The Contribution of Environmental Science to Mental Health Research: A Scoping Review

Mental health is influenced by multiple complex and interacting genetic, psychological, social, and environmental factors. As such, developing state-of-the-art mental health knowledge requires collaboration across academic disciplines, including environmental science. To assess the current contribution of environmental science to this field, a scoping review of the literature on environmental influences on mental health (including conditions of cognitive development and decline) was conducted. The review protocol was developed in consultation with experts working across mental health and environmental science. The scoping review included 202 English-language papers, published between 2010 and 2020 (prior to the COVID-19 pandemic), on environmental themes that had not already been the subject of recent systematic reviews; 26 reviews on climate change, flooding, air pollution, and urban green space were additionally considered. Studies largely focused on populations in the USA, China, or Europe and involved limited environmental science input. Environmental science research methods are primarily focused on quantitative approaches utilising secondary datasets or field data. Mental health measurement was dominated by the use of self-report psychometric scales. Measures of environmental states or exposures were often lacking in specificity (e.g., limited to the presence or absence of an environmental state). Based on the scoping review findings and our synthesis of the recent reviews, a research agenda for environmental science's future contribution to mental health scholarship is set out. This includes recommendations to expand the geographical scope and broaden the representation of different environmental science areas, improve measurement of environmental exposure, prioritise experimental and longitudinal research designs, and giving greater consideration to variation between and within communities and the mediating pathways by which environment influences mental health. There is also considerable opportunity to increase interdisciplinarity within the field via the integration of conceptual models, the inclusion of mixed methods and qualitative approaches, as well as further consideration of the socio-political context and the environmental states that can help support good mental health. The findings were used to propose a conceptual model to parse contributions and connections between environmental science and mental health to inform future studies.

Nature, smells, and human wellbeing

The link between nature and human wellbeing is well established. However, few studies go beyond considering the visual and auditory underpinnings of this relationship, even though engaging with nature is a multisensory experience. While research linking smell to wellbeing exists, it focuses predominantly on smells as a source of nuisance/offence. Smells clearly have a prominent influence, but a significant knowledge gap remains in the nexus of nature, smell, and wellbeing. Here, we examine how smells experienced in woodlands contribute to wellbeing across four seasons. We show that smells are associated with multiple wellbeing domains, both positively and negatively. They are linked to memories, and specific ecological characteristics and processes over space/time. By making the link between the spatiotemporal variability in biodiversity and wellbeing explicit, we unearth a new line of enquiry. Overall, the multisensory experience must be considered by researchers, practitioners, policy-makers and planners looking to improve wellbeing through nature.

Logged tropical forests have amplified and diverse ecosystem energetics

Old-growth tropical forests are widely recognized as being immensely important for their biodiversity and high biomass1. Conversely, logged tropical forests are usually characterized as degraded ecosystems2. However, whether logging results in a degradation in ecosystem functions is less clear: shifts in the strength and resilience of key ecosystem processes in large suites of species have rarely been assessed in an ecologically integrated and quantitative framework. Here we adopt an ecosystem energetics lens to gain new insight into the impacts of tropical forest disturbance on a key integrative aspect of ecological function: food pathways and community structure of birds and mammals. We focus on a gradient spanning old-growth and logged forests and oil palm plantations in Borneo. In logged forest there is a 2.5-fold increase in total resource consumption by both birds and mammals compared to that in old-growth forests, probably driven by greater resource accessibility and vegetation palatability. Most principal energetic pathways maintain high species diversity and redundancy, implying maintained resilience. Conversion of logged forest into oil palm plantation results in the collapse of most energetic pathways. Far from being degraded ecosystems, even heavily logged forests can be vibrant and diverse ecosystems with enhanced levels of ecological function.

Safeguarding Imperiled Biodiversity and Evolutionary Processes in the Wallacea Center of Endemism

Wallacea-the meeting point between the Asian and Australian fauna-is one of the world's largest centers of endemism. Twenty-three million years of complex geological history have given rise to a living laboratory for the study of evolution and biodiversity, highly vulnerable to anthropogenic pressures. In the present article, we review the historic and contemporary processes shaping Wallacea's biodiversity and explore ways to conserve its unique ecosystems. Although remoteness has spared many Wallacean islands from the severe overexploitation that characterizes many tropical regions, industrial-scale expansion of agriculture, mining, aquaculture and fisheries is damaging terrestrial and aquatic ecosystems, denuding endemics from communities, and threatening a long-term legacy of impoverished human populations. An impending biodiversity catastrophe demands collaborative actions to improve community-based management, minimize environmental impacts, monitor threatened species, and reduce wildlife trade. Securing a positive future for Wallacea's imperiled ecosystems requires a fundamental shift away from managing marine and terrestrial realms independently.

Can biodiverse streetscapes mitigate the effects of noise and air pollution on human wellbeing?

