scholarly journals On the problem of natural savanna fires

2021 ◽  
Author(s):  
Paul Laris ◽  
Rebecca Jacobs
Keyword(s):  
Savanna Fires

Resource selection by grazing herbivores on post-fire regrowth in a West African woodland savanna

2007 ◽  
Vol 34 (2) ◽  
pp. 77 ◽  
Author(s):  
Erik Klop ◽  
Janneke van Goethem ◽  
Hans H. de Iongh
Keyword(s):  
Resource Selection ◽  
West African ◽  
Tree Cover ◽  
Resource Selection Functions ◽  
Risk Of Predation ◽  
Savanna Fires ◽  
Grass Sward ◽  
Burnt Areas ◽  
Good Visibility ◽  
Selection Of

The preference of grazing herbivores to feed on grass regrowth following savanna fires rather than on unburnt grass swards is widely recognised. However, there is little information on which factors govern patterns of resource selection within burnt areas. In this study, we attempted to disentangle the effects of different habitat and grass sward characteristics on the utilisation of post-fire regrowth by nine species of ungulates in a fire-dominated woodland savanna in north Cameroon. We used resource-selection functions based on logistic regression. Overall, the resource-selection functions identified the time elapsed since burning as the most influential parameter in determining probability of use by ungulates, as most species strongly selected swards that were recently burned. This pattern might be related to nutrient levels in the grass sward. In addition, most species selected areas with high grass cover and avoided grass swards with high amounts of dead stem material. This is likely to increase bite mass and, hence, intake rates. The avoidance of high tree cover by some species may suggest selection for open areas with good visibility and, hence, reduced risk of predation. Body mass seemed to have no effect on differential selection of post-fire regrowth, irrespective of feeding style.

Influence of timing and spatial extent of savanna fires in southern Africa on atmospheric emissions

2003 ◽  
Vol 54 (2) ◽  
pp. 395-404 ◽  
Author(s):  
Stefania Korontzi ◽  
Christopher O Justice ◽  
Robert J Scholes
Keyword(s):  
Southern Africa ◽  
Spatial Extent ◽  
Atmospheric Emissions ◽  
Savanna Fires

scholarly journals Emissions from miombo woodland and dambo grassland savanna fires

2004 ◽  
Vol 109 (D11) ◽  
Author(s):  
Parikhit Sinha
Keyword(s):  
Miombo Woodland ◽  
Savanna Fires

scholarly journals Seasonal distribution of African savanna fires

Nature ◽  
1992 ◽  
Vol 359 (6398) ◽  
pp. 812-815 ◽  
Author(s):  
Donald R. Cahoon ◽  
Brian J. Stocks ◽  
Joel S. Levine ◽  
Wesley R. Cofer ◽  
Katherine P. O'Neill
Keyword(s):  
Seasonal Distribution ◽  
African Savanna ◽  
Savanna Fires

scholarly journals Methane gas emissions from savanna fires: What analysis of local burning regimes in a working West African landscape tell us

2021 ◽  
Author(s):  
Paul Laris ◽  
Moussa Koné ◽  
Fadiala Dembélé ◽  
Lilian Yang ◽  
Rebecca Jacobs
Keyword(s):  
Ambient Air ◽  
Methane Emissions ◽  
Dry Season ◽  
West African ◽  
Biomass Composition ◽  
Fire Intensity ◽  
Methane Cycle ◽  
Gas Emissions ◽  
Savanna Fires ◽  
Fire Type

Abstract. Savanna fires contribute significantly to greenhouse gas emissions. While it is recognized that these fires play an important role in the global methane cycle, there are too few accurate estimates of emissions from West Africa, the continent's most active fire region. Most estimates of methane emissions contain high levels of uncertainty because they are based on generalizations of diverse landscapes that are burned by complex fire regimes. To improve estimates we used an approach grounded in the burning practices of people who set fires to working landscapes. We conducted 97 experimental fires collecting data for savanna type, grass type, biomass composition and amount consumed, scorch height, speed of fire front, fire type and ambient air conditions for two sites in Mali. We collected smoke samples for 36 fires using a canister method. We report values for fire intensity, combustion completeness, patchiness, modified combustion efficiency (MCE) and emission factor (EF). Our study finds that methane EFs ranged from 3.71 g/kg in the early dry season (EDS) to 2.86 in the mid-dry season (MDS). We found head fires had nearly double the CH4 EF of backfires (4.89 g/kg to 2.92). Fires during the MDS have the lowest intensity values and the lowest methane emissions 0.981 g/m2 compared with 1.030 g/m2 for EDS and 1.102 g/m2 for the late dry season (LDS). We conclude that policies aimed at shifting the burning regime earlier to reduce methane emissions will not have the desired effects, especially if fire type is not considered. We recommend using the adjusted mean value of 0.862 g/m2—based on the carbon content for West African grasses—for calculating emissions for West African savannas.

