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Pattnaik N, Honold M, Franceschi E, Moser-Reischl A, Rötzer T, Pretzsch H, Pauleit S, Rahman MA. Growth and cooling potential of urban trees across different levels of imperviousness. JOURNAL OF ENVIRONMENTAL MANAGEMENT 2024; 361:121242. [PMID: 38810461 DOI: 10.1016/j.jenvman.2024.121242] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/23/2024] [Revised: 05/10/2024] [Accepted: 05/24/2024] [Indexed: 05/31/2024]
Affiliation(s)
- Nayanesh Pattnaik
- Strategic Landscape Planning and Management, School of Life Sciences, Technical University of Munich, Emil-Ramann-Str. 6, 85354, Freising, Germany.
| | - Martin Honold
- Forest Growth and Yield Science, School of Life Sciences, Technical University of Munich, Hans-Carl-von-Carlowitz-Platz 2, 85354, Freising, Germany
| | - Eleonora Franceschi
- Forest Growth and Yield Science, School of Life Sciences, Technical University of Munich, Hans-Carl-von-Carlowitz-Platz 2, 85354, Freising, Germany
| | - Astrid Moser-Reischl
- Strategic Landscape Planning and Management, School of Life Sciences, Technical University of Munich, Emil-Ramann-Str. 6, 85354, Freising, Germany; Forest Growth and Yield Science, School of Life Sciences, Technical University of Munich, Hans-Carl-von-Carlowitz-Platz 2, 85354, Freising, Germany
| | - Thomas Rötzer
- Forest Growth and Yield Science, School of Life Sciences, Technical University of Munich, Hans-Carl-von-Carlowitz-Platz 2, 85354, Freising, Germany
| | - Hans Pretzsch
- Forest Growth and Yield Science, School of Life Sciences, Technical University of Munich, Hans-Carl-von-Carlowitz-Platz 2, 85354, Freising, Germany; Sustainable Forest Management Research Institute IuFOR, University Valladolid, Spain
| | - Stephan Pauleit
- Strategic Landscape Planning and Management, School of Life Sciences, Technical University of Munich, Emil-Ramann-Str. 6, 85354, Freising, Germany
| | - Mohammad A Rahman
- Strategic Landscape Planning and Management, School of Life Sciences, Technical University of Munich, Emil-Ramann-Str. 6, 85354, Freising, Germany; The University of Melbourne, Burnley, Victoria, Australia
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2
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Xu C, Huang Q, Haase D, Dong Q, Teng Y, Su M, Yang Z. Cooling Effect of Green Spaces on Urban Heat Island in a Chinese Megacity: Increasing Coverage versus Optimizing Spatial Distribution. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2024; 58:5811-5820. [PMID: 38502088 DOI: 10.1021/acs.est.3c11048] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 03/20/2024]
Abstract
Enhancing the cooling effectiveness of green spaces (GSs) is crucial for improving urban thermal environments in the context of global warming. Increasing GS coverage and optimizing its spatial distribution individually proved to be effective urban cooling measures. However, their comparative cooling effectiveness and potential interaction remain unclear. Here, using the moving window approach and random forest algorithm, we established a robust model (R2 = 0.89 ± 0.01) to explore the relationship between GS and land surface temperature (LST) in the Chinese megacity of Guangzhou. Subsequently, the response of LST to varying GS coverage and its spatial distribution was simulated, both individually and in combination. The results indicate that GS with higher coverage and more equitable spatial distribution is conducive to urban heat mitigation. Increasing GS coverage was found to lower the city's average LST by up to 4.73 °C, while optimizing GS spatial distribution led to a decrease of 1.06 °C. Meanwhile, a synergistic cooling effect was observed when combining both measures, resulting in additional cooling benefits (0.034-0.341 °C). These findings provide valuable insights into the cooling potential of GS and crucial guidance for urban green planning aimed at heat mitigation in cities.