Most of the global population are urban, with inhabitants exposed to raised levels of pollution. Pollutants negatively impact human wellbeing, and can alter the structure and diversity of ecosystems. Contrastingly, urban biodiversity can positively contribute to human wellbeing. We know little, however, about whether the negative impacts of pollution on wellbeing could be lessened for householders living on more biodiverse streets, as the complex interlinkages between pollution, biodiversity and wellbeing have rarely been examined. Here, we used structural equation modelling to simultaneously test whether biodiversity (actual and perceived) mediates the relationship between traffic-related pollution (noise, dB; nitrogen dioxide, NO₂) or air pollution (PM_2.5) and wellbeing (mental wellbeing, happiness). In summer 2019, we conducted questionnaires and biodiversity surveys, and collected noise and air pollution data, from households (n = 282) across the streetscapes of Leeds, UK. Biodiversity (actual or perceived) showed no mediating effects. However, increased flowering plant richness was positively associated with mental wellbeing. Traffic-related pollution negatively affected pollinator and flowering plant richness, but not wellbeing. This could be because householders are not exposed to high levels of noise or NO₂ because they do not maintain front gardens on noisier streets. There was no measurable effect of air pollution on biodiversity or wellbeing. These findings shed light on the complex mechanisms through which biodiversity could improve human wellbeing. Enhancing the diversity of plant species in streetscapes would have a positive effect on wellbeing, further emphasising the important role that biodiverse urban streetscapes play in improving the liveability of cities.

Drivers of Predator Killing by Rural Residents and Recommendations for Fostering Coexistence in Agricultural Landscapes

Predators inhabiting human-dominated landscapes are vulnerable to various anthropogenic actions, including people killing them. We assess potential drivers of predator killing in an agricultural landscape in southern Chile, and discuss the implications for policies and interventions to promote coexistence. We evaluate five different types of motivation: (i) sociodemographics and household economy; (ii) livestock loss; (iii) predator encounter rates; (iv) knowledge of legal protection (all native predators are currently protected); and, (v) tolerance to livestock predation. As the killing of native predators is illegal, the prevalence of this behavior by rural residents was estimated using a symmetrical forced-response randomized response technique (RRT), a method designed to ask sensitive questions. A total of 233 rural residents from randomly assigned sample units (4 km2) across the study region completed our questionnaire. More conspicuous species, such as hawks (Falconiformes sp), foxes (Lycalopex sp) and free-roaming domestic dogs (Canis lupus familiaris), were killed by a higher proportion of farmers than more cryptic species, like the felid güiña (Leopardus guigna), skunk (Conepatus chinga) and pumas (Puma concolor). The proportion of respondents admitting to killing predators was highest for hawks (mean = 0.46, SE = 0.08), foxes (mean = 0.29, SE = 0.08) and dogs (mean = 0.30, SE = 0.08) and lowest for güiña (mean = 0.10, SE = 0.09), which is the only species of conservation concern we examine (considered Vulnerable on the IUCN Red List). From our five motivation categories, past killing of predators was associated with higher reported predator encounter rates (guina, hawks), lower tolerance to livestock predation (hawks, dogs), higher reported livestock loss (dogs) and sociodemographics and household economy (foxes). Our results demonstrate that a one-size-fits-all approach to predator persecution is unlikely to reduce or eliminate illegal killings for the suite of species we examined. We identify and describe two main types of intervention that could foster coexistence, improvement of livestock management and domestic dog management in rural areas, as well as discussing the potential for social marketing.

Bird diversity and psychological wellbeing: A comparison of green and coastal blue space in a neotropical city

Accelerating rates of urbanisation are contributing to biodiversity declines worldwide. However, urban green (e.g. parks) and blue spaces (e.g. coast) provide important habitat for species. Emerging evidence also shows that green and blue spaces can benefit human psychological wellbeing, although few studies originate from the Global South and it is unclear whether more biodiverse spaces offer greater wellbeing gains. We examine how bird diversity (abundance, species richness, Shannon diversity, and community composition) in green and coastal blue space in Georgetown, Guyana, is associated with people's wellbeing (positive and negative affect, anxiety) in situ, using point counts and questionnaires. Bird community composition differed between green and coastal sites, and diversity was significantly higher in green sites. Positive affect and anxiety did not differ between green and coastal sites, but negative affect was higher in coastal sites. Mixed-effect models showed no associations between biodiversity and wellbeing, implying other features are contributing to people's positive wellbeing. Despite no association between biodiversity and wellbeing, both green and coastal blue sites are important for wellbeing and supporting different bird communities. City planning authorities and public health professionals should ensure these social and environmental needs are met in developing cities in the Global South.

The features and processes underpinning high‐quality data generation in participatory research and engagement activities

Participatory approaches are widely used by researchers to gather data and insight about how the environment is perceived, valued and used. The participatory activities may be creating information as part of curiosity‐driven blue‐skies research or to inform policy/practise decision‐making.

