The Experts below are selected from a list of 1005498 Experts worldwide ranked by ideXlab platform
Barbara A. Richardson - One of the best experts on this subject based on the ideXlab platform.
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Functional traits and Environmental Conditions predict community isotopic niches and energy pathways across spatial scales
Functional Ecology, 2018Co-Authors: Olivier Dézerald, Diane S. Srivastava, Jean-françois Carrias, Bruno Corbara, Vinicius F. Farjalla, Nicholas A. C. Marino, Gustavo C. O. Piccoli, Regis Cereghino, Céline Leroy, Barbara A. RichardsonAbstract:Despite ongoing research in food web ecology and functional biogeography, the links between food web structure, functional traits and Environmental Conditions across spatial scales remain poorly understood. Trophic niches, defined as the amount of energy and elemental space occupied by species and food webs, may help bridge this divide. Here, we ask how the functional traits of species, the Environmental Conditions of habitats and the spatial scale of analysis jointly determine the characteristics of trophic niches. We used isotopic niches as a proxy of trophic niches, and conducted analyses at spatial scales ranging from local food webs and metacommunities to geographically distant sites.We sampled aquatic macroinvertebrates from 104 tank bromeliads distributed across five sites from Central to South America and compiled the macroinvertebrates’ functional traits and stable isotope values (δ15N and δ13C). We assessed how isotopic niches within each bromeliad were influenced by the functional trait composition of their associated invertebrates and Environmental Conditions (i.e., habitat size, canopy cover [CC] and detrital concentration [DC]). We then evaluated whether the diet of dominant predators and, consequently, energy pathways within food webs reflected functional and Environmental changes among bromeliads across sites. At last, we determined the extent to which the isotopic niches of macroinvertebrates within each bromeliad contributed to the metacommunity isotopic niches within each site and compared these metacommunity‐level niches over biogeographic scales. At the bromeliad level, isotopic niches increased with the functional richness of species in the food web and the DC in the bromeliad. The diet of top predators tracked shifts in prey biomass along gradients of CC and DC. Bromeliads that grew under heterogeneous CC displayed less trophic redundancy and therefore combined to form larger metacommunity isotopic niches. At last, the size of metacommunity niches depended on within‐site heterogeneity in CC. Our results suggest that the trophic niches occupied by food webs can predictably scale from local food webs to metacommunities to biogeographic regions. This scaling process is determined by both the functional traits of species and heterogeneity in Environmental Conditions.
Olivier Dézerald - One of the best experts on this subject based on the ideXlab platform.
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Functional traits and Environmental Conditions predict community isotopic niches and energy pathways across spatial scales
Functional Ecology, 2018Co-Authors: Olivier Dézerald, Diane S. Srivastava, Jean-françois Carrias, Bruno Corbara, Vinicius F. Farjalla, Nicholas A. C. Marino, Gustavo C. O. Piccoli, Regis Cereghino, Céline Leroy, Barbara A. RichardsonAbstract:Despite ongoing research in food web ecology and functional biogeography, the links between food web structure, functional traits and Environmental Conditions across spatial scales remain poorly understood. Trophic niches, defined as the amount of energy and elemental space occupied by species and food webs, may help bridge this divide. Here, we ask how the functional traits of species, the Environmental Conditions of habitats and the spatial scale of analysis jointly determine the characteristics of trophic niches. We used isotopic niches as a proxy of trophic niches, and conducted analyses at spatial scales ranging from local food webs and metacommunities to geographically distant sites.We sampled aquatic macroinvertebrates from 104 tank bromeliads distributed across five sites from Central to South America and compiled the macroinvertebrates’ functional traits and stable isotope values (δ15N and δ13C). We assessed how isotopic niches within each bromeliad were influenced by the functional trait composition of their associated invertebrates and Environmental Conditions (i.e., habitat size, canopy cover [CC] and detrital concentration [DC]). We then evaluated whether the diet of dominant predators and, consequently, energy pathways within food webs reflected functional and Environmental changes among bromeliads across sites. At last, we determined the extent to which the isotopic niches of macroinvertebrates within each bromeliad contributed to the metacommunity isotopic niches within each site and compared these metacommunity‐level niches over biogeographic scales. At the bromeliad level, isotopic niches increased with the functional richness of species in the food web and the DC in the bromeliad. The diet of top predators tracked shifts in prey biomass along gradients of CC and DC. Bromeliads that grew under heterogeneous CC displayed less trophic redundancy and therefore combined to form larger metacommunity isotopic niches. At last, the size of metacommunity niches depended on within‐site heterogeneity in CC. Our results suggest that the trophic niches occupied by food webs can predictably scale from local food webs to metacommunities to biogeographic regions. This scaling process is determined by both the functional traits of species and heterogeneity in Environmental Conditions.
