Fire as a tool in the management of a savanna/dry forest reserve in Madagascar

Bloesch, Urs

doi:10.2307/1478888

Cited by 63 publications

(88 citation statements)

References 8 publications

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“…Sampling took place where the continuous forest bordered a savannah dominated by invasive South African grasses, such as Aristida barbicollis , Hyparrhenia rufa and Heteropogon contortus [Bloesch, 1999]. There is anecdotal evidence that the savannah may be a natural landscape feature, but continued erosion in the area due to cattle grazing coupled with monsoon winds has caused the savannah area to increase in size each year.…”

Section: Methodsmentioning

confidence: 99%

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Edge Effects on Morphometrics and Body Mass in Two Sympatric Species of Mouse Lemurs in Madagascar

Burke¹,

Lehman²

2015

IJFP

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Edge effects are an inevitable and important consequence of forest loss and fragmentation. These effects include changes in species biology and biogeography. Here we examine variations in body mass and morphometrics for 2 sympatric species of mouse lemurs (Microcebus murinus and M. ravelobensis) between edge and interior habitats in the dry deciduous forest at Ankarafantsika National Park. Between May and August 2012, we conducted mark-recapture experiments on mouse lemurs trapped along edge and interior forest transects within continuous forest adjacent to a large savannah. Of the 34 M. murinus captured during our study, 82% (n = 28) were trapped in interior habitats. Conversely, 72% (n = 47) of M. ravelobensis were captured in edge habitats. We found that mean body mass of M. murinus and M. ravelobensis did not differ between edge and interior habitats. However, female M. ravelobensis weighed significantly more in edge habitats (56.09 ± 1.74 g) than in interior habitats (48.14 ± 4.44 g). Our study provides some of the first evidence of sex differences in edge responses for a primate species.

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Section: Methodsmentioning

confidence: 99%

“…This conversion has resulted from a complex pattern of slash-and-burn agriculture, anthropogenic fires used to create cattle pasture, and climate change [Gade, 1996;Bloesch, 1999;Hannah et al, 2008]. The remaining forest is highly fragmented and prone to extreme edge effects [Harper et al, 2007].…”

Section: Introductionmentioning

confidence: 99%

Edge Effects on Morphometrics and Body Mass in Two Sympatric Species of Mouse Lemurs in Madagascar

Burke¹,

Lehman²

2015

IJFP

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“…Fire is a key environmental driver that controls the function of savanna ecosystems (e.g. Bloesch 1999;Hudak 1999) and performs an essential ecological role in shaping the structure and composition of vegetation (e.g. Walker et al 1981;Kull 2004;Moreira 2000;Laris 2002).…”

Section: Introductionmentioning

confidence: 99%

Herder Perceptions on Impacts of Range Enclosures, Crop Farming, Fire Ban and Bush Encroachment on the Rangelands of Borana, Southern Ethiopia

2008

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This study focuses on community-based knowledge to analyze the impacts of range enclosures, crop farming, fire suppression and bush encroachment on the communal rangelands of Borana, southern Ethiopia. The knowledge of local herders is the basis for decision making in the utilization and management of grazing lands. We used Borana oral history associated with the period of the gada system to reconstruct environmental change that spans a period of 48 years. Our results show that the use of communities' perceptions as a basis for evaluating the impacts of land use change on the environment makes an important methodological contribution. Communities' responses to changing land use resulted in the development of range enclosures, the expansion of crop farming and the fragmentation of the communal rangelands, while the suppression of fire contributed to the expansion of bush encroachment. The overall impact was forage scarcity and greater vulnerability of stock during drought years. We conclude that policymakers could use communities' knowledge of environmental change to improve the use of the rangelands. We propose that sustainable use of the southern rangelands in the future will require a greater focus on regulating the expansion of enclosures, crop farming and ranching, as well as reintroducing fire where necessary, to control the expansion of bush cover.

