The Experts below are selected from a list of 37302 Experts worldwide ranked by ideXlab platform
Clifford W. Heil - One of the best experts on this subject based on the ideXlab platform.
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CO_2 and fire influence Tropical Ecosystem stability in response to climate change
Scientific Reports, 2016Co-Authors: Timothy M. Shanahan, Konrad A. Hughen, Nicholas P. Mckay, Jonathan T. Overpeck, Christopher A. Scholz, William D. Gosling, Charlotte S. Miller, John A. Peck, John W. King, Clifford W. HeilAbstract:Interactions between climate, fire and CO_2 are believed to play a crucial role in controlling the distributions of Tropical woodlands and savannas, but our understanding of these processes is limited by the paucity of data from undisturbed Tropical Ecosystems. Here we use a 28,000-year integrated record of vegetation, climate and fire from West Africa to examine the role of these interactions on Tropical Ecosystem stability. We find that increased aridity between 28–15 kyr B.P. led to the widespread expansion of Tropical grasslands, but that frequent fires and low CO_2 played a crucial role in stabilizing these Ecosystems, even as humidity changed. This resulted in an unstable Ecosystem state, which transitioned abruptly from grassland to woodlands as gradual changes in CO_2 and fire shifted the balance in favor of woody plants. Since then, high atmospheric CO_2 has stabilized Tropical forests by promoting woody plant growth, despite increased aridity. Our results indicate that the interactions between climate, CO_2 and fire can make Tropical Ecosystems more resilient to change, but that these systems are dynamically unstable and potentially susceptible to abrupt shifts between woodland and grassland dominated states in the future.
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CO2 and fire influence Tropical Ecosystem stability in response to climate change.
Scientific reports, 2016Co-Authors: Timothy M. Shanahan, Konrad A. Hughen, Nicholas P. Mckay, Jonathan T. Overpeck, Christopher A. Scholz, William D. Gosling, John A. Peck, John W. King, Charlotte Miller, Clifford W. HeilAbstract:Interactions between climate, fire and CO2 are believed to play a crucial role in controlling the distributions of Tropical woodlands and savannas, but our understanding of these processes is limited by the paucity of data from undisturbed Tropical Ecosystems. Here we use a 28,000-year integrated record of vegetation, climate and fire from West Africa to examine the role of these interactions on Tropical Ecosystem stability. We find that increased aridity between 28–15 kyr B.P. led to the widespread expansion of Tropical grasslands, but that frequent fires and low CO2 played a crucial role in stabilizing these Ecosystems, even as humidity changed. This resulted in an unstable Ecosystem state, which transitioned abruptly from grassland to woodlands as gradual changes in CO2 and fire shifted the balance in favor of woody plants. Since then, high atmospheric CO2 has stabilized Tropical forests by promoting woody plant growth, despite increased aridity. Our results indicate that the interactions between climate, CO2 and fire can make Tropical Ecosystems more resilient to change, but that these systems are dynamically unstable and potentially susceptible to abrupt shifts between woodland and grassland dominated states in the future.
Robert S. Lanciotti - One of the best experts on this subject based on the ideXlab platform.