Francois Mougeot - One of the best experts on this subject based on the ideXlab platform.
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Environmental Conditions influence red grouse ornamentation at a population level
Biological Journal of The Linnean Society, 2012Co-Authors: Pablo Vergara, Stephen M Redpath, Jesus Martinezpadilla, Francois MougeotAbstract:Theory suggests that condition-dependent sexual displays should be more weakly expressed under adverse Conditions than under more favourable ones. Here, we tested this hypothesis in wild red grouse Lagopus lagopus scoticus using a data set of nearly 1500 individuals from nine populations over 8 years, covering varying Environmental Conditions. We analysed whether male and female ornament expression (i.e. comb size) in a given site and year varied with various indices of Environmental Conditions: population density, Trichostrongylus tenuis nematode infection at the population level, and climate Conditions [measured as winter North Atlantic oscillation (NAO) index]. We found that average comb size in males, but not in females, negatively correlated with population density, parasite infection levels, and winter NAO index. Furthermore, the coefficient of variation (CV) of comb size was higher in females than in males. CVs in both males and females were not clearly associated with the studied Environmental variables. Our results support the idea that the expression of condition-dependent sexual traits should be lower under more stressful Environmental Conditions, but only in males. We discuss the potential reasons behind the effect of Environmental Conditions on secondary sexual traits, and why these effects differ between sexes. © 2012 The Linnean Society of London, Biological Journal of the Linnean Society, 2012, 107, 788–798.
Jesus Martinezpadilla - One of the best experts on this subject based on the ideXlab platform.
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Environmental Conditions influence red grouse ornamentation at a population level
Biological Journal of The Linnean Society, 2012Co-Authors: Pablo Vergara, Stephen M Redpath, Jesus Martinezpadilla, Francois MougeotAbstract:Theory suggests that condition-dependent sexual displays should be more weakly expressed under adverse Conditions than under more favourable ones. Here, we tested this hypothesis in wild red grouse Lagopus lagopus scoticus using a data set of nearly 1500 individuals from nine populations over 8 years, covering varying Environmental Conditions. We analysed whether male and female ornament expression (i.e. comb size) in a given site and year varied with various indices of Environmental Conditions: population density, Trichostrongylus tenuis nematode infection at the population level, and climate Conditions [measured as winter North Atlantic oscillation (NAO) index]. We found that average comb size in males, but not in females, negatively correlated with population density, parasite infection levels, and winter NAO index. Furthermore, the coefficient of variation (CV) of comb size was higher in females than in males. CVs in both males and females were not clearly associated with the studied Environmental variables. Our results support the idea that the expression of condition-dependent sexual traits should be lower under more stressful Environmental Conditions, but only in males. We discuss the potential reasons behind the effect of Environmental Conditions on secondary sexual traits, and why these effects differ between sexes. © 2012 The Linnean Society of London, Biological Journal of the Linnean Society, 2012, 107, 788–798.
Wolfram Burgard - One of the best experts on this subject based on the ideXlab platform.
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adapnet adaptive semantic segmentation in adverse Environmental Conditions
International Conference on Robotics and Automation, 2017Co-Authors: Abhinav Valada, Johan Vertens, Ankit Dhall, Wolfram BurgardAbstract:Robust scene understanding of outdoor environments using passive optical sensors is a onerous and essential task for autonomous navigation. The problem is heavily characterized by changing Environmental Conditions throughout the day and across seasons. Robots should be equipped with models that are impervious to these factors in order to be operable and more importantly to ensure safety in the real-world. In this paper, we propose a novel semantic segmentation architecture and the convoluted mixture of deep experts (CMoDE) fusion technique that enables a multi-stream deep neural network to learn features from complementary modalities and spectra, each of which are specialized in a subset of the input space. Our model adaptively weighs class-specific features of expert networks based on the scene condition and further learns fused representations to yield robust segmentation. We present results from experimentation on three publicly available datasets that contain diverse Conditions including rain, summer, winter, dusk, fall, night and sunset, and show that our approach exceeds the state-of-the-art. In addition, we evaluate the performance of autonomously traversing several kilometres of a forested environment using only the segmentation for perception.
