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Lepoint Gilles - One of the best experts on this subject based on the ideXlab platform.

  • Trophic diversity of seagrass detritus copepods: A consequence of species-specific specialization or a random diet?
    'PeerJ', 2016
    Co-Authors: Mascart Thibaud, De Troch Marleen, Remy François, Michel Loïc, Lepoint Gilles
    Abstract:

    audience: researcher, professional, studentOne of the major ecological research questions is understanding how biodiversity influences ecosystem functioning. Unravelling interspecific feeding preferences of organisms with overlapping trophic niches will give part of the answer. Subsequently, the present study displays the trophic diversity of a benthic copepod community in a North-Western Corsican Posidonia oceanica seagrass ecosystem. These seagrass meadows are often interrupted by bare sand patches serving as Deposition Area for loose detritus. The accumulated macrophytodetritus, mainly derived from senescent macrophytes, harbour a diverse community of Harpacticoida (Crustacea, Copepoda). The most abundant copepods (i.e. three harpacticoids and one calanoid, belonging to different eco-morphological types) and their potential food sources (i.e. macrophytodetritus, epiphytic biofilm and suspended organic matter) were analysed for stable isotope ratios (δ13C, δ15N) and total lipids content. The results revealed a harpacticoid copepod feeding preference towards the epiphytic biofilm, while calanoid copepods preferred suspended organic matter. Additionally, a species-specific composition variation revealed finer partitioning of food resources (e.g. different micro-organisms present in the biofilm like bacteria, diatoms, fungi) over time.In conclusion, results showed species-specific food preferences, resulting in trophic niche and resource partitioning. Every eco-morphological type seems to cope in different ways with temporal fluctuations of food sources to comply with their nutritional needs. This illustrates the high resilience of the copepod community present in macrophytodetritus accumulations. Moreover, our results underlined the importance of multiple biomarker species-specific analysis in trophic ecology studies, especially in complex and dynamic environments offering numerous food items to consumers

  • Trophic diversity of seagrass detritus copepods: A consequence of species-specific specialization or a random diet?
    2016
    Co-Authors: Mascart Thibaud, De Troch Marleen, Remy François, Michel Loïc, Lepoint Gilles
    Abstract:

    One of the major ecological research questions is understanding how biodiversity influences ecosystem functioning. Unravelling interspecific feeding preferences of organisms with overlapping trophic niches will give part of the answer. Subsequently, the present study displays the trophic diversity of a benthic copepod community in a North-Western Corsican Posidonia oceanica seagrass ecosystem. These seagrass meadows are often interrupted by bare sand patches serving as Deposition Area for loose detritus. The accumulated macrophytodetritus, mainly derived from senescent macrophytes, harbour a diverse community of Harpacticoida (Crustacea, Copepoda). The most abundant copepods (i.e. three harpacticoids and one calanoid, belonging to different eco-morphological types) and their potential food sources (i.e. macrophytodetritus, epiphytic biofilm and suspended organic matter) were analysed for stable isotope ratios (δ13C, δ15N) and total lipids content. The results revealed a harpacticoid copepod feeding preference towards the epiphytic biofilm, while calanoid copepods preferred suspended organic matter. Additionally, a species-specific composition variation revealed finer partitioning of food resources (e.g. different micro-organisms present in the biofilm like bacteria, diatoms, fungi) over time.In conclusion, results showed species-specific food preferences, resulting in trophic niche and resource partitioning. Every eco-morphological type seems to cope in different ways with temporal fluctuations of food sources to comply with their nutritional needs. This illustrates the high resilience of the copepod community present in macrophytodetritus accumulations. Moreover, our results underlined the importance of multiple biomarker species-specific analysis in trophic ecology studies, especially in complex and dynamic environments offering numerous food items to consumers

Xin Quan - One of the best experts on this subject based on the ideXlab platform.

