Artificial nighttime light drives evolution

Hopkins, G.R., Gaston, K.J., Marcel E. Visser, M.E., Elgar, M.A. & Jones, T.M. 2018. Artificial light at night as a driver of evolutionary change across the urban-rural landscapes. Frontiers in Ecology and the Environment, online early. 

Light is fundamental to biological systems, affecting the daily rhythms of bacteria, plants, and animals. Artificial light at night (ALAN), a ubiquitous feature of urbanization, interferes with these rhythms and has the potential to exert strong selection pressures on organisms living in urban environments. ALAN also fragments landscapes, altering the movement of animals into and out of artificially lit habitats. Although research has documented phenotypic and genetic differentiation between urban and rural organisms, ALAN has rarely been considered as a driver of evolution. We argue that the fundamental importance of light to biological systems, and the capacity for ALAN to influence multiple processes contributing to evolution, makes this an important driver of evolutionary change, one with the potential to explain broad patterns of population differentiation across urban–rural landscapes. Integrating ALAN’s evolutionary potential into urban ecology is a targeted and powerful approach to understanding the capacity for life to adapt to an increasingly urbanized world.

When a little light goes a long way

Sanders, D., Kehoe, R., Cruse, D., van Veen, F.J.F. & Gaston, K.J. 2018. Low levels of artificial light at night change food web dynamics. Current Biology, in press. 

Artificial light has transformed the nighttime environment of large areas of the earth, with 88% of Europe and almost 50% of the United States experiencing light-polluted night skies. The consequences for ecosystems range from exposure to high light intensities in the vicinity of direct light sources to the very widespread but lower lighting levels further away. While it is known that species exhibit a range of physiological and behavioural responses to artificial nighttime lighting, there is a need to gain a mechanistic understanding of whole ecological community impacts, especially to different light intensities. Using a mesocosm field experiment with insect communities, we determined the impact of intensities of artificial light ranging from 0.1 to 100 lux on different trophic levels and interactions between species. Strikingly, we found the strongest impact at low levels of artificial lighting (0.1 to 5 lux), which led to a 1.8 times overall reduction in aphid densities. Mechanistically, artificial light at night increased the efficiency of parasitoid wasps in attacking aphids, with twice the parasitism rate under low light levels compared to unlit controls. However at higher light levels, parasitoid wasps spent longer away from the aphid host plants, diminishing this increased efficiency. Therefore aphids reached higher densities under increased light intensity as compared to low levels of lighting where they were limited by higher parasitoid efficiency. Our study highlights the importance of different intensities of artificial light in driving the strength of species interactions and ecosystem functions.


Gaps in cactus conservation

Goettsch, B.,, Durán, A.P. & Gaston, K.J. 2018. Global gap analysis of cactus species and priority sites for their conservation. Conservation Biology, in press. 

Determining how much biodiversity is captured by protected areas (PAs) can play a key role in meeting country commitments to international agreements such as the Convention on Biological Diversity, while analysing gaps in species coverage by PAs can greatly contribute to better locating new PAs and conserving species. It is troublesome, however, that regardless of their importance, global gap analyses have only been conducted for major taxonomic groups of vertebrates, such as amphibians, birds and mammals. Here we present the first global gap analysis for a complete plant group, the highly threatened Cactaceae. Using geographic distribution data of 1438 cactus species we assessed how well the current PA network represents them. Additionally, we performed systematic conservation planning analyses to identify priority conservation areas for cactus species that met and failed to meet conservation targets accounting for their conservation status. We found a total of 261 species with no coverage by PAs. Our results show that a greater percentage of cacti species (18%) are lacking such protection than for mammals (9.7%) and birds (5.6%), and there is also a greater percentage of threatened cacti species (32%) outside protected areas than for amphibians (26.5%), birds (19.9%) and mammals (16%). We found that the top 17% of the landscape that best captures covered species represents on average 52.9% of species ranges and half of its extent is distributed across 14 PAs. The priority areas for the gap and the unprotected ranges of partially‐gap species captured on average 75.2% of their ranges, of which 100 were threatened gap species. These findings, paired with knowledge of the threats affecting species, give important information better to plan conservation action for cacti and also support the importance of assessing the representation of major groups such as plants in determining the real performance of the current PA network.


Drones diagnose coral health

Parsons, M., Bratanov, D., Gaston, K.J. & Gonzalez, F. 2018. UAVs, hyperspectral remote sensing and machine learning revolutionizing reef monitoring. Sensors 18, 2026. 

