Kahindo C.M.,University Officielle Of Bukavu |
Bates J.M.,Integrative Research Center |
Bowie R.C.K.,University of California at Berkeley
Ibis | Year: 2017
The endangered warbler Bradypterus graueri is endemic to the Albertine Rift, where it is restricted to montane swamps above 1900 m across the region. We studied genetic structure among six populations sampled across the species’ distribution in northern Burundi, Rwanda, Uganda and the eastern Democratic Republic of Congo. A total of 2117 base pairs of mitochondrial data were sequenced. Phylogenetic analyses and network reconstruction of B. graueri haplotypes recovered three clades with a defined geographical pattern: clade 1, Virunga Volcanoes and Kigezi Highlands; clade 2, Rugege Highlands; and clade 3, Kahuzi-Biega Highlands; clades 2 and 3 are sisters to each other. Both landscape dynamics and historical climate are likely to have played a role in the diversification of this species. The divergence between clade 1 and clades 2 and 3 (168.5 ka, 95% HPD 108.5, 244.4) coincides with a prolonged period of aridity in tropical Africa between 130 and 270 ka. Similarly, the divergence between clades 2 and 3 (99.4 ka, 95% HPD 55.4, 153.8) corresponds with a period of aridity just prior to 94 ka. Populations sampled from the eastern arm of the central Albertine Rift (Kigezi and Rugege Highlands) show a coincident increase in effective population size after the Last Glacial Maximum at c. 15 ka, whereas those sampled from Kahuzi-Biega on the western arm of the rift do not. Despite the perceived higher vagility of bird species relative to other vertebrates, the degree of phylogeographical structure among populations of B. graueri is similar to that reported for small mammals (Hylomyscus vulcanorum, Lophuromys woosnami, Sylvisorex vulcanorum) and a frog Hyperolius castaneus sampled across the central Albertine Rift. Collectively our results suggest that climate dynamics associated with late Pleistocene cycles had a significant influence on driving the population genetic structure and associated levels of genetic diversity in B. graueri and other small terrestrial vertebrates. Our results have implications for the conservation of B. graueri and other endemics to the Albertine Rift, particularly in the context of other phylogegeographical studies centred on this biodiversity hotspot. © 2016 British Ornithologists’ Union
Lushombo M.,University Officielle Of Bukavu
Aquatic Ecosystem Health and Management | Year: 2014
This study describes the inshore fishery on the littoral cichlids in Lake Tanganyika, to evaluate the potential impact of fishing gear on the cichlid fishes and their diversity. The fishing activity at the northwestern end of Lake Tanganyika in Uvira was examined from March to July 2010. In total, the catch examined was composed of 3,555 cichlid fish: 47 species and 30 genera identified representing 10 of the 16 tribes of Lake Tanganyika cichlids. Fishermen in Uvira, exploiting littoral cichlids, used three main fishing gears including beach seine, frame gillnet and mosquito net, varying according to the substrates of the littoral habitat at different study sites. They generally captured immature fishes (63%) and small-sized fish due to their small mesh size and unsuitable fishing techniques. The beach seine caught more species on the sandy substrate while the frame gillnets caught more individuals. The cichlid species Aulonocranus dewindti was the most abundant in the catches. © 2014 Copyright Taylor & Francis Group, LLC.
Moeyersons J.,Royal Museum for Central Africa |
Trefois P.,Royal Museum for Central Africa |
Nahimana L.,University of Burundi |
Ilunga L.,Kigali Institute of Education |
And 3 more authors.