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Affiliation(s)
- Chao Xu
- Institute of Geography, Humboldt University of Berlin, Berlin 12489, Germany
| | - Qianyuan Huang
- State Key Joint Laboratory of Environment Simulation and Pollution Control, School of Environment, Beijing Normal University, Beijing 100875, China
| | - Dagmar Haase
- Institute of Geography, Humboldt University of Berlin, Berlin 12489, Germany
- Department of Computational Landscape Ecology, Helmholtz Centre for Environmental Research - UFZ, Leipzig 04318, Germany
| | - Qi Dong
- Faculty of Geo-information Science and Earth Observation (ITC), University of Twente, Enschede 7522 NB, Netherlands
| | - Yanmin Teng
- Research Center for Eco-Environmental Engineering, Dongguan University of Technology, Dongguan 523808, China
| | - Meirong Su
- Key Laboratory for City Cluster Environmental Safety and Green Development of the Ministry of Education, School of Ecology, Environment and Resources, Guangdong University of Technology, Guangzhou 510006, China
| | - Zhifeng Yang
- Key Laboratory for City Cluster Environmental Safety and Green Development of the Ministry of Education, School of Ecology, Environment and Resources, Guangdong University of Technology, Guangzhou 510006, China
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Kumar P, Debele SE, Khalili S, Halios CH, Sahani J, Aghamohammadi N, Andrade MDF, Athanassiadou M, Bhui K, Calvillo N, Cao SJ, Coulon F, Edmondson JL, Fletcher D, Dias de Freitas E, Guo H, Hort MC, Katti M, Kjeldsen TR, Lehmann S, Locosselli GM, Malham SK, Morawska L, Parajuli R, Rogers CD, Yao R, Wang F, Wenk J, Jones L. Urban heat mitigation by green and blue infrastructure: Drivers, effectiveness, and future needs. Innovation (N Y) 2024; 5:100588. [PMID: 38440259 PMCID: PMC10909648 DOI: 10.1016/j.xinn.2024.100588] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2023] [Accepted: 02/05/2024] [Indexed: 03/06/2024] Open
Abstract
The combination of urbanization and global warming leads to urban overheating and compounds the frequency and intensity of extreme heat events due to climate change. Yet, the risk of urban overheating can be mitigated by urban green-blue-grey infrastructure (GBGI), such as parks, wetlands, and engineered greening, which have the potential to effectively reduce summer air temperatures. Despite many reviews, the evidence bases on quantified GBGI cooling benefits remains partial and the practical recommendations for implementation are unclear. This systematic literature review synthesizes the evidence base for heat mitigation and related co-benefits, identifies knowledge gaps, and proposes recommendations for their implementation to maximize their benefits. After screening 27,486 papers, 202 were reviewed, based on 51 GBGI types categorized under 10 main divisions. Certain GBGI (green walls, parks, street trees) have been well researched for their urban cooling capabilities. However, several other GBGI have received negligible (zoological garden, golf course, estuary) or minimal (private garden, allotment) attention. The most efficient air cooling was observed in botanical gardens (5.0 ± 3.5°C), wetlands (4.9 ± 3.2°C), green walls (4.1 ± 4.2°C), street trees (3.8 ± 3.1°C), and vegetated balconies (3.8 ± 2.7°C). Under changing climate conditions (2070-2100) with consideration of RCP8.5, there is a shift in climate subtypes, either within the same climate zone (e.g., Dfa to Dfb and Cfb to Cfa) or across other climate zones (e.g., Dfb [continental warm-summer humid] to BSk [dry, cold semi-arid] and Cwa [temperate] to Am [tropical]). These shifts may result in lower efficiency for the current GBGI in the future. Given the importance of multiple services, it is crucial to balance their functionality, cooling performance, and other related co-benefits when planning for the future GBGI. This global GBGI heat mitigation inventory can assist policymakers and urban planners in prioritizing effective interventions to reduce the risk of urban overheating, filling research gaps, and promoting community resilience.
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Affiliation(s)
- Prashant Kumar
- Global Centre for Clean Air Research (GCARE), School of Sustainability, Civil and Environmental Engineering, Faculty of Engineering and Physical Sciences, University of Surrey, Guildford GU2 7XH, UK
- Institute for Sustainability, University of Surrey, Guildford GU2 7XH, Surrey, UK
- School of Architecture, Southeast University, 2 Sipailou, Nanjing 210096, China
| | - Sisay E. Debele
- Global Centre for Clean Air Research (GCARE), School of Sustainability, Civil and Environmental Engineering, Faculty of Engineering and Physical Sciences, University of Surrey, Guildford GU2 7XH, UK
| | - Soheila Khalili
- Global Centre for Clean Air Research (GCARE), School of Sustainability, Civil and Environmental Engineering, Faculty of Engineering and Physical Sciences, University of Surrey, Guildford GU2 7XH, UK
| | - Christos H. Halios
- School of Built Environment, University of Reading, Whiteknights, Reading RG6 6BU, UK
| | - Jeetendra Sahani
- Global Centre for Clean Air Research (GCARE), School of Sustainability, Civil and Environmental Engineering, Faculty of Engineering and Physical Sciences, University of Surrey, Guildford GU2 7XH, UK
| | - Nasrin Aghamohammadi
- School Design and the Built Environment, Curtin University Sustainability Policy Institute, Kent St, Bentley 6102, Western Australia
- Harry Butler Institute, Murdoch University, Murdoch 6150, Western Australia
| | - Maria de Fatima Andrade
