scholarly journals Effects of Low-Level Artificial Light at Night on Kentucky Bluegrass and an Introduced Herbivore

2021 ◽  
Vol 9 ◽  
Author(s):  
Morgan C. Crump ◽  
Cassandra Brown ◽  
Robert J. Griffin-Nolan ◽  
Lisa Angeloni ◽  
Nathan P. Lemoine ◽  
...  
Keyword(s):  
Poa Pratensis ◽  
Single Species ◽  
Kentucky Bluegrass ◽  
Light Treatment ◽  
Urban Environments ◽  
Acheta Domesticus ◽  
Artificial Light ◽  
Light At Night ◽  
Leaf Level ◽  
Low Levels

Increasing evidence suggests that artificial light at night (ALAN) can negatively impact organisms. However, most studies examine the impacts of ALAN on a single species or under high levels of artificial light that are infrequent or unrealistic in urban environments. We currently have little information on how low levels of artificial light emanating from urban skyglow affect plants and their interactions with herbivores. We examined how short-term, low levels of ALAN affect grass and insects, including growth rate, photosynthesis, and stomatal conductance in grass, and foraging behavior and survival in crickets. We compared growth and leaf-level gas exchange of Kentucky Bluegrass (Poa pratensis) under low-levels of ALAN (0.3 lux) and starlight conditions (0.001 lux). Furthermore, each light treatment was divided into treatments with and without house crickets (Acheta domesticus). Without crickets present, bluegrass grown under ALAN for three weeks grew taller than plants grown under natural night light levels. In the fourth week when crickets were introduced, grass height decreased resulting in no measurable effects of light treatment. There were no measurable differences in grass physiology among treatments. Our results indicate that low levels of light resulting from skyglow affect plant growth initially. However, with herbivory, the effects of ALAN on grass may be inconsequential. Gaining an understanding of how ALAN affects plant-insect interactions is critical to predicting the ecological and evolutionary consequences of anthropogenic light pollution.

The physical environment

2018 ◽  
Author(s):  
Philip James
Keyword(s):  
Physical Environment ◽  
Urban Climate ◽  
Urban Environments ◽  
Artificial Light ◽  
Noise Levels ◽  
Light At Night ◽  
High Noise ◽  
P Elements ◽  
Micro Organisms ◽  
Diversity Of Life

Elements of the physical aspects of urban environments determine which micro-organisms, plants, and animals live in urban environments. In this chapter, climate, air, water, soil, noise, and light are discussed. Urban environments are affected by the climate of the region in which they are located, and in turn and create their own, distinctive urban climate. Air, water, and soil are all affected by urbanization. Pollution of these elements is common. High noise levels and artificial light at night (ALAN—a new phenomenon) are both strongly associated with urban environments. Details of both are discussed. The discussion in this chapter provides a foundation for further exploration of the diversity of life in urban environments and for later exploration of how organisms adapt to urban living, which will be discussed in Parts II and III.

scholarly journals Artificial light at night amplifies seasonal relapse of haemosporidian parasites in a widespread songbird

2020 ◽  
Vol 287 (1935) ◽  
pp. 20201831 ◽  
Author(s):  
Daniel J. Becker ◽  
Devraj Singh ◽  
Qiuyun Pan ◽  
Jesse D. Montoure ◽  
Katherine M. Talbott ◽  
...  
Keyword(s):  
Annual Cycle ◽  
Early Spring ◽  
Urban Environments ◽  
Control Group ◽  
Artificial Light ◽  
Chronic Infections ◽  
Light At Night ◽  
Haemosporidian Parasite ◽  
Infection Dynamics ◽  
Additive Mixed Models

Urban habitats can shape interactions between hosts and parasites by altering not only exposure rates but also within-host processes. Artificial light at night (ALAN) is common in urban environments, and chronic exposure can impair host immunity in ways that may increase infection. However, studies of causal links between this stressor, immunity, and infection dynamics are rare, particularly in migratory animals. Here, we experimentally tested how ALAN affects cellular immunity and haemosporidian parasite intensity across the annual cycle of migrant and resident subspecies of the dark-eyed junco ( Junco hyemalis ). We monitored an experimental group exposed to light at night and a control group under natural light/dark cycles as they passed through short days simulating early spring to longer days simulating the breeding season, followed by autumn migration. Using generalized additive mixed models, we show that ALAN increased inflammation, and leucocyte counts were greatest in early spring and autumn. At the start of the experiment, few birds had active infections based on microscopy, but PCR revealed many birds had chronic infections. ALAN increased parasitaemia across the annual cycle, with strong peaks in spring and autumn that were largely absent in control birds. As birds were kept in indoor aviaries to prevent vector exposure, this increased parasitaemia indicates relapse of chronic infection during costly life-history stages (i.e. reproduction). Although the immunological and parasitological time series were in phase for control birds, cross-correlation analyses also revealed ALAN desynchronized leucocyte profiles and parasitaemia, which could suggest a general exaggerated inflammatory response. Our study shows how a common anthropogenic influence can shape within-host processes to affect infection dynamics.