Recent advances in unmanned aerial system (UAS) sensed imagery, sensor quality/size, and geospatial image processing can enable UASs to rapidly and continually monitor coral reefs, to determine the type of coral and signs of coral bleaching. This paper describes an unmanned aerial vehicle (UAV) remote sensing methodology to increase the efficiency and accuracy of existing surveillance practices. The methodology uses a UAV integrated with advanced digital hyperspectral, ultra HD colour (RGB) sensors, and machine learning algorithms. This paper describes the combination of airborne RGB and hyperspectral imagery with in-water survey data of several types in-water survey of coral under diverse levels of bleaching. The paper also describes the technology used, the sensors, the UAS, the flight operations, the processing workflow of the datasets, the methods for combining multiple airborne and in-water datasets, and finally presents relevant results of material classification. The development of the methodology for the collection and analysis of airborne hyperspectral and RGB imagery would provide coral reef researchers, other scientists, and UAV practitioners with reliable data collection protocols and faster processing techniques to achieve remote sensing objectives.

Health benefits of nature relatedness

Dean, J.H., Shanahan, D.F., Bush, R., Gaston, K.J., Lin, B.B., Barber, E., Franco, L. & Fuller, R.A. 2018. Is nature relatedness associated with better mental and physical health? International Journal of Environmental Research and Public Health 15, 1371. 

Nature relatedness is a psychological characteristic with the potential to drive interaction with nature and influence well-being. We surveyed 1538 people in Brisbane, Australia to investigate how nature relatedness varies among socio-demographic groups. We determined whether people with higher nature relatedness reported fewer symptoms of depression, anxiety, stress and better overall health, controlling for potentially confounding socio-demographic and health-related variables. Overall nature relatedness was higher in older people, females, those without children living at home, not working, and people speaking English at home. Aspects of nature relatedness reflecting enjoyment of nature were consistently associated with reduced ill health, consistent with widespread evidence of the health and well-being benefits of experiencing nature. In contrast, aspects of nature relatedness reflecting self-identification with nature, and a conservation worldview, were associated with increased depression, anxiety or stress, after accounting for potential confounding factors. Detailed investigation of causal pathways among nature relatedness, socio-demographic factors and health is warranted, with particular focus on the relationship between stress and nature orientation.

Visualising the urban green

Anderson, K., Hancock, S. Casalegno, S., Griffiths, A., Griffiths, D., Sargent, F., McCallum, J., Cox, D.T.C. & Gaston, K.J. 2018. Visualising the urban green volume: Exploring LiDAR voxels with tangible technologies and virtual models. Landscape and Urban Planning 178, 248-260. 

The distribution of vegetation within urban zones is well understood to be important for delivery of a range of ecosystem services. While urban planners and human geographers are conversant with methodologies for describing and exploring the volumetric nature of built spaces there is less research that has developed imaginative ways of visualising the complex spatial and volumetric structure of urban vegetation from the treetops to the ground. Using waveform LiDAR data to measure the three-dimensional nature of the urban greenspace, we explore different ways of virtually, and tangibly engaging with volumetric models describing the 3D distribution of urban vegetation. Using waveform LiDAR data processed into voxels (volumetric pixels) and experimenting with a variety of creative approaches to visualise the volumetric nature of the data, we describe the development of new methods for mapping the urban green volume, using a combination of Geographic Information Systems (GIS), Minecraft, 3D printing and Computer Numerical Control (CNC) milling processes. We demonstrate how such methodologies can be used to reveal and explore the complex nature of the urban green volume. We also describe the outcome of using these models to engage diverse audiences with the volumetric data. We explain how the products could be used readily by a range of urban researchers and stakeholders: from town and city councils, to architects and ecologists.

Research priorities for protected areas

Dudley, N., Hockings, M., Stolton, S., Amend, T., Badola, R., Bianco, M., Chetri, N., Cook, C., Day, J.C., Dearden, P., Edwards, M., Ferraro, P., Foden, W., Gambino, R., Gaston, K.J., Hayward, N., Hickey, V., Irving, J., Jeffries, B., Karapetyan, A., Kettunen, M., Laestadius, L., Laffoley, D., Lham, D., Lichtenstein, G., Makombo, J., Marshall, N., McGeoch, M., Nguyen, D., Nogué, S., Paxton, M., Rao, M., Reichelt, R., Rivas, J., Roux, D., Rutte, C., Schreckenberg, K., Sovinc, A., Sutyrina, S., Utomo, A., Vallauri, D.,, Vedeld, P.O., Verschuuren, B., Waithaka, J., Woodley, S., Wyborn, C. & Zhang, Y. 2018. Priorities for protected area research. Parks 24, 35-50.

