The Experts below are selected from a list of 240 Experts worldwide ranked by ideXlab platform
T. Matthew Robson - One of the best experts on this subject based on the ideXlab platform.
-
The influence of Spectral Composition on spring and autumn phenology in trees.
Tree physiology, 2019Co-Authors: Craig C. Brelsford, Line Nybakken, Titta Kotilainen, T. Matthew RobsonAbstract:Several recent reviews highlight the molecular mechanisms that underpin phenological responses to temperature and photoperiod; however, these have mostly overlooked the influence of solar radiation and its Spectral Composition on these processes. For instance, solar radiation in the blue and ultraviolet (UV) regions of the spectrum, as well as the red/far-red (R:FR) ratio, can influence spring and autumn phenology. Solar radiation reaching the Earth changes diurnally and seasonally; however, rising global temperatures, latitudinal range shifts and light pollution are likely to produce novel combinations of phenological cues for tree species. Here, we review the literature on phenological responses to Spectral Composition. Our objective was to explore the natural variation in Spectral Composition using radiative transfer models and to reveal any species-specific or ecotype-specific responses relating to latitudinal origin. These responses are likely to be most pronounced at high latitudes where Spectral Composition varies most throughout the year. For instance, trees from high latitudes tend to be more sensitive to changes in R:FR than those from low latitudes. The effects of blue light and UV radiation on phenology have not been studied as much as those of R:FR, but the limited results available suggest both could be candidate cues affecting autumn leaf colouration and senescence. Failure of more-southern species and ecotypes to adapt and use Spectral cues during northwards range shifts could result in mistimed phenology, potentially resulting in frost damage, reduced fitness and limited range expansion. Future areas for research should look to establish how consistently different functional types of tree respond to Spectral cues and identify photoreceptor-mediated mechanisms that allow plants to combine information from multiple light cues to coordinate the timing of phenological events. It should then be feasible to consider the synchronous or sequential action of light cues within a hierarchy of environmental factors regulating phenology.
-
The influence of Spectral Composition on spring and autumn phenology in trees
2019Co-Authors: Craig C. Brelsford, Line Nybakken, Titta K Kotilainen, T. Matthew RobsonAbstract:Several recent reviews have highlighted the molecular mechanisms which underpin phenological responses to temperature and photoperiod, however these have mostly overlooked the influence of solar radiation and its Spectral Composition on these processes. For instance, solar radiation in the blue (B) and ultraviolet (UV) regions of the spectrum, as well as the red/far-red ratio (R:FR), can all influence spring and autumn phenology. Solar radiation reaching the Earth changes diurnally and seasonally, however rising global temperatures, latitudinal range shifts and light pollution are likely to produce novel combinations of phenological cues for tree species. Here, we review the literature on phenological responses to Spectral Composition, and discuss the ecological relevance of Spectral Composition as a cue influencing the timing of trees’ life cycles. Our objective was to reveal any species-specific, or ecotype-specific responses relating to latitudinal origin. Furthermore, we sought to identify neglected regions of the solar spectrum which may affect phenological responses. Trees from high latitudes tend to be more sensitive to changes in R:FR in comparison to those from low latitudes. The effects on phenology of blue light and UV have not been studied as much as those of R:FR, but demonstrate that both blue light and UV-B affect autumnal bud set in trees. Given that R:FR was not found to affect the leaf senescence of six woody species, but blue light can accelerate leaf senescence in Glycine max, we suggest it could be worth investigating the role of blue light on leaf senescence in trees. Future areas for research should look to establish how consistently different functional types of trees respond to Spectral cues, and identify photoreceptor-mediated mechanisms which allow plants to combine information from multiple light cues to coordinate the timing of phenological events
Craig C. Brelsford - One of the best experts on this subject based on the ideXlab platform.
-
The influence of Spectral Composition on spring and autumn phenology in trees.
Tree physiology, 2019Co-Authors: Craig C. Brelsford, Line Nybakken, Titta Kotilainen, T. Matthew RobsonAbstract:Several recent reviews highlight the molecular mechanisms that underpin phenological responses to temperature and photoperiod; however, these have mostly overlooked the influence of solar radiation and its Spectral Composition on these processes. For instance, solar radiation in the blue and ultraviolet (UV) regions of the spectrum, as well as the red/far-red (R:FR) ratio, can influence spring and autumn phenology. Solar radiation reaching the Earth changes diurnally and seasonally; however, rising global temperatures, latitudinal range shifts and light pollution are likely to produce novel combinations of phenological cues for tree species. Here, we review the literature on phenological responses to Spectral Composition. Our objective was to explore the natural variation in Spectral Composition using radiative transfer models and to reveal any species-specific or ecotype-specific responses relating to latitudinal origin. These responses are likely to be most pronounced at high latitudes where Spectral Composition varies most throughout the year. For instance, trees from high latitudes tend to be more sensitive to changes in R:FR than those from low latitudes. The effects of blue light and UV radiation on phenology have not been studied as much as those of R:FR, but the limited results available suggest both could be candidate cues affecting autumn leaf colouration and senescence. Failure of more-southern species and ecotypes to adapt and use Spectral cues during northwards range shifts could result in mistimed phenology, potentially resulting in frost damage, reduced fitness and limited range expansion. Future areas for research should look to establish how consistently different functional types of tree respond to Spectral cues and identify photoreceptor-mediated mechanisms that allow plants to combine information from multiple light cues to coordinate the timing of phenological events. It should then be feasible to consider the synchronous or sequential action of light cues within a hierarchy of environmental factors regulating phenology.