scholarly journals Moving in the Dark—Evidence for an Influence of Artificial Light at Night on the Movement Behaviour of European Hedgehogs (Erinaceus europaeus)

Animals ◽  
2020 ◽  
Vol 10 (8) ◽  
pp. 1306
Author(s):  
Anne Berger ◽  
Briseida Lozano ◽  
Leon M. F. Barthel ◽  
Nadine Schubert
Keyword(s):  
Light Intensity ◽  
Urban Areas ◽  
Species Conservation ◽  
Urban Environments ◽  
Artificial Light ◽  
Movement Behaviour ◽  
Light At Night ◽  
Very High Frequency ◽  
Erinaceus Europaeus ◽  
The Mean

With urban areas growing worldwide comes an increase in artificial light at night (ALAN), causing a significant impact on wildlife behaviour and its ecological relationships. The effects of ALAN on nocturnal and protected European hedgehogs (Erinaceus europaeus) are unknown but their identification is important for sustainable species conservation and management. In a pilot study, we investigated the influence of ALAN on the natural movement behaviour of 22 hedgehogs (nine females, 13 males) in urban environments. Over the course of four years, we equipped hedgehogs at three different study locations in Berlin with biologgers to record their behaviour for several weeks. We used Global Positioning System (GPS) tags to monitor their spatial behaviour, very high-frequency (VHF) loggers to locate their nests during daytime, and accelerometers to distinguish between active and passive behaviours. We compared the mean light intensity of the locations recorded when the hedgehogs were active with the mean light intensity of simulated locations randomly distributed in the individual’s home range. We were able to show that the ALAN intensity of the hedgehogs’ habitations was significantly lower compared to the simulated values, regardless of the animal’s sex. This ALAN-related avoidance in the movement behaviour can be used for applied hedgehog conservation.

scholarly journals The Endosymbiotic Coral Algae Symbiodiniaceae Are Sensitive to a Sensory Pollutant: Artificial Light at Night, ALAN

2021 ◽  
Vol 12 ◽  
Author(s):  
Inbal Ayalon ◽  
Jennifer I. C. Benichou ◽  
Dror Avisar ◽  
Oren Levy
Keyword(s):  
Cell Cultures ◽  
Marine Ecosystem ◽  
Photochemical Quenching ◽  
Artificial Light ◽  
Light At Night ◽  
Symbiotic Algae ◽  
Light Spectra ◽  
Clade C ◽  
Low Levels ◽  
Non Photochemical Quenching

Artificial Light at Night, ALAN, is a major emerging issue in biodiversity conservation, which can negatively impact both terrestrial and marine environments. Therefore, it should be taken into serious consideration in strategic planning for urban development. While the lion’s share of research has dealt with terrestrial organisms, only a handful of studies have focused on the marine milieu. To determine if ALAN impacts the coral reef symbiotic algae, that are fundamental for sustainable coral reefs, we conducted a short experiment over a period of one-month by illuminating isolated Symbiodiniaceae cell cultures from the genera Cladocopium (formerly Clade C) and Durusdinium (formerly Clade D) with LED light. Cell cultures were exposed nightly to ALAN levels of 0.15 μmol quanta m–2 s–1 (∼4–5 lux) with three light spectra: blue, yellow and white. Our findings showed that even in very low levels of light at night, the photo-physiology of the algae’s Electron Transport Rate (ETR), Non-Photochemical Quenching, (NPQ), total chlorophyll, and meiotic index presented significantly lower values under ALAN, primarily, but not exclusively, in Cladocopium cell cultures. The findings also showed that diverse Symbiodiniaceae types have different photo-physiology and photosynthesis performances under ALAN. We believe that our results sound an alarm for the probable detrimental effects of an increasing sensory pollutant, ALAN, on the eco-physiology of symbiotic corals. The results of this study point to the potential effects of ALAN on other organisms in marine ecosystem such as fish, zooplankton, and phytoplankton in which their biorhythms is entrained by natural light and dark cycles.

scholarly journals 0038 Sleeping with Low Levels of Artificial Light at Night Increases Systemic Inflammation in Humans

SLEEP ◽  
2019 ◽  
Vol 42 (Supplement_1) ◽  
pp. A15-A16 ◽  
Author(s):  
Jesse W Mindel ◽  
Samantha L Rojas ◽  
David Kline ◽  
Shengying Bao ◽  
Ali Rezai ◽  
...  
Keyword(s):  
Systemic Inflammation ◽  
Artificial Light ◽  
Light At Night ◽  
Low Levels

scholarly journals Low Levels of Artificial Light at Night Strengthen Top-Down Control in Insect Food Web

