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Anthropogenic light is ubiquitous in areas where humans are present and is showing a progressive increase worldwide. This has far-reaching consequences for most species and their ecosystems. The effects of anthropogenic light on natural ecosystems are highly variable and complex. Many species suffer from adverse effects and often respond in a highly specific manner. Ostensibly surveyable effects such as attraction and deterrence become complicated because these can depend on the type of behavior and specific locations. Here, we considered how solutions and new technologies could reduce the adverse effects of anthropogenic light. A simple solution to reducing and mitigating the ecological effects of anthropogenic light seems unattainable, because frugal lighting practices and turning off lights may be necessary to eliminate them. [ABSTRACT FROM AUTHOR]

Road lighting uniformity is an essential lighting quality parameter for motorists and pedestrians and varies with lighting design parameters. Increased road lighting uniformity may result in benefits, such as increased reassurance and perceived safety for pedestrians or an increased overall visual perception. However, no previous study has investigated how road lighting uniformity varies with lighting design scenarios or how the uniformity of various lighting design scenarios affects other essential parameters, such as energy performance and obtrusive light. This study aimed to investigate: (I) how uniformity varies with different road lighting design scenarios, and (II) how uniformity correlates with energy performance and risk for increasing spill light. The study is limited to pedestrian roads. We performed photometric calculations in ReluxDesktop for more than 1.5 million cases with single-sided pole arrangements and for various geometries of road width, pole distance, pole height, overhang, and luminaire tilt. The results were analyzed with a set of five relevant metrics that were calculated and analyzed together with uniformity. For the evaluation, we used the minimum luminaire power needed to achieve an average illuminance of 10 lx, the power density indicator (DP), edge illuminance ratio (REI), and we introduced two new indicators for spill light on the ground in the border areas: the extended edge illuminance ratio (extended REI) and the spill flux ratio (RSF). The results show that increased uniformity levels may significantly increase energy consumption and spill light, but that both these impacts can be relatively controlled if uniformity is kept under certain limits. The investigated cases also demonstrated that improper lighting planning significantly increases adverse effects, such as spill light. [ABSTRACT FROM AUTHOR]

Premise: Climate change is having major impacts on alpine and arctic regions, and inter‐annual variations in temperature are likely to increase. How increased climate variability will impact plant reproduction is unclear. Methods: In a 4‐year study on fruit production by an alpine plant community in northern Sweden, we applied three warming regimes: (1) a static level of warming with open‐top chambers (OTC), (2) press warming, a yearly stepwise increase in warming, and (3) pulse warming, a single‐year pulse event of higher warming. We analyzed the relationship between fruit production and monthly temperatures during the budding period, fruiting period, and whole fruit production period and the effect of winter and summer precipitation on fruit production. Results: Year and treatment had a significant effect on total fruit production by evergreen shrubs, Cassiope tetragona, and Dryas octopetala, with large variations between treatments and years. Year, but not treatment, had a significant effect on deciduous shrubs and graminoids, both of which increased fruit production over the 4 years, while forbs were negatively affected by the press warming, but not by year. Fruit production was influenced by ambient temperature during the previous‐year budding period, current‐year fruiting period, and whole fruit production period. Minimum and average temperatures were more important than maximum temperature. In general, fruit production was negatively correlated with increased precipitation. Conclusions: These results indicate that predicted increased climate variability and increased precipitation due to climate change may affect plant reproductive output and long‐term community dynamics in alpine meadow communities. [ABSTRACT FROM AUTHOR]

