Lighting up a nation

Cox, D.T.C., Sánchez de Miguel, A., Dzurjak, S.A., Bennie, J. & Gaston, K.J. 2020. National scale spatial variation in artificial light at night. Remote Sensing 12, 1591.

[Image: NASA]

 The disruption to natural light regimes caused by outdoor artificial nighttime lighting has significant impacts on human health and the natural world. Artificial light at night takes two forms, light emissions and skyglow (caused by the scattering of light by water, dust and gas molecules in the atmosphere). Key to determining where the biological impacts from each form are likely to be experienced is understanding their spatial occurrence, and how this varies with other landscape factors. To examine this, we used data from the Visible Infrared Imaging Radiometer Suite (VIIRS) day/night band and the World Atlas of Artificial Night Sky Brightness, to determine covariation in (a) light emissions, and (b) skyglow, with human population density, landcover, protected areas and roads in Britain. We demonstrate that, although artificial light at night increases with human density, the amount of light per person decreases with increasing urbanization (with per capita median direct emissions three times greater in rural than urban populations, and per capita median skyglow eleven times greater). There was significant variation in artificial light at night within different landcover types, emphasizing that light pollution is not a solely urban issue. Further, half of English National Parks have higher levels of skyglow than light emissions, indicating their failure to buffer biodiversity from pressures that artificial lighting poses. The higher per capita emissions in rural than urban areas provide different challenges and opportunities for mitigating the negative human health and environmental impacts of light pollution. 

Internet ecology

Jarić, I., Correia, R.A., Brookl B.W., Buettel, J.C., Courchamp, F., Di Minin, E., Firth, J.A., Gaston, K.J., Jepson, P., Kalinkat, G., Ladle, R., Soriano-Redondo, A., Souza, A.T. & Roll, U. 2020. iEcology: Harnessing large online resources to generate ecological insights. Trends in Ecology and Evolution [online early].

Digital data are accumulating at unprecedented rates. These contain a lot of information about the natural world, some of which can be used to answer key ecological questions. Here, we introduce iEcology (i.e., internet ecology), an emerging research approach that uses diverse online data sources and methods to generate insights about species distribution over space and time, interactions and dynamics of organisms and their environment, and anthropogenic impacts. We review iEcology data sources and methods, and provide examples of potential research applications. We also outline approaches to reduce potential biases and improve reliability and applicability. As technologies and expertise improve, and costs diminish, iEcology will become an increasingly important means to gain novel insights into the natural world.

Diffuse light is real light

Sánchez de Miguel, A., Kyba, C.C.M., Zamorano, J., Gallego, J. & Gaston, K.J. 2020. The nature of the diffuse light near cities detected in nighttime satellite imagery. Scientific Reports 10, 7829.

Diffuse glow has been observed around brightly lit cities in nighttime satellite imagery since at least the first publication of large scale maps in the late 1990s. In the literature, this has often been assumed to be an error related to the sensor, and referred to as “blooming”, presumably in relation to the effect that can occur when using a CCD to photograph a bright light source. Here we show that the effect seen on the DMSP/OLS, SNPP/VIIRS-DNB and ISS is not only instrumental, but in fact represents a real detection of light scattered by the atmosphere. Data from the Universidad Complutense Madrid sky brightness survey are compared to nighttime imagery from multiple sensors with differing spatial resolutions, and found to be strongly correlated. These results suggest that it should be possible for a future space-based imaging radiometer to monitor changes in the diffuse artificial skyglow of cities.

Ecology of interactions between people and nature

Soga, M. & Gaston, K.J. (2020) The ecology of human-nature interactions. Proc. R. Soc. B, online early.

The direct interactions between people and nature are critically important in many ways, with growing attention particularly on their impacts on human health and wellbeing (both positive and negative), on people’s attitudes and behaviour towards nature, and on the benefits and hazards to wildlife. A growing evidence base is accelerating the understanding of different forms that these direct human–nature interactions take, novel analyses are revealing the importance of the opportunity and orientation of individual people as key drivers of these interactions, and methodological develop- ments are increasingly making apparent their spatial, temporal and socio- economic dynamics. Here, we provide a roadmap of these advances and identify key, often interdisciplinary, research challenges that remain to be met. We identified several key challenges, including the need to characterize individual people’s nature interactions through their life course, to deter- mine in a comparable fashion how these interactions vary across much more diverse geographical, cultural and socio-economic contexts that have been explored to date, and to quantify how the relative contributions of people’s opportunity and orientation vary in shaping their nature inter- actions. A robust research effort, guided by a focus on such unanswered questions, has the potential to yield high-impact insights into the fundamen- tal nature of human–nature interactions and contribute to developing strategies for their appropriate management.

