Resilience in urban socioecological systems: residential water management as a driver of biodiversity

Cities are unique ecosystems where human social-economic-cultural activities prominently shape the landscape, influencing the distribution and abundance of other species, and consequent patterns of biodiversity. The long-term sustainability of cities is of increasing concern as they continue to grow, straining infrastructure and pushing against natural resources constraints. A key resource is water, esp. in the more rapidly urbanizing arid regions. Understanding water management is thus critical for a deeper theoretical understanding of urban ecosystems and for effective urban policy. Landscaping and irrigation at any urban residence is a product of local geophysical/ecological conditions, homeowners’ cultural preferences, socioeconomic status, neighborhood dynamics, zoning laws, and city/state/federal regulations. Since landscape structure and water availability are key determinants of habitat for other species, urban biodiversity is strongly driven by the outcome of interactions between these variables. Yet the relative importance of ecological variables vs human socioeconomic variables in driving urban biodiversity remains poorly understood. Here we analyze data from the Fresno Bird Count, a citizen science project in California’s Central Valley, to show that spatial variation in bird diversity is best explained by a multivariate model including significant negative correlations with % building and grass cover, and positive correlations with interactions between irrigation intensity, median family income, and grass height. We discuss implications of our findings for urban water management policies in general, and for Fresno’s planned switch to metering water use in 2013. Ecological theory, conservation, and urban policy all benefit if we recognize cities as coupled socioecological systems

Indigenous ecological knowledge as social capital: How citizen science can help us replenish the bank

*Background/Question/Methods* 

In our increasingly urban world, indigenous knowledge of local ecology is declining rapidly, because survival in industrialized urban environments does not depend on knowing the details of local flora, fauna, or phenologies. While traditional ecological knowledge has been documented since 1980s, this is has been largely descriptive, e.g., ethnobotany of sacred groves, cultivation practices, or use of medicinal plants. Until recently, conservation biologists and managers of protected areas have followed western models of conservation that exclude local people and often abandon local ecological knowledge. However, many scientific studies of local ecosystems would not have been possible without the knowledge-base of indigenous people helping researchers. Yet, careful scientific analysis of such knowledge systems is scarce, except in some commercial applications such as forestry or fisheries. Further, even in rare instances when park managers have recruited knowledgeable locals as partners in PA management, the bureaucracy ended up dissipating ecological knowledge rather than sustaining it. The challenge therefore is to understand the epistemology of ecological knowledge, especially the costs and benefits to local people, to help create novel management regimes which provide new incentives for sustaining such knowledge even as traditional dependencies on natural resources are transformed for long-term sustainability of biodiversity. 

*Results/Conclusions*

This paper reviews the literature on indigenous ecological knowledge in South Asia, to establish a baseline for systematic epistemological analyses. Examples include the Bihari bird-trappers assisting the Bombay Natural History Society's bird-ringing projects, Irulas helping snake research at Madras Crocodile Bank, Kanis supporting a variety of research projects, including our own, in Kalakad-Mundanthurai Tiger Reserve over the past two decades, and the modern day settlers in Andaman Islands who have turned from over-harvesting and poaching to sustainable cultivation of Edible-nest Swiftlets. We argue that indigenous knowledge is useful not only for monitoring ecosystems or determining use of natural resources, but more importantly for generating fundamental scientific insights, and adding to the knowledge part of our collective social capital. Even as indigenous knowledge is being lost, volunteer-based Citizen Science projects are recruiting amateur naturalists, especially in urban areas, to monitor and study local biodiversity. Such approaches need to be extended into genuinely participatory research programs where indigenous people are engaged in generating and sustaining ecological knowledge, from traditional and modern scientific perspectives, to become well-informed stewards of the socio-ecological systems we inhabit from local to global scales. This is a crucial step towards slowing the loss of biodiversity by reversing our collective loss of knowledge of biodiversity