Natural Hazards | Year: 2010
Uvira occupies a series of narrow alluvial fans squeezed between the NW corner of Lake Tanganyika (±710 m asl) and the W-shoulder of the Tanganyika rift, the Itombwe-Mitumba Plateau (±3,000 m asl). In 50 years, the fans progressed into the lake over distances up to some hundreds of metres. This happened during a few catastrophic flash floods issued from the torrents which cascade from the rift shoulder with a mean longitudinal gradient of 0.2 m m-1. The last event in 2002 led to the destruction of parts of the town and to some 50 casualties. Landslides occurred in the hills. On the base of stereoscopic interpretation of aerial photographs from 1959, complemented with data from 2000 ETM and 2004 IKONOS imagery, a geographical inventory has been made of strongly incising (10-1 to 0 m in 43-45 years) river sections, of all types of landslides and of all tectonic structures, visible in the rugged hinterland of the fans. Traces of active N-S as well as E-W trending faults are present. Some of these faults and some surfaces, interpreted as degraded fault facets dip at angles of 40° or less and are probably remnants of formerly active lystric extension faults, originally at a depth of some 2 km, but now at the surface as a result of posterior uplift and erosion. Sixty landslides could be identified. Six slides fall far below the topographic threshold envelope, where the slope at the incision head is expressed as a function of drained surface. Therefore, they are considered to be seismic in origin. Most of the other landslides are located along strongly incising river sections. Temporary landslide barriers contribute to irregular river hydrographs. It is concluded that Uvira is threatened by landsliding, potentially massive (<18 × 106 m3 debris), in the case of heavy seismicity. It is further discussed that the regularisation of the river regime depends on soil and water conservation strategies, to be developed in the headwaters of the torrents Kavimvira, Mulongwe and Kalimabenge. © Springer Science+Business Media B.V. 2009.
Vleminckx J.,Roosevelt University |
Drouet T.,Roosevelt University |
Amani C.,University Officielle Of Bukavu |
Lisingo J.,University of Kisangani |
And 2 more authors.
Journal of Vegetation Science | Year: 2015
Questions: Soil properties have been shown to partially explain tree species distribution in tropical forests. Locally, species turnover across space can result not only from edaphic heterogeneities but also from limited seed dispersal. To characterize the contribution of each process, contact areas between contrasted soil types offer ideal settings. In the present study, we aimed to test species and species assemblage responses to a sharp edaphic discontinuity in a tropical forest tree community. Location: Yoko forest reserve (6975 ha), Democratic Republic of the Congo. Methods: We set up four 500-600-m long parallel transects crossing two contrasted edaphic habitats, one lying on clayey soil and the other on sandy soil. The canopy and subcanopy trees were identified and geo-referenced along the transects over a width of 50 m and 5 m, respectively, and soil samples were collected every 50 m to characterize each habitat. Results: Correspondence analyses indicated a clear differentiation of tree communities between sandy and clayey soils. Using a torus-translation method combined with Chi-squared non-parametric tests, we observed that ca. 40% and 18% of the species represented by at least 12 individuals displayed significant density differences according to habitat in the canopy and subcanopy, respectively, although very few species displayed significant differences in their relative abundance. Nevertheless, whole community tests of differentiation (in species relative abundances) between soil types were significant in both strata, even after removing individual species or families displaying a significant habitat preference. Conclusion: While only a minority of species displayed a clear habitat preference, we still observed a community-wide impact of the edaphic discontinuity on species assemblages at a local scale. Our results provide further evidence for the major contribution of environmental heterogeneity in maintaining biodiversity in tropical forests. © 2014 International Association for Vegetation Science.
Woody climbing plants influence the structure of the mountain forest in the Kahuzi-Biega National Park, DR Congo [Des lianes influencent la structure de la forêt de montagne au Parc National de Kahuzi-Biega]
Masumbuko N.C.,University Officielle Of Bukavu |
Habiyaremye M.F.,Institute Royal Des Science Naturelles Of Belgique |
Lejoly J.,Roosevelt University
Regional Environmental Change | Year: 2012
In the mountain forests of the Kahuzi-Biega National Park (KBNP), in the Democratic Republic of Congo, where Sericostachys scandens, a woody climbing plant in the Amaranthaceae family, is expanding, trees appear to be negatively affected by this liana. In order to contribute to the understanding of the links between the expansion of the liana and the decline of its hosts, we compared the density and the species richness of the trees of dbh (diameter at breast height) ≥5 cm from the plots invaded by S. scandens with those from parcels that are still free from the invasion. The results of the paired unilateral t test applied to the overall sample showed that the tree density is very low in the plots dominated by the liana (p < 0.01), but that species richness is not affected (p > 0.05). In the class with diameter [10-30 cm], the lowest density of trees corresponds to the plots colonized by S. scandens, compared to the places where the liana is not abundant (p < 0.01). Further, the density of trees is significantly lower (p < 0.05) in the classes with diameters [5-10 cm] and ≥30 cm, in plots dominated by S. scandens. In conclusion, the emergence of the liana S. scandens has a negative effect on the density of the trees in the mountain forest of the KBNP. © 2012 Springer-Verlag.