- Atmospheric Sciences Department, Institute of Astronomy, Geophysics and Atmospheric Sciences, University of Sao Paulo, Sao Paulo 05508-090, Brazil
| | | | - Kamaldeep Bhui
- Department of Psychiatry and Nuffield Department of Primary Care Health Sciences, Wadham College, University of Oxford, Oxford, UK
| | - Nerea Calvillo
- Centre for Interdisciplinary Methodologies, University of Warwick, Warwick, UK
| | - Shi-Jie Cao
- Global Centre for Clean Air Research (GCARE), School of Sustainability, Civil and Environmental Engineering, Faculty of Engineering and Physical Sciences, University of Surrey, Guildford GU2 7XH, UK
- School of Architecture, Southeast University, 2 Sipailou, Nanjing 210096, China
| | - Frederic Coulon
- Cranfield University, School of Water, Environment and Energy, Cranfield MK43 0AL, UK
| | - Jill L. Edmondson
- Plants, Photosynthesis, Soil Cluster, School of Biosciences, University of Sheffield, Sheffield S10 2TN, UK
| | - David Fletcher
- UK Centre for Ecology & Hydrology, Environment Centre Wales, Deiniol Road, Bangor LL57 2UW, UK
| | - Edmilson Dias de Freitas
- Atmospheric Sciences Department, Institute of Astronomy, Geophysics and Atmospheric Sciences, University of Sao Paulo, Sao Paulo 05508-090, Brazil
| | - Hai Guo
- Air Quality Studies, Department of Civil and Environmental Engineering, The Hong Kong Polytechnic University, Hong Kong, China
| | | | - Madhusudan Katti
- Department of Forestry and Environmental Resources, Faculty Excellence Program for Leadership in Public Science, North Carolina State University, Chancellor, Raleigh, NC 27695, USA
| | - Thomas Rodding Kjeldsen
- Departments of Architecture & Civil Engineering, and Chemical Engineering, University of Bath, Bath BA2 7AY, UK
| | - Steffen Lehmann
- School of Architecture, University of Nevada, Las Vegas, NV 89154, USA
| | - Giuliano Maselli Locosselli
- Department of Tropical Ecosystems Functioning, Center of Nuclear Energy in Agriculture, University of São Paulo, Piracicaba 13416-000, Sao Paulo, Brazil
| | - Shelagh K. Malham
- School of Ocean Sciences, Bangor University, Menai Bridge, Anglesey LL59 5 AB, UK
| | - Lidia Morawska
- Global Centre for Clean Air Research (GCARE), School of Sustainability, Civil and Environmental Engineering, Faculty of Engineering and Physical Sciences, University of Surrey, Guildford GU2 7XH, UK
- International Laboratory for Air Quality and Health, Science and Engineering Faculty, Queensland University of Science and Technology, QLD, Australia
| | - Rajan Parajuli
- Department of Forestry and Environmental Resources, North Carolina State University, Raleigh, NC 27695, USA
| | - Christopher D.F. Rogers
- Department of Civil Engineering, School of Engineering, University of Birmingham, Edgbaston, Birmingham B15 2TT, UK
| | - Runming Yao
- School of Built Environment, University of Reading, Whiteknights, Reading RG6 6BU, UK
- Joint International Research Laboratory of Green Buildings and Built Environments, Ministry of Education, School of the Civil Engineering, Chongqing University, Chongqing, China
| | - Fang Wang
- State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Science, Chinese Academy of Sciences, Nanjing 210008, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Jannis Wenk
- Departments of Architecture & Civil Engineering, and Chemical Engineering, University of Bath, Bath BA2 7AY, UK
| | - Laurence Jones
- UK Centre for Ecology & Hydrology, Environment Centre Wales, Deiniol Road, Bangor LL57 2UW, UK
- Liverpool Hope University, Department of Geography and Environmental Science, Hope Park, Liverpool L16 9JD, UK
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4
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Kim J, Khouakhi A, Corstanje R, Johnston ASA. Greater local cooling effects of trees across globally distributed urban green spaces. THE SCIENCE OF THE TOTAL ENVIRONMENT 2024; 911:168494. [PMID: 37979859 DOI: 10.1016/j.scitotenv.2023.168494] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/19/2023] [Revised: 10/18/2023] [Accepted: 11/09/2023] [Indexed: 11/20/2023]
Abstract
Urban green spaces (UGS) are an effective mitigation strategy for urban heat islands (UHIs) through their evapotranspiration and shading effects. Yet, the extent to which local UGS cooling effects vary across different background climates, plant characteristics and urban settings across global cities is not well understood. This study analysed 265 local air temperature (TA) measurements from 58 published studies across globally distributed sites to infer the potential influence of background climate, plant and urban variables among different UGS types (trees, grass, green roofs and walls). We show that trees were more effective at reducing local TA, with reductions 2-3 times greater than grass and green roofs and walls. We use a hierarchical linear mixed effects model to reveal that background climate (mean annual temperature) and plant characteristics (specific leaf area vegetation index) had the greatest influence on cooling effects across UGS types, while urban characteristics did not significantly influence the cooling effects of UGS. Notably, trees dominated the overall local cooling effects across global cities, indicating that greater tree growth in mild climates with lower mean annual temperatures has the greatest mitigation potential against UHIs. Our findings provide insights for urban heat mitigation using UGS interventions, particularly trees across cities worldwide with diverse climatic and environmental conditions and highlight the essential role of trees in creating healthy urban living environments for citizens under extreme weather conditions.