The quality and usability of data derived from participatory approaches are heavily influenced by how activities are conducted. We share a set of features and processes that underpin the generation of high‐quality data, based on our collective experience of developing and undertaking participatory activities with an environmental and conservation focus.

We propose four general features: (a) Depth and breadth of engagement; (b) robustness of the approach; (c) allowing space for surprises; (d) usability across contexts. We also provide a practical toolbox of processes, and associated facilitation techniques, which can be employed to maximise participant engagement and generate quality data.

The features and processes are a practical guide for project leaders/teams to consider in the context of their work, rather than a set of inflexible rules. They should be relevant regardless of the participatory methods used, or the research, policy or practice setting being addressed.

Do ecosystem service frameworks represent people's values?

Since the Millennium Ecosystem Assessment was published, a plethora of ecosystem service frameworks have been developed to conceptualise the links between the natural environment and society. The intended geographic scales of application, the policy/practice context, and the scientific disciplines involved have driven variations in how the frameworks are constructed. However, the frameworks are homogenous in that they have been created predominately based on expert opinions and views of how ecosystem services are structured. Here, we use the Common International Classification of Ecosystem Services (CICES) to examine the extent to which frameworks capture people's values for British woodlands. Our findings reveal several disparities between how experts and the public conceptualise ecosystem services. The considerable refinement and specificity provided by CICES does not align with public values (e.g. some provisioning, and regulation and maintenance, services), which tend to be more generalised. We also demonstrate differences in values explained by social characteristics (e.g. ethnicity) that need to be accounted for in decision-making processes. Moving forwards, we need to consider how society views the services derived from nature and reflect this in frameworks to ensure ecosystem service approaches are effective, transparent and widely supported.

What motivates the masses: Understanding why people contribute to conservation citizen science projects

Participation in conservation citizen science projects is growing rapidly and approaches to project design are diversifying. There has been a recent shift towards projects characterised by contributors collecting data in isolation and submitting findings online, with little training or opportunities for direct social interaction with other citizen scientists. While research is emerging on developing citizen science projects by optimising technological modalities, little consideration has been given to understanding what motivates individuals to voluntarily contribute data. Here, we use the Volunteer Functions Inventory, combined with open-ended questions, to demonstrate that the two strongest motivations underpinning participation, for both individuals who contribute data systematically (regularly; n = 177) and opportunistically (ad hoc basis; n = 218), are 'Values' and 'Understanding'. People take part in such projects because they have an intrinsic value for the environment and want to support research efforts (representing 'Values'), as well as wanting to learn and gain knowledge (signifying 'Understanding'). Unlike more traditional citizen science projects that involve specific training and considerable time investments, contributors to these newer types of project are not motivated by the potential to develop their career or opportunities for social interaction. The person-level characteristics of contributors considered in this study did not reliably forecast levels of motivation, suggesting that predicting high levels of motivation is inherently more complex than is often speculated. We recommend avenues for future research that may further enhance our understanding of contributor motivations and the characteristics that may underpin levels of motivation.

Conservation must capitalise on climate's moment

The health of the natural environment has never been a greater concern, but attention to biodiversity loss is being eclipsed by the climate crisis. We argue that conservationists must seize the agenda to put biodiversity at the heart of climate policy.

Gardner and colleagues argue that efforts to conserve biodiversity should capitalise on current momentum in the realm of climate change policy.

Wetlands for Wellbeing: Piloting a Nature-Based Health Intervention for the Management of Anxiety and Depression

Nature-based health interventions (NBIs) for the treatment of poor mental health are becoming increasingly common, yet evidence to support their effectiveness is lacking. We conduct a pilot study of a six-week intervention, aiming to engage individuals with wetland nature for the treatment of anxiety and/or depression. We employed a mixed methods design, using questionnaires, focus groups and semi-structured interviews to evaluate the intervention from the perspective of participants (n = 16) and healthcare professionals (n = 2). Results demonstrate significant improvements in mental health across a range of indicators, including mental wellbeing (Warwick and Edinburgh Mental Wellbeing Scale), anxiety (Generalised Anxiety Disorder-7), stress (Perceived Stress Scale) and emotional wellbeing (Positive and Negative Affect Schedule). Participants and healthcare professionals cited additional outcomes including improved physical health and reduced social isolation. The wetland site provided a sense of escape from participants’ everyday environments, facilitating relaxation and reductions in stress. Wetland staff knowledge of the natural world, transportation and group organisation also played a considerable role in the intervention’s success. These aspects should be considered in future and existing NBIs to maximise benefits to participants. We propose NBIs based in wetlands are an effective therapy option for individuals diagnosed with anxiety and/or depression.

