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Misganaw Tamrat - One of the best experts on this subject based on the ideXlab platform.
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the effect of season and post fire on habitat preferences of the endangered swayne s hartebeest alcelaphus buselaphus swaynei in maze national park ethiopia
BMC Ecology, 2020Co-Authors: Afework Bekele, Misganaw Tamrat, Anagaw Atickem, Diress Tsegaye, Paul H Evangelista, Nils Christian StensethAbstract:The availability of preferred habitats determines the spatial and temporal distribution of herbivores in savanna ecosystems. Understanding habitat preference of a targeted wildlife species is crucial for developing effective conservation strategies. Habitat preference of large grazers in connection to grass height and post-fire effect has been debated for the last century. Here, we examined the effects of season, grass height and Burning on the habitat preference on Swayne’s hartebeest (Alcelaphus buselaphus swaynei) in Maze National Park. Data for seasonal habitat selection were collected using both direct observation along established transect lines and pellet counting using permanently established plots. Every month, we measured grass height commonly preferred by Swayne’s hartebeest in grassland habitat. Starting from the first week of Burning, we recorded the abundance of Swayne’s hartebeest in both burned and unburned grassland patches. From detected pellets, 94.3% were recorded in the grassland habitat indicating that other habitat types are less used despite their extensive cover > 50% of the Park. During wet and early dry seasons, Swayne’s hartebeest exclusively preferred grassland habitat. We found that 85.2% (n = 1079) and 85.3% (n = 593) of individuals observed in areas with a grass height below 30 cm during wet and early-dry seasons, respectively; while 70.9% (n = 2288) preferred grass height below 30 cm during the dry season. The density of Swayne’s hartebeest in burned grassland area was higher than unburned grassland areas up to 150 days since Burning. However, in unburned grassland areas, the density was initially low but showed increasing trend for consecutive days, reaching similar density with burned areas after 150 days since Burning. Swayne’s hartebeest exclusively preferred grassland habitat, particularly during wet and early-dry seasons, shortest available grass height in all seasons and were attracted to burned grassland areas. Our results suggested that fire played an important role in maintaining habitat quality in grassland, and that management should continue using Controlled Burning as a tool for the conservation of Swayne’s hartebeest. However, we remain cautious of our findings given the paucity of information regarding other confounding factors and the absence of long-term data on fire disturbance.
Holmer Savastano - One of the best experts on this subject based on the ideXlab platform.
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brazilian sugar cane bagasse ashes from the cogeneration industry as active pozzolans for cement manufacture
Cement & Concrete Composites, 2011Co-Authors: Moises Frias, Ernesto Villar, Holmer SavastanoAbstract:For proper management of wastes and their possible recycling as raw materials, complete characterization of the materials is necessary to evaluate the main scientific aspects and potential applications. The current paper presents a detailed scientific study of different Brazilian sugar cane bagasse ashes from the cogeneration industry as alternative cementing materials (active addition) for cement manufacture. The results show that the ashes from the industrial process (filter and bottom ones) present different chemical and mineralogical compositions and pozzolanic properties as well. As a consequence of its nature, the kinetic rate constant (K) states that the pozzolanic activity is null for the bottom ash and very low for the filter ash with respect to a sugar cane bagasse ash obtained in the laboratory under Controlled Burning conditions (reference). The scarce pozzolanic activity showed by ashes could be related to a possible contamination of bagasse wastes (with soils) before their use as alternative combustibles. For this reason, an optimization process for these wastes is advisable, if the ashes are to be used as pozzolans.
Nils Christian Stenseth - One of the best experts on this subject based on the ideXlab platform.
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the effect of season and post fire on habitat preferences of the endangered swayne s hartebeest alcelaphus buselaphus swaynei in maze national park ethiopia
BMC Ecology, 2020Co-Authors: Afework Bekele, Misganaw Tamrat, Anagaw Atickem, Diress Tsegaye, Paul H Evangelista, Nils Christian StensethAbstract:The availability of preferred habitats determines the spatial and temporal distribution of herbivores in savanna ecosystems. Understanding habitat preference of a targeted wildlife species is crucial for developing effective conservation strategies. Habitat preference of large grazers in connection to grass height and post-fire effect has been debated for the last century. Here, we examined the effects of season, grass height and Burning on the habitat preference on Swayne’s hartebeest (Alcelaphus buselaphus swaynei) in Maze National Park. Data for seasonal habitat selection were collected using both direct observation along established transect lines and pellet counting using permanently established plots. Every month, we measured grass height commonly preferred by Swayne’s hartebeest in grassland habitat. Starting from the first week of Burning, we recorded the abundance of Swayne’s hartebeest in both burned and unburned grassland patches. From detected pellets, 94.3% were recorded in the grassland habitat indicating that other habitat types are less used despite their extensive cover > 50% of the Park. During wet and early dry seasons, Swayne’s hartebeest exclusively preferred grassland habitat. We found that 85.2% (n = 1079) and 85.3% (n = 593) of individuals observed in areas with a grass height below 30 cm during wet and early-dry seasons, respectively; while 70.9% (n = 2288) preferred grass height below 30 cm during the dry season. The density of Swayne’s hartebeest in burned grassland area was higher than unburned grassland areas up to 150 days since Burning. However, in unburned grassland areas, the density was initially low but showed increasing trend for consecutive days, reaching similar density with burned areas after 150 days since Burning. Swayne’s hartebeest exclusively preferred grassland habitat, particularly during wet and early-dry seasons, shortest available grass height in all seasons and were attracted to burned grassland areas. Our results suggested that fire played an important role in maintaining habitat quality in grassland, and that management should continue using Controlled Burning as a tool for the conservation of Swayne’s hartebeest. However, we remain cautious of our findings given the paucity of information regarding other confounding factors and the absence of long-term data on fire disturbance.