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Affiliation(s)
- Jiyoung Kim
- Cranfield Environment Centre, School of Water, Energy and Environment, Cranfield University, Cranfield, Bedfordshire MK43 0AL, UK.
| | - Abdou Khouakhi
- Cranfield Environment Centre, School of Water, Energy and Environment, Cranfield University, Cranfield, Bedfordshire MK43 0AL, UK
| | - Ronald Corstanje
- Cranfield Environment Centre, School of Water, Energy and Environment, Cranfield University, Cranfield, Bedfordshire MK43 0AL, UK
| | - Alice S A Johnston
- Cranfield Environment Centre, School of Water, Energy and Environment, Cranfield University, Cranfield, Bedfordshire MK43 0AL, UK
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5
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Huang Q, Xu C, Haase D, Teng Y, Su M, Yang Z. Heterogeneous effects of the availability and spatial configuration of urban green spaces on their cooling effects in China. ENVIRONMENT INTERNATIONAL 2024; 183:108385. [PMID: 38109832 DOI: 10.1016/j.envint.2023.108385] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/12/2023] [Revised: 11/15/2023] [Accepted: 12/11/2023] [Indexed: 12/20/2023]
Abstract
The impacts of the availability and spatial configuration of urban green spaces (UGS) on their cooling effects can vary with background climate conditions. However, large-scale studies that assess the potential heterogeneous relationships of UGS availability and spatial configuration with urban thermal environment are still lacking. In this study, we investigated the impacts of UGS availability and spatial configuration on urban land surface temperature (LST) taking 306 cities in China as a case study covering a multi-biome-scale. We first calculated the availability of surrounding UGS for urban built-up pixels in each city using a distance-weighted approach, and its spatial configuration was quantified through the Gini coefficient. Then, we employed various regression models to explore how the impacts of UGS availability and the Gini coefficient on LST varies across different LST quantiles and between day- and nighttime. The results revealed that UGS availability was negatively associated with both daytime and nighttime LST, while the Gini coefficient showed a positive impact solely on daytime LST, indicating that an adequate and equally distributed UGS contributes to lower environmental temperatures during the daytime. Furthermore, the impact of UGS availability on LST decreased during both day- and nighttime with increased background LST quantiles. Whereas the impact of the Gini coefficient increased only with daytime LST quantile levels, with its effect remaining almost insignificant during the night. Our findings provide new insights into the impacts of UGS on urban thermal environment, offering significant implications for urban green infrastructure planning aiming at lowering the urban heat island.
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Affiliation(s)
- Qianyuan Huang
- School of Environment, Beijing Normal University, Beijing 100875, China
| | - Chao Xu
- Institute of Geography, Humboldt University of Berlin, Berlin 12489, Germany.
| | - Dagmar Haase
- Institute of Geography, Humboldt University of Berlin, Berlin 12489, Germany; Department of Computational Landscape Ecology, Helmholtz Centre for Environmental Research - UFZ, Leipzig 04318, Germany
| | - Yanmin Teng
- Research Center for Eco-environmental Engineering, Dongguan University of Technology, Dongguan 523808, China
| | - Meirong Su
- Key Laboratory for City Cluster Environmental Safety and Green Development of the Ministry of Education, School of Ecology, Environment and Resources, Guangdong University of Technology, Guangzhou 510006, China.