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doi:10.4269/ajtmh.2012.12-0276 Copyright © 2013 by The American Society of Tropical Medicine and Hygiene West Nile Virus Ecology in a Tropical Ecosystem in Guatemala
2016Co-Authors: Maria Morales-betoulle, Nicholas Komar, Nicholas A. Panella, Danilo Alvarez, Jean-luc Betoulle, Silvia M. Sosa, Robert S. Lanciotti, Marm A. Kilpatrick, Barbara W. Johnson, Ann M. PowersAbstract:Abstract. West Nile virus ecology has yet to be rigorously investigated in the Caribbean Basin. We identified a transmission focus in Puerto Barrios, Guatemala, and established systematic monitoring of avian abundance and infec-tion, seroconversions in domestic poultry, and viral infections in mosquitoes. West Nile virus transmission was detected annually between May and October from 2005 to 2008. High temperature and low rainfall enhanced the probability of chicken seroconversions, which occurred in both urban and rural sites. West Nile virus was isolated from Culex quinquefasciatus and to a lesser extent, from Culex mollis/Culex inflictus, but not from the most abundant Culex mosquito, Culex nigripalpus. A calculation that combined avian abundance, seroprevalence, and vertebrate reservoir competence suggested that great-tailed grackle (Quiscalus mexicanus) is the major amplifying host in this Ecosystem. West Nile virus transmission reached moderate levels in sentinel chickens during 2007, but less than that observed during outbreaks of human disease attributed to West Nile virus in the United States
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West Nile Virus Ecology in a Tropical Ecosystem in Guatemala
The American journal of tropical medicine and hygiene, 2012Co-Authors: Maria Morales-betoulle, Nicholas Komar, Nicholas A. Panella, Danilo Alvarez, Maria Renee Lopez, Jean-luc Betoulle, Silvia M. Sosa, Maria L. Müller, A. Marm Kilpatrick, Robert S. LanciottiAbstract:West Nile virus ecology has yet to be rigorously investigated in the Caribbean Basin. We identified a transmission focus in Puerto Barrios, Guatemala, and established systematic monitoring of avian abundance and infection, seroconversions in domestic poultry, and viral infections in mosquitoes. West Nile virus transmission was detected annually between May and October from 2005 to 2008. High temperature and low rainfall enhanced the probability of chicken seroconversions, which occurred in both urban and rural sites. West Nile virus was isolated from Culex quinquefasciatus and to a lesser extent, from Culex mollis/Culex inflictus, but not from the most abundant Culex mosquito, Culex nigripalpus. A calculation that combined avian abundance, seroprevalence, and vertebrate reservoir competence suggested that great-tailed grackle (Quiscalus mexicanus) is the major amplifying host in this Ecosystem. West Nile virus transmission reached moderate levels in sentinel chickens during 2007, but less than that observed during outbreaks of human disease attributed to West Nile virus in the United States.
Djail Santos - One of the best experts on this subject based on the ideXlab platform.
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Soil physico-chemical properties, biomass production, and root density in a green manure farming system from Tropical Ecosystem, North-eastern Brazil
Journal of Soils and Sediments, 2021Co-Authors: Gislaine Dos Santos Nascimento, Tancredo Augusto Feitosa De Souza, Lucas Jónatan Rodrigues Da Silva, Djail SantosAbstract:Soil physico-chemical properties, biomass production, and root density are considered key factors indicating soil health in an agroEcosystem. The soil physico-chemical changes and plant growth (e.g., shoot biomass production and root density) in a 6-year cultivation of plant species used as green manure in a sandy soil from Tropical Ecosystem, North-eastern Brazil, were investigated between July and December 2019. We characterized soil physical and chemical properties, shoot biomass production, and root density under ten plant species used as green manure: Brachiaria decumbens Stapf. cv. Basilisk, Canavalia ensiformis (L.) DC, Crotalaria juncea L., Crotalaria ochroleuca G. Don, Crotalaria spectabilis Roth, Lablab purpureus (L.) Sweet, Mucuna pruriens (L.) DC, Neonotonia wightii (Wight & Arn.) J.A. Lackey, Pennisetum glaucum L., and Stilozobium aterrimum Piper and Tracy. The highest values of soil pH, exchangeable cations, CEC, and soil available water capacity were found on the plots where Poaceae plants were cultivated, whereas for H++Al3+, C.E.C., soil available water, and soil available water capacity were found on the plots where Fabaceae plants were cultivated. On the plots where C. ensiformis and N. wightii were cultivated, we found the highest shoot dry biomass and root density, respectively. The results highlight the importance to consider plant species from both Poaceae and Fabaceae family used as green manure as soil conditioner (by promoting soil fertility, nutrient cycling, and hydraulic properties into plant root zone), and thus creating a positive plant-soil feedback. Our findings suggest that (1) a consecutive green manure practice without any input of fertilizers after 6 years changed positively both soil physical and chemical properties, and improve plant growth (e.g., shoot dry biomass and root density) in Tropical savanna climate conditions; and (2) by altering soil fertility, both Poaceae and Fabaceae plants used as green manure may create a sustainable cycle into the soil profile thus promoting soil health.