Voelker G.,Texas A&M University |
Marks B.D.,Texas A&M University |
Kahindo C.,University Officielle Of Bukavu |
A'genonga U.,British Petroleum |
And 6 more authors.
Ecology and Evolution | Year: 2013
The Riverine Barriers Hypothesis (RBH) posits that tropical rivers can be effective barriers to gene flow, based on observations that range boundaries often coincide with river barriers. Over the last 160 years, the RBH has received attention from various perspectives, with a particular focus on vertebrates in the Amazon Basin. To our knowledge, no molecular assessment of the RBH has been conducted on birds in the Afrotropics, despite its rich avifauna and many Afrotropical bird species being widely distributed across numerous watersheds and basins. Here, we provide the first genetic evidence that an Afrotropical river has served as a barrier for birds and for their lice, based on four understory bird species collected from sites north and south of the Congo River. Our results indicate near-contemporaneous, Pleistocene lineage diversification across the Congo River in these species. Our results further indicate differing levels of genetic variation in bird lice; the extent of this variation appears linked to the life-history of both the host and the louse. Extensive cryptic diversity likely is being harbored in Afrotropical forests, in both understory birds and their lice. Therefore, these forests may not be "museums" of old lineages. Rather, substantial evolutionary diversification may have occurred in Afrotropical forests throughout the Pleistocene, supporting the Pleistocene Forest Refuge Hypothesis. Strong genetic variation in birds and their lice within a small part of the Congo Basin forest indicates that we may have grossly underestimated diversity in the Afrotropics, making these forests home of substantial biodiversity in need of conservation. © 2013 The Authors. Ecology and Evolution published by Blackwell Publishing Ltd.
Mokoso J.M.,University of Antwerp |
Mokoso J.M.,University Officielle Of Bukavu |
Habiyaremye F.M.,Institute Royal Des Science Naturelles Of Belgique |
Janssen T.,Institute Of Biologie Of Lhumboldt University |
And 3 more authors.
International Journal of Environmental Studies | Year: 2013
Cette étude se focalise sur la vérification de l'hypothèse que l'altitude influence l'occurrence de la flore des Fougères et leurs alliées au sein de l'écosystème forestier des montagnes du Parc National de Kahuzi-Biega. Un échantillonnage de la végétation y a été effectué en considérant 24 parcelles localisées par paires le long de 12 transects installés entre 1278 m et 3123 m d'altitude. Les données obtenues ont été traitées par des méthodes statistiques, principalement la régression et des analyses multivariées. Au total, 157 espèces ont été recensées. Les résultats montrent que la richesse spécifique décroît linéairement avec l'augmentation de l'altitude à partir de 2600 m. Cette tendance prévaut à la fois dans les sites perturbés (R 2 = 0.58; P < 0.001) et dans les endroits non perturbés (R 2 = 0.81; P < 0.001). Trente-sept espèces (soit 23.56%) représentent les espèces communes dans les trois étages du site d'étude et s'adaptent à toutes les conditions altitudinales. Une analyse canonique a montré que les facteurs abiotiques pris en compte dans cette recherche absorbent de 71.7% de la variance de la distribution des Fougères et leurs alliées trouvées et que l'altitude qui est prépondérante. Comme la température est tributaire de ce paramètre, les Fougères et leurs alliées circonscrites dans les étages ci-dessus se révèlent respectivement macrothermes, mésothermes et microthermes. This study concerns the hypothesis that altitude influences the occurrence of ferns and their allies in the forest ecosystem of the mountains in Kahuzi-Biega National Park. To obtain an inventory of the ferns and their allies, a sampling of the vegetation was made in 24 squares located in pairs along 12 transects lying between 1278 metres and 3123 metres altitude. The data were statistically analysed, mainly with regression methods and multivariate analysis. A total of 157 species were recorded. Species richness decreases in a linear way with higher altitude from 2600 metres. This tendency is observed in disturbed (R 2 = 0.58; P < 0.001) as well as in intact sites (R 2 = 0.81; P < 0.001). Among the observed species, only 37 (i.e. 23.56%) are common elements of the three vegetation belts in the study area (submontane, montane and subalpine) and are adapted to all altitudinal conditions. A canonical analysis (DCA) showed that the abiotical factors considered in the study (altitude, slope, substrates, temperature) explain 71.7% of the variance of the distribution of the ferns and their allies found, with altitude being the dominant factor. As temperature depends on this factor, the ferns and their allies occurring in the belts mentioned above can be characterised as macrothermal, mesothermal and microthermal. © 2013 Copyright Taylor and Francis Group, LLC.