scholarly journals The Distribution in Time and Space of Savanna Fires in Burkina Faso as Determined from NOAA AVHRR Data

1997 ◽  
Vol 97 (1) ◽  
pp. 86-97 ◽  
Author(s):  
Thomas Theis Nielsen ◽  
Kjeld Rasmussen
Keyword(s):  
Burkina Faso ◽  
Time And Space ◽  
Noaa Avhrr ◽  
Avhrr Data ◽  
Savanna Fires

North African savanna fires and atmospheric carbon dioxide

1994 ◽  
Vol 99 (D4) ◽  
pp. 8321 ◽  
Author(s):  
Sam F. Iacobellis ◽  
Robert Frouin ◽  
Herisoa Razafimpanilo ◽  
Richard C. J. Somerville ◽  
Stephen C. Piper
Keyword(s):  
Carbon Dioxide ◽  
Atmospheric Carbon Dioxide ◽  
North African ◽  
African Savanna ◽  
Savanna Fires ◽  
Atmospheric Carbon

scholarly journals Diurnal cycles in savanna fires

Nature ◽  
1993 ◽  
Vol 363 (6425) ◽  
pp. 120-120 ◽  
Author(s):  
Sindre Langaas
Keyword(s):  
Diurnal Cycles ◽  
Savanna Fires

Fuels and fire at savanna-gallery forest boundaries in southeastern Venezuela

1998 ◽  
Vol 14 (4) ◽  
pp. 445-461 ◽  
Author(s):  
Jason Biddulph ◽  
Martin Kellman
Keyword(s):  
Rain Forest ◽  
Dry Season ◽  
Field Observations ◽  
Litter Layer ◽  
Gallery Forest ◽  
Fuel Type ◽  
Forest Fuels ◽  
Savanna Fires ◽  
Gallery Forests ◽  
Forest Microclimate

ABSTRACT. Factors contributing to the resistance of gallery forests in savannas to the entry of fire were investigated using field observations and manipulation experiments. Mass of savanna fuels did not decrease close to forest boundaries, and in some instances increased, while savanna fuels adjacent to forests were moister than in the savanna beyond for only 1 d after rainfall. A fuel drying experiment conducted in both forest and savanna microclimates indicated that both fuel type and microclimate contributed to the resistance of forests to fire entry, although the former played a larger role. While savanna fuels in a savanna microclimate became ignitable in c. 1 d after rain, forest fuels in a forest microclimate required 4 wk to achieve ignitability. A further experiment juxtaposing forest fuels to burning savanna indicated that fire entry into forests was faciliated by deep root mats and the presence of a superficial litter layer, both of which become attenuated at the forest/savanna contact. It is concluded that fuels in these forests can reach an ignitable state late in the dry season, but that frequent fire entry is probably precluded by the tendency of savanna fires to occur earlier in the dry season and by discontinuities in fuels at the savanna/forest contact.RESUMEN. Se investigaron los factores que contribuyen a la resistencia de la entrada del fuego a los bosques en galería de las savanas mediante observaciones de campo y experimentos de manipulación. La masa de los combustibles de la savana no decrecieron cerca de los bordes del bosque; por el contrario, en algunos casos se incrementaron, mientras que los combustibles de la savana cercanos al bosque eran mas húmedos que en la savana restante, solamente por un día despues de un evento de lluvia. Un experimento de secado de combustible, que fue conducido en los microclimas de bosque y de savana, indica que tanto el tipo de combustible como el microclima contribuyen a la resistencia de los bosques a la entrada del fuego, aunque el primer factor tuvo un papel de mayor importancia. Mientras que los combustibles de la savana en el microclima de la savana se volvieron ‘encendibles’ cerca de un día despues de lluvia, los combustibles del bosque dentro del microlima del bosque tomaron cuatro semanas para llegar a dicho estado. Un experimento que sobrepuso combustibles del bosque a la savana ardiente indicó que la entrada del fuego a los bosques se facilitó por la presencia de mantillos orgánicos profundos y de una capa superficial de hojarasca, presencia que se ve atenuada en la zona de contacto bosque/savana. Se concluye que los combustibles en estos bosques pueden alcanzar un estado de ignición tarde en la estación de sequía, pero que la entrada frecuente del fuego es probablemente evitada por la tendencia que tienen los fuegos de savana a presentarse temprano en la estación seca y por las discontinuidades de combustibles en la zona de contacto savana/bosque.

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