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Soil physico-chemical properties, biomass production, and root density in a green manure farming system from Tropical Ecosystem, North-eastern Brazil
Journal of Soils and Sediments, 2021Co-Authors: Gislaine Santos Nascimento, Tancredo Augusto Feitosa De Souza, Lucas Jónatan Rodrigues Da Silva, Djail SantosAbstract:Purpose Soil physico-chemical properties, biomass production, and root density are considered key factors indicating soil health in an agroEcosystem. The soil physico-chemical changes and plant growth (e.g., shoot biomass production and root density) in a 6-year cultivation of plant species used as green manure in a sandy soil from Tropical Ecosystem, North-eastern Brazil, were investigated between July and December 2019. Material and methods We characterized soil physical and chemical properties, shoot biomass production, and root density under ten plant species used as green manure: Brachiaria decumbens Stapf. cv. Basilisk, Canavalia ensiformis (L.) DC, Crotalaria juncea L., Crotalaria ochroleuca G. Don, Crotalaria spectabilis Roth, Lablab purpureus (L.) Sweet, Mucuna pruriens (L.) DC, Neonotonia wightii (Wight & Arn.) J.A. Lackey, Pennisetum glaucum L., and Stilozobium aterrimum Piper and Tracy. Results and discussion The highest values of soil pH, exchangeable cations, CEC, and soil available water capacity were found on the plots where Poaceae plants were cultivated, whereas for H^++Al^3+, C.E.C., soil available water, and soil available water capacity were found on the plots where Fabaceae plants were cultivated. On the plots where C. ensiformis and N. wightii were cultivated, we found the highest shoot dry biomass and root density, respectively. The results highlight the importance to consider plant species from both Poaceae and Fabaceae family used as green manure as soil conditioner (by promoting soil fertility, nutrient cycling, and hydraulic properties into plant root zone), and thus creating a positive plant-soil feedback. Conclusions Our findings suggest that (1) a consecutive green manure practice without any input of fertilizers after 6 years changed positively both soil physical and chemical properties, and improve plant growth (e.g., shoot dry biomass and root density) in Tropical savanna climate conditions; and (2) by altering soil fertility, both Poaceae and Fabaceae plants used as green manure may create a sustainable cycle into the soil profile thus promoting soil health.
Maria Morales-betoulle - One of the best experts on this subject based on the ideXlab platform.
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doi:10.4269/ajtmh.2012.12-0276 Copyright © 2013 by The American Society of Tropical Medicine and Hygiene West Nile Virus Ecology in a Tropical Ecosystem in Guatemala
2016Co-Authors: Maria Morales-betoulle, Nicholas Komar, Nicholas A. Panella, Danilo Alvarez, Jean-luc Betoulle, Silvia M. Sosa, Robert S. Lanciotti, Marm A. Kilpatrick, Barbara W. Johnson, Ann M. PowersAbstract:Abstract. West Nile virus ecology has yet to be rigorously investigated in the Caribbean Basin. We identified a transmission focus in Puerto Barrios, Guatemala, and established systematic monitoring of avian abundance and infec-tion, seroconversions in domestic poultry, and viral infections in mosquitoes. West Nile virus transmission was detected annually between May and October from 2005 to 2008. High temperature and low rainfall enhanced the probability of chicken seroconversions, which occurred in both urban and rural sites. West Nile virus was isolated from Culex quinquefasciatus and to a lesser extent, from Culex mollis/Culex inflictus, but not from the most abundant Culex mosquito, Culex nigripalpus. A calculation that combined avian abundance, seroprevalence, and vertebrate reservoir competence suggested that great-tailed grackle (Quiscalus mexicanus) is the major amplifying host in this Ecosystem. West Nile virus transmission reached moderate levels in sentinel chickens during 2007, but less than that observed during outbreaks of human disease attributed to West Nile virus in the United States
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West Nile Virus Ecology in a Tropical Ecosystem in Guatemala
The American journal of tropical medicine and hygiene, 2012Co-Authors: Maria Morales-betoulle, Nicholas Komar, Nicholas A. Panella, Danilo Alvarez, Maria Renee Lopez, Jean-luc Betoulle, Silvia M. Sosa, Maria L. Müller, A. Marm Kilpatrick, Robert S. LanciottiAbstract:West Nile virus ecology has yet to be rigorously investigated in the Caribbean Basin. We identified a transmission focus in Puerto Barrios, Guatemala, and established systematic monitoring of avian abundance and infection, seroconversions in domestic poultry, and viral infections in mosquitoes. West Nile virus transmission was detected annually between May and October from 2005 to 2008. High temperature and low rainfall enhanced the probability of chicken seroconversions, which occurred in both urban and rural sites. West Nile virus was isolated from Culex quinquefasciatus and to a lesser extent, from Culex mollis/Culex inflictus, but not from the most abundant Culex mosquito, Culex nigripalpus. A calculation that combined avian abundance, seroprevalence, and vertebrate reservoir competence suggested that great-tailed grackle (Quiscalus mexicanus) is the major amplifying host in this Ecosystem. West Nile virus transmission reached moderate levels in sentinel chickens during 2007, but less than that observed during outbreaks of human disease attributed to West Nile virus in the United States.
