scholarly journals The effect of artificial light at night on the biomass of caterpillars feeding in urban tree canopies

2020 ◽  
Vol 23 (6) ◽  
pp. 1311-1319 ◽  
Author(s):  
Áron Péter ◽  
Gábor Seress ◽  
Krisztina Sándor ◽  
Ernő Vincze ◽  
Krisztián Pál Klucsik ◽  
...  

Abstract Alternation of day and night is the oldest cycle on Earth, which is increasingly disturbed by the accelerating rate of urbanization and technological development. Despite the ubiquity of light pollution in cities, many aspects of its influence on urban ecosystems are still poorly understood. Here we studied the effect of artificial light at night (ALAN) on the biomass of arboreal caterpillar populations, which are a major component of the diet of many insectivorous animals. We predicted that increasing ALAN intensity is associated with reduced caterpillar biomass, because ALAN may increase predation risk for both caterpillars and adult lepidopterans (i.e. moths), and can also hinder the moths’ reproductive rate. We estimated caterpillar biomass from frass samples (n = 3061) collected from 36 focal trees in two cities in Hungary during four consecutive years. To quantify ALAN we measured light intensity during night at each focal tree (range of illumination: 0.69–3.18 lx). We found that caterpillar biomass of individual trees was repeatable over the four years. This temporal consistency in prey biomass production may be important for birds because it can help predict territory quality, especially in cities where caterpillar abundance is generally low. Our results did not support the negative effect of ALAN on urban caterpillar populations, because ALAN intensity was not related to caterpillar biomass, and this lack of effect was consistent between study sites and tree species. We suggest that the effect of ALAN on urban caterpillar biomass is either weak and thus can be masked by other, local environmental factors, or light pollution may have antagonistic effects acting during different stages of the lepidopteran life cycle. Another explanation could be that even the lower levels of our sites’ public lighting are strong enough to cause serious detrimental effects for caterpillars, resulting in their uniformly low biomass.

2021 ◽  
Vol 9 ◽  
Author(s):  
Wouter Halfwerk ◽  
Paul Jerem

Levels of anthropogenic noise and artificial light at night (ALAN) are rapidly rising on a global scale. Both sensory pollutants are well known to affect animal behavior and physiology, which can lead to substantial ecological impacts. Most studies on noise or light pollution to date have focused on single stressor impacts, studying both pollutants in isolation despite their high spatial and temporal co-occurrence. However, few studies have addressed their combined impact, known as multisensory pollution, with the specific aim to assess whether the interaction between noise and light pollution leads to predictable, additive effects, or less predictable, synergistic or antagonistic effects. We carried out a systematic review of research investigating multisensory pollution and found 28 studies that simultaneously assessed the impact of anthropogenic noise and ALAN on animal function (e.g., behavior, morphology or life-history), physiology (e.g., stress, oxidative, or immune status), or population demography (e.g., abundance or species richness). Only fifteen of these studies specifically tested for possible interactive effects when both sensory pollutants were combined. Four out of eight experimental studies revealed a significant interaction effect, in contrast to only three out seven observational studies. We discuss the benefits and limitations of experimental vs. observational studies addressing multisensory pollution and call for more specific testing of the diverse ways in which noise and light pollution can interact to affect wildlife.


2019 ◽  
Vol 6 (6) ◽  
pp. 1728-1739 ◽  
Author(s):  
Gaozhong Pu ◽  
Danjuan Zeng ◽  
Ling Mo ◽  
Wen He ◽  
Longwu Zhou ◽  
...  

The negative effect of AgNP on leaf litter decomposition was alleviated by artificial light at night (ALAN).


Land ◽  
2020 ◽  
Vol 9 (10) ◽  
pp. 374
Author(s):  
Radoslava Kanianska ◽  
Jana Škvareninová ◽  
Stanislav Kaniansky

Astrotourism is considered to be a modern form of ecotourism. The main resource for astrotourism is a high-quality night sky, but this is very sensitive to natural as well as anthropogenic factors; for example, land utilization and expansion of urban areas often cause the negative effect of light pollution. The aim of the study is to perform a lighting survey by night sky brightness (NSB) measurements using the sky quality meter (SQM-L) at 20 study sites of the Slovenské stredohorie Upland region (Slovakia) and to assess the region’s potential for astrotourism development (PAD) using a multicriteria analysis. The NSB values ranged from 19.90 (city Žiar nad Hronom at Žiarska kotlina Basin) to 21.54 mag/arcsec2 (recreation area Poľana at Poľana Mountains). At 14 out of 20 study sites, the NSB values even reached 21.2 mag/arcsec2, as recommended by the International Dark-Sky Association for dark-sky parks. Four study sites were categorized as sites with medium PAD, and sixteen with low PAD. No study site reached a high or very high PAD. The best conditions for astrotourism development are fulfilled mainly by the Poľana Mountains geographical unit. The findings can be used for sustainable astrotourism development, land management, and planning to ensure socioeconomic development, together with nature and dark-sky conservation.


