Recognition that climate change could have negative consequences for agricultural production has generated a desire to build resilience into agricultural systems. One rational and cost-effective ...method may be the implementation of increased agricultural crop diversification. Crop diversification can improve resilience in a variety of ways: by engendering a greater ability to suppress pest outbreaks and dampen pathogen transmission, which may worsen under future climate scenarios, as well as by buffering crop production from the effects of greater climate variability and extreme events. Such benefits point toward the obvious value of adopting crop diversification to improve resilience, yet adoption has been slow. Economic incentives encouraging production of a select few crops, the push for biotechnology strategies, and the belief that monocultures are more productive than diversified systems have been hindrances in promoting this strategy. However, crop diversification can be implemented in a variety of forms and at a variety of scales, allowing farmers to choose a strategy that both increases resilience and provides economic benefits.
There is growing recognition that interactions with nature provide many desirable human well-being outcomes, yet increasing urbanization is degrading the quality and quantity of nature experiences. ...Thus, it has become increasingly important to understand how and why urban dwellers interact with nature. Studies of urban green space use have largely focused on the availability and ease of access to green space, suggesting that greater opportunities to experience such space will lead to increased use. However, a growing literature emphasizes the potential for an individual's nature orientation to affect their interaction with green space. Here we measure the importance of both opportunity and orientation factors in explaining urban park use. An urban lifestyle survey was deployed across Brisbane, Australia in November 2012 to assess patterns of green space use. Participants (n=1479) were asked to provide information on demographics, private yard use, park visitations in the past week, and their orientation toward nature. About 60% of those surveyed had visited a park in the past week, and while this park user population had significantly greater nearby park coverage (within a 250 m radius; p=0.006), a much stronger determinant of visitation was their higher nature orientation (p<0.00001), suggesting that while both opportunity and orientation are important drivers for park visitation, nature orientation is the primary effect. Park users also spent significantly more time in their yards than non-park users (p<0.00001), suggesting that yard use does not necessarily compensate for lower park use. Park users with stronger nature orientation (i) spent more time in their yard, (ii) traveled further to green spaces, and (iii) made longer visits than park visitors with weaker nature orientation. Overall, our results suggest that measures to increase people's connection to nature could be more important than measures to increase urban green space availability if we want to encourage park visitation.
The Health Benefits of Urban Nature SHANAHAN, DANIELLE F.; FULLER, RICHARD A.; BUSH, ROBERT ...
Bioscience,
05/2015, Letnik:
65, Številka:
5
Journal Article
Recenzirano
Odprti dostop
Over 30 years of research has shown that urban nature is a promising tool for enhancing the physical, psychological, and social well-being of the world’s growing urban population. However, little is ...known about the type and amount of nature people require in order to receive different health benefits, preventing the development of recommendations for minimum levels of exposure and targeted city planning guidelines for public health outcomes. Dose–response modelling, when a dose of nature is modeled against a health response, could provide a key method for addressing this knowledge gap. In this overview, we explore how “nature dose” and health response have been conceptualized and examine the evidence for different shapes of dose–response curves. We highlight the crucial need to move beyond simplistic measures of nature dose to understand how urban nature can be manipulated to enhance human health.
•We synthesize three years of research in urban community gardens in Central Coast, California.•Global social and environmental change factors impact management and delivery of ecosystem ...services.•Garden regulations and management decisions by gardeners determine the ecological complexity of gardens.•Ecological complexity can affect the ecosystem service, such as food provision, coming from gardens.•Active management can increase social-ecological outcomes that feedback to the larger system.
Urban community gardens are vital green spaces threatened by global social and environmental change factors. Population growth has reduced the amount of space available in cities, and climate change challenges plant growth thresholds. Urban community gardens provide dynamic socio-ecological systems to study how such social and environmental change factors affect the management and delivery of ecosystem services. They provide spaces where urban citizens purposefully interact with nature and receive multiple benefits. In this paper, we synthesize the results of three years of research in a case study of urban community gardens across the Central Coast of California and present a framework showing how both social and environmental change factors at the regional scale affect the ecological make-up of urban community gardens, which in turn affect the ecosystem services coming from such systems. Our study reveals that global environmental change felt at the regional level (e.g., increased built environment, climate change) interact with social change and policy (e.g., population growth, urbanization, water use policy), thus affecting regulations over garden resources (e.g., water availability) and management decisions by gardeners (e.g., soil management, crop planting decisions). These management decisions at the plot-scale, determine the ecological complexity and quality of the gardens and affect the resulting ecosystem services that come from these systems, such as food provision for both humans and urban animals. A greater understanding of how environmental and social change factors drive the management processes of urban community gardens is necessary to design policy support systems that encourage the continued use and benefits arising from such green spaces. Policies that can support urban community gardens to maintain ecological complexity and increase biodiversity through active management of soil quality and plant diversity have the potential to increase social and environmental outcomes that feedback to the larger environmental and social system.