  • soil erosion and Deposition characteristics of slope surfaces for two loess soils using indoor simulated rainfall experiment
    Soil & Tillage Research, 2020
    Co-Authors: Liying Sun, Xin Quan, Qiangguo Cai, Shuo Wang
    Abstract:

    Abstract Sediment Deposition is an important part of the erosion process. Slope and soil type affect the spatial distribution of erosion–Deposition; however, little is known about where erosion and Deposition occur specifically and how they interact with influencing factors. To address this issue, four rainfall simulation experiments were conducted in a 1 m × 5 m plot with varying slopes (i.e., 5°, 10°, 15°, and 20°) and simulated rainfall for 1 h at a rate of 60 mm h−1. For the two soils, the runoff rate and sediment concentration were correlated with a similar temporal pattern. Runoff increased gradually and ultimately approached a steady state, and the sediment concentration decreased gradually and ultimately approached a steady state, which indicated that the erosion processes of the two soils were controlled by the detachment-limited condition. The sediment concentration and erosion rate were positively correlated with slope. However, the onset of runoff was delayed for AS soil, which also had a relatively high sediment concentration. The distribution range and Area of Deposition for the two soils were negatively correlated with the slope gradient, and the main Deposition Area occurred at the bottom of the plots. In contrast, the SD soil was more susceptible to Deposition, and the Deposition thickness was mainly concentrated within a 0–4 mm depth; this concentration was not observed for AS soil because of its high erosion intensity. Overall, this similarity also existed in the spatial variations of silt and fine sand contents in the soil surface. The silt and fine sand-sized particles were the primary eroded particle sizes; however, selective mechanisms of these two particle sizes were obviously different in the two soils. The results indicated that the erosion–Deposition characteristics and the main eroded materials differed with varying erosion intensities and soil types. These findings are essential for a more comprehensive understanding of soil erosion mechanisms under conditions without rill formation.

Mauro Boreggio - One of the best experts on this subject based on the ideXlab platform.

  • gis based cell model for simulating debris flow runout on a fan
    Journal of Hydrology, 2016
    Co-Authors: Carlo Gregoretti, Massimo Degetto, Mauro Boreggio
    Abstract:

    Summary A GIS-based cell model, based on a kinematic approach is proposed to simulate debris flow routing on a fan. The sediment–water mixture is modeled as a monophasic continuum, and the flow pattern is discretized by square cells, 1 m in size, that coincide with the DEM cells. Flow occurs from cells with a higher mixture free surface to those with a lower mixture free surface. A uniform-flow law is used if the elevation of the former cell is higher than that of the latter; otherwise, the flow is simulated using the broad-crested weir law. Erosion and Deposition are simulated using an empirical law that is adjusted for a monophasic continuum. The sediment concentration in the routing volume is computed at each time step and controls both erosion and Deposition. The cell model is used to simulate a debris flow that occurred on the Rio Lazer (Dolomites, North-Eastern Italian Alps) on November 4th, 1966. Furthermore, the hydrologic and the hydraulic conditions for the initiation of debris flow are simulated, providing the solid–liquid hydrograph of the resulting debris flow. A number of simulations has been carried out with physically reasonable parameters. The results are compared with the extension of the debris-flow Deposition Area and the map of observed depths of deposited sediments. This comparison shows that the proposed model provides good performance. The analysis of sensitivity carried out by systematically varying the model parameters shows that lower performances are associated with parameter values that are not physically reasonable. The same event is also simulated using a cellular automata model and a finite volume two-dimensional model. The results show that the two models provide a sediment Deposition pattern less accurate than that provided by the present cell model.

Shuo Wang - One of the best experts on this subject based on the ideXlab platform.

  • soil erosion and Deposition characteristics of slope surfaces for two loess soils using indoor simulated rainfall experiment
    Soil & Tillage Research, 2020
    Co-Authors: Liying Sun, Xin Quan, Qiangguo Cai, Shuo Wang
    Abstract:

    Abstract Sediment Deposition is an important part of the erosion process. Slope and soil type affect the spatial distribution of erosion–Deposition; however, little is known about where erosion and Deposition occur specifically and how they interact with influencing factors. To address this issue, four rainfall simulation experiments were conducted in a 1 m × 5 m plot with varying slopes (i.e., 5°, 10°, 15°, and 20°) and simulated rainfall for 1 h at a rate of 60 mm h−1. For the two soils, the runoff rate and sediment concentration were correlated with a similar temporal pattern. Runoff increased gradually and ultimately approached a steady state, and the sediment concentration decreased gradually and ultimately approached a steady state, which indicated that the erosion processes of the two soils were controlled by the detachment-limited condition. The sediment concentration and erosion rate were positively correlated with slope. However, the onset of runoff was delayed for AS soil, which also had a relatively high sediment concentration. The distribution range and Area of Deposition for the two soils were negatively correlated with the slope gradient, and the main Deposition Area occurred at the bottom of the plots. In contrast, the SD soil was more susceptible to Deposition, and the Deposition thickness was mainly concentrated within a 0–4 mm depth; this concentration was not observed for AS soil because of its high erosion intensity. Overall, this similarity also existed in the spatial variations of silt and fine sand contents in the soil surface. The silt and fine sand-sized particles were the primary eroded particle sizes; however, selective mechanisms of these two particle sizes were obviously different in the two soils. The results indicated that the erosion–Deposition characteristics and the main eroded materials differed with varying erosion intensities and soil types. These findings are essential for a more comprehensive understanding of soil erosion mechanisms under conditions without rill formation.