-
The influence of Spectral Composition on spring and autumn phenology in trees
2019Co-Authors: Craig C. Brelsford, Line Nybakken, Titta K Kotilainen, T. Matthew RobsonAbstract:Several recent reviews have highlighted the molecular mechanisms which underpin phenological responses to temperature and photoperiod, however these have mostly overlooked the influence of solar radiation and its Spectral Composition on these processes. For instance, solar radiation in the blue (B) and ultraviolet (UV) regions of the spectrum, as well as the red/far-red ratio (R:FR), can all influence spring and autumn phenology. Solar radiation reaching the Earth changes diurnally and seasonally, however rising global temperatures, latitudinal range shifts and light pollution are likely to produce novel combinations of phenological cues for tree species. Here, we review the literature on phenological responses to Spectral Composition, and discuss the ecological relevance of Spectral Composition as a cue influencing the timing of trees’ life cycles. Our objective was to reveal any species-specific, or ecotype-specific responses relating to latitudinal origin. Furthermore, we sought to identify neglected regions of the solar spectrum which may affect phenological responses. Trees from high latitudes tend to be more sensitive to changes in R:FR in comparison to those from low latitudes. The effects on phenology of blue light and UV have not been studied as much as those of R:FR, but demonstrate that both blue light and UV-B affect autumnal bud set in trees. Given that R:FR was not found to affect the leaf senescence of six woody species, but blue light can accelerate leaf senescence in Glycine max, we suggest it could be worth investigating the role of blue light on leaf senescence in trees. Future areas for research should look to establish how consistently different functional types of trees respond to Spectral cues, and identify photoreceptor-mediated mechanisms which allow plants to combine information from multiple light cues to coordinate the timing of phenological events
James D Metzger - One of the best experts on this subject based on the ideXlab platform.
-
tall fescue photomorphogenesis as influenced by changes in the Spectral Composition and light intensity
Crop Science, 2005Co-Authors: Benjamin Wherley, David S Gardner, James D MetzgerAbstract:The influence of deciduous foliage shade on turfgrass development has not been fully investigated. Previous research neglects changes in Spectral distribution, e.g., red:far-red light (R:FR) ratios common of foliage shade. Turfgrass plants may respond simultaneously but in different ways to changes in light intensity and Spectral Composition. A field study was conducted in 2001-2002 at the Ohio Turfgrass Research and Educational Fadlity, Columbus, OH. Two tall fescue (Festuca arundinacea Schreb.) cultivars of differing shade tolerance were established under low photosynthetic photon flux (PPF) in approximately 8% of full sunlight with high (>1) and low (<1) R:FR ratios to distinguish between developmental effects of R:FR ratio (Spectral Composition) and PPF (light intensity) on turfgrass photomorphogenesis. Few morphological differences in shade tolerance between the two cultivars were observed during the 2-yr study. However, under low PPF, high R:FR ratios led to increased tillering, leaf blade width and thickness, and chlorophyll contents. Root mass declined under reduced PPF regardless of R:FR ratio. Results suggest that while turfgrass photomorphogenesis in shade is influenced by changes in PPF, many characters are further influenced by changes in the R:FR ratio.
-
Tall Fescue Photomorphogenesis as Influenced by Changes in the Spectral Composition and Light Intensity
Crop Science, 2005Co-Authors: Benjamin Wherley, David S Gardner, James D MetzgerAbstract:The influence of deciduous foliage shade on turfgrass development has not been fully investigated. Previous research neglects changes in Spectral distribution, e.g., red:far-red light (R:FR) ratios common of foliage shade. Turfgrass plants may respond simultaneously but in different ways to changes in light intensity and Spectral Composition. A field study was conducted in 2001-2002 at the Ohio Turfgrass Research and Educational Fadlity, Columbus, OH. Two tall fescue (Festuca arundinacea Schreb.) cultivars of differing shade tolerance were established under low photosynthetic photon flux (PPF) in approximately 8% of full sunlight with high (>1) and low (
U.ali Rahoma - One of the best experts on this subject based on the ideXlab platform.