2021 ◽  
Vol 75 (11) ◽  
Author(s):  
Christina Elgert ◽  
Topi K. Lehtonen ◽  
Arja Kaitala ◽  
Ulrika Candolin

Abstract Artificial light at night is increasing globally, interfering with both sensory ecology and temporal rhythms of organisms, from zooplankton to mammals. This interference can change the behaviour of the affected organisms, and hence compromise the viability of their populations. Limiting the use of artificial light may mitigate these negative effects. Accordingly, we investigated whether the duration of artificial light affects sexual signalling in female glow-worms, Lampyris noctiluca, which are flightless and attract flying males to mate by emitting glow that is interfered by light pollution. The study included three treatments: no artificial light (control), 15 min of artificial light, and 45 min of artificial light. The results show that females were more likely to cease glowing when the exposure to light was longer. Furthermore, small females were more likely to cease their glow, and responded faster to the light, than larger females. These findings suggest that glow-worms can react rapidly to anthropogenic changes in nocturnal light levels, and that prolonged periods of artificial light trigger females to stop sexual signalling. Thus, limiting the duration of artificial light can mitigate the adverse effects of light pollution on sexual signalling, highlighting the importance of such mitigation measures. Significance statement Interest in the effects of artificial light at night on animal behaviour has increased in recent years. With evidence for its negative impact accumulating, potential remedies, such as limiting the duration of light exposure, have emerged. To date, however, knowledge on the effectiveness of these methods has remained very limited. We show that female European common glow-worms, which are wingless beetles that glow to attract flying males to mate, responded to prolonged artificial light exposure by discontinuing their glow. Such non-glowing females are not expected to find a mate, making it difficult for them to reproduce. Hence, our study indicates that the duration of artificial light should be limited to protect this night-active beetle and its opportunities for effective sexual signalling. Because many other nocturnal species also need darkness, this study provides valuable information for the development and use of less disruptive night-time lights.


2020 ◽  
Vol 12 (6) ◽  
pp. 2551 ◽  
Author(s):  
Sibylle Schroer ◽  
Benedikt John Huggins ◽  
Clementine Azam ◽  
Franz Hölker

The fundamental change in nocturnal landscapes due to the increasing use of artificial light at night (ALAN) is recognized as being detrimental to the environment and raises important regulatory questions as to whether and how it should be regulated based on the manifold risks to the environment. Here, we present the results of an analysis of the current legal obligations on ALAN in context with a systematic review of adverse effects. The legal analysis includes the relevant aspects of European and German environmental law, specifically nature conservation and immission control. The review represents the results of 303 studies indicating significant disturbances of organisms and landscapes. We discuss the conditions for prohibitions by environmental laws and whether protection gaps persist and, hence, whether specific legislation for light pollution is necessary. While protection is predominantly provided for species with special protection status that reveal avoidance behavior of artificially lit landscapes and associated habitat loss, adverse effects on species and landscapes without special protection status are often unaddressed by existing regulations. Legislative shortcomings are caused by difficulties in proving adverse effect on the population level, detecting lighting malpractice, and applying the law to ALAN-related situations. Measures to reduce ALAN-induced environmental impacts are highlighted. We discuss whether an obligation to implement such measures is favorable for environmental protection and how regulations can be implemented.


2019 ◽  
Vol 11 (6) ◽  
pp. 1696 ◽  
Author(s):  
Nona Schulte-Römer ◽  
Josiane Meier ◽  
Etta Dannemann ◽  
Max Söding

Concerns about the potential negative effects of artificial light at night on humans, flora and fauna, were originally raised by astronomers and environmentalists. Yet, we observe a growing interest in what is called light pollution among the general public and in the lighting field. Although lighting professionals are often critical of calling light ‘pollution’, they increasingly acknowledge the problem and are beginning to act accordingly. Are those who illuminate joining forces with those who take a critical stance towards artificial light at night? We explore this question in more detail based on the results of a non-representative worldwide expert survey. In our analysis, we distinguish between “lighting professionals” with occupational backgrounds linked to lighting design and the lighting industry, and “light pollution experts” with mostly astronomy- and environment-related professional backgrounds, and explore their opposing and shared views vis-à-vis issues of light pollution. Our analysis reveals that despite seemingly conflicting interests, lighting professionals and light pollution experts largely agree on the problem definition and problem-solving approaches. However, we see diverging views regarding potential obstacles to light pollution mitigation and associated governance challenges.