| | - Zhifeng Yang
- Key Laboratory for City Cluster Environmental Safety and Green Development of the Ministry of Education, School of Ecology, Environment and Resources, Guangdong University of Technology, Guangzhou 510006, China
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6
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Smith IA, Fabian MP, Hutyra LR. Urban green space and albedo impacts on surface temperature across seven United States cities. THE SCIENCE OF THE TOTAL ENVIRONMENT 2023; 857:159663. [PMID: 36302415 DOI: 10.1016/j.scitotenv.2022.159663] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/15/2022] [Revised: 10/19/2022] [Accepted: 10/19/2022] [Indexed: 06/16/2023]
Abstract
Extreme heat represents a growing threat to public health, especially across the densely populated, developed landscape of cities. Climate adaptation strategies that aim to manage urban microclimates through purposeful design can reduce the heat exposure of urban populations, however, it is unclear how the temperature impacts of urban green space and albedo vary across cities and background climate. This study quantifies the sensitivity of surface temperature to landcover characteristics tied to two widely used climate adaptation strategies, urban greening and albedo manipulation (e.g. white roofs), by combining long-term remote sensing observations of land surface temperature, albedo, and moisture with high-resolution landcover datasets in a spatial regression analysis at the census block scale across seven United States cities. We find tree cover to have an average cooling impact of -0.089 K per % cover, which is approximately four times stronger than the average grass cover cooling impact of -0.021 K per % cover. Variability in the magnitude of grass cover cooling impacts was primarily a function of vegetation moisture content, with the Land Surface Water Index (LSWI) explaining 89 % of the variability in grass cover cooling impacts across cities. Variability in tree cover cooling impacts was primarily a function of sunlight and vegetation moisture content, with solar irradiance and LSWI explaining 97 % of the cooling variability across cities. Albedo cooling impacts were consistent across cities with an average cooling impact of -0.187 K per increase of 0.01. While these interventions are broadly effective across cities, there are critical regional trade-offs between vegetation cooling efficiency, irrigation requirements, and the temporal duration and evolution of the cooling benefits. In warm, arid cities, high albedo surfaces offer multifaceted benefits such as cooling and water conservation, whereas temperate, mesic cities likely benefit from a combination of strategies, with greening efforts targeting highly paved neighborhoods.
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Affiliation(s)
- Ian A Smith
- Boston University, Department of Earth & Environment, 685 Commonwealth Ave., Boston, MA 02215, USA.
| | - M Patricia Fabian
- Boston University, Department of Environmental Health, 715 Albany St., Boston, MA 02118, USA
| | - Lucy R Hutyra
- Boston University, Department of Earth & Environment, 685 Commonwealth Ave., Boston, MA 02215, USA
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7
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Ibsen PC, Santiago LS, Shiflett SA, Chandler M, Jenerette GD. Irrigated urban trees exhibit greater functional trait plasticity compared to natural stands. Biol Lett 2023; 19:20220448. [PMID: 36596464 PMCID: PMC9810417 DOI: 10.1098/rsbl.2022.0448] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023] Open
Abstract
Urbanization creates novel ecosystems comprised of species assemblages and environments with no natural analogue. Moreover, irrigation can alter plant function compared to non-irrigated systems. However, the capacity of irrigation to alter functional trait patterns across multiple species is unknown but may be important for the dynamics of urban ecosystems. We evaluated the hypothesis that urban irrigation influences plasticity in functional traits by measuring carbon-gain and water-use traits of 30 tree species planted in Southern California, USA spanning a coastal-to-desert gradient. Tree species respond to irrigation through increasing the carbon-gain trait relationship of leaf nitrogen per specific leaf area compared to their native habitat. Moreover, most species shift to a water-use strategy of greater water loss through stomata when planted in irrigated desert-like environments compared to coastal environments, implying that irrigated species capitalize on increased water availability to cool their leaves in extreme heat and high evaporative demand conditions. Therefore, irrigated urban environments increase the plasticity of trait responses compared to native ecosystems, allowing for novel response to climatic variation. Our results indicate that trees grown in water-resource-rich urban ecosystems can alter their functional traits plasticity beyond those measured in native ecosystems, which can lead to plant trait dynamics with no natural analogue.
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Affiliation(s)
- Peter C. Ibsen
- Department of Botany and Plant Sciences, University of California Riverside, Riverside, CA 92521, USA,Geosciences and Environmental Change Science Center, United States Geological Survey, Denver, CO 80225, USA
| | - Louis S. Santiago
- Department of Botany and Plant Sciences, University of California Riverside, Riverside, CA 92521, USA
| | - Sheri A. Shiflett
- Department of Environmental Sciences, University of North Carolina Wilmington, Wilmington, NC 28403, USA
| | | | - G. Darrel Jenerette
- Department of Botany and Plant Sciences, University of California Riverside, Riverside, CA 92521, USA
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8
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Marchin RM, Esperon-Rodriguez M, Tjoelker MG, Ellsworth DS. Crown dieback and mortality of urban trees linked to heatwaves during extreme drought. THE SCIENCE OF THE TOTAL ENVIRONMENT 2022; 850:157915. [PMID: 35944640 DOI: 10.1016/j.scitotenv.2022.157915] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/23/2022] [Revised: 08/02/2022] [Accepted: 08/04/2022] [Indexed: 06/15/2023]
Abstract
Cities have been described as 'heat islands' and 'dry islands' due to hotter, drier air in urban areas, relative to the surrounding landscape. As climate change intensifies, the health of urban trees will be increasingly impacted. Here, we posed the question: Is it possible to predict urban tree species mortality using (1) species climate envelopes and (2) plant functional traits? To answer these, we tracked patterns of crown dieback and recovery for 23 common urban tree and shrub species in Sydney, Australia during the record-breaking austral 2019-2020 summer. We identified 10 heat-tolerant species including five native and five exotic species, which represent climate-resilient options for urban plantings that are likely to continue to thrive for decades. Thirteen species were considered vulnerable to adverse conditions due to their mortality, poor health leading to tree removal, and/or extensive crown dieback. Crown dieback increased with increasing precipitation of the driest month of species climate of origin, suggesting that species from dry climates may be better suited for urban forests in future climates. We effectively grouped species according to their drought strategy (i.e., tolerance versus avoidance) using a simple trait-based framework that was directly linked with species mortality. The seven most climate-vulnerable species used a drought-avoidance strategy, having low wood density and high turgor loss points along with large, thin leaves with low heat tolerance. Overall, plant functional traits were better than species climate envelopes at explaining crown dieback. Recovery after stress required two mild, wet years for most species, resulting in prolonged loss of cooling benefits as well as economic losses due to replacement of dead/damaged trees. Hotter, longer, and more frequent heatwaves will require selection of more climate-resilient species in urban forests, and our results suggest that future research should focus on plant thermal traits to improve prediction models and species selection.