2018 ◽  
Vol 28 (15) ◽  
pp. 2474-2478.e3 ◽  
Author(s):  
Dirk Sanders ◽  
Rachel Kehoe ◽  
Dave Cruse ◽  
F.J. Frank van Veen ◽  
Kevin J. Gaston
Keyword(s):  
Food Web ◽  
Artificial Light ◽  
Top Down ◽  
Light At Night ◽  
Low Levels

scholarly journals Artificial light at night desynchronizes strictly seasonal reproduction in a wild mammal

2015 ◽  
Vol 282 (1816) ◽  
pp. 20151745 ◽  
Author(s):  
Kylie A. Robert ◽  
John A. Lesku ◽  
Jesko Partecke ◽  
Brian Chambers
Keyword(s):  
Maternal Investment ◽  
Population Level ◽  
Tammar Wallaby ◽  
Urban Environments ◽  
Day Length ◽  
Artificial Light ◽  
Light At Night ◽  
Night Time ◽  
Induced Changes ◽  
Seasonally Breeding

Change in day length is an important cue for reproductive activation in seasonally breeding animals to ensure that the timing of greatest maternal investment (e.g. lactation in mammals) coincides with favourable environmental conditions (e.g. peak productivity). However, artificial light at night has the potential to interfere with the perception of such natural cues. Following a 5-year study on two populations of wild marsupial mammals exposed to different night-time levels of anthropogenic light, we show that light pollution in urban environments masks seasonal changes in ambient light cues, suppressing melatonin levels and delaying births in the tammar wallaby. These results highlight a previously unappreciated relationship linking artificial light at night with induced changes in mammalian reproductive physiology, and the potential for larger-scale impacts at the population level.

scholarly journals Artificial light at night increases growth and reproductive output in Anolis lizards

2020 ◽  
Vol 287 (1919) ◽  
pp. 20191682 ◽  
Author(s):  
Christopher J. Thawley ◽  
Jason J. Kolbe
Keyword(s):  
Reproductive Output ◽  
Urban Environments ◽  
Egg Laying ◽  
Endocrine Function ◽  
Artificial Light ◽  
Negative Effects ◽  
Light At Night ◽  
Brown Anole ◽  
Negative Impacts ◽  
Growth And Reproduction

Since the invention of electric lighting, artificial light at night (ALAN) has become a defining, and evolutionary novel, feature of human-altered environments especially in cities. ALAN imposes negative impacts on many organisms, including disrupting endocrine function, metabolism, and reproduction. However, we do not know how generalized these impacts are across taxa that exploit urban environments. We exposed brown anole lizards, an abundant and invasive urban exploiter, to relevant levels of ALAN in the laboratory and assessed effects on growth and reproduction at the start of the breeding season. Male and female anoles exposed to ALAN increased growth and did not suffer increased levels of corticosterone. ALAN exposure induced earlier egg-laying, likely by mimicking a longer photoperiod, and increased reproductive output without reducing offspring quality. These increases in growth and reproduction should increase fitness. Anoles, and potentially other taxa, may be resistant to some negative effects of ALAN and able to take advantage of the novel niche space ALAN creates. ALAN and both its negative and positive impacts may play a crucial role in determining which species invade and exploit urban environments.

scholarly journals Large-scale deregulation of gene expression by artificial light at night in tadpoles of common toads

2021 ◽  
Author(s):  
Morgane Touzot ◽  
Tristan Lefebure ◽  
Thierry Lengagne ◽  
Jean Secondi ◽  
Adeline Dumet ◽  
...  
Keyword(s):  
Gene Expression ◽  
Large Scale ◽  
Bufo Bufo ◽  
Artificial Light ◽  
Light At Night ◽  
Light Levels ◽  
Immune Challenges ◽  
Physiological Pathways ◽  
Low Levels ◽  
Dose Dependent

Artificial light at night (ALAN) affects numerous physiological and behavioural mechanisms in various species by potentially disturbing circadian timekeeping systems. Although gene-specific approaches have already shown the deleterious effect of ALAN on the circadian clock, immunity and reproduction, large-scale transcriptomic approaches with ecologically relevant light levels are still lacking to assess the global impact of ALAN on biological processes. Moreover, studies have focused mainly on variations in gene expression during the night in the presence of ALAN but never during the day. In a controlled laboratory experiment, transcriptome sequencing of Bufo bufo tadpoles revealed that ALAN affected gene expression at both night and daytime with a dose-dependent effect and globally induced a downregulation of genes. ALAN effects were detected at very low levels of illuminance (0.1 lux) and affected mainly genes related to the innate immune system and, to a lesser extend to lipid metabolism. These results indicate that a broad range of physiological pathways is impacted at the molecular level by very low levels of ALAN potentially resulting in reduced survival under environmental immune challenges.

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