Light conditions are essential factors in traffic safety, but the relationship between light conditions and vehicle speed is not fully understood and has rarely been examined for trucks. We asked the following questions: I) if vehicle speed between brighter and darker conditions in clear weather will be different? II) if vehicle speeds are lower during rain and snow than in clear weather conditions? and if so III) if the speed reduction in rainy and snowy weather conditions is more substantial on roads without road lighting in darkness? We investigated how the speed of trucks was affected by weather conditions (clear, rain, and snowfall), daylight, darkness, and road lighting by using traffic and weather data from 25 locations on the Swedish road network. Seventeen of the 25 locations were roads with road lighting. Speed responses by 5,344,287 vehicle passages by trucks was included in the analyses, more specifically 3,659,940 passages by light-duty vehicles and 1,684,347 passages by heavy-duty vehicles. The data was extracted from hourly measurements for the period 2012-09-01 to 2014-05-31. No evidence of consistent patterns of speed differences with respect to lighting conditions (darkness, daylight, twilight or road lighting) under clear weather conditions were detected. Truck speeds decreased in response to snowfall, but not to rain, with the decrease dependant on the amount of snow. Effects of road lighting on speed reduction in rainy and snowy weather was not shown. [ABSTRACT FROM AUTHOR]

• Background and Aims Climate change is expected to have major impacts on high alpine and arctic ecosystems in the future, but empirical data on the impact of long-term warming on lichen diversity and richness are sparse. This study report the effects of 18 years of ambient and experimental warming on lichens and vascular plant cover in two alpine plant communities, a dry heath with sparse canopy cover (54 %) and a mesic meadow with a more developed (67 %) canopy cover, in sub-arctic Sweden. • Methods The effects of long-term passive experimental warming using open top chambers (OTCs) on lichens and total vascular plant cover, and the impact of plant cover on lichen community parameters, were analysed. • Key Results Between 1993 and 2013, mean annual temperature increased about 2 °C. Both site and experimental warming had a significant effect on cover, species richness, effective number of species evenness of lichens, and total plant canopy cover. Lichen cover increased in the heath under ambient conditions, and remained more stable under experimental warming. The negative effect on species richness and effective number of species was driven by a decrease in lichens under experimental warming in the meadow. Lichen cover, species richness, effective number of species evenness were negatively correlated with plant canopy cover. There was a significant negative impact on one species and a non-significant tendency of lower abundance of the most common species in response to experimental warming. • Conclusions The results from the long-term warming study imply that arctic and high alpine lichen communities are likely to be negatively affected by climate change and an increase in plant canopy cover. Both biotic and abiotic factors are thus important for future impacts of climate change on lichens. [ABSTRACT FROM AUTHOR]

In a driving simulator study, driving behaviour responses (speed and deceleration) to encountering a moose, automatic speed camera, wildlife warning sign and radio message, with or without a wildlife fence and in dense forest or open landscape, were analysed. The study consisted of a factorial experiment that examined responses to factors singly and in combination over 9-km road stretches driven eight times by 25 participants (10 men, 15 women). The aims were to: determine the most effective animal–vehicle collision (AVC) countermeasures in reducing vehicle speed and test whether these are more effective in combination for reducing vehicle speed; identify the most effective countermeasures on encountering moose; and determine whether the driving responses to AVC countermeasures are affected by the presence of wildlife fences and landscape characteristics. The AVC countermeasures that proved most effective in reducing vehicle speed were a wildlife warning sign and radio message, while automatic speed cameras had a speed-increasing effect. There were no statistically significant interactions between different countermeasures and moose encounters. However, there was a tendency for a stronger speed-reducing effect from the radio message warning and from a combination of a radio message and wildlife warning sign in velocity profiles covering longer driving distances than the statistical tests. Encountering a moose during the drive had the overall strongest speed-reducing effect and gave the strongest deceleration, indicating that moose decoys or moose artwork might be useful as speed-reducing countermeasures. Furthermore, drivers reduced speed earlier on encountering a moose in open landscape and had lower velocity when driving past it. The presence of a wildlife fence on encountering the moose resulted in smaller deceleration. [ABSTRACT FROM AUTHOR]

Environmental changes are predicted to have severe and rapid impacts on polar and alpine regions. At high latitudes/altitudes, cryptogams such as bryophytes and lichens are of great importance in terms of biomass, carbon/nutrient cycling, cover and ecosystem functioning. This seven-year factorial experiment examined the effects of fertilizing and experimental warming on bryophyte and lichen abundance in an alpine meadow and a heath community in subarctic Sweden. The aim was to determine whether short-term responses (five years) are good predictors of longer-term responses (seven years). Fertilizing and warming had significant negative effects on total and relative abundance of bryophytes and lichens, with the largest and most rapid decline caused by fertilizing and combined fertilizing and warming. Bryophytes decreased most in the alpine meadow community, which was bryophyte-dominated, and lichens decreased most in the heath community, which was lichen-dominated. This was surprising, as the most diverse group in each community was expected to be most resistant to perturbation. Warming alone had a delayed negative impact. Of the 16 species included in statistical analyses, seven were significantly negatively affected. Overall, the impacts of simulated warming on bryophytes and lichens as a whole and on individual species differed in time and magnitude between treatments and plant communities (meadow and heath). This will likely cause changes in the dominance structures over time. These results underscore the importance of longer-term studies to improve the quality of data used in climate change models, as models based on short-term data are poor predictors of long-term responses of bryophytes and lichens. [ABSTRACT FROM AUTHOR]

Thermal acclimatisations are important for the survival and growth of individuals and populations but seldom studied for different populations of bryophytes. The aims of this study were to (I) investigate if responses to temperature treatments were independent of the site sampled or if the intra- and interpopulation variation in responses were larger than the responses to the temperature treatments (control, press, and pulse), and to (II) examine if experimental responses varied, depending on the sampled sites. We collected samples of the circumpolar bryophyte species, Pleurozium schreberi (Willd. ex Brid.) Mitt., originating from eight altitude sites on Mt. Oakan in Hokkaido, Japan, and exposed them to three different temperature treatments ex situ for four weeks. Thermal acclimatisation was estimated by measuring responses in growth length increase, biomass increase, number of branches, and the maximum quantum yield of PS II (Fv/Fm). We found that responses to temperature treatments were dependent on the site sampled, and that differences were most pronounced in the length increase. Results also shows that the responses to experimental treatments may differ between sites. Our results therefore raise important concerns regarding the general validity of both ex situ and in situ experiments when performed on a single or a limited number of sites. [ABSTRACT FROM AUTHOR]

Litter decomposition is a key driver of ecosystem processes and carbon cycling. Decomposition rate is influenced by numerous factors, such as temperature, humidity, litter properties, soil properties, and properties of soil fauna/microbial communities. The aim of this review was to summarize current knowledge on litter decomposition above the treeline in alpine regions worldwide and identify: I) factors that have been studied in great detail, II) factors that have been less intensively investigated, III) geographical regions that have been less well studied, and IV) factors with consistent or inconsistent effects on decomposition. The review showed inconsistent results for all factors covered by two or more studies regarding their effect on decomposition rate (positive, negative, no effect), usually a result of interactions between factors. Studies examining one or several factors in the physical environment (i.e., altitude, experimental warming, microclimate, snow cover and soil moisture) were most common, while studies on different aspects of resource quality were the second most common. The impacts of trophic interactions on soil microbes and fauna were less frequently studied. Europe and Asia were the best-represented regions, in terms of number of studies and geographical distribution, while there were no studies from Africa and very few from South America and Australia. North American studies were all from Colorado, and those from Asia were all from China. In order to obtain better global representation, there is a need for studies in Africa, South America, and Australia. There is also a need for more studies to explain the large variation in responses of litter decomposition rates to different influencing factors in alpine environments. Future research should focus on interactions between different factors and on experiments testing specific relationships, such as the potential interaction between temperature and soil moisture and its effect on litter decomposition above the treeline in alpine regions. • Decomposition rate is influenced by numerous factors. • We review studies on factors affecting decomposition above treeline. • All factors show inconsistent results regarding their effect on decomposition rate. • Decomposition rate commonly influenced by interactions between factors. • Future research should focus on interactions between different factors. [ABSTRACT FROM AUTHOR]

Climate change was simulated by increasing temperature and nutrient availability in an alpine landscape. We conducted a field experiment of BACI-design (before/after control/impact) running for five seasons in two alpine communities (heath and meadow) with the factors temperature (increase of ca. 1.5–3.0°C) and nutrients (5 g N, 5 g P per m2) in a fully factorial design in northern Swedish Lapland. The response variables were abundances of plant species and functional types. Plant community responses to the experimental perturbations were investigated, and the responses of plant functional types were examined in comparison to responses at the species level. Nutrient addition, exclusively and in combination with enhanced temperature increase, exerted the most pronounced responses at the species-specific and community levels. The main responses to nutrient addition were increases in graminoids and forbs, whereas deciduous shrubs, evergreen shrubs, bryophytes, and lichens decreased. The two plant communities of heath or meadow showed different vegetation responses to the environmental treatments despite the fact that both communities were located on the same subarctic-alpine site. Furthermore, we showed that the abundance of forbs increased in response to the combined treatment of temperature and nutrient addition in the meadow plant community. Within a single-plant functional type, most species responded similarly to the enhanced treatments although there were exceptions, particularly in the moss and lichen functional types. Plant community structure showed BACI responses in that vegetation dominance relationships in the existing plant functional types changed to varying degrees in all plots, including control plots. Betula nana and lichens increased in the temperature-increased enhancements and in control plots in the heath plant community during the treatment period. The increases in control plots were probably a response to the observed warming during the treatment period in the region. [ABSTRACT FROM AUTHOR]

We simulated a predicted environmental change in a subarctic-alpine plant community to study short-term growth in Hylocomium splendens, and three-year effects in abundance changes of the five most common bryophytes at Latnjajaure, northern Sweden. The experiment had a factorial design with increased temperature and nutrients, alone and in combination. Moss growth was measured during the 1995 growing season, and we measured species abundance before and after three years of environmental perturbation. The combined treatments of fertilizer and temperature enhancement caused a decreased growth in length and dry weight in H. splendens. There was a significant decrease in abundance of Rhytidium rugosum in the combined temperature and fertilizer treatment. The other four common bryophyte species (Aulacomnium turgidum, Dicranum groenlandicum, Hylocomium splendens, and Ptilidium ciliare) showed weaker, but not significant trends in the same direction. As the bryophytes are an important component of arctic and subarctic vegetation, we expect that they will play a key role in the impact of anticipated Global Change on the ecosystems. [ABSTRACT FROM AUTHOR]

Lighting uniformity is a key factor in traffic safety, and it could even result in energy savings for light installations. However, highly uniform horizontal road lighting for motorized vehicles may not be optimal for pedestrian roads. Therefore, it is important to evaluate the way in which pedestrians experience road lighting uniformity. Accordingly, we employed a qualitative approach to examine pedestrian road lighting uniformity. Visual analyses were used to exemplify and discuss the perceived uniformity. The case studies were performed on three pedestrian roads with similar light installations. The results show that the experience of road lighting uniformity differs substantially between the three roads. Based on the case studies, there are many aspects that need to be considered beyond the light falling on the horizontal surfaces. This study suggests that the visual experience of road lighting uniformity for pedestrians is difficult to estimate with photometric values because the visual impact of uniformity is highly influenced by the spatial context and landscape. [ABSTRACT FROM AUTHOR]

The paper presents the opportunities to apply computer graphics in an object floodlighting design process and in an analysis of object illumination. The course of object floodlighting design has been defined based on a virtual three-dimensional geometric model. The problems related to carrying out the analysis of lighting, calculating the average illuminance, luminance levels and determining the illuminated object surface area are also described. These parameters are directly tied with the calculations of the Floodlighting Utilisation Factor, and therefore, with the energy efficiency of the design as well as the aspects of light pollution of the natural environment. The paper shows how high an impact of the geometric model of the object has on the accuracy of photometric calculations. Very often the model contains the components that should not be taken into account in the photometric calculations. The research on what influence the purity of the geometric mesh of the illuminated object has on the obtained results is presented. It shows that the errors can be significant, but it is possible to optimise the 3D object model appropriately in order to receive the precise results. For the example object presented in this paper, removing the planes that do not constitute its external surface has caused a two-fold increase in the average illuminance and average luminance. This is dangerous because a designer who wants to achieve a specific average luminance level in their design without optimizing the model will obtain the luminance values that will actually be much higher. [ABSTRACT FROM AUTHOR]

The aim of this review was to map synergies and trade-offs between sustainable development and energy efficiency and savings regarding exterior lighting. Exterior lighting, such as public road and street lighting, requires significant amounts of energy and hinders sustainable development through its increasing of light pollution, ecological impact, and global climate change. Interlinkages between indicators in sustainability and energy that have positive interactions will lead to a mutual reinforcement in the decision-making process, and vice versa, interlinkages between trade-offs may lead to unwanted and conflicting effects. Very few studies have presented a clear vision of how exterior lighting should be contributing to, and not counteracting, the sustainable development of our planet. This study was conducted through a theoretical and systematic analysis that examined the interactions between sustainable development and energy performance based on a framework using indicators and variables, and by reviewing the current literature. Additionally, 17 indicators of energy efficiency and energy savings were identified and used in the analysis. Most interactions between variables for sustainable development and energy performance (52%) were found to be synergistic. The synergistic interactions were mostly found (71%) in the ecological and environmental dimension showing that environmental and ecological sustainability goes hand in hand with energy efficiency and savings. Trade-offs were found only in the economic and social dimensions accounting for 18% of the interactions identified. This review shows that the interactions between sustainable development and energy performance can be used to establish more efficient policies for decision-making processes regarding exterior lighting. [ABSTRACT FROM AUTHOR]

There are several environmental and ecological effects of shipping. However, these are rarely assessed in total in the scientific literature. Thus, the aim of this study was to summarize the different impacts of water-based transport on aquatic and nearshore ecosystems and to identify knowledge gaps and areas for future research. The review identified several environmental and ecological consequences within the main impact categories of water discharges, physical impacts, and air emissions. However, although quantitative data on these consequences are generally scarce the shipping contribution to acidification by SO x - and NO x -emissions has been quantified to some extent. There are several knowledge gaps regarding the ecological consequences of, for example, the increasing amount of chemicals transported on water, the spread of non-indigenous species coupled with climate change, and physical impacts such as shipping noise and artificial light. The whole plethora of environmental consequences, as well as potential synergistic effects, should be seriously considered in transport planning. Unlabelled Image • There is a plethora of environmental and ecological effects of shipping. • Main impact categories are water discharges, physical impacts and air emissions. • A general lack of quantitative data on shipping derived environmental effects. • The shipping contribution to acidification has been quantified. • A holistic approach and synergistic effects of parameters are missing. [ABSTRACT FROM AUTHOR]

This study estimated the external cost of air pollution from shipping by means of a meta-regression analysis, which has not been made before. Three pollutants, which were included in most of the primary studies, were considered: nitrogen oxides (NOx), sulphur dioxides (SO2) and particulate matters with a diameter of max 2.5 micrometres (PM2.5). All primary studies included damages of health and a majority added impacts on agriculture and estimated the cost of air pollutants by transferring cost estimates from studies on costs of air emissions from transports in Europe. Different regression models and estimators were used and robust results were found of statistically significant emission elasticities of below one, i.e. total external costs increase by less than 1% when emissions increase by 1%. There was a small variation between the pollutants, with the highest elasticity for PM2.5 and lowest for NOx. Calculations of the marginal external cost of the pollutants showed the same pattern, with this cost being approximately six times higher for PM2.5 than for the other pollutants. Common to all pollutants was that the marginal external cost decreases when emission increases. Another robust result was a significant increase in the cost of studies published in journals compared with other publication outlets. These findings point out some caution when transferring constant external unit cost of air pollutant from shipping, which is much applied in the literature, and the cost functions estimated in this study could thus provide a complementary transfer mechanism. [ABSTRACT FROM AUTHOR]

High-altitude and alpine areas are predicted to experience rapid and substantial increases in future temperature, which may have serious impacts on soil carbon, nutrient and soil fauna. Here we report the impact of 20 years of experimental warming on soil properties and soil mites in three contrasting plant communities in alpine/subarctic Sweden. Long-term warming decreased juvenile oribatid mite density, but had no effect on adult oribatids density, total mite density, any major mite group or the most common species. Long-term warming also caused loss of nitrogen, carbon and moisture from the mineral soil layer in mesic meadow, but not in wet meadow or heath or from the organic soil layer. There was a significant site effect on the density of one mite species, Oppiella neerlandica, and all soil parameters. A significant plot-scale impact on mites suggests that small-scale heterogeneity may be important for buffering mites from global warming. The results indicated that juvenile mites may be more vulnerable to global warming than adult stages. Importantly, the results also indicated that global warming may cause carbon and nitrogen losses in alpine and tundra mineral soils and that its effects may differ at local scale. [ABSTRACT FROM AUTHOR]

The article focuses on the development of an artificial trap for the collection of fragments of dispersed bryophytes and lichens. The device, which was made of plastic FinnTurf doormats that are connected to the ground with large nails, was used for studying seed banks and seed dispersal in harsh environment. However, it has not been used to evaluate colonization of dispersal of bryophytes. In research on forests, colonization was initiated after a disturbance in a previous examination which suitable on branches and forest floors. If the method is successful, colonizing processes and vegetation dynamics would not be hard to perform in harsh locations.

Global change is predicted to cause shifts in species distributions and biodiversity in arctic tundra. We applied factorial warming and nutrient manipulation to a nutrient and species poor alpine/arctic heath community for seven years. Vascular plant abundance in control plots increased by 31%. There were also notable changes in cover in the nutrient and combined nutrient and warming treatments, with deciduous and evergreen shrubs declining, grasses overgrowing these plots. Sedge abundance initially increased significantly with nutrient amendment and then declined, going below initial values in the combined nutrient and warming treatment. Nutrient addition resulted in a change in dominance hierarchy from deciduous shrubs to grasses. We found significant declines in vascular plant diversity and evenness in the warming treatment and a decline in diversity in the combined warming and nutrient addition treatment, while nutrient addition caused a decline in species richness. The results give some experimental support that species poor plant communities with low diversity may be more vulnerable to loss of species diversity than communities with higher initial diversity. The projected increase in nutrient deposition and warming may therefore have negative impacts on ecosystem processes, functioning and services due to loss of species diversity in an already impoverished environment. [ABSTRACT FROM AUTHOR]

Phototactic and polarotactic aquatic insects, such as mayflies, can be drawn to electric lighting on bridges at night. Past research investigating the effect of light intensity, polarization, and spectrum on mayflies suggests that a combination of different techniques can reduce the number of mayflies attracted to bridges. Here, various lighting strategies are systematically tested on Veterans Memorial Bridge in Pennsylvania to investigate the effect of lighting on mayflies and address safety concerns caused by their mass crowding. Isolated trials on different parts of the bridge tested the effectiveness of correlated color temperature, chromaticity, ultraviolet radiation, shielding, and polarization. Results indicate that mayflies were more attracted to ultraviolet radiation, blue and green light, and polarized light than other lighting conditions. Shielding was minimally effective in reducing the number of mayflies on the bridge when supported by the change in light source spectrum. While the correlated color temperature did not result in a statistically significant impact, the spectral power distribution of the light sources was a major influencer for mayfly activity. Future research should investigate the effect of radiant intensity and timing on mayfly activity. Smart solid-state lighting systems and controls can also be used to adjust the light levels when needed to reduce adverse effects on aquatic insects and aid traffic safety. [ABSTRACT FROM AUTHOR]