References of "Geo-Eco-Trop : Revue Internationale de Géologie, de Géographie et d'Ecologie Tropicales"
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See detailAnalyse écogéographique de la fragmentation du couvert végétal au nord Bénin : paramètres dendrométriques et phytoécologiques comme indicateurs in situ de la dégradation des peuplements ligneux
Hountondji, Yvon-Carmen; Gaoué, Orou Gandé; Sokpon, Nestor et al

in Geo-Eco-Trop : Revue Internationale de Géologie, de Géographie et d'Ecologie Tropicales (2013), 37(1), 53-70

In order to access the state of ligneous cover in the north of Benin Republic, in situ measurements were made in woody vegetation (non-protected areas) in three eco-geographical zones selected following a ... [more ▼]

In order to access the state of ligneous cover in the north of Benin Republic, in situ measurements were made in woody vegetation (non-protected areas) in three eco-geographical zones selected following a climatic gradient. Ecological and structural characterization of different plant communities was conducted to identify the main functional groups of the woody stands and to assess their level of degradation. Multivariate analysis technics were used to analyze the data. The results show that basal area and species richness of stands are the parameters that allow a clear differentiation of the status of woody areas at the level of ecogeographical zones. The productivity gradient opposes a disturbance gradient suggesting a severe degradation of ligneous area in the Sudano-Sahelian and North-Sudanian zones compared to those of the southern Sudanese zone. Our study showed that woody cover degradation and reduction across the studied area are mainly explained by uncontrolled utilization of forest resources and an evolution in farming systems. In addition is grafted the energy crisis that affects populations in semi-arid area that use exclusively wood and charcoal as the main sources of domestic energy. [less ▲]

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See detailLe milieu naturel de l’Agame-papillon géant [Leiolepis guttata (Cuvier, 1829), Leiolepidinae, Agamidae, Iguania, Sauria, Diapsida, Squamata, Reptilia] au Vietnam sud-central
Tran, Tinh ULg; Rochette, Anne-Julie; De Martynoff, Abigail et al

in Geo-Eco-Trop : Revue Internationale de Géologie, de Géographie et d'Ecologie Tropicales (2012), 36

Après avoir esquissé l’intérêt actuel porté à Leiolepis guttata, sa distribution naturelle est actualisée. Le climatope des stations concernées est défini. Les unités géomorphologiques qui s’y observent ... [more ▼]

Après avoir esquissé l’intérêt actuel porté à Leiolepis guttata, sa distribution naturelle est actualisée. Le climatope des stations concernées est défini. Les unités géomorphologiques qui s’y observent sont énumérées et les formations végétales décrites. La flore des sites naturels est dressée à partir de la littérature et de relevés effectués sur une dizaine de sites. La pédologie et la végétation d’une station naturelle sont décrites. La discussion aborde le régime alimentaire de l’espèce en milieu naturel et sa survie dans l’évolution climatique prédite et en réponse à la pression anthropique subie tant par la chasse que par la dégradation des écosystèmes naturels. [less ▲]

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See detailIs the fishing village of Phan Thiet victim of climate change ?
Ozer, Pierre ULg

in Geo-Eco-Trop : Revue Internationale de Géologie, de Géographie et d'Ecologie Tropicales (2012), 36

Warming of the climate system is unequivocal, as it is now evident from observations of increases in global average air and ocean temperatures, widespread melting of snow and ice and rising global average ... [more ▼]

Warming of the climate system is unequivocal, as it is now evident from observations of increases in global average air and ocean temperatures, widespread melting of snow and ice and rising global average sea level. In this framework, sea level rise is virtually certain. This will impact ecosystems, coastal areas, human health, and economies. Vietnam is very likely to be one of the most affected countries with its 3200 km of shorelines with amplified vulnerability in large areas already affected by subsidence such as the Mekong and Red River deltas. In January 2009, international broadcast news have relayed the information that 27 houses located on the southern coast of Vietnam, in the fishing village of Phan Thiet, 200 km east of Ho Chi Minh City, have collapsed and that another hundred buildings were also threatened of destruction. According to experts, this event was definitely one of the consequences of global warning. This article shows, using the multi dates of Google Earth, that this assumption is not correct and highlights the real causes of this rapid and inevitable retreat of the coastline in this village, namely the mismanagement of natural resources, the lack of land use planning and the non-existence of policies focused on natural hazard management in the uncontrolled construction the seaside resort of Mui Ne, a few kilometers east. [less ▲]

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See detailEvolution des caractéristiques pluviométriques dans la zone urbaine de Butembo (RDC) de 1957 À 2010
Sahani, Muhindo; Moeyersons, Jan; Vandecasteele, Ine et al

in Geo-Eco-Trop : Revue Internationale de Géologie, de Géographie et d'Ecologie Tropicales (2012), 36

In recent years, the city of Butembo faced unprecedented damaging floods. This study aims to analyze the rainfall variations recorded at the meteorological station of the Agricultural and Veterinary ... [more ▼]