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“…L'hypothèse que le feu ne détruit pas les savanes mais qu'il est au contraire le principal facteur de leur maintien agissant comme un agent de régulation et de stabilisation (Fournier 2001, Eva et al 2003 ne fait pas l'unanimité. Elle est en partie controversée par les résultats d'études réalisées à partir d'observations in situ (Bloesch 1999). Ainsi, à l'échelle interannuelle, un brûlage régulier induirait une dégradation progressive de la savane herbacée en altérant les relations de compétition inter-espèces (Schule 1990).…”

Section: Analyse De La Fréquence De Passage Des Feux à L'échelle Inteunclassified

Détermination du régime des feux en milieu de savane à Madagascar à partir de séries temporelles d'images MODIS

Jacquin

Chéret

Balent

2011

International Journal of Remote Sensing

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Dans les milieux de savanes, l'identification des surfaces brûlées et leur suivi sont des informations essentielles pour assurer une bonne gestion et conservation de ces écosystèmes. L'approche choisie repose sur l'analyse de séries temporelles d'images de télédétection à moyenne résolution spatiale. Les savanes étudiées sont situées sur le bassin versant de Marovoay au nord-ouest de Madagascar : elles présentent la particularité d'un taux de recouvrement de la végétation faible. Les développe-ments méthodologiques ont été concentrés sur deux thèmes : la signature spectrale des surfaces brûlées et la méthode de cartographie de ces surfaces. Dans un premier temps, une analyse spectrale est menée pour évaluer la capacité de six indices spectraux (NDVI, SAVI, BAI, GEMI, Albédo et Indice de Brillance) à discriminer les surfaces brûlées. Les résultats montrent que l'Indice de Brillance est le plus performant. Dans un second temps, une méthode de cartographie des surfaces brûlées annuellement est développée. Elle s'appuie sur le traitement d'une série temporelle de synthèses MODIS à huit jours sur la période 2000-2007. À partir de l'analyse des variations intra-annuelles de l'Indice de Brillance, deux indicateurs spatiauxannuel et saisonnier -sont élaborés pour localiser les surfaces brûlées et déter-miner la période de passage du feu. L'utilisation des courbes ROC pour le seuillage de l'indicateur de surface brûlée permet de définir la valeur optimale pour laquelle les erreurs d'omission et de commission sont minimisées. Les résultats sont évalués par comparaison avec des cartes de surfaces brûlées produites à partir d'images à haute résolution spatiale. La qualité d'identification des surfaces brûlées est bonne, avec un indice Kappa entre 0,74 et 0,76 et une précision cartographique entre 76% et 79%.In savannah areas where fire is a predominant practice, the localization and the monitoring of burned areas are essential information to develop an accurate management system of this ecosystem. This problem is addressed through the analysis of time series of medium spatial-resolution remotely sensed images. The authors studied the savannah localized on the Marovoay watershed, on the north-west coast of Madagascar. These present the particularity of a low vegetation cover. The methodological developments proposed in this article concern more specifically two domains: the spectral signature of burned areas and the method for mapping these areas. First, a spectral analysis is undertaken to assess the capacity of six spectral indexes (NDVI, SAVI, BAI, GEMI, Albedo and Brightness Index) to discriminate burned areas. Results show that the Brightness Index is the best. Then, a A. Jacquin et al. method for mapping annual burned areas at the scale of the watershed is developed. It is based on the processing of a MODIS eight-day composite times series over the period [2000][2001][2002][2003][2004][2005][2006][2007]. Analysis of the intra-annual variations of the Brightness Index leads to the definition of two spatial indicators -an...

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Fire as a tool in the management of a savanna/dry forest reserve in Madagascar

Cited by 63 publications

References 8 publications

Edge Effects on Morphometrics and Body Mass in Two Sympatric Species of Mouse Lemurs in Madagascar

Edge Effects on Morphometrics and Body Mass in Two Sympatric Species of Mouse Lemurs in Madagascar

Herder Perceptions on Impacts of Range Enclosures, Crop Farming, Fire Ban and Bush Encroachment on the Rangelands of Borana, Southern Ethiopia

Détermination du régime des feux en milieu de savane à Madagascar à partir de séries temporelles d'images MODIS

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