Hutyra, Lucy R.; Yoon, Byungman; Alberti, Marina. (2011). Terrestrial Carbon Stocks across a Gradient of Urbanization: A Study of the Seattle, WA Region. Global Change Biology, 17(2), 783 – 797.
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Abstract
Most of our global population and its CO2 emissions can be attributed to urban areas. The process of urbanization changes terrestrial carbon stocks and fluxes, which, in turn, impact ecosystem functions and atmospheric CO2 concentrations. Using the Seattle, WA, region as a case study, this paper explores the relationships between aboveground carbon stocks and land cover within an urbanizing area. The major objectives were to estimate aboveground live and dead terrestrial carbon stocks across multiple land cover classes and quantify the relationships between urban cover and vegetation across a gradient of urbanization. We established 154 sample plots in the Seattle region to assess carbon stocks as a function of distance from the urban core and land cover [urban (heavy, medium, and low), mixed forest, and conifer forest land covers]. The mean (and 95% CI) aboveground live biomass for the region was 89 +/- 22 Mg C ha-1 with an additional 11.8 +/- 4 Mg C ha-1 of coarse woody debris biomass. The average live biomass stored within forested and urban land covers was 140 +/- 40 and 18 +/- 14 Mg C ha-1, respectively, with a 57% mean vegetated canopy cover regionally. Both the total carbon stocks and mean vegetated canopy cover were surprisingly high, even within the heavily urbanized areas, well exceeding observations within other urbanizing areas and the average US forested carbon stocks. As urban land covers and populations continue to rapidly increase across the globe, these results highlight the importance of considering vegetation in urbanizing areas within the terrestrial carbon cycle.
Keywords
Urbanization & The Environment; Carbon Cycle; Carbon In Soils; Climate Change Prevention; Population & The Environment; Land Cover; Cities & Towns -- Environmental Conditions; Seattle (wash.); Washington (state); Climate Change; Development; Mitigation; Pacific Northwest; Urban; United-states; Woody Debris; Storage; Growth; Responses; Fluxes; Co2; Sequestration; Landscape; Forests
Des Roches, Simone; Brans, Kristien, I; Lambert, Max R.; Rivkin, L. Ruth; Savage, Amy Marie; Schell, Christopher J.; Correa, Cristian; De Meester, Luc; Diamond, Sarah E.; Grimm, Nancy B.; Harris, Nyeema C.; Govaert, Lynn; Hendry, Andrew P.; Johnson, Marc T. J.; Munshi-south, Jason; Palkovacs, Eric P.; Szulkin, Marta; Urban, Mark C.; Verrelli, Brian C.; Alberti, Marina. (2021). Socio-evolutionary Dynamics in Cities. Evolutionary Applications, 14(1), 248 – 267.
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Abstract
Cities are uniquely complex systems regulated by interactions and feedbacks between nature and human society. Characteristics of human society-including culture, economics, technology and politics-underlie social patterns and activity, creating a heterogeneous environment that can influence and be influenced by both ecological and evolutionary processes. Increasing research on urban ecology and evolutionary biology has coincided with growing interest in eco-evolutionary dynamics, which encompasses the interactions and reciprocal feedbacks between evolution and ecology. Research on both urban evolutionary biology and eco-evolutionary dynamics frequently focuses on contemporary evolution of species that have potentially substantial ecological-and even social-significance. Still, little work fully integrates urban evolutionary biology and eco-evolutionary dynamics, and rarely do researchers in either of these fields fully consider the role of human social patterns and processes. Because cities are fundamentally regulated by human activities, are inherently interconnected and are frequently undergoing social and economic transformation, they represent an opportunity for ecologists and evolutionary biologists to study urban socio-eco-evolutionary dynamics. Through this new framework, we encourage researchers of urban ecology and evolution to fully integrate human social drivers and feedbacks to increase understanding and conservation of ecosystems, their functions and their contributions to people within and outside cities.