A hundred research priorities of critical importance to protected area management were identified by a targeted survey of conservation professionals; half researchers and half practitioners. Respondents were selected to represent a range of disciplines, every continent except Antarctica and roughly equal numbers of men and women. The results analysed thematically and grouped as potential research topics as by both practitioners and researchers. Priority research gaps reveal a high interest to demonstrate the role of protected areas within a broader discussion about sustainable futures and if and how protected areas can address a range of conservation and socio-economic challenges effectively. The paper lists the hundred priorities structured under broad headings of management, ecology, governance and social (including political and economic issues) and helps contribute to setting future research agendas.


‘People and Nature’ launches

So, you have a great idea for a new paper. It looks at some aspect of the interactions between people and nature. It will have some ecological relevance, but may not be a pure ecology paper. It will also have a good bit of material drawn from one or more other disciplines – it could be economics, geography, history, law, literature, medicine, philosophy, politics, psychology, or sociology, to name just a few possibilities. But it is not a mainstream paper for one of those disciplines either. So, where will you submit your latest contribution? You will want a journal that not just considers outputs from this kind of cross/multi/interdisciplinary work, but really values them. You will want one that understands both the importance of your paper being promptly and fairly handled by people who are knowledgeable about the topic, and that takes seriously the challenges that can arise when reviewing work that crosses disciplinary specialisms. You will want one backed by a respected organisation, with a track record of publishing high quality journals.

Welcome to People and Nature – a journal of relational thinking.

The British Ecological Society is launching this new journal in recognition of the rapid growth in inter-, multi-, and transdisciplinary research concerning the relationships between humans and nature. Much of this research addresses issues of vital importance.

We look forward to receiving your submissions.

Moving soil, moving plants

Robinson, B.S., Bennie, J. Inger, R., Early, R. & Gaston, K.J. 2018. Sweet flowers are slow and weeds make haste: anthropogenic dispersal of plants via garden and construction soil. Journal of Urban Ecology, in press.

Anthropogenic activities are increasingly responsible for the dispersal of plants. Of particular concern is anthropogenic dispersal of problematic invasive non-native plants. A common dispersal vector is the movement of soil containing seeds or rhizomes. Housing development and domestic gardening activities cause large quantities of soil to be moved, and understanding the role of these activities is critical for informing policy and management to reduce the spread of problematic plants. Here, by collecting soil samples being moved for housing development and domestic gardening, and observing the species that germinated from these samples, we determined the quantities and invasive status of plants moved. From our samples nearly 2000 individuals representing 90 species germinated. Our results suggest that given the quantity of topsoil needed to cover an average-sized UK garden (190m2), there could be 2.2 million and c.2 million viable seeds in soil sourced from housing developments and gardens, respectively. In both housing development and garden samples, native species were more abundant and species-rich than non-native naturalised and invasive species. Buddleia (an invasive) was the most common species overall and in garden samples; this is likely due to multiple traits that adapt it to dispersal, such as prolific seed production. The abundance of invasive and naturalised species was significantly higher in garden than in housing development samples, suggesting that informal movement of soil between gardens poses a greater risk of spreading invasive plants than commercial sources. Consequences for models predicting future distributions of plants, and strategies to mitigate anthropogenic dispersal of problematic plants are considered.

Throwing light on communities

Sanders, D. & Gaston, K.J. 2018. How ecological communities respond to artificial light at night. Journal of Experimental Zoology Part A: Ecological and Integrative Physiology, in press [online early].

Many ecosystems worldwide are exposed to artificial light at night (ALAN), from streetlights and other sources, and a wide range of organisms has been shown to respond to this anthropogenic pressure. This raises concerns about the consequences for major ecosystem functions and their stability. However, there is limited understanding of how whole ecological communities respond to ALAN, and this cannot be gained simply by making predictions from observed single species physiological, behavioral, or ecological responses. Research needs to include an important building block of ecological communities, namely the interactions between species that drive ecological and evolutionary processes in ecosystems. Here, we summarize current knowledge about community responses to ALAN and illustrate different pathways and their impact on ecosystem functioning and stability. We discuss that documentation of the impact of ALAN on species interaction networks and trait distributions provides useful tools to link changes in community structure to ecosystem functions. Finally, we suggest several approaches to advance research that will link the diverse impact of ALAN to changes in ecosystems.
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