The Experts below are selected from a list of 3561 Experts worldwide ranked by ideXlab platform
John C Brock - One of the best experts on this subject based on the ideXlab platform.
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Airborne lidar sensing of massive stony coral colonies on patch reefs in the northern Florida reef tract
Remote Sensing of Environment, 2006Co-Authors: John C Brock, Ilsa B Kuffner, C. Wayne Wright, Raquel Hernandez, Philip ThompsonAbstract:In this study we examined the ability of the NASA Experimental Advanced Airborne Research Lidar (EAARL) to discriminate cluster zones of massive stony coral colonies on northern Florida reef tract (NFRT) patch reefs based on their topographic complexity (Rugosity). Spatially dense EAARL laser submarine topographic soundings acquired in August 2002 were used to create a 1-m resolution digital Rugosity map for adjacent NFRT study areas characterized by patch reefs (Region A) and diverse substratums (Region B). In both regions, sites with lidar-sensed rugosities above 1.2 were imaged by an along-track underwater videography system that incorporated the acquisition of instantaneous GPS positions. Subsequent manual interpretation of videotape segments was performed to identify substratum types that caused elevated lidar-sensed Rugosity. Our study determined that massive coral colony formation, modified by subsequent physical and biological processes that breakdown patch reef framework, was the primary source of topographic complexity sensed by the EAARL in the NFRT. Sites recognized by lidar scanning to be topographically complex preferentially occurred around the margins of patch reefs, constituted a minor fraction of the reef system, and usually reflected the presence of massive coral colonies in cluster zones, or their derivatives created by mortality, bioerosion, and physical breakdown.
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relationships between reef fish communities and remotely sensed Rugosity measurements in biscayne national park florida usa
Environmental Biology of Fishes, 2006Co-Authors: Ilsa B Kuffner, John C Brock, Rikki Groberdunsmore, Victor Bonito, Donald T Hickey, Wayne C WrightAbstract:The realization that coral reef ecosystem management must occur across multiple spatial scales and habitat types has led scientists and resource managers to seek variables that are easily measured over large areas and correlate well with reef resources. Here we investigate the utility of new technology in airborne laser surveying (NASA Experimental Advanced Airborne Research Lidar (EAARL)) in assessing topographical complexity (Rugosity) to predict reef fish community structure on shallow (<10 m deep) patch reefs. Marine portions of Biscayne National Park, Florida, USA, were surveyed remotely using the EAARL, and reef fish populations were visually surveyed on 10 patch reefs at independent, randomly selected stations (n = 10–13 per reef). Rugosity at each station was assessed in situ by divers using the traditional chain-transect method (10-m scale), and remotely using the EAARL submarine topography data at multiple spatial scales (2, 5, and 10 m). The Rugosity and biological datasets were analyzed together to elucidate the predictive power of EAARL Rugosity in describing the variance in reef fish community variables and to assess the correlation between chain-transect and EAARL Rugosity. EAARL Rugosity was not well correlated with chain-transect Rugosity, or with species richness of fishes (although statistically significant, the amount of variance explained by the model was very low). Variance in reef fish community attributes was better explained in reef-by-reef variability than by physical variables. However, once the reef-by-reef variability was taken into account in a two-way analysis of variance, the importance of Rugosity could be seen on individual reefs. Fish species richness and abundance were statistically higher at high Rugosity stations compared to medium and low Rugosity stations, as predicted by prior ecological research. The EAARL shows promise as an important mapping tool for reef resource managers as they strive to inventory and protect coral reef resources.
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Relationships between reef fish communities and remotely sensed Rugosity measurements in Biscayne National Park, Florida, USA
Environmental Biology of Fishes, 2006Co-Authors: Ilsa B Kuffner, John C Brock, Victor Bonito, Rikki Grober-dunsmore, T. Donald Hickey, C. Wayne WrightAbstract:The realization that coral reef ecosystem management must occur across multiple spatial scales and habitat types has led scientists and resource managers to seek variables that are easily measured over large areas and correlate well with reef resources. Here we investigate the utility of new technology in airborne laser surveying (NASA Experimental Advanced Airborne Research Lidar (EAARL)) in assessing topographical complexity (Rugosity) to predict reef fish community structure on shallow (
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lidar optical Rugosity of coral reefs in biscayne national park florida
Coral Reefs, 2004Co-Authors: John C Brock, Wayne C Wright, Tonya D Clayton, Amar NayegandhiAbstract:The NASA Experimental Advanced Airborne Research Lidar (EAARL), a temporal waveform-resolving, airborne, green wavelength LIDAR (light detection and ranging), is designed to measure the submeter-scale topography of shallow reef substrates. Topographic variability is a prime component of habitat complexity, an ecological factor that both expresses and controls the abundance and distribution of many reef organisms. Following the acquisition of EAARL coverage over both mid-platform patch reefs and shelf-margin bank reefs within Biscayne National Park in August 2002, EAARL-based optical indices of topographic variability were evaluated at 15 patch reef and bank reef sites. Several sites were selected to match reefs previously evaluated in situ along underwater video and belt transects. The analysis used large populations of submarine topographic transects derived from the examination of closely spaced laser spot reflections along LIDAR raster scans. At all 15 sites, each LIDAR transect was evaluated separately to determine optical Rugosity (Rotran), and the average elevation difference between adjacent points (Av(δEap)). Further, the whole-site mean and maximum values of Rotran and Av(δEap) for the entire population of transects at each analysis site, along with their standard deviations, were calculated. This study revealed that the greater habitat complexity of inshore patch reefs versus outer bank reefs results in relative differences in topographic complexity that can be discerned in the laser returns. Accordingly, LIDAR sensing of optical Rugosity is proposed as a complementary new technique for the rapid assessment of shallow coral reefs.