Summary
There has long been a debate amongst conservation biologists about how agricultural land use should be distributed spatially. Advocates of land sparing argue that high‐intensity food ...production on small units of land will conserve more natural habitat than low‐intensity farming spread across larger areas. Others argue that less intensive production over a greater area of land will reduce the overall load of human stressors upon ecosystems.
Although agricultural and urban systems have traditionally been considered as different fields of research, there are strong parallels between the two landscapes in the patterns of their spatial configuration and the trade‐offs associated with their development. Continued and rapid urbanization, with associated losses in vegetation, highlights the need for a uniting spatial framework to assess the ecological impacts of urbanization. Here, we apply some of the thinking emerging from the agricultural land‐sparing debate to urbanization, review the similarities and differences between the two systems and set out a research agenda.
Intensification of urban systems to increase housing density leads to buildings being interspersed with small tracts of natural or semi‐natural habitat patches (e.g. forest patches, parks). Urban extensification, on the other hand, is characterized by sprawling suburbanization with less concentrated, more distributed green space, often predominantly in the form of backyard or streetscape vegetation. We argue that regional scale analyses are urgently needed to determine which of these patterns of urban growth has a lower overall impact on biodiversity and to explore the geographical and taxonomic variation in the most ecologically appropriate city layout.
Synthesis and applications. The spatial pattern of urban development will affect biodiversity conservation within and beyond a city's borders. We chart the early progress of empirical work on the land‐sparing debate in an urban context and suggest that to yield development patterns that minimize overall ecological impact, urban planners must work at the scale of at least the entire city rather than on a case‐by‐case basis.
The spatial pattern of urban development will affect biodiversity conservation within and beyond a city's borders. We chart the early progress of empirical work on the land‐sparing debate in an urban context and suggest that to yield development patterns that minimize overall ecological impact, urban planners must work at the scale of at least the entire city rather than on a case‐by‐case basis.
With increasing patterns of climate change and variability, water resources for agriculture may become more unpredictable. The possibilities of decreased precipitation and increased competition for ...water resources will be especially important for farmers who depend on rainfed agriculture. A study of coffee agroforestry systems in Southern Mexico (Chiapas, Mexico) was conducted to examine the ability of shade trees to maintain water availability for the coffee crop in a shade agroecosystem. Soil moisture, soil evaporation rates, and the evaporative transpiration potential of coffee plants were measured to examine the amount of water available to coffee plants and potential amount of water lost by the soil and coffee plants in systems under varying levels of shade cover. Soil evaporation and evaporative demand for crop transpiration were compared in coffee systems under different levels of shade canopy during both the wet season and dry season between July 2004 and June 2005. With 60–80% shade cover, daily soil evaporation rates significantly decreased by 41% compared to the low shade site (10–30% shade), although high levels of soil moisture were maintained in the dry season with only 30–65% shade cover. Coffee transpiration demand was strongly affected by shade cover as shade cover affects microclimate and the radiant energy within the system. Microclimate factors (light, temperature, and air saturation vapor pressure deficit) showed strong correlations to evaporative demand as a result. Shade cover ≥30% showed significant reductions of 32% in evaporative transpiration demand when compared to the low shade site. The presence of shade cover in agroforestry systems is capable of reducing overall evaporative demand from soil evaporation and coffee transpiration, therefore offering a higher level of crop protection for farmers with agricultural vulnerability to reduced water resources.
Nature within cities will have a central role in helping address key global public health challenges associated with urbanization. However, there is almost no guidance on how much or how frequently ...people need to engage with nature, and what types or characteristics of nature need to be incorporated in cities for the best health outcomes. Here we use a nature dose framework to examine the associations between the duration, frequency and intensity of exposure to nature and health in an urban population. We show that people who made long visits to green spaces had lower rates of depression and high blood pressure, and those who visited more frequently had greater social cohesion. Higher levels of physical activity were linked to both duration and frequency of green space visits. A dose-response analysis for depression and high blood pressure suggest that visits to outdoor green spaces of 30 minutes or more during the course of a week could reduce the population prevalence of these illnesses by up to 7% and 9% respectively. Given that the societal costs of depression alone in Australia are estimated at AUD$12.6 billion per annum, savings to public health budgets across all health outcomes could be immense.