Residential irrigation as a driver of urban bird communities

*Background/Question/Methods*
The demand for fresh water has largely outpaced supply both globally and locally with current water management policies unable to meet the needs of urban, agricultural, and industrial activities. Irrigation is one of the many anthropogenic uses of water and is arguably the most important maintenance factor in a landscape. This is particularly true in an arid climate, such as the Central Valley of California. Urban residents' decisions about the design and maintenance of their landscapes affect bird species richness. Published research indicates that these decisions are also affected by the residents' socioeconomic status. However, the driver of this relationship remains unknown. This paper uses data from the Fresno Bird Count, a citizen science organization, to test the hypothesis that neighborhood socioeconomic status influences residential irrigation regimes, which influences plant cover, in turn influencing bird diversity and abundance. A random sampling grid containing 460 points are used as locations for five minute point counts for the Fresno Bird Count ("fresnobirds.org":http://fresnobirds.org/). Socioeconomic data has been obtained from the U.S. Census and irrigation regimes from the city of Fresno. Aerial imagery and ground sampling on point count locations are used for characterizing habitat.

*Results/Conclusions*
Preliminary analysis of the first year of data (2008) supports this hypothesis and reveals a north/south gradient of bird diversity paralleling the socioeconomic gradient of Fresno. This paper will present results from a more comprehensive analysis of data including the spring 2009 bird census. Policies in the U.S. regarding the distribution and cost of water are changing in response to increased water demands, and the city of Fresno is about to undergo such a change. In 2013 a policy of metered water is scheduled to begin, which is predicted to increase water conservation by residents due to an increase in it overall cost. In addition to examining coupled socio-ecological drivers of urban diversity, this study will be the first part of a Before After Control Impact experiment taking advantage of the planned implementation of metering the cost of water use. The results can help guide the city in improving its management of urban habitat and biodiversity.
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Participant and Socio-Ecological Outcomes of the Hofmann Open-Water Laboratory (HOWL) Citizen Science Project

Citizen science, also known as participatory research, combines the efforts of professional researchers and community volunteers to collect data. We have established one such collaborative project in eastern North Carolina, near the 79,000-acre Hofmann Forest, called the Hofmann Open-Water Laboratory (HOWL) citizen science project. The White Oak River, New River, and Trent River all flow out of the Hofmann. The Hofmann is an ecological keystone in the region, acting as a natural filtration system for harmful runoff that occurs in the coastal plain of North Carolina. Our purposes for this study were twofold: (a) to evaluate the HOWL project by assessing the perceptions of HOWL participants and determining whether the project achieved its goals of individual development and community engagement and (b) to provide recommendations for the HOWL project as well as suggestions for other participatory research projects in their beginning phases. We interviewed 12 HOWL citizen scientists who participated in the project, and we drew two major conclusions from our research. First, we recognized that community engagement and collaboration drastically increased in rural eastern North Carolina due to the community members’ participation in water monitoring and natural resource management. Second, citizen scientists achieved their personal goals and objectives by participating in the HOWL project: Participants reported that they learned new skills, gained knowledge of scientific and research procedures, developed an attachment to their community and region, and acted as environmental stewards

Effects of Urbanization on Native Bird Species in Three Southwestern US Cities

Urbanization presents novel challenges to native species by altering both the biotic and abiotic environment. Studies have attempted to make generalizations about how species with similar traits respond to urbanization, although existing results are idiosyncratic across cities and often fail to account for seasonality. Here, we present a comparative study in three US cities: Fresno, California; Tucson, Arizona; and Phoenix, Arizona. Using presence-absence data to define regional bird species pools and urban assemblages in non-breeding (winter) and breeding (spring) seasons, we tested whether urban avian assemblages were a random subset of regional assemblages on the basis of both traits and phylogeny, and whether urbanization was associated with homogenization among avian assemblages. We found evidence for non-random trait filtering into urban assemblages, including of diet guilds, migratory status, and primary habitat, but filtering differed across cities and seasons, being strongest for diet and in Fresno. There was no evidence for non-random phylogenetic-based filtering in urban avian assemblages. Dissimilarity in species and diet guild composition within each season was higher between cities than between regional species pools. These findings show the potential for biotic differentiation as opposed to homogenization as the outcome of environmental filtering processes operating on species traits across cities and seasons

Interactions between urban water policy, residential irrigation, and plant & bird diversity in the Fresno-Clovis Metro Area

