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Kernif T.,French National Center for Scientific Research | Socolovschi C.,French National Center for Scientific Research | Wells K.,Biodiversity and Climate Research Center Bik F | Wells K.,University of Ulm | And 9 more authors.
Comparative Immunology, Microbiology and Infectious Diseases | Year: 2012

Rickettsioses and bartonelloses are arthropod-borne diseases of mammals with widespread geographical distributions. Yet their occurrence in specific regions, their association with different vectors and hosts and the infection rate of arthropod-vectors with these agents remain poorly studied in South-east Asia. We conducted entomological field surveys in the Lao PDR (Laos) and Borneo, Malaysia by surveying fleas, ticks, and lice from domestic dogs and collected additional samples from domestic cows and pigs in Laos. . Rickettsia felis was detected