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Affiliation(s)
- Renée M Marchin
- Hawkesbury Institute for the Environment, Western Sydney University, Penrith, NSW 2751, Australia.
| | - Manuel Esperon-Rodriguez
- Hawkesbury Institute for the Environment, Western Sydney University, Penrith, NSW 2751, Australia
| | - Mark G Tjoelker
- Hawkesbury Institute for the Environment, Western Sydney University, Penrith, NSW 2751, Australia
| | - David S Ellsworth
- Hawkesbury Institute for the Environment, Western Sydney University, Penrith, NSW 2751, Australia
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9
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Tieskens KF, Smith IA, Jimenez RB, Hutyra LR, Fabian MP. Mapping the gaps between cooling benefits of urban greenspace and population heat vulnerability. THE SCIENCE OF THE TOTAL ENVIRONMENT 2022; 845:157283. [PMID: 35820520 DOI: 10.1016/j.scitotenv.2022.157283] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/14/2022] [Revised: 06/17/2022] [Accepted: 07/06/2022] [Indexed: 06/15/2023]
Abstract
We provide a novel method to assess the heat mitigation impacts of greenspace though studying the mechanisms of ecosystems responsible for benefits and connecting them to heat exposure metrics. We demonstrate how the ecosystem services framework can be integrated into current practices of environmental health research using supply/demand state-of-the-art methods of ecological modeling of urban greenspace. We compared the supply of cooling ecosystem services in Boston measured through an indicator of high resolution evapotranspiration modeling, with the demand for benefits from cooling measured as a heat exposure risk score based on exposure, hazard and population characteristics. The resulting evapotranspiration indicator follows a pattern similar to conventional greenspace indicators based on vegetation abundance, except in warmer areas such as those with higher levels of impervious surface. We identified demand-supply mismatch areas across the city of Boston, some coinciding with affordable housing complexes and long term care facilities. This novel ES-framework provides cross-disciplinary methods to prioritize urban areas where greenspace interventions can have the most impact based on heat-related demand.
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Affiliation(s)
- Koen F Tieskens
- Department of Environmental Health, Boston University School of Public Health, Boston, MA 02118, USA.
| | - Ian A Smith
- Department of Earth and Environment, Boston University, Boston, MA 02215, USA
| | - Raquel B Jimenez
- Department of Environmental Health, Boston University School of Public Health, Boston, MA 02118, USA
| | - Lucy R Hutyra
- Department of Earth and Environment, Boston University, Boston, MA 02215, USA
| | - M Patricia Fabian
- Department of Environmental Health, Boston University School of Public Health, Boston, MA 02118, USA
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10
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Ibsen PC, Jenerette GD, Dell T, Bagstad KJ, Diffendorfer JE. Urban landcover differentially drives day and nighttime air temperature across a semi-arid city. THE SCIENCE OF THE TOTAL ENVIRONMENT 2022; 829:154589. [PMID: 35306078 DOI: 10.1016/j.scitotenv.2022.154589] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/29/2021] [Revised: 03/11/2022] [Accepted: 03/11/2022] [Indexed: 06/14/2023]
Abstract
Semi-arid urban environments are undergoing an increase in both average air temperatures and in the frequency and intensity of extreme heat events. Within cities, different composition and densities of urban landcovers (ULC) influence local air temperatures, either mitigating or increasing heat. Currently, understanding how combinations of ULC influence air temperature at the block to neighborhood scale is necessary for heat mitigation plans, and yet limited due to the complexities integrating high-resolution ULC with spatial and temporally high-resolution microclimate data. We quantify how ULC influences air temperature at 60 m resolution for day and nighttime climate normals and extreme heat conditions by integrating microclimate sensor data sensor and high-resolution (1 m2) ULC for Denver, Colorado's urban core. We derive ULC drivers of air temperature using a structural equation model, then use a random forest algorithm to predict air temperatures for 30-year climate normals and an extreme heat condition. We find that, in conjunction with other ULC, urban tree canopy reduces daytime air temperatures (-0.026 °C per % cover), and the combination of impervious surfaces and buildings increases daytime air temperature (0.021 °C per % cover). Compared to daytime hours, nighttime irrigated turf temperature cooling effects are increased from being non-significant to -0.022 °C per % cover, while tree canopy effects are reduced from -0.026 °C during the day to -0.016 °C at night. Overall, ULC drives ~17% and 25% of local air temperature during the day and night, respectively. ULC influence on daytime air temperatures is altered in extreme heat events, both depending on the ULC type and time of day. Our findings inform urban planners seeking to identify potential hot and cool spots within a semi-arid city and mitigate high urban air temperatures through using ULC within larger urban climate mitigation strategies.