Nshagali B.G.,University of Yaounde I |
Nshagali B.G.,University Officielle Of Bukavu |
Njandjock Nouck P.,University of Yaounde I |
Meli'i J.L.,University of Yaounde I |
And 3 more authors.
Environmental Earth Sciences | Year: 2015
To mitigate the disasters caused by the consumption of poor quality of water, the World Health Organization (WHO) has established standards for testing the quality of drinking water that must be met. The purpose of this study is to verify the relevance of these tests in crystalline basement aquifers in equatorial areas. The global analysis of water quality was conducted by comparing the measured concentration of iron, calcium, pH change and other major ions in the 70 water samples which were collected at different sites in the Centre Cameroun area with the WHO standards. The water quality index was estimated in the entire area using the block ordinary kriging technique. The results show a high concentration of iron, a very high or very low pH, and high temperature values at certain sites, exceeding sometimes the standard values. Finally, this study shows that the control of groundwater quality following WHO standards must always be conducted. © 2014, Springer-Verlag Berlin Heidelberg.
Yombiyeni P.,Institute Of Recherche En Ecologie Tropicale Iret |
Balezi A.,University Officielle Of Bukavu |
Amalfi M.,Catholic University of Louvain |
Decock C.,Catholic University of Louvain
Mycologia | Year: 2015
Four species are added to Phylloporia. Three species, originating from the western edge of the Guineo-Congolian rainforest in Gabon (central Africa), are described as new. Phylloporia afrospathulata sp. nov. forms seasonal, stipitate, solitary basidiomata emerging from soil, more likely connected to buried roots, and has broadly ellipsoid basidiospores. Phylloporia inonotoides sp. nov. forms seasonal sessile, soft basidiomata, solitary at the base of small-stemmed trees including Crotonogyne manniana (Euphorbiaceae) and Garcinia cf. smeathmannii (Clusiaceae). It has a homogeneous context, large pores (2-3 mm), and oblong-ellipsoid to suballantoid basidiospores. Phylloporia fulva sp. nov. forms sessile, conchate, mostly pendant, gregarious basidiomata emerging from the trunk of an unidentified small-stemmed tree and has small, subglobose basidiospores. This species is compared to Polyporus pullus and Phylloporia pulla comb. nov. and proposed based on the study of the type specimen. Phylogenetic inferences using partial nuc 28S DNA sequence data (region including the D1/D2/D3 domains) and the most exhaustive dataset available to date resolved these new morphospecies as three distinct terminal lineages. No sequence data of P. pulla currently is available. The 28S-based phylogenic inferences poorly resolved the interspecific relationships within the Phylloporia clade. © 2015 by The Mycological Society of America, Lawrence, KS 66044-8897.
PubMed | University Officielle Of Bukavu, Catholic University of Louvain and Institute Of Recherche En Ecologie Tropicale Iret
Type: Journal Article | Journal: Mycologia | Year: 2015
Four species are added to Phylloporia. Three species, originating from the western edge of the Guineo-Congolian rainforest in Gabon (central Africa), are described as new. Phylloporia afrospathulata sp. nov. forms seasonal, stipitate, solitary basidiomata emerging from soil, more likely connected to buried roots, and has broadly ellipsoid basidiospores. Phylloporia inonotoides sp. nov. forms seasonal sessile, soft basidiomata, solitary at the base of small-stemmed trees including Crotonogyne manniana (Euphorbiaceae) and Garcinia cf. smeathmannii (Clusiaceae). It has a homogeneous context, large pores (2-3 mm), and oblong-ellipsoid to suballantoid basidiospores. Phylloporia fulva sp. nov. forms sessile, conchate, mostly pendant, gregarious basidiomata emerging from the trunk of an unidentified small-stemmed tree and has small, subglobose basidiospores. This species is compared to Polyporus pullus and Phylloporia pulla comb. nov. and proposed based on the study of the type specimen. Phylogenetic inferences using partial nuc 28S DNA sequence data (region including the D1/D2/D3 domains) and the most exhaustive dataset available to date resolved these new morphospecies as three distinct terminal lineages. No sequence data of P. pulla currently is available. The 28S-based phylogenic inferences poorly resolved the interspecific relationships within the Phylloporia clade.