Quantifying the impacts of defaunation on natural forest regeneration in a global meta-analysis

Intact forests provide diverse and irreplaceable ecosystem services that are critical to human well-being, such as carbon storage to mitigate climate change. However, the ecosystem functions that underpin these services are highly dependent on the woody vegetation-animal interactions occurring within forests. While vertebrate defaunation is of growing policy concern, the effects of vertebrate loss on natural forest regeneration have yet to be quantified globally. Here we conduct a meta-analysis to assess the direction and magnitude of defaunation impacts on forests. We demonstrate that real-world defaunation caused by hunting and habitat fragmentation leads to reduced forest regeneration, although manipulation experiments provide contrasting findings. The extirpation of primates and birds cause the greatest declines in forest regeneration, emphasising their key role in maintaining carbon stores, and the need for national and international climate change and conservation strategies to protect forests from defaunation fronts as well as deforestation fronts.

The defaunation of vertebrates may disrupt forest functioning through the loss of plant-animal interactions, but impacts on forests remain unquantified. Here the authors show that seed dispersal is a key interaction and defaunation of primates and birds negatively impacts forest regeneration.

Assessing the ecological and societal impacts of alien parrots in Europe using a transparent and inclusive evidence-mapping scheme

Globally, the number of invasive alien species (IAS) continues to increase and management and policy responses typically need to be adopted before conclusive empirical evidence on their environmental and socioeconomic impacts are available. Consequently, numerous protocols exist for assessing IAS impacts and differ considerably in which evidence they include. However, inclusive strategies for building a transparent evidence base underlying IAS impact assessments are lacking, potentially affecting our ability to reliably identify priority IAS. Using alien parrots in Europe as a case study, here we apply an evidence-mapping scheme to classify impact evidence and evaluate the consequences of accepting different subsets of available evidence on impact assessment outcomes. We collected environmental and socioeconomic impact data in multiple languages using a “wiki-review” process, comprising a systematic evidence search and an online editing and consultation phase. Evidence was classified by parrot species, impact category (e.g. infrastructure), geographical area (e.g. native range), source type (e.g. peer-review), study design (e.g. experimental) and impact direction (deleterious, beneficial and no impact). Our comprehensive database comprised 386 impact entries from 233 sources. Most evidence was anecdotal (50%). A total of 42% of entries reported damage to agriculture (mainly in native ranges), while within Europe most entries concerned interspecific competition (39%). We demonstrate that the types of evidence included in assessments can strongly influence impact severity scores. For example, including evidence from the native range or anecdotal evidence resulted in an overall switch from minimal-moderate to moderate-major overall impact scores. We advise using such an evidence-mapping approach to create an inclusive and updatable database as the foundation for more transparent IAS impact assessments. When openly shared, such evidence-mapping can help better inform IAS research, management and policy.

A spatially integrated framework for assessing socioecological drivers of carnivore decline

Habitat loss, fragmentation and degradation are key threats to the long‐term persistence of carnivores, which are also susceptible to direct persecution by people. Integrating natural and social science methods to examine how habitat configuration/quality and human–predator relations may interact in space and time to effect carnivore populations within human‐dominated landscapes will help prioritise conservation investment and action effectively.

We propose a socioecological modelling framework to evaluate drivers of carnivore decline in landscapes where predators and people coexist. By collecting social and ecological data at the same spatial scale, candidate models can be used to quantify and tease apart the relative importance of different threats.

We apply our methodological framework to an empirical case study, the threatened güiña (Leopardus guigna) in the temperate forest ecoregion of southern Chile, to illustrate its use. Existing literature suggests that the species is declining due to habitat loss, fragmentation and persecution in response to livestock predation. Data used in modelling were derived from four seasons of camera‐trap surveys, remote‐sensed images and household questionnaires.

Occupancy dynamics were explained by habitat configuration/quality covariates rather than by human–predator relations. Güiñas can tolerate a high degree of habitat loss (>80% within a home range). They are primarily impacted by fragmentation and land subdivision (larger farms being divided into smaller ones). Ten per cent of surveyed farmers (N = 233) reported illegally killing the species over the past decade.

Synthesis and applications. By integrating ecological and social data, collected at the same spatial scale, within a single modelling framework, our study demonstrates the value of an interdisciplinary approach to assessing the potential threats to a carnivore. It has allowed us to tease apart effectively the relative importance of different potential extinction pressures for the güiña (Leopardus guigna), make informed conservation recommendations and prioritise where future interventions should be targeted. We have identified that human‐dominated landscapes with large intensive farms can be of conservation value, as long as an appropriate network of habitat patches is maintained within the matrix. Conservation efforts to secure the long‐term persistence of the species should focus on reducing habitat fragmentation rather than human persecution.