Urban landscapes are spatially constrained, and vegetative land uses that provide beneficial ecosystem services are difficult to maintain. Urban agricultural (UA) systems appear in many forms – from ...community farms and rooftop gardens to edible landscaping and urban orchards – and can be productive features of cities and provide important environmental services. As highly managed plant communities, UA can exhibit high levels of biodiversity, often exceeding that of other green space areas within the city. Additionally, it is likely that variation in vegetation cover, diversity, and structure influence not only the biodiversity in UA, but also the quantity and quality of ecosystem services supported by such systems. The biodiversity and ecosystem services (B&ES) of UA can have potentially large societal and environmental benefits for cities, such as enhanced food security, air quality, and water regulation. Yet few studies have synthesized knowledge regarding UA vegetation management impacts on the quantity, quality, and stability of B&ES provided. This article presents the first survey of the existing research on the characteristics of UA management and their potential to support ecosystem service delivery. Specifically, we examine: (1) biodiversity patterns in UA, (2) ecosystem services provided by UA, and (3) the challenges of promoting UA systems that support B&ES. Overall, our review reveals that varied vegetative structure, increased native plant diversity, and reduction of urban impervious surface are key features of UA systems that contribute significantly to urban biodiversity and provide important ecosystem services such as pollination, pest control, and climate resilience. We conclude with a discussion of critical gaps in current research and strategies to better understand and support UA and ecosystem services.
Urbane Landschaften sind räumlich eingegrenzt, und Landnutzungen durch Pflanzungen, die nützliche Ökosystemdienstleistungen erbringen, sind schwer zu unterhalten. Systeme der urbanen Landwirtschaft (UL) erscheinen in vielerlei Formen -von Gemeinschaftshöfen und Dachgärten bis hin zu ‘edible landscaping’ und urbanen Obstplantagen- und können produktive Elemente in Städten sein und wichtige Umweltdienstleistungen erbringen. Als intensiv bewirtschaftete Pflanzengemeinschaften kann UL reiche Biodiversität aufweisen, die oft die von anderen urbanen Grünzonen übertrifft. Zudem ist es wahrscheinlich, dass die Variation der Vegetation, Diversität und Struktur nicht nur die Biodiversität in der UL beeinflusst, sondern auch Quantität und Qualität der Ökosystemdienstleistungen, die von solchen Systemen erbracht werden. Die Biodiversitäts- und Ökosystemdienstleistungen der UL können potentiell großen Nutzen für Gesellschaft und Umwelt der Städte haben, z.B. bessere Nahrungsv ersorgung, Luftqualität und Wasserregulation. Nur wenige Studien haben indessen den Wissensstand zum Einfluss des Managements der Vegetation in der UL auf die Quantität, Qualität und Stabilität der erbrachten Biodiversitäts- und Ökosystemdienstleistungen zusammengefasst. Dieser Artikel bietet den ersten Überblick über die Forschung zu den Merkmalen der UL und ihrem Potential Ökosystemleistungen zu unterstützen. Im Einzelnen untersuchen wir die Biodiversitätsmuster in der UL, die erbrachten Ökosystemdienstleistungen und die Schwierigkeiten bei der Förderung von UL-Systemen, die Biodiversitäts- und Ökosystemdienstleistungen unterstützen. Insgesamt zeigt unser Review, dass eine vielfältige Vegetationsstruktur, erhöhte Pflanzendiversität und die Reduktion von undurchlässigen urbanen Bodenoberflächen die Schlüsselfaktoren sind, die UL signifikant zu urbaner Biodiversität beitragen lassen und für wichtige Ökosystemdienstleistungen wie Bestäubung, Schädlingskontrolle und ein ausgeglicheneres Stadtklima sorgen. Abschließend diskutieren wir die kritischen Lücken der gegenwärtigen Forschung und Strategien, um die UL und ihre Ökosystemdienstleistungen besser zu verstehen und zu unterstützen.
Current climate change patterns may cause more extreme and variable climates in the future, threatening agricultural productivity in many areas of the world. Because many smallholder, rural farmers ...depend on subsistence, rainfed agriculture, priorities should be focused on coping mechanisms that protect these farmers from future vulnerabilities. This paper examines one possible adaptive strategy for coffee agriculture. A high (60–80%), medium (35–65%), and low (10–30%) shade coffee site were chosen in the Soconusco region of Chiapas, Mexico. Microclimate and soil moisture data were collected to examine the ability of shade tree cover in an agroforestry system to protect crop plants against extremes in microclimate and soil moisture fluctuation. Site and site by time effects were analyzed using linear mixed models to compare mean differences of microclimate measurements (temperature, relative humidity, and solar radiation) by site as well as by time of the day. Although there were not large differences in seasonal means for these factors, site by time effects show that temperature, humidity, and solar radiation fluctuations increase significantly as shade cover decreases. Soil data showed significantly larger fluctuations in soil moisture gain and loss in the low shade site respective of patterns of precipitation. Overall, the amount of shade cover was directly related to the mitigation of variability in microclimate and soil moisture for the crop of interest. The use of agroforestry systems is an economically feasible way to protect crop plants from extremes in microclimate and soil moisture and should be considered a potential adaptive strategy for farmers in areas that will suffer from extremes in climate.
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