Keywords
Urban Ecology (biology); Urban Research; Urban Ecology (sociology); Social Processes; Biologists; Adaptation; Anthropogenic; Coupled Human-natural Systems; Eco-evo; Socio-ecological Systems; Urbanization; Rapid Evolution; Ecosystem Services; Long-term; Ecological Consequences; Partitioning Metrics; Evosystem Services; Genetic Diversity; Rattus-norvegicus; Local Adaptation; Urban Landscapes; Coupled Human-natural Systems; Eco-evo; Socio-ecological Systems
Hutyra, Lucy R.; Yoon, Byungman; Hepinstall-Cymerman, Jeffrey; Alberti, Marina. (2011). Carbon Consequences of Land Cover Change and Expansion of Urban Lands: A Case Study in the Seattle Metropolitan Region. Landscape And Urban Planning, 103(1), 83 – 93.
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Abstract
Understanding the role humans play in modifying ecosystems through changing land cover is central to addressing our current and emerging environmental challenges. In particular, the consequences of urban growth and land cover change on terrestrial carbon budgets is a growing issue for our rapidly urbanizing planet. Using the lowland Seattle Statistical Metropolitan Area (MSA) region as a case study, this paper explores the consequences of the past land cover changes on vegetative carbon stocks with a combination of direct field measurements and a time series of remote sensing data. Between 1986 and 2007, the amount of urban land cover within the lowland Seattle MSA more than doubled, from 1316 km(2) to 2798 km(2), respectively. Virtually all of the urban expansion was at the expense of forests with the forested area declining from 4472 km(2) in 1986 to 2878 km(2) in 2007. The annual mean rate of urban land cover expansion was 1 +/- 0.6% year(-1). We estimate that the impact of these regional land cover changes on aboveground carbon stocks was an average loss of 1.2 Mg C ha(-1) yr(-1) in vegetative carbon stocks. These carbon losses from urban expansion correspond to nearly 15% of the lowland regional fossil fuel emissions making it an important, albeit typically overlooked, term in regional carbon emissions budgets. As we plan for future urban growth and strive for more ecologically sustainable cities, it is critical that we understand the past patterns and consequences of urban development to inform future land development and conservation strategies. (C) 2011 Elsevier B.V. All rights reserved.
Keywords
Sprawl; Growth; Carbon Cycle; Emissions; Land Cover; Urbanization; Seattle; Vegetation; Carbon; Carbon Sinks; Case Studies; Cities; Ecosystems; Forests; Fossil Fuels; Humans; Land Use; Planning; Remote Sensing; Time Series Analysis
Jung, Meen Chel; Dyson, Karen; Alberti, Marina. (2021). Urban Landscape Heterogeneity Influences the Relationship Between Tree Canopy and Land Surface Temperature. Urban Forestry & Urban Greening, 57.
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Abstract
Urban trees play a key role in alleviating elevated summertime land surface temperatures in cities. However, urban landscape influences the capacity of urban trees to mitigate higher temperatures. We propose that both developed land characteristics and tree cover should be considered to accurately estimate the mitigation effects of canopy cover. We subclassified original land cover based on the canopy cover ratio to capture the within-land cover heterogeneity. We selected two coastal cities with different summertime climatic conditions: Seattle, Washington, USA, and Baltimore, Maryland, USA. We used Landsat-based grid cells (30 m x 30 m) as our spatial analytical unit, with corresponding land surface temperature, canopy area, canopy compactness, population size, and National Land Cover Database (NLCD)-based land cover group. We first used grouped boxplots, Kruskal-Wallis H tests, and post-hoc multiple comparison tests to detect the distribution of land surface temperatures by the land cover group. We then introduced statistical models to test the group effects on the relationship between land surface temperatures and canopy cover variables. We found: (1) land surface temperature increases with level of development, (2) land surface temperature decreases with canopy cover level, (3) the magnitude of the mitigation effects from canopy area differs based on development level and current canopy cover, (4) the differing efficacies of canopy area in decreasing land surface temperature follows a nonlinear threshold relationship, and (5) compactness of canopy cover was not significant in reducing the land surface temperature. These findings suggest the importance of considering heterogeneous canopy cover within developed land cover classes in urban heat island research. Tree planting strategies need to consider the nonlinear relationships between tree canopy cover and land surface temperature alongside environmental equity concerns.