By integrating ecological and social data, collected at the same spatial scale, within a single modelling framework, our study demonstrates the value of an interdisciplinary approach to assessing the potential threats to a carnivore. It has allowed us to tease apart effectively the relative importance of different potential extinction pressures for the güiña (Leopardus guigna), make informed conservation recommendations and prioritise where future interventions should be targeted. We have identified that human‐dominated landscapes with large intensive farms can be of conservation value, as long as an appropriate network of habitat patches is maintained within the matrix. Conservation efforts to secure the long‐term persistence of the species should focus on reducing habitat fragmentation rather than human persecution.

The extent of shifts in vegetation phenology between rural and urban areas within a human-dominated region

Urbanization is one of the major environmental challenges facing the world today. One of its particularly pressing effects is alterations to local and regional climate through, for example, the Urban Heat Island. Such changes in conditions are likely to have an impact on the phenology of urban vegetation, which will have knock-on implications for the role that urban green infrastructure can play in delivering multiple ecosystem services. Here, in a human-dominated region, we undertake an explicit comparison of vegetation phenology between urban and rural zones. Using satellite-derived MODIS-EVI data from the first decade of the 20th century, we extract metrics of vegetation phenology (date of start of growing season, date of end of growing season, and length of season) for Britain's 15 largest cities and their rural surrounds. On average, urban areas experienced a growing season 8.8 days longer than surrounding rural zones. As would be expected, there was a significant decline in growing season length with latitude (by 3.4 and 2.4 days/degree latitude in rural and urban areas respectively). Although there is considerable variability in how phenology in urban and rural areas differs across our study cities, we found no evidence that built urban form influences the start, end, or length of the growing season. However, the difference in the length of the growing season between rural and urban areas was significantly negatively associated with the mean disposable household income for a city. Vegetation in urban areas deliver many ecosystem services such as temperature mitigation, pollution removal, carbon uptake and storage, the provision of amenity value for humans and habitat for biodiversity. Given the rapid pace of urbanization and ongoing climate change, understanding how vegetation phenology will alter in the future is important if we wish to be able to manage urban greenspaces effectively.

Reconciling timber extraction with biodiversity conservation in tropical forests using reduced-impact logging

Over 20% of the world's tropical forests have been selectively logged, and large expanses are allocated for future timber extraction. Reduced‐impact logging (RIL) is being promoted as best practice forestry that increases sustainability and lowers CO₂ emissions from logging, by reducing collateral damage associated with timber extraction. RIL is also expected to minimize the impacts of selective logging on biodiversity, although this is yet to be thoroughly tested.

We undertake the most comprehensive study to date to investigate the biodiversity impacts of RIL across multiple taxonomic groups. We quantified birds, bats and large mammal assemblage structures, using a before‐after control‐impact (BACI) design across 20 sample sites over a 5‐year period. Faunal surveys utilized point counts, mist nets and line transects and yielded >250 species. We examined assemblage responses to logging, as well as partitions of feeding guild and strata (understorey vs. canopy), and then tested for relationships with logging intensity to assess the primary determinants of community composition.

Community analysis revealed little effect of RIL on overall assemblages, as structure and composition were similar before and after logging, and between logging and control sites. Variation in bird assemblages was explained by natural rates of change over time, and not logging intensity. However, when partitioned by feeding guild and strata, the frugivorous and canopy bird ensembles changed as a result of RIL, although the latter was also associated with change over time. Bats exhibited variable changes post‐logging that were not related to logging, whereas large mammals showed no change at all.

Indicator species analysis and correlations with logging intensities revealed that some species exhibited idiosyncratic responses to RIL, whilst abundance change of most others was associated with time.

Synthesis and applications. Our study demonstrates the relatively benign effect of reduced‐impact logging (RIL) on birds, bats and large mammals in a neotropical forest context, and therefore, we propose that forest managers should improve timber extraction techniques more widely. If RIL is extensively adopted, forestry concessions could represent sizeable and important additions to the global conservation estate – over 4 million km².

Our study demonstrates the relatively benign effect of reduced‐impact logging (RIL) on birds, bats and large mammals in a neotropical forest context, and therefore, we propose that forest managers should improve timber extraction techniques more widely. If RIL is extensively adopted, forestry concessions could represent sizeable and important additions to the global conservation estate – over 4 million km².

What personal and environmental factors determine frequency of urban greenspace use?