Allotments for food

Edmondson, J.L., Childs, D.Z., Dobson, M.C., Gaston, K.J., Warren, P.H. & Leake, J.R. 2020. Feeding a city – Leicester as a case study of the importance of allotments for horticultural production in the UK. Science of the Total Environment, in press.

The process of urbanization has detached a large proportion of the global population from involvement with food production. However, there has been a resurgence in interest in urban agriculture and there is widespread recognition by policy-makers of its potential contribution to food security. Despite this, there is little data on urban agricultural production by non-commercial small-scale growers. We combine citizen science data for self-provisioning crop yields with field-mapping and GIS-based analysis of allotments in Leicester, UK, to provide an estimate of allotment fruit and vegetable production at a city-scale. In addition, we examine city-scale changes in allotment land provision on potential crop production over the past century. The average area of individual allotment plots used to grow crops was 52%. Per unit area yields for the majority of crops grown in allotments were similar to those of UK commercial horticulture. We estimate city-wide allotment production of >1200 t of fruit and vegetables and 200 t of potatoes per annum, equivalent to feeding >8500 people. If the 13% of plots that are completely uncultivated were used this could increase production to >1400 t per annum, feeding ~10,000 people, however this production may not be located in areas where there is greatest need for increased access to fresh fruits and vegetables. The citywide contribution of allotment cultivation peaked in the 1950s when 475 ha of land was allotments, compared to 97 ha currently. This suggests a decline from >45,000 to <10,000 of people fed per annum. We demonstrate that urban allotments make a small but important contribution to the fruit and vegetable diet of a UK city. However, further urban population expansion will exert increasing development pressure on allotment land. Policy-makers should both protect allotments within cities, and embed urban agricultural land within future developments to improve local food security.

Road verge ecosystem services

Phillips, B.B., Bullock, J.M., Osborne, J.L. & Gaston, K.J. 2020. Ecosystem service provision by road verges. Journal of Applied Ecology, in press.

1. Roads form a vast, rapidly growing global network that has diverse, detrimental ecological impacts. However, the habitats that border roads (‘road verges’) form a parallel network that might help mitigate these impacts and provide additional benefits (ecosystem services; ES).

2. We evaluate the capacity of road verges to provide ES by reviewing existing research and considering their relevant characteristics; area, connectivity, shape, and contextual ES supply and demand. We consider the present situation, and how this is likely to change based on future projections for growth in road extent, traffic densities and urban populations.

3. Road verges provide a wide range of ES, including biodiversity provision, regulating services (e.g. air and water filtration) and cultural services (e.g. health and aesthetic benefits by providing access to nature), but also displace other habitats and provide ecosystem disservices (e.g. plant allergens and damage to infrastructure). Globally, road verges may currently cover 270,000 km2 and store 0.015 Gt C year‐1, which will further increase with 70% projected growth in the global road network.

4. Road verges are well placed to mitigate traffic pollution and address demand for ES in surrounding ES‐impoverished landscapes, thereby improving human health and wellbeing in urban areas, and improving agricultural production and sustainability in farmland. Demand for ES provided by road verges will likely increase due to projected growth in traffic densities and urban populations, though traffic pollution will be reduced by technological advances (e.g. electric vehicles). Road verges form a highly connected network, which may enhance ES provision but facilitate the dispersal of invasive species and increase vehicle‐wildlife collisions.

5. Synthesis and applications. Road verges offer a significant opportunity to mitigate the negative ecological effects of roads and to address demand for ecosystem services (ES) in urban and agricultural landscapes. Their capacity to provide ES might be enhanced considerably if they were strategically designed and managed for environmental outcomes, namely by optimizing the selection, position and management of plant species and habitats. Specific opportunities include reducing mowing frequencies and planting trees in large verges. Road verge management for ES must consider safety guidelines, financial costs and ecosystem disservices, but is likely to provide long‐term financial returns if environmental benefits are considered.

Circular Economy

This is one of a series of videos being posted about the Tevi project that I co-lead. Tevi is a business support programme for Cornwall and the Isles of Scilly that builds businesses and enhances the natural environment (