has a vital role in highlighting the character and values of urban vegetation, and in analysing the current models used to manage its continued existence. This study examines the importance of charting and managing biodiversity and focuses on managed amenity and scientific tree collections in the Auckland region. This regional study seeks to characterise the biodiversity of tree collections in Auckland, and describe how landscape management can best contribute to their biological and human-use values. The literature review establishes the importance and values of trees and urban vegetation as critical to the fabric of human lifestyles and the ecology of the city. It then reviews the basis for the preservation of biodiversity in managed plant collections. Management principles and systems are reviewed along with the legislative context in Auckland. No mandate is established for exotic plant collection managment under the Resource Management Act, 1991 (RMA1991). Management of this resource is found to lack the focus and funding from which natural and rural biodiversity benefit under the RMA and other national legislation. A biodiversity survey of thirty-eight collections of trees characterises the biodiversity in the collections, and a survey of twelve tree collection managers provides data about the goals, practices and tools used in the management of those collections. Results reveal the diverse and unique flora of Auckland tree collections, and establish a baseline for comparison over time. The regional mix of native and exotic species found in Auckland collections is compared with other national plant surveys, and demonstrates differences consistent with regional climatic character and a differing research focus. The largest collection of trees and the most specialist genera collections were found at the Auckland Regional Botanic Garden, while the university of Auckland provides the most extensive range of scientific plant-collection facilities. There is evidence of sequential open space acquisition for tree collections in the Auckland region. Comparison of best management practices put forward in current literature with current practices of collection managers in Auckland reveals some significant issues. There is little evidence found to suggest strategic plant acquisition goal setting. It is also of concern that only half the collection managers used computerised plant record systems such as inventories and specialised database systems. Only one third of the managers had management plans, and therefore documented collection goals. There was no significant difference in the use of best management practices between the private and publicly owned collections. Well-managed collections are characterised by high or specialist tree species diversity, clear strategic goal setting and management planning, computerised plant record systems, adequate resources, appropriate staffing and the use of monitoring tools. Discussion of these research results leads to three recommendations. Firstly, the management of specific sites is discussed in light of a proposed model for plant collection management. Secondly, management policy for the regional urban Forest is recommended. Lastly, the finding that Auckland's exotic tree collections are a valuable resource worthy of protection, currently having little status under the law, leads to the recommendation for the empowering of a national body (central agency) with a mandate for the national coordination of botanic gardens and plant collections. This research therefore charts aspects of Auckland's urban biodiversity with reference to current legislation and management models. Its findings and recommendations are of importance to reviewers of national environmental legislation, regional policymakers and tree collection managers