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Affiliation(s)
- Peter C Ibsen
- U.S. Geological Survey, Geosciences & Environmental Change Science Center, Denver, CO 80225, United States.
| | - G Darrel Jenerette
- Department of Botany and Plant Sciences, University of California Riverside, Riverside, CA 92507, United States
| | - Tyler Dell
- Civil and Environmental Engineering, Colorado State University, Fort Collins, CO 80523, United States
| | - Kenneth J Bagstad
- U.S. Geological Survey, Geosciences & Environmental Change Science Center, Denver, CO 80225, United States
| | - Jay E Diffendorfer
- U.S. Geological Survey, Geosciences & Environmental Change Science Center, Denver, CO 80225, United States
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11
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A Review on Evapotranspiration Estimation in Agricultural Water Management: Past, Present, and Future. HYDROLOGY 2022. [DOI: 10.3390/hydrology9070123] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Abstract
Evapotranspiration (ET) is a major component of the water cycle and agricultural water balance. Estimation of water consumption over agricultural areas is important for agricultural water resources planning, management, and regulation. It leads to the establishment of a sustainable water balance, mitigates the impacts of water scarcity, as well as prevents the overusing and wasting of precious water resources. As evapotranspiration is a major consumptive use of irrigation water and rainwater on agricultural lands, improvements of water use efficiency and sustainable water management in agriculture must be based on the accurate estimation of ET. Applications of precision and digital agricultural technologies, the integration of advanced techniques including remote sensing and satellite technology, and usage of machine learning algorithms will be an advantage to enhance the accuracy of the ET estimation in agricultural water management. This paper reviews and summarizes the technical development of the available methodologies and explores the advanced techniques in the estimation of ET in agricultural water management and highlights the potential improvements to enhance the accuracy of the ET estimation to achieve precise agricultural water management.
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12
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Urban Sensory Gardens with Aromatic Herbs in the Light of Climate Change: Therapeutic Potential and Memory-Dependent Smell Impact on Human Wellbeing. LAND 2022. [DOI: 10.3390/land11050760] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
The aim of this study was to analyze urban sensory gardens containing aromatic herbs in terms of the plants used in them. The analysis considered the impact of climate change, particularly of higher temperatures, which may affect the character of contemporary urban gardens. The study was planned primarily in the context of the gardens’ therapeutic significance to their users. An important part of the work was to analyze how particular aromatic plants are perceived and received by the inhabitants, using the example of one of Poland's largest cities, Kraków, to assess whether they can have an impact on the inhabitants’ positive memories and thus improve their well-being. Initially, the plant composition of gardens located in Poland that feature aromatic herbs was analyzed. This was followed by a survey and an analysis of therapeutic gardens using the Trojanowska method as modified by Krzeptowska-Moszkowicz et al. The plant composition analysis of sensory gardens featuring herbs demonstrated that vulnerable plants in the Central European climate are being introduced to urban sensory gardens. In terms of major aromatic plants, it was found that almost every respondent reported the existence of scents that had some form of essential significance associated with personal memories. Considering the important sensory impact of water elements in therapeutic gardens, as well as problems related to the acquisition of drinking water or water used in agriculture or horticulture, the paper also addresses this topic. It was found that the city dwellers who filled in the questionnaire strongly preferred the introduction of more ecological solutions in the gardens related to water use—to collect and use rainwater, e.g., for watering, instead of piped water.