For many people, urban greenspaces are the only places where they encounter the natural world. This is concerning as there is growing evidence demonstrating that human well-being is enhanced by exposure to nature. There is, therefore, a compelling argument to increase how frequently people use urban greenspaces. This may be achieved in two complementary ways by encouraging: (I) non-users to start visiting urban greenspaces; (II) existing users to visit more often. Here we examine the factors that influence frequency of greenspace visitation in the city of Sheffield, England. We demonstrate that people who visit a site least frequently state lower self-reported psychological well-being. We hypothesised that a combination of socio-demographic characteristics of the participants, and the biophysical attributes of the greenspaces that they were visiting, would be important in influencing visit frequency. However, socio-demographic characteristics (income, age, gender) were not found to be predictors. In contrast, some biophysical attributes of greenspaces were significantly related to use frequency. Frequent use was more likely when the time taken to reach a greenspace was shorter and for sites with a higher index of greenspace neglect, but were unrelated to tree cover or bird species richness. We related these results to the motivations that people provide for their visits. Infrequent users were more likely to state motivations associated with the quality of the space, while frequent users gave motivations pertaining to physical, repeated activities. This suggests that there may be no simple way to manage greenspaces to maximise their use across user cohorts as the motivations for visits are very different.

Urban cultivation in allotments maintains soil qualities adversely affected by conventional agriculture

Modern agriculture, in seeking to maximize yields to meet growing global food demand, has caused loss of soil organic carbon (SOC) and compaction, impairing critical regulating and supporting ecosystem services upon which humans also depend. Own‐growing makes an important contribution to food security in urban areas globally, but its effects on soil qualities that underpin ecosystem service provision are currently unknown.

We compared the main indicators of soil quality; SOC storage, total nitrogen (TN), C : N ratio and bulk density (BD) in urban allotments to soils from the surrounding agricultural region, and between the allotments and other urban greenspaces in a typical UK city. A questionnaire was used to investigate allotment management practices that influence soil properties.

Allotment soils had 32% higher SOC concentrations and 36% higher C : N ratios than pastures and arable fields and 25% higher TN and 10% lower BD than arable soils.

There was no significant difference between SOC concentration in allotments and urban non‐domestic greenspaces, but it was higher in domestic gardens beneath woody vegetation. Allotment soil C : N ratio exceeded that in non‐domestic greenspaces, but was lower than that in garden soil.

Three‐quarters of surveyed allotment plot holders added manure, 95% composted biomass on‐site, and many added organic‐based fertilizers and commercial composts. This may explain the maintenance of SOC, C : N ratios, TN and low BD, which are positively associated with soil functioning.

Synthesis and applications. Maintenance and protection of the quality of our soil resource is essential for sustainable food production and for regulating and supporting ecosystem services upon which we depend. Our study establishes, for the first time, that small‐scale urban food production can occur without the penalty of soil degradation seen in conventional agriculture, and maintains the high soil quality seen in urban greenspaces. Given the involvement of over 800 million people in urban agriculture globally, and its important contribution to food security, our findings suggest that to better protect soil functions, local, national and international urban planning and policy making should promote more urban own‐growing in preference to further intensification of conventional agriculture to meet increasing food demand.

Maintenance and protection of the quality of our soil resource is essential for sustainable food production and for regulating and supporting ecosystem services upon which we depend. Our study establishes, for the first time, that small‐scale urban food production can occur without the penalty of soil degradation seen in conventional agriculture, and maintains the high soil quality seen in urban greenspaces. Given the involvement of over 800 million people in urban agriculture globally, and its important contribution to food security, our findings suggest that to better protect soil functions, local, national and international urban planning and policy making should promote more urban own‐growing in preference to further intensification of conventional agriculture to meet increasing food demand.

Land-cover effects on soil organic carbon stocks in a European city

Soil is the vital foundation of terrestrial ecosystems storing water, nutrients, and almost three-quarters of the organic carbon stocks of the Earth's biomes. Soil organic carbon (SOC) stocks vary with land-cover and land-use change, with significant losses occurring through disturbance and cultivation. Although urbanisation is a growing contributor to land-use change globally, the effects of urban land-cover types on SOC stocks have not been studied for densely built cities. Additionally, there is a need to resolve the direction and extent to which greenspace management such as tree planting impacts on SOC concentrations. Here, we analyse the effect of land-cover (herbaceous, shrub or tree cover), on SOC stocks in domestic gardens and non-domestic greenspaces across a typical mid-sized U.K. city (Leicester, 73 km(2), 56% greenspace), and map citywide distribution of this ecosystem service. SOC was measured in topsoil and compared to surrounding extra-urban agricultural land. Average SOC storage in the city's greenspace was 9.9 kg m(-2), to 21 cm depth. SOC concentrations under trees and shrubs in domestic gardens were greater than all other land-covers, with total median storage of 13.5 kg m(-2) to 21 cm depth, more than 3 kg m(-2) greater than any other land-cover class in domestic and non-domestic greenspace and 5 kg m(-2) greater than in arable land. Land-cover did not significantly affect SOC concentrations in non-domestic greenspace, but values beneath trees were higher than under both pasture and arable land, whereas concentrations under shrub and herbaceous land-covers were only higher than arable fields. We conclude that although differences in greenspace management affect SOC stocks, trees only marginally increase these stocks in non-domestic greenspaces, but may enhance them in domestic gardens, and greenspace topsoils hold substantial SOC stores that require protection from further expansion of artificial surfaces e.g. patios and driveways.