2020 ◽  
Vol 499 (4) ◽  
pp. 5075-5089
Author(s):  
S Cavazzani ◽  
S Ortolani ◽  
A Bertolo ◽  
R Binotto ◽  
P Fiorentin ◽  
...  

ABSTRACT The study of artificial light at night (ALAN) by satellite is very important for the analysis of new astronomical sites and for the long-term temporal evolution observation of the emission from the ground. The analysis of satellite data presents many advantages but also some critical points because of fluctuations in measurements. The main result of this paper is the discovery of a correlation between these fluctuations and the aerosol concentration combined with cloud cover and lunar cycles. In this work, we also present a mathematical empirical model for the light pollution propagation study in relation to the aerosol concentration detected by satellite. We apply this model to the astronomical site of Asiago (Ekar Observatory) providing a possible explanation for the temporal ALAN fluctuations detected by satellite. Finally, we validate the results with the ground collected data.


2020 ◽  
Vol 12 (10) ◽  
pp. 1591 ◽  
Author(s):  
Daniel T.C. Cox ◽  
Alejandro Sánchez de Miguel ◽  
Simon A. Dzurjak ◽  
Jonathan Bennie ◽  
Kevin J. Gaston

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.


2019 ◽  
Vol 20 (6) ◽  
pp. 1343 ◽  
Author(s):  
Gaozhong Pu ◽  
Danjuan Zeng ◽  
Ling Mo ◽  
Jianxiong Liao ◽  
Xiaxia Chen

Artificial light at night (ALAN) is an increasing phenomenon worldwide that can cause a series of biological and ecological effects, yet little is known about its potential interaction with other stressors in aquatic ecosystems. Here, we tested whether the impact of lead (Pb) on litter decomposition was altered by ALAN exposure using an indoor microcosm experiment. The results showed that ALAN exposure alone significantly increased leaf litter decomposition, decreased the lignin content of leaf litter, and altered fungal community composition and structure. The decomposition rate was 51% higher in Pb with ALAN exposure treatments than in Pb without ALAN treatments, resulting in increased microbial biomass, β-glucosidase (β-G) activity, and the enhanced correlation between β-G and litter decomposition rate. These results indicate that the negative effect of Pb on leaf litter decomposition in aquatic ecosystems may be alleviated by ALAN. In addition, ALAN exposure also alters the correlation among fungi associated with leaf litter decomposition. In summary, this study expands our understanding of Pb toxicity on litter decomposition in freshwater ecosystems and highlights the importance of considering ALAN when assessing environmental metal pollutions.


2021 ◽  
Vol 13 (11) ◽  
pp. 5991
Author(s):  
Annika K. Jägerbrand ◽  
Constantinos A. Bouroussis

When conserving or protecting rare or endangered species, current general guidelines for reducing light pollution might not suffice to ensure long-term threatened species’ survival. Many protected areas are exposed to artificial light at levels with the potential to induce ecological impacts with unknown implications for the ecosystems they are designated to protect. Consequently, it is recommended that precautionary methods for the avoidance and mitigation of light pollution in protected areas be integrated into their management plans. This paper’s aims are to present an overview of best practices in precautionary methods to avoid and mitigate light pollution in protected areas and to identify and discuss what ecosystems should be considered light-sensitive and how to prioritise species and habitats that need protection from artificial light, including examples of legislation covering ecological light pollution in the European Union and in Sweden. The important aspects to include when considering light pollution at a landscape level are listed, and a proposal for prioritisation among species and habitats is suggested. Sensitive and conservation areas and important habitats for particularly vulnerable species could be prioritised for measures to minimise artificial lighting’s negative effects on biodiversity. This may be done by classifying protected natural environments into different zones and applying more constrained principles to limit lighting. The light pollution sensitivity of various environments and ecosystems suggests that different mitigation strategies and adaptations should be used depending on landscape characteristics, species sensitivity and other factors that may determine whether artificial light may be detrimental. Issues of the currently used measurement methods for artificial light at night are reviewed. We also propose and discuss the principles and benefits of using standardized measurement methods and appropriate instrumentation for field measurements of artificial light concerning the environmental impact of light pollution.


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