-
Clearness index estimation for Spectral Composition of direct and global solar radiations
Applied Energy, 2001Co-Authors: U.ali RahomaAbstract:Abstract Measurements of cloudless direct, global, and diffuse solar radiations, taken over a one year period at Helwan, are analyzed in terms of global index and diffuse fraction for clear-sky conditions. The dependence of the diffuse fraction on the global index was represented by a polynomial. These results support the use of routine instantaneous surface meteorological data to calculate global and diffuse radiations on a horizontal surface in the absence of any other radiation measurements. The Spectral Composition of the global solar-radiation was found to be 4.3% UV band, 32.5% band range 250–630 nm, 13.74% red band, 52.75% infrared band and 29.7% diffuse solar-radiation. The Spectral distribution of direct solar-radiation ratio of the extraterrestrial solar radiation was found to be: 0.69% green and blue band, 47.5% yellow and orange band 45% red band, and 52.7% infra-red band.
Line Nybakken - One of the best experts on this subject based on the ideXlab platform.
-
The influence of Spectral Composition on spring and autumn phenology in trees.
Tree physiology, 2019Co-Authors: Craig C. Brelsford, Line Nybakken, Titta Kotilainen, T. Matthew RobsonAbstract:Several recent reviews highlight the molecular mechanisms that underpin phenological responses to temperature and photoperiod; however, these have mostly overlooked the influence of solar radiation and its Spectral Composition on these processes. For instance, solar radiation in the blue and ultraviolet (UV) regions of the spectrum, as well as the red/far-red (R:FR) ratio, can influence spring and autumn phenology. Solar radiation reaching the Earth changes diurnally and seasonally; however, rising global temperatures, latitudinal range shifts and light pollution are likely to produce novel combinations of phenological cues for tree species. Here, we review the literature on phenological responses to Spectral Composition. Our objective was to explore the natural variation in Spectral Composition using radiative transfer models and to reveal any species-specific or ecotype-specific responses relating to latitudinal origin. These responses are likely to be most pronounced at high latitudes where Spectral Composition varies most throughout the year. For instance, trees from high latitudes tend to be more sensitive to changes in R:FR than those from low latitudes. The effects of blue light and UV radiation on phenology have not been studied as much as those of R:FR, but the limited results available suggest both could be candidate cues affecting autumn leaf colouration and senescence. Failure of more-southern species and ecotypes to adapt and use Spectral cues during northwards range shifts could result in mistimed phenology, potentially resulting in frost damage, reduced fitness and limited range expansion. Future areas for research should look to establish how consistently different functional types of tree respond to Spectral cues and identify photoreceptor-mediated mechanisms that allow plants to combine information from multiple light cues to coordinate the timing of phenological events. It should then be feasible to consider the synchronous or sequential action of light cues within a hierarchy of environmental factors regulating phenology.
-
The influence of Spectral Composition on spring and autumn phenology in trees
2019Co-Authors: Craig C. Brelsford, Line Nybakken, Titta K Kotilainen, T. Matthew RobsonAbstract:Several recent reviews have highlighted the molecular mechanisms which underpin phenological responses to temperature and photoperiod, however these have mostly overlooked the influence of solar radiation and its Spectral Composition on these processes. For instance, solar radiation in the blue (B) and ultraviolet (UV) regions of the spectrum, as well as the red/far-red ratio (R:FR), can all influence spring and autumn phenology. Solar radiation reaching the Earth changes diurnally and seasonally, however rising global temperatures, latitudinal range shifts and light pollution are likely to produce novel combinations of phenological cues for tree species. Here, we review the literature on phenological responses to Spectral Composition, and discuss the ecological relevance of Spectral Composition as a cue influencing the timing of trees’ life cycles. Our objective was to reveal any species-specific, or ecotype-specific responses relating to latitudinal origin. Furthermore, we sought to identify neglected regions of the solar spectrum which may affect phenological responses. Trees from high latitudes tend to be more sensitive to changes in R:FR in comparison to those from low latitudes. The effects on phenology of blue light and UV have not been studied as much as those of R:FR, but demonstrate that both blue light and UV-B affect autumnal bud set in trees. Given that R:FR was not found to affect the leaf senescence of six woody species, but blue light can accelerate leaf senescence in Glycine max, we suggest it could be worth investigating the role of blue light on leaf senescence in trees. Future areas for research should look to establish how consistently different functional types of trees respond to Spectral cues, and identify photoreceptor-mediated mechanisms which allow plants to combine information from multiple light cues to coordinate the timing of phenological events