Identifying potential sources of variability between vegetation carbon storage estimates for urban areas

Although urbanisation is a major cause of land-use change worldwide, towns and cities remain relatively understudied ecosystems. Research into urban ecosystem service provision is still an emerging field, yet evidence is accumulating rapidly to suggest that the biological carbon stores in cities are more substantial than previously assumed. However, as more vegetation carbon densities are derived, substantial variability between these estimates is becoming apparent. Here, we review procedural differences evident in the literature, which may be drivers of variation in carbon storage assessments. Additionally, we quantify the impact that some of these different approaches may have when extrapolating carbon figures derived from surveys up to a city-wide scale. To understand how/why carbon stocks vary within and between cities, researchers need to use more uniform methods to estimate stores and relate this quantitatively to standardised 'urbanisation' metrics, in order to facilitate comparisons.

Organic carbon hidden in urban ecosystems

Urbanization is widely presumed to degrade ecosystem services, but empirical evidence is now challenging these assumptions. We report the first city-wide organic carbon (OC) budget for vegetation and soils, including under impervious surfaces. Urban soil OC storage was significantly greater than in regional agricultural land at equivalent soil depths, however there was no significant difference in storage between soils sampled beneath urban greenspaces and impervious surfaces, at equivalent depths. For a typical U.K. city, total OC storage was 17.6 kg m(-2) across the entire urban area (assuming 0 kg m(-2) under 15% of land covered by buildings). The majority of OC (82%) was held in soils, with 13% found under impervious surfaces, and 18% stored in vegetation. We reveal that assumptions underpinning current national estimates of ecosystem OC stocks, as required by Kyoto Protocol signatories, are not robust and are likely to have seriously underestimated the contributions of urban areas.

Household factors influencing participation in bird feeding activity: a national scale analysis

Ameliorating pressures on the ecological condition of the wider landscape outside of protected areas is a key focus of conservation initiatives in the developed world. In highly urbanized nations, domestic gardens can play a significant role in maintaining biodiversity and facilitating human-wildlife interactions, which benefit personal and societal health and well-being. The extent to which sociodemographic and socioeconomic factors are associated with engagement in wildlife gardening activities remain largely unresolved. Using two household-level survey datasets gathered from across Britain, we determine whether and how the socioeconomic background of a household influences participation in food provision for wild birds, the most popular and widespread form of human-wildlife interaction. A majority of households feed birds (64% across rural and urban areas in England, and 53% within five British study cities). House type, household size and the age of the head of the household were all important predictors of bird feeding, whereas gross annual household income, the occupation of the head of the household, and whether the house is owned or rented were not. In both surveys, the prevalence of bird feeding rose as house type became more detached and as the age of the head of the household increased. A clear, consistent pattern between households of varying size was less evident. When regularity of food provision was examined in the study cities, just 29% of households provided food at least once a week. The proportion of households regularly feeding birds was positively related to the age of the head of the household, but declined with gross annual income. As concerns grow about the lack of engagement between people and the natural environment, such findings are important if conservation organizations are successfully to promote public participation in wildlife gardening specifically and environmentally beneficial behaviour in society more generally.

Are soils in urban ecosystems compacted? A citywide analysis

Soil compaction adversely influences most terrestrial ecosystem services on which humans depend. This global problem, affecting over 68 million ha of agricultural land alone, is a major driver of soil erosion, increases flood frequency and reduces groundwater recharge. Agricultural soil compaction has been intensively studied, but there are no systematic studies investigating the extent of compaction in urban ecosystems, despite the repercussions for ecosystem function. Urban areas are the fastest growing land-use type globally, and are often assumed to have highly compacted soils with compromised functionality. Here, we use bulk density (BD) measurements, taken to 14 cm depth at a citywide scale, to compare the extent of surface soil compaction between different urban greenspace classes and agricultural soils. Urban soils had a wider BD range than agricultural soils, but were significantly less compacted, with 12 per cent lower mean BD to 7 cm depth. Urban soil BD was lowest under trees and shrubs and highest under herbaceous vegetation (e.g. lawns). BD values were similar to many semi-natural habitats, particularly those underlying woody vegetation. These results establish that, across a typical UK city, urban soils were in better physical condition than agricultural soils and can contribute to ecosystem service provision.