Vasyl Yoschenko - One of the best experts on this subject based on the ideXlab platform.
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resuspension and redistribution of radionuclides during grassland and forest fires in the chernobyl exclusion zone part ii modeling the transport process
Journal of Environmental Radioactivity, 2006Co-Authors: Vasyl Yoschenko, V A Kashparov, S Levchuk, A S Glukhovskiy, Yu V Khomutinin, V P Protsak, S M Lundin, Jochen TschierschAbstract:Abstract To predict parameters of radionuclide resuspension, transport and deposition during forest and grassland fires, several model modules were developed and adapted. Experimental data of Controlled Burning of prepared experimental plots in the Chernobyl exclusion zone have been used to evaluate the prognostic power of the models. The predicted trajectories and elevations of the plume match with those visually observed during the fire experiments in the grassland and forest sites. Experimentally determined parameters could be successfully used for the calculation of the initial plume parameters which provide the tools for the description of various fire scenarios and enable prognostic calculations. In summary, the model predicts a release of some ‰ from the radionuclide inventory of the fuel material by the grassland fires. During the forest fire, up to 4% of 137 Cs and 90 Sr and up to 1% of the Pu isotopes can be released from the forest litter according to the model calculations. However, these results depend on the parameters of the fire events. In general, the modeling results are in good accordance with the experimental data. Therefore, the considered models were successfully validated and can be recommended for the assessment of the resuspension and redistribution of radionuclides during grassland and forest fires in contaminated territories.
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resuspension and redistribution of radionuclides during grassland and forest fires in the chernobyl exclusion zone part i fire experiments
Journal of Environmental Radioactivity, 2006Co-Authors: Vasyl Yoschenko, V A Kashparov, S Levchuk, Yu V Khomutinin, V P Protsak, S M Lundin, A M Kadygrib, S I Zvarich, I M Maloshtan, V P LanshinAbstract:Controlled Burning of experimental plots of forest or grassland in the Chernobyl exclusion zone has been carried out in order to estimate the parameters of radionuclide resuspension, transport and deposition during forest and grassland fires and to evaluate the working conditions of firemen. An increase of several orders of magnitude of the airborne radionuclide concentration was observed in the territory near the fire area. The resuspension factor for (137)Cs and (90)Sr was determined to range from 10(-6) to 10(-5) m(-1), and for the plutonium radionuclides from 10(-7) to 10(-6) m(-1) (related to the nuclides in the combustible biomass). These values are 2 orders of magnitude lower if they are calculated relatively to the total contamination density (including the nuclides in the soil). The radionuclide fallout along the plume axis is negligible in comparison to the existing contamination. However, the additional inhalation dose for firemen exposed in the affected area can reach the level of the additional external irradiation in the period of their mission. The plutonium nuclides constitute the dominating contribution to the inhalation dose.
Diress Tsegaye - One of the best experts on this subject based on the ideXlab platform.
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the effect of season and post fire on habitat preferences of the endangered swayne s hartebeest alcelaphus buselaphus swaynei in maze national park ethiopia
BMC Ecology, 2020Co-Authors: Afework Bekele, Misganaw Tamrat, Anagaw Atickem, Diress Tsegaye, Paul H Evangelista, Nils Christian StensethAbstract:The availability of preferred habitats determines the spatial and temporal distribution of herbivores in savanna ecosystems. Understanding habitat preference of a targeted wildlife species is crucial for developing effective conservation strategies. Habitat preference of large grazers in connection to grass height and post-fire effect has been debated for the last century. Here, we examined the effects of season, grass height and Burning on the habitat preference on Swayne’s hartebeest (Alcelaphus buselaphus swaynei) in Maze National Park. Data for seasonal habitat selection were collected using both direct observation along established transect lines and pellet counting using permanently established plots. Every month, we measured grass height commonly preferred by Swayne’s hartebeest in grassland habitat. Starting from the first week of Burning, we recorded the abundance of Swayne’s hartebeest in both burned and unburned grassland patches. From detected pellets, 94.3% were recorded in the grassland habitat indicating that other habitat types are less used despite their extensive cover > 50% of the Park. During wet and early dry seasons, Swayne’s hartebeest exclusively preferred grassland habitat. We found that 85.2% (n = 1079) and 85.3% (n = 593) of individuals observed in areas with a grass height below 30 cm during wet and early-dry seasons, respectively; while 70.9% (n = 2288) preferred grass height below 30 cm during the dry season. The density of Swayne’s hartebeest in burned grassland area was higher than unburned grassland areas up to 150 days since Burning. However, in unburned grassland areas, the density was initially low but showed increasing trend for consecutive days, reaching similar density with burned areas after 150 days since Burning. Swayne’s hartebeest exclusively preferred grassland habitat, particularly during wet and early-dry seasons, shortest available grass height in all seasons and were attracted to burned grassland areas. Our results suggested that fire played an important role in maintaining habitat quality in grassland, and that management should continue using Controlled Burning as a tool for the conservation of Swayne’s hartebeest. However, we remain cautious of our findings given the paucity of information regarding other confounding factors and the absence of long-term data on fire disturbance.