*Background/Question/Methods:*

Ecological theory has begun to incorporate humans as part of coupled socio-ecological systems. Modern urban development provides an excellent laboratory to examine the interplay among socio-ecological relationships. Urban land and water management decisions result from dynamic interactions between institutional, individual and ecological factors. Landscaping and irrigation at any particular residence, for example, is a product of geography, hydrology, soil, and other local environmental conditions, the homeowners’ cultural preferences, socioeconomic status, identity construction, neighborhood dynamics, as well as zoning laws, market conditions, city policies, and county/state/federal government regulations. Since land and water management are key determinants of habitat for other species, urban biodiversity is strongly driven by the outcome of interactions between these variables. This study addresses the significance of water as a key variable in the Fresno-Clovis Metropolitan Area (FCMA), shaping current patterns of landscape and water use, at a time when the city of Fresno is installing meters as a regulatory tool to conserve water. We combine data from a citizen science bird monitoring project, field surveys of trees, and mail surveys of residents to address interactions among key components of the urban socioecological system.

*Results/Conclusions:*

We present results of multivariate analyses of bird and tree surveys to show that neighborhood income and irrigation levels interact to influence species diversity of both taxa. Data from the Fresno Bird Count found that bird species richness and functional group diversity are both strongly correlated with residential irrigation and neighborhood income levels. Tree species diversity shows a similar pattern. We examine these results to test and develop several theoretical models explaining outdoor water use behaviors, with the aim of assessing the resilience of such behaviors with the introduction of water metering in Fresno, and the resilience of urban plant and bird communities to resulting changes in water use in the landscape. We argue that socioeconomic status results from a complex interplay of cultural, economic, structural, and social-psychological factors, influencing institutional policies regarding the governance of water resources, and in turn impacts biodiversity within the urban landscape through spatial and temporal variations in water usage. This study is part of a long-term research project that examines the impacts of human water usage and water use policies on biodiversity within an urban environment

The effects of human socioeconomic status and cultural characteristics on urban patterns of biodiversity

ABSTRACT. We present evidence that there can be substantial variation in species richness in residential areas differing in their socioeconomic and cultural characteristics. Many analyses of the impacts of urbanization on biodiversity rely on traditional "urban-to-rural" gradient measures, such as distance from urban center or population density, and thus can fail to account for the ways in which human socioeconomic and cultural characteristics are shaping the human-environment interaction and ecological outcomes. This influence of residential values and economic resources on biodiversity within the urban matrix has implications for human quality of life, for urban conservation strategies, and for urban planning

Urban biodiversity : State of the science and future directions

Since the 1990s, recognition of urban biodiversity research has increased steadily. Knowledge of how ecological communities respond to urban pressures can assist in addressing global questions related to biodiversity. To assess the state of this research field in meeting this aim, we conducted a systematic review of the urban biodiversity literature published since 1990. We obtained data from 1209 studies that sampled ecological communities representing 12 taxonomic groups. While advances have been made in the field over the last 30 years, we found that urban biodiversity research has primarily been conducted in single cities within the Palearctic and Nearctic realms, within forest remnants and residential locations, and predominantly surveys plants and birds, with significant gaps in research within the Global South and little integration of multi-species and multi-trophic interactions. Sample sizes remain limited in spatial and temporal scope, but citizen science and remote sensing resources have broadened these efforts. Analytical approaches still rely on taxonomic diversity to describe urban plant and animal communities, with increasing numbers of integrated phylogenetic and trait-based analyses. Despite the implementation of nature-based solutions across the world's cities, only 5% of studies link biodiversity to ecosystem function and services, pointing to substantial gaps in our understanding of such solutions. We advocate for future research that encompasses a greater diversity of taxonomic groups and urban systems, focusing on biodiversity hotspots. Implementing such research would enable researchers to move forward in an equitable and multidisciplinary way to tackle the complex issues facing global urban biodiversity.Peer reviewe

Urban heat mitigation by green and blue infrastructure: drivers, effectiveness, and future needs

The combination of urbanisation 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 infrastructures (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 synthesises the evidence base for heat mitigation and related co-benefits, identifies knowledge gaps, and proposes recommendations for their implementation to maximise their benefits. After screening 27,486 papers, 202 were reviewed, based on 51 GBGI types categorised 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 prioritising effective interventions to reduce the risk of urban overheating, filling research gaps, and promoting community resilience