Temporal changes in greenspace in a highly urbanized region

The majority of the world's population now lives in towns and cities, and urban areas are expanding faster than any other land-use type. In response to this phenomenon, two opposing arguments have emerged: whether cities should 'sprawl' into the wider countryside, or 'densify' through the development of existing urban greenspace. However, these greenspaces are increasingly recognized as being central to the amelioration of urban living conditions, supporting biodiversity conservation and ecosystem service provision. Taking the highly urbanized region of England as a case study, we use data from a variety of sources to investigate the impact of national-level planning policy on temporal patterns in the extent of greenspace in cities. Between 1991 and 2006, greenspace showed a net increase in all but one of 13 cities. However, the majority of this gain occurred prior to 2001, and greenspace has subsequently declined in nine cities. Such a dramatic shift in land use coincides with policy reforms in 2000, which favoured densification. Here, we illustrate the dynamic and policy-responsive nature of urban land use, thereby highlighting the need for a detailed investigation of the trade-offs associated with different mechanisms of urban densification to optimize and secure the diverse benefits associated with greenspaces.

Modelling the effect of habitat fragmentation on range expansion in a butterfly

There is an increasing need for conservation programmes to make quantitative predictions of biodiversity responses to changed environments. Such predictions will be particularly important to promote species recovery in fragmented landscapes, and to understand and facilitate distribution responses to climate change. Here, we model expansion rates of a test species (a rare butterfly, Hesperia comma) in five landscapes over 18 years (generations), using a metapopulation model (the incidence function model). Expansion rates increased with the area, quality and proximity of habitat patches available for colonization, with predicted expansion rates closely matching observed rates in test landscapes. Habitat fragmentation constrained expansion, but in a predictable way, suggesting that it will prove feasible both to understand variation in expansion rates and to develop conservation programmes to increase rates of range expansion in such species.

Meta-analysis of the effects of predation on animal prey abundance: evidence from UK vertebrates

Background

Controlling vertebrate predators is one of the most widespread forms of wildlife management and it continues to cause conflict between stakeholders worldwide. It is important for managers and policy-makers to make decisions on this issue that are based on the best available scientific evidence. Therefore, it is first important to understand if there is indeed an impact of vertebrate predators on prey, and then to quantify this impact.

Methodology/Principal Findings

Using the UK as a case study, we use a meta-analytical approach to review the available evidence to assess the effect of vertebrate predation on animal prey abundance. We find a significant effect of predators on prey abundance across our studies. On average, there is a 1.6 fold increase in prey abundance in the absence of predation. However, we show significant heterogeneity in effect sizes, and discuss how the method of predator control, whether the predator is native or non-native, and aspects of study design, may be potential causes.

Conclusions/Significance

Our results allow some cautious policy recommendations to be made regarding the management of predator and prey populations. Meta-analysis is an important tool for understanding general patterns in the effect of predators on prey abundance across studies. Such an approach is especially valuable where management decisions need to be made in the absence of site-specific information.

Changing habitat associations of a thermally constrained species, the silver-spotted skipper butterfly, in response to climate warming

1. The impact of climate change on the distribution, abundance, phenology and ecophysiology of species is already well documented, whereas the influence of climate change on habitat choice and utilization has received little attention. Here we report the changing habitat associations of a thermally constrained grassland butterfly, Hesperia comma, over 20 years. 2. Between 1982 and 2001-2, the optimum percentage of bare ground within habitat used for egg-laying shifted from 41% to 21%. 3. Egg-laying rates are temperature-dependent and females actively adjust microhabitat usage in response to temperature variations; relatively warmer host plants are chosen or oviposition at low ambient temperatures, and cooler host plants at high ambient temperatures. 4. Climate warming has increased the availability of thermally suitable habitat for H. comma at the cool, northern edge of the species' distribution, therefore increasing: (a) egg-laying rate and potentially the realized rate of population increase; (b) effective area of habitat patches as more microhabitats within a given vegetation fragment are now suitable for egg-laying; (c) buffering of populations against environmental variation as eggs are laid within a wider range of microhabitats; and (d) the number of habitat patches in the landscape that are currently available for colonization (including the use of more northerly facing aspects; Thomas et al., Nature, 2001, 411, 577-581). 5. Conservationists often assume the habitat requirements of a species to be constant, and manage habitats to maintain these conditions. For many species, these requirements are likely to change in response to climate warming, and care must be taken not to manage habitats based on outdated prescriptions.

Ecological and evolutionary processes at expanding range margins

Many animals are regarded as relatively sedentary and specialized in marginal parts of their geographical distributions. They are expected to be slow at colonizing new habitats. Despite this, the cool margins of many species' distributions have expanded rapidly in association with recent climate warming. We examined four insect species that have expanded their geographical ranges in Britain over the past 20 years. Here we report that two butterfly species have increased the variety of habitat types that they can colonize, and that two bush cricket species show increased fractions of longer-winged (dispersive) individuals in recently founded populations. Both ecological and evolutionary processes are probably responsible for these changes. Increased habitat breadth and dispersal tendencies have resulted in about 3- to 15-fold increases in expansion rates, allowing these insects to cross habitat disjunctions that would have represented major or complete barriers to dispersal before the expansions started. The emergence of dispersive phenotypes will increase the speed at which species invade new environments, and probably underlies the responses of many species to both past and future climate change.