Timothy M. Shanahan - One of the best experts on this subject based on the ideXlab platform.
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CO_2 and fire influence Tropical Ecosystem stability in response to climate change
Scientific Reports, 2016Co-Authors: Timothy M. Shanahan, Konrad A. Hughen, Nicholas P. Mckay, Jonathan T. Overpeck, Christopher A. Scholz, William D. Gosling, Charlotte S. Miller, John A. Peck, John W. King, Clifford W. HeilAbstract:Interactions between climate, fire and CO_2 are believed to play a crucial role in controlling the distributions of Tropical woodlands and savannas, but our understanding of these processes is limited by the paucity of data from undisturbed Tropical Ecosystems. Here we use a 28,000-year integrated record of vegetation, climate and fire from West Africa to examine the role of these interactions on Tropical Ecosystem stability. We find that increased aridity between 28–15 kyr B.P. led to the widespread expansion of Tropical grasslands, but that frequent fires and low CO_2 played a crucial role in stabilizing these Ecosystems, even as humidity changed. This resulted in an unstable Ecosystem state, which transitioned abruptly from grassland to woodlands as gradual changes in CO_2 and fire shifted the balance in favor of woody plants. Since then, high atmospheric CO_2 has stabilized Tropical forests by promoting woody plant growth, despite increased aridity. Our results indicate that the interactions between climate, CO_2 and fire can make Tropical Ecosystems more resilient to change, but that these systems are dynamically unstable and potentially susceptible to abrupt shifts between woodland and grassland dominated states in the future.
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CO2 and fire influence Tropical Ecosystem stability in response to climate change.
Scientific reports, 2016Co-Authors: Timothy M. Shanahan, Konrad A. Hughen, Nicholas P. Mckay, Jonathan T. Overpeck, Christopher A. Scholz, William D. Gosling, John A. Peck, John W. King, Charlotte Miller, Clifford W. HeilAbstract:Interactions between climate, fire and CO2 are believed to play a crucial role in controlling the distributions of Tropical woodlands and savannas, but our understanding of these processes is limited by the paucity of data from undisturbed Tropical Ecosystems. Here we use a 28,000-year integrated record of vegetation, climate and fire from West Africa to examine the role of these interactions on Tropical Ecosystem stability. We find that increased aridity between 28–15 kyr B.P. led to the widespread expansion of Tropical grasslands, but that frequent fires and low CO2 played a crucial role in stabilizing these Ecosystems, even as humidity changed. This resulted in an unstable Ecosystem state, which transitioned abruptly from grassland to woodlands as gradual changes in CO2 and fire shifted the balance in favor of woody plants. Since then, high atmospheric CO2 has stabilized Tropical forests by promoting woody plant growth, despite increased aridity. Our results indicate that the interactions between climate, CO2 and fire can make Tropical Ecosystems more resilient to change, but that these systems are dynamically unstable and potentially susceptible to abrupt shifts between woodland and grassland dominated states in the future.