Keywords
Extreme Heat Events; Climate-change; Cover Data; Island; Pattern; Cities; Vegetation; Mortality; Phoenix; Impact; Canopy Cover; Environmental Equity; Land Cover; Land Surface Temperature; Mitigation Effect; Area; Canopy; Cells; Climatic Factors; Databases; Heat Island; Landscapes; Multiple Comparison Test; Planting; Population Size; Research; Statistical Models; Summer; Surface Temperature; Testing; Trees; Urban Forestry; Maryland
Larson, Elisabeth K.; Grimm, Nancy B. (2012). Small-Scale and Extensive Hydrogeomorphic Modification and Water Redistribution in a Desert City and Implications for Regional Nitrogen Removal. Urban Ecosystems, 15(1), 71 – 85.
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Abstract
There are numerous examples of small-scale hydrogeomorphic manipulations within urban ecosystems. These modifications are motivated both by a need to handle storm drainage and by a human desire for aquatic ecosystems as places for recreation and aesthetics. In the Phoenix Arizona metropolitan area, two examples of these local modifications are artificial lakes and stormwater retention basins. Although lakes are not a natural feature of Sonoran Desert ecosystems, numerous artificial lakes are evident in the region. Retention basins are a common landscaping practice for preventing damage from rare but potentially large storm events. Here we attempt to quantify the heretofore unknown number and extent of these designed aquatic ecosystems and consider their potential impact on hydrologic landscape connectivity and regional nitrogen (N) removal. For lakes, we found that official GIS layers from local and state agencies had significant misclassifications and omissions. We used two published GIS datasets and state impoundment-permit information to determine the number, areal extent, and water source for artificial lakes. We discovered that there are 908-1,390 lakes in the Phoenix area, with the number varying according to level of aggregation. There are no existing GIS data on retention basins, so we employed drywell-permit data to estimate that there may be 10,000 retention basins in the region. Basic data on N stocks in these ecosystems are discussed within the context of the regional N budget. Accurate data on the extent and distribution of these designed ecosystems will be vital for water-resources planning and stormwater management.
Keywords
Urban; Urbanization; Retention; Phoenix
Lin, Brenda B.; Ossola, Alessandro; Alberti, Marina; Andersson, Erik; Bai, Xuemei; Dobbs, Cynnamon; Elmqvist, Thomas; Evans, Karl L.; Frantzeskaki, Niki; Fuller, Richard A.; Gaston, Kevin J.; Haase, Dagmar; Jim, Chi Yung; Konijnendijk, Cecil; Nagendra, Harini; Niemela, Jari; Mcphearson, Timon; Moomaw, William R.; Parnell, Susan; Pataki, Diane; Ripple, William J.; Tan, Puay Yok. (2021). Integrating Solutions to Adapt Cities for Climate Change. Lancet Planetary Health, 5(7), E479 – E486.
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Abstract
Record climate extremes are reducing urban liveability, compounding inequality, and threatening infrastructure. Adaptation measures that integrate technological, nature-based, and social solutions can provide multiple co-benefits to address complex socioecological issues in cities while increasing resilience to potential impacts. However, there remain many challenges to developing and implementing integrated solutions. In this Viewpoint, we consider the value of integrating across the three solution sets, the challenges and potential enablers for integrating solution sets, and present examples of challenges and adopted solutions in three cities with different urban contexts and climates (Freiburg, Germany; Durban, South Africa; and Singapore). We conclude with a discussion of research directions and provide a road map to identify the actions that enable successful implementation of integrated climate solutions. We highlight the need for more systematic research that targets enabling environments for integration; achieving integrated solutions in different contexts to avoid maladaptation; simultaneously improving liveability, sustainability, and equality; and replicating via transfer and scale-up of local solutions. Cities in systematically disadvantaged countries (sometimes referred to as the Global South) are central to future urban development and must be prioritised. Helping decision makers and communities understand the potential opportunities associated with integrated solutions for climate change will encourage urgent and deliberate strides towards adapting cities to the dynamic climate reality.
Keywords
Urban; Resilience; Energy; Water; Transformations; Sustainability; Opportunities; Challenges; Mitigation; Knowledge
Alberti, Marina. (2015). Eco-Evolutionary Dynamics in an Urbanizing Planet. Trends In Ecology & Evolution, 30(2), 114 – 126.