Mascart Thibaud - One of the best experts on this subject based on the ideXlab platform.

  • Trophic diversity of seagrass detritus copepods: A consequence of species-specific specialization or a random diet?
    'PeerJ', 2016
    Co-Authors: Mascart Thibaud, De Troch Marleen, Remy François, Michel Loïc, Lepoint Gilles
    Abstract:

    audience: researcher, professional, studentOne of the major ecological research questions is understanding how biodiversity influences ecosystem functioning. Unravelling interspecific feeding preferences of organisms with overlapping trophic niches will give part of the answer. Subsequently, the present study displays the trophic diversity of a benthic copepod community in a North-Western Corsican Posidonia oceanica seagrass ecosystem. These seagrass meadows are often interrupted by bare sand patches serving as Deposition Area for loose detritus. The accumulated macrophytodetritus, mainly derived from senescent macrophytes, harbour a diverse community of Harpacticoida (Crustacea, Copepoda). The most abundant copepods (i.e. three harpacticoids and one calanoid, belonging to different eco-morphological types) and their potential food sources (i.e. macrophytodetritus, epiphytic biofilm and suspended organic matter) were analysed for stable isotope ratios (δ13C, δ15N) and total lipids content. The results revealed a harpacticoid copepod feeding preference towards the epiphytic biofilm, while calanoid copepods preferred suspended organic matter. Additionally, a species-specific composition variation revealed finer partitioning of food resources (e.g. different micro-organisms present in the biofilm like bacteria, diatoms, fungi) over time.In conclusion, results showed species-specific food preferences, resulting in trophic niche and resource partitioning. Every eco-morphological type seems to cope in different ways with temporal fluctuations of food sources to comply with their nutritional needs. This illustrates the high resilience of the copepod community present in macrophytodetritus accumulations. Moreover, our results underlined the importance of multiple biomarker species-specific analysis in trophic ecology studies, especially in complex and dynamic environments offering numerous food items to consumers

  • Trophic diversity of seagrass detritus copepods: A consequence of species-specific specialization or a random diet?
    2016
    Co-Authors: Mascart Thibaud, De Troch Marleen, Remy François, Michel Loïc, Lepoint Gilles
    Abstract:

    One of the major ecological research questions is understanding how biodiversity influences ecosystem functioning. Unravelling interspecific feeding preferences of organisms with overlapping trophic niches will give part of the answer. Subsequently, the present study displays the trophic diversity of a benthic copepod community in a North-Western Corsican Posidonia oceanica seagrass ecosystem. These seagrass meadows are often interrupted by bare sand patches serving as Deposition Area for loose detritus. The accumulated macrophytodetritus, mainly derived from senescent macrophytes, harbour a diverse community of Harpacticoida (Crustacea, Copepoda). The most abundant copepods (i.e. three harpacticoids and one calanoid, belonging to different eco-morphological types) and their potential food sources (i.e. macrophytodetritus, epiphytic biofilm and suspended organic matter) were analysed for stable isotope ratios (δ13C, δ15N) and total lipids content. The results revealed a harpacticoid copepod feeding preference towards the epiphytic biofilm, while calanoid copepods preferred suspended organic matter. Additionally, a species-specific composition variation revealed finer partitioning of food resources (e.g. different micro-organisms present in the biofilm like bacteria, diatoms, fungi) over time.In conclusion, results showed species-specific food preferences, resulting in trophic niche and resource partitioning. Every eco-morphological type seems to cope in different ways with temporal fluctuations of food sources to comply with their nutritional needs. This illustrates the high resilience of the copepod community present in macrophytodetritus accumulations. Moreover, our results underlined the importance of multiple biomarker species-specific analysis in trophic ecology studies, especially in complex and dynamic environments offering numerous food items to consumers