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13
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Recent Developments in Some Long-Term Drought Drivers. CLIMATE 2022. [DOI: 10.3390/cli10030031] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
The droughts that hit North and North Western Europe in 2018 and 2019 served as a wake-up call that temperate regions are also affected by these kinds of slow progressing or creeping disasters. Long-term drivers, such as land-use changes, may have exacerbated the impacts of these meteorological droughts. These changes, which are spread over a long time span, may even be difficult to perceive for an individual, but make a big difference in how these rare weather events impact a region. In this paper, we introduce three long-term drivers: forest fires in Europe, global urbanisation, and global deforestation. We attempt to provide a first assessment of their trends, mainly using statistics derived from satellite imagery published in recent literature. Due to the complexity of drought impacts, and the scarcity of quantitative impact data, the relationship between drought impact and these three processes for land use change is difficult to quantify; however, hence we present a survey of the recent trends in these land use change processes and the possible mechanics by which they affect drought impacts. Based on this survey we can conclude that the extent and the number of wildfires have increased markedly in Europe since 2010. Deforestation is still occurring in the tropics, with a loss of 12% in the last 30 years but has halted in the northern regions. Urbanisation has more than doubled in the same time span in the tropics and subtropics, mostly at the expense of forests, while in Europe urbanisation took place mainly in the northern part of the continent. We can conclude that none of these implicit drought drivers followed a favourable trend in the last 30 years. With consistent and worldwide monitoring, for example, by using satellite imagery, we can regularly inform the scientific community on the trends in these drought impact affecting processes, thus helping decision makers to understand how far we have progressed in making the world resilient to drought impacts.
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14
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Schwaab J, Meier R, Mussetti G, Seneviratne S, Bürgi C, Davin EL. The role of urban trees in reducing land surface temperatures in European cities. Nat Commun 2021; 12:6763. [PMID: 34815395 PMCID: PMC8611034 DOI: 10.1038/s41467-021-26768-w] [Citation(s) in RCA: 22] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2020] [Accepted: 10/20/2021] [Indexed: 11/21/2022] Open
Abstract
Urban trees influence temperatures in cities. However, their effectiveness at mitigating urban heat in different climatic contexts and in comparison to treeless urban green spaces has not yet been sufficiently explored. Here, we use high-resolution satellite land surface temperatures (LSTs) and land-cover data from 293 European cities to infer the potential of urban trees to reduce LSTs. We show that urban trees exhibit lower temperatures than urban fabric across most European cities in summer and during hot extremes. Compared to continuous urban fabric, LSTs observed for urban trees are on average 0-4 K lower in Southern European regions and 8-12 K lower in Central Europe. Treeless urban green spaces are overall less effective in reducing LSTs, and their cooling effect is approximately 2-4 times lower than the cooling induced by urban trees. By revealing continental-scale patterns in the effect of trees and treeless green spaces on urban LST our results highlight the importance of considering and further investigating the climate-dependent effectiveness of heat mitigation measures in cities.
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Affiliation(s)
- Jonas Schwaab
- Institute for Atmospheric and Climate Science, ETH Zurich, Zurich, Switzerland.
| | - Ronny Meier
- Institute for Atmospheric and Climate Science, ETH Zurich, Zurich, Switzerland
| | - Gianluca Mussetti
- Institute for Atmospheric and Climate Science, ETH Zurich, Zurich, Switzerland
| | - Sonia Seneviratne
- Institute for Atmospheric and Climate Science, ETH Zurich, Zurich, Switzerland
| | - Christine Bürgi
- Institute for Atmospheric and Climate Science, ETH Zurich, Zurich, Switzerland
| | - Edouard L Davin
- Institute for Atmospheric and Climate Science, ETH Zurich, Zurich, Switzerland
- Wyss Academy for Nature, Climate and Environmental Physics, Oeschger Centre for Climate Change Research, University of Bern, Bern, Switzerland
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15
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Smith IA, Winbourne JB, Tieskens KF, Jones TS, Bromley FL, Li D, Hutyra LR. A Satellite-Based Model for Estimating Latent Heat Flux From Urban Vegetation. Front Ecol Evol 2021. [DOI: 10.3389/fevo.2021.695995] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
The impacts of extreme heat events are amplified in cities due to unique urban thermal properties. Urban greenspace mitigates high temperatures through evapotranspiration and shading; however, quantification of vegetative cooling potential in cities is often limited to simple remote sensing greenness indices or sparse, in situ measurements. Here, we develop a spatially explicit, high-resolution model of urban latent heat flux from vegetation. The model iterates through three core equations that consider urban climatological and physiological characteristics, producing estimates of latent heat flux at 30-m spatial resolution and hourly temporal resolution. We find strong agreement between field observations and model estimates of latent heat flux across a range of ecosystem types, including cities. This model introduces a valuable tool to quantify the spatial heterogeneity of vegetation cooling benefits across the complex landscape of cities at an adequate resolution to inform policies addressing the effects of extreme heat events.
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