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Abstract
A great challenge for ecology in the coming decades is to understand the role humans play in eco-evolutionary dynamics. If, as emerging evidence shows, rapid evolutionary change affects ecosystem functioning and stability, current rapid environmental change and its evolutionary effects might have significant implications for ecological and human wellbeing on a relatively short time scale. Humans are major selective agents with potential for unprecedented evolutionary consequences for Earth's ecosystems, especially as cities expand rapidly. In this review, I identify emerging hypotheses on how urbanization drives eco-evolutionary dynamics. Studying how human-driven micro-evolutionary changes interact with ecological processes offers us the chance to advance our understanding of eco-evolutionary feedbacks and will provide new insights for maintaining biodiversity and ecosystem function over the long term.
Keywords
Biological Evolution; Urbanization; Climate Change; Ecosystems; Well-being; Co-evolution; Eco-evolutionary Dynamics; Ecosystem Function; Urban Ecosystems; Ecological Consequences; Phenotypic Plasticity; Rapid Evolution; Regime Shifts; Elevated Co2; Biodiversity; Selection; Community; Patterns
Pataki, Diane E.; Alberti, Marina; Cadenasso, Mary L.; Felson, Alexander J.; McDonnell, Mark J.; Pincetl, Stephanie; Pouyat, Richard V.; Setala, Heikki; Whitlow, Thomas H. (2021). The Benefits and Limits of Urban Tree Planting for Environmental and Human Health. Frontiers In Ecology And Evolution, 9.
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Abstract
Many of the world's major cities have implemented tree planting programs based on assumed environmental and social benefits of urban forests. Recent studies have increasingly tested these assumptions and provide empirical evidence for the contributions of tree planting programs, as well as their feasibility and limits, for solving or mitigating urban environmental and social issues. We propose that current evidence supports local cooling, stormwater absorption, and health benefits of urban trees for local residents. However, the potential for urban trees to appreciably mitigate greenhouse gas emissions and air pollution over a wide array of sites and environmental conditions is limited. Consequently, urban trees appear to be more promising for climate and pollution adaptation strategies than mitigation strategies. In large part, this is due to space constraints limiting the extent of urban tree canopies relative to the current magnitude of emissions. The most promising environmental and health impacts of urban trees are those that can be realized with well-stewarded tree planting and localized design interventions at site to municipal scales. Tree planting at these scales has documented benefits on local climate and health, which can be maximized through targeted site design followed by monitoring, adaptive management, and studies of long-term eco-evolutionary dynamics.
Keywords
Outdoor Thermal Comfort; Improved Public-health; Carbon Storage; Ecosystem Services; Air-quality; Rainfall Interception; Vegetation; Cover; Design; Impact; Urban Ecology; Forestry; Sustainability; Policy; Climate Mitigation; Climate Adaptation; Ecosystem Disservices
The Urban Ecology Research Laboratory (UERL) is an interdisciplinary team of University of Washington researchers and Ph.D. students studying cities as urban ecosystems. The lab studies urban landscapes as hybrid phenomena that emerge from the interactions between human and ecological processes, and the interactions between urban development and ecosystem dynamics.
As part of the University of Washington’s innovative leadership in urban ecology research and education, the UERL transcends traditional disciplinary boundaries to address some of society’s most challenging problems. UERL research interests include: complexity and resilience in coupled natural and human systems, urban landscape patterns and ecosystem function, urban ecosystem management, modeling land cover change, adaptation and scenario planning. The UERL assists planners, decision makers and non-governmental organizations in making informed decisions about urban development in a rapidly changing environment.
The Urban Ecology Research Laboratory is directed by Professor Marina Alberti, and includes interdisciplinary PhD students, post-doctoral research associates, research scientists, and affiliate faculty from diverse disciplines who collaborate to study coupled natural and human systems.
The Urban@UW initiative brings together labs that study urban issues from across the University of Washington. Urban@UW works with scholars, policymakers, and community stakeholders in order to strengthen the connection between research and solutions to urban issues through cross-disciplinary and cross-sector collaborative research. Key functions of Urban@UW include amplifying public awareness of ongoing projects, connecting researchers with outside constituencies, providing staff and administrative support services, and providing pilot funding and fundraising assistance. Multiple BE labs are involved, including the Northwest…