Cherisse Du Preez - One of the best experts on this subject based on the ideXlab platform.
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a new arc chord ratio acr Rugosity index for quantifying three dimensional landscape structural complexity
Landscape Ecology, 2015Co-Authors: Cherisse Du PreezAbstract:Introduction Rugosity is an index of surface roughness that is widely used as a measure of landscape structural complexity in studies investigating spatially explicit ecological patterns and processes. This paper identifies and demonstrates significant issues with how we presently measure Rugosity and, by building on recent advances, proposes a novel Rugosity index that overcomes these issues.
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A new arc–chord ratio (ACR) Rugosity index for quantifying three-dimensional landscape structural complexity
Landscape Ecology, 2014Co-Authors: Cherisse Du PreezAbstract:Introduction Rugosity is an index of surface roughness that is widely used as a measure of landscape structural complexity in studies investigating spatially explicit ecological patterns and processes. This paper identifies and demonstrates significant issues with how we presently measure Rugosity and, by building on recent advances, proposes a novel Rugosity index that overcomes these issues.
Mark E. Monaco - One of the best experts on this subject based on the ideXlab platform.
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Using bathymetric lidar to define nearshore benthic habitat complexity: Implications for management of reef fish assemblages in Hawaii
Remote Sensing of Environment, 2008Co-Authors: Lisa M. Wedding, Matthew Mcgranaghan, Arthur M Friedlander, Russell Yost, Mark E. MonacoAbstract:Abstract Habitat complexity plays a major role in determining the distribution and structure of fish assemblages in the aquatic environment. These locations are critical for ecosystem function and have significant implications for conservation and management. In this study, we evaluated the utility of remotely sensed lidar (light detection and ranging) data for deriving substrate Rugosity (a measure of habitat complexity) on a coral reef in Hawaii. We also assessed the potential application of lidar data for examining the relationship between habitat complexity and Hawaiian reef fish assemblage characteristics. Lidar-derived Rugosity (4 m grid size) was found to be highly correlated with in-situ Rugosity and was concluded to be a viable method for measuring Rugosity in analogous coral reef environments. We established that lidar-derived Rugosity was a good predictor of fish biomass and demonstrated a strong relationship with several fish assemblage metrics in hard bottom habitat at multiple spatial resolutions. This research demonstrates (i) the efficacy of lidar data to provide substrate Rugosity measures at scales commensurate with the resources and their environment (ii) the applicability of lidar-derived Rugosity for examining fish–habitat relationships on a coral reef in Hawaii and (iii) the potential of lidar to provide information about the seascape structure that can ultimately be used to prioritize areas for conservation and management.
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Using bathymetric lidar to define nearshore benthic habitat complexity: Implications for management of reef fish assemblages in Hawaii
Remote Sensing of Environment, 2008Co-Authors: Lisa M. Wedding, Matthew Mcgranaghan, Russell S. Yost, Arthur M Friedlander, Mark E. MonacoAbstract:Habitat complexity plays a major role in determining the distribution and structure of fish assemblages in the aquatic environment. These locations are critical for ecosystem function and have significant implications for conservation and management. In this study, we evaluated the utility of remotely sensed lidar (light detection and ranging) data for deriving substrate Rugosity (a measure of habitat complexity) on a coral reef in Hawaii. We also assessed the potential application of lidar data for examining the relationship between habitat complexity and Hawaiian reef fish assemblage characteristics. Lidar-derived Rugosity (4 m grid size) was found to be highly correlated with in-situ Rugosity and was concluded to be a viable method for measuring Rugosity in analogous coral reef environments. We established that lidar-derived Rugosity was a good predictor of fish biomass and demonstrated a strong relationship with several fish assemblage metrics in hard bottom habitat at multiple spatial resolutions. This research demonstrates (i) the efficacy of lidar data to provide substrate Rugosity measures at scales commensurate with the resources and their environment (ii) the applicability of lidar-derived Rugosity for examining fish-habitat relationships on a coral reef in Hawaii and (iii) the potential of lidar to provide information about the seascape structure that can ultimately be used to prioritize areas for conservation and management. © 2008 Elsevier Inc.
Amar Nayegandhi - One of the best experts on this subject based on the ideXlab platform.
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lidar optical Rugosity of coral reefs in biscayne national park florida
Coral Reefs, 2004Co-Authors: John C Brock, Wayne C Wright, Tonya D Clayton, Amar NayegandhiAbstract:The NASA Experimental Advanced Airborne Research Lidar (EAARL), a temporal waveform-resolving, airborne, green wavelength LIDAR (light detection and ranging), is designed to measure the submeter-scale topography of shallow reef substrates. Topographic variability is a prime component of habitat complexity, an ecological factor that both expresses and controls the abundance and distribution of many reef organisms. Following the acquisition of EAARL coverage over both mid-platform patch reefs and shelf-margin bank reefs within Biscayne National Park in August 2002, EAARL-based optical indices of topographic variability were evaluated at 15 patch reef and bank reef sites. Several sites were selected to match reefs previously evaluated in situ along underwater video and belt transects. The analysis used large populations of submarine topographic transects derived from the examination of closely spaced laser spot reflections along LIDAR raster scans. At all 15 sites, each LIDAR transect was evaluated separately to determine optical Rugosity (Rotran), and the average elevation difference between adjacent points (Av(δEap)). Further, the whole-site mean and maximum values of Rotran and Av(δEap) for the entire population of transects at each analysis site, along with their standard deviations, were calculated. This study revealed that the greater habitat complexity of inshore patch reefs versus outer bank reefs results in relative differences in topographic complexity that can be discerned in the laser returns. Accordingly, LIDAR sensing of optical Rugosity is proposed as a complementary new technique for the rapid assessment of shallow coral reefs.
Wayne C Wright - One of the best experts on this subject based on the ideXlab platform.
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relationships between reef fish communities and remotely sensed Rugosity measurements in biscayne national park florida usa
Environmental Biology of Fishes, 2006Co-Authors: Ilsa B Kuffner, John C Brock, Rikki Groberdunsmore, Victor Bonito, Donald T Hickey, Wayne C WrightAbstract:The realization that coral reef ecosystem management must occur across multiple spatial scales and habitat types has led scientists and resource managers to seek variables that are easily measured over large areas and correlate well with reef resources. Here we investigate the utility of new technology in airborne laser surveying (NASA Experimental Advanced Airborne Research Lidar (EAARL)) in assessing topographical complexity (Rugosity) to predict reef fish community structure on shallow (<10 m deep) patch reefs. Marine portions of Biscayne National Park, Florida, USA, were surveyed remotely using the EAARL, and reef fish populations were visually surveyed on 10 patch reefs at independent, randomly selected stations (n = 10–13 per reef). Rugosity at each station was assessed in situ by divers using the traditional chain-transect method (10-m scale), and remotely using the EAARL submarine topography data at multiple spatial scales (2, 5, and 10 m). The Rugosity and biological datasets were analyzed together to elucidate the predictive power of EAARL Rugosity in describing the variance in reef fish community variables and to assess the correlation between chain-transect and EAARL Rugosity. EAARL Rugosity was not well correlated with chain-transect Rugosity, or with species richness of fishes (although statistically significant, the amount of variance explained by the model was very low). Variance in reef fish community attributes was better explained in reef-by-reef variability than by physical variables. However, once the reef-by-reef variability was taken into account in a two-way analysis of variance, the importance of Rugosity could be seen on individual reefs. Fish species richness and abundance were statistically higher at high Rugosity stations compared to medium and low Rugosity stations, as predicted by prior ecological research. The EAARL shows promise as an important mapping tool for reef resource managers as they strive to inventory and protect coral reef resources.
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lidar optical Rugosity of coral reefs in biscayne national park florida
Coral Reefs, 2004Co-Authors: John C Brock, Wayne C Wright, Tonya D Clayton, Amar NayegandhiAbstract:The NASA Experimental Advanced Airborne Research Lidar (EAARL), a temporal waveform-resolving, airborne, green wavelength LIDAR (light detection and ranging), is designed to measure the submeter-scale topography of shallow reef substrates. Topographic variability is a prime component of habitat complexity, an ecological factor that both expresses and controls the abundance and distribution of many reef organisms. Following the acquisition of EAARL coverage over both mid-platform patch reefs and shelf-margin bank reefs within Biscayne National Park in August 2002, EAARL-based optical indices of topographic variability were evaluated at 15 patch reef and bank reef sites. Several sites were selected to match reefs previously evaluated in situ along underwater video and belt transects. The analysis used large populations of submarine topographic transects derived from the examination of closely spaced laser spot reflections along LIDAR raster scans. At all 15 sites, each LIDAR transect was evaluated separately to determine optical Rugosity (Rotran), and the average elevation difference between adjacent points (Av(δEap)). Further, the whole-site mean and maximum values of Rotran and Av(δEap) for the entire population of transects at each analysis site, along with their standard deviations, were calculated. This study revealed that the greater habitat complexity of inshore patch reefs versus outer bank reefs results in relative differences in topographic complexity that can be discerned in the laser returns. Accordingly, LIDAR sensing of optical Rugosity is proposed as a complementary new technique for the rapid assessment of shallow coral reefs.