In recent years, the city of Butembo faced unprecedented damaging floods. This study aims to analyze the rainfall variations recorded at the meteorological station of the Agricultural and Veterinary Technical Institute (ITAV) in Butembo between 1957 and 2010. It appears that rainfall features have remained relatively stable over the analyzed period.Linear upward trends were observed for the simple day intensity index (SDII) and for the total number of days characterized by precipitation >= 10 mm (P10). In contrast, seven other rainfall indices recorded a decreasing trend: the total annual precipitation (PTOT), the total number of wet days (rainfall >=1 mm) (JP), the total number of days characterized by precipitation >= 20 mm (P20), the maximum daily rainfall (Px1J), the frequency of intense (P95p), extreme (P99p) and very extreme (P99,5p) rainfall. However, none of these trends were statistically significant. Although the floods recurrence became prevalent, the study reports that extreme rainfall events do not reveal exceptional rains in the past few years. Yet, all recent maximum daily rainfalls are considered as normal since their return period is less than six years. This suggests a significant increase in flood risk mainly due to human impacts over the urban area and increasing vulnerability. This study also underlines that the length of the rainy season is shortening, undermining urban agriculture production and therefore food security. [less ▲]

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See detailDynamique de la végétation d'altitude en Afrique centrale atlantique depuis 17 000 ans BP. Analyses préliminaires de la carotte de Bambili (Nord-Ouest du Cameroun).
Assi Kaudjhis, Chimène Cloche M ULg; LEZINE, ANNE - MARIE; Roche, Emile ULg

in Geo-Eco-Trop : Revue Internationale de Géologie, de Géographie et d'Ecologie Tropicales (2008), 32

This article presents the preliminary results of pollen analyses carried out on a 13.5m long core taken from the shore of the crater lake of Bambili, Cameroon (05°56'11.9N; 10°14' 31.6E; 2273m alt.). This ... [more ▼]

This article presents the preliminary results of pollen analyses carried out on a 13.5m long core taken from the shore of the crater lake of Bambili, Cameroon (05°56'11.9N; 10°14' 31.6E; 2273m alt.). This allows us to reconstruct the history of montane forest ecosystems from Atlantic Central Africa since 17 000 years BP. Well diversified microflora, show several changes. At the base of the pollen sequence, the vegetation is dominated by herbaceous plant populations such as Poaceae, associated with “dry” plant types from Amaranthaceae/ Chenopodiaceae families and tree and shrub plant types from savannas and open forest formations types such as Gnidia, Lannea, Combretaceae, Cussonia… The montane forest expansion started from 14 080cal BP with the appearance of the pioneer taxon Myrica. This taxon is followed by Schefflera, Podocarpus, Olea, Syzygium… which widely expanded in the immediate surroundings of the lake from 12 310 to 4 590 cal BP. After this date, the montane forest was strongly reduced. However a short phase of forest regrowth is recorded around 2000 BP during which Schefflera dominated the forest assemblage. [less ▲]

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See detailRéponses de Cedrus atlantica aux changements climatiques passés et futurs
Demarteau, Maxime; François, Louis ULg; Cheddadi, Rachid et al

in Geo-Eco-Trop : Revue Internationale de Géologie, de Géographie et d'Ecologie Tropicales (2007)

This work addresses the responses of the Atlas Mountain Cedar tree (Cedrus atlantica Manetti) when faced with past and future climactic changes. The ecological study of this species proposes three ... [more ▼]

This work addresses the responses of the Atlas Mountain Cedar tree (Cedrus atlantica Manetti) when faced with past and future climactic changes. The ecological study of this species proposes three simulations based on reliable and precise data: - Simulation in 6000 B.P. with the GCM UBRIS-HadCM3M2 climatic data - Simulation in the year 2000 with NEW et al. climactic data (2002) - Simulation in the year 2100 with the ARPEGE Climactic Model data - following the IPCC's scenario A2 These simulations were realized using the CARAIB model, which simulates Carbon stocks in vegetation and Carbon flux between vegetation, soil and atmosphere. In part one, the Moroccan Atlas Mountains, which constitute the principal natural area of the Atlas Cedar tree are described in detail. The different data describing this species' distribution at three periods are summarized: 1) at the present time, 2) at Holocene period and 3) at the end of the Upper Pleniglacial period . The distribution of the species is specified. A map of the Cedar tree's actual distribution in Morocco was drawn from a series of population maps - scale 1/25,000- kept at the Moroccan Ministry of Forestry and Water conservation. So as to improve the sequential study of fossils of Cedar pollen was defined the percentage threshold at which samples containing pollen from the Cedrus atlantica are described as autochtonous or allochthonous. The study of 514 samples of Moroccan Cedar pollen permittted to define this threshold as 1% with minimal risk of error. The last part of the work is focused on modelling. It starts with a description of IBM and CARAIB models used in the three simulations. The data essential for these models are reviewed. Considering the climactic data for these three periods, climate is globally warmer in 6000 BP and in 2100 than today, with the problems of drought becoming more severe in the future. The analysis of the three simulations brings us to two conclusions. Cedrus antlantica is sensitive to climactic change and shows that, at three different periods, its potential distribution areas are quite different. At 6000 BP, the species sought refuge in the high mountains of North Africa. Today's distribution is well simulated in our model. Its good survival in Europe makes it an interesting species for reforestation. In 2100, if IPCC's A2 scenario is validated, modifications in the Cedar's potential and real area of distribution will be considerable. The tree will find little refuge in North Africa. On the other hand, the climate of the land between the Northern Alps and the South of Sweden, associated with a strong concentration of CO2 in the atmosphere may well provide it with an acceptable environment. [less ▲]

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