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Macgregor, C. J., Evans, D. M., Fox, R., & Pocock, M. J. O. (2016). The dark side of street lighting: impacts on moths and evidence for the disruption of nocturnal pollen transport. Glob Chang Biol, 23(2), 697–707.
Abstract: Among drivers of environmental change, artificial light at night is relatively poorly understood, yet is increasing on a global scale. The community-level effects of existing street lights on moths and their biotic interactions have not previously been studied. Using a combination of sampling methods at matched-pairs of lit and unlit sites, we found significant effects of street lighting: moth abundance at ground level was halved at lit sites, species richness was >25% lower, and flight activity at the level of the light was 70% greater. Furthermore, we found that 23% of moths carried pollen of at least 28 plant species and that there was a consequent overall reduction in pollen transport at lit sites. These findings support the disruptive impact of lights on moth activity, which is one proposed mechanism driving moth declines, and suggest that street lighting potentially impacts upon pollination by nocturnal invertebrates. We highlight the importance of considering both direct and cascading impacts of artificial light.
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Schroer, S., & Hölker, F. (2016). Impact of Lighting on Flora and Fauna. In Handbook of Advanced Lighting Technology (pp. 1–33). Springer.
Abstract: Technology, especially artificial light at night (ALAN), often has unexpected impacts on the environment. This chapter addresses both the perception of light by various organisms and the impact of ALAN on flora and fauna. The responses to ALAN are subdivided into the effects of light intensity, color spectra, and duration and timing of illumination. The ways organisms perceive light can be as variable as the habitats they live in. ALAN often interferes with natural light information. It is rarely neutral and has significant impacts beyond human perception. For example, UV light reflection of generative plant parts or the direction of light is used by many organisms as information for foraging, finding spawning sites, or communication. Contemporary outdoor lighting often lacks sustainable planning, even though the protection of species, habitat, and human well-being could be improved by adopting simple technical measures. The increasing use of ALAN with high intensities in the blue part of the spectrum, e.g., fluorescent light and LEDs, is discussed as a critical trend. Blue light is a major circadian signal in higher vertebrates and can substantially impact the orientation of organisms such as numerous insect species. A better understanding of how various types and sources of artificial light, and how organisms perceive ALAN, will be an important step towards more sustainable lighting. Such knowledge is the basis for sustainable lighting planning and the development of solutions to protect biodiversity from the effects of outdoor lighting. Maps that describe the rapid changes in ALAN are urgently needed. In addition, measures are required to reduce the increasing use and intensity of ALAN in more remote areas as signaling thresholds in flora and fauna at night are often close to moonlight intensity and far below streetlight levels.
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Son, K. - H., Jeon, Y. - M., & Oh, M. - M. (2016). Application of supplementary white and pulsed light-emitting diodes to lettuce grown in a plant factory with artificial lighting. Hortic. Environ. Biotechnol., 57(6), 560–572.
Abstract: Light-emitting diodes (LEDs) are currently undergoing rapid development as plant growth light sources in a plant factory with artificial lighting (PFAL). However, little is known about the effects of supplementary light and pulsed LEDs on plant growth, bioactive compound productions, and energy efficiency in lettuce. In this study, we aimed to determine the effects of supplementary white LEDs (study I) and pulsed LEDs (study II) on red leaf lettuce (Lactuca sativa L. ‘Sunmang’). In study I, six LED sources were used to determine the effects of supplementary white LEDs (RGB 7:1:1, 7:1:2, RWB 7:1:2, 7:2:1, 8:1:1, 8:2:0 [based on chip number] on lettuce). Fluorescent lamps were used as the control. In study II, pulsed RWB 7:2:1 LED treatments (30, 10, 1 kHz with a 50 or 75% duty ratio) were applied to lettuce. In study I, the application of red and blue fractions improved plant growth characteristics and the accumulation of antioxidant phenolic compounds, respectively. In addition, the application of green light increased plant growth, including the fresh and dry weights of shoots and roots, as well as leaf area. However, the substitution of green LEDs with white LEDs induced approximately 3.4-times higher light and energy use efficiency. In study II, the growth characteristics and photosynthesis of lettuce were affected by various combinations of duty ratio and frequency. In particular, biomass under a 1 kHz 75% duty ratio of pulsed LEDs was not significantly different from that of the control (continuous LEDs). Moreover, no significant difference in leaf photosynthetic rate was observed between any pulsed LED treatment utilizing a 75% duty ratio versus continuous LEDs. However, some pulsed LED treatments may potentially improve light and energy use efficiency compared to continuous LEDs. These results suggest that the fraction of red, blue, and green wavelengths of LEDs is an important factor for plant growth and the biosynthesis of bioactive compounds in lettuce and that supplementary white LEDs (based on a combination of red and blue LEDs) might be more suitable as a commercial lighting source than green LEDs. In addition, the use of suitable pulses of LEDs might save energy while inducing plant growth similar to that under continuous LEDs. Our findings provide important basic information for designing optimal light sources for use in a PFAL.
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Polivka, T. N., Wang, J., Ellison, L. T., Hyer, E. J., & Ichoku, C. M. (2016). Improving Nocturnal Fire Detection With the VIIRS Day-Night Band. IEEE Trans. Geosci. Remote Sensing, 54(9), 5503–5519.
Abstract: Building on existing techniques for satellite remote sensing of fires, this paper takes advantage of the day-night band (DNB) aboard the Visible Infrared Imaging Radiometer Suite (VIIRS) to develop the Firelight Detection Algorithm (FILDA), which characterizes fire pixels based on both visible-light and infrared (IR) signatures at night. By adjusting fire pixel selection criteria to include visible-light signatures, FILDA allows for significantly improved detection of pixels with smaller and/or cooler subpixel hotspots than the operational Interface Data Processing System (IDPS) algorithm. VIIRS scenes with near-coincident Advanced Spaceborne Thermal Emission and Reflection (ASTER) overpasses are examined after applying the operational VIIRS fire product algorithm and including a modified “candidate fire pixel selection†approach from FILDA that lowers the 4-μm brightness temperature (BT) threshold but includes a minimum DNB radiance. FILDA is shown to be effective in detecting gas flares and characterizing fire lines during large forest fires (such as the Rim Fire in California and High Park fire in Colorado). Compared with the operational VIIRS fire algorithm for the study period, FILDA shows a large increase (up to 90%) in the number of detected fire pixels that can be verified with the finer resolution ASTER data (90 m). Part (30%) of this increase is likely due to a combined use of DNB and lower 4-μm BT thresholds for fire detection in FILDA. Although further studies are needed, quantitative use of the DNB to improve fire detection could lead to reduced response times to wildfires and better estimate of fire characteristics (smoldering and flaming) at night.
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Rund, S., O'Donnell, A., Gentile, J., & Reece, S. (2016). Daily Rhythms in Mosquitoes and Their Consequences for Malaria Transmission. Insects, 7(2), 14.
Abstract: The 24-h day involves cycles in environmental factors that impact organismal fitness. This is thought to select for organisms to regulate their temporal biology accordingly, through circadian and diel rhythms. In addition to rhythms in abiotic factors (such as light and temperature), biotic factors, including ecological interactions, also follow daily cycles. How daily rhythms shape, and are shaped by, interactions between organisms is poorly understood. Here, we review an emerging area, namely the causes and consequences of daily rhythms in the interactions between vectors, their hosts and the parasites they transmit. We focus on mosquitoes, malaria parasites and vertebrate hosts, because this system offers the opportunity to integrate from genetic and molecular mechanisms to population dynamics and because disrupting rhythms offers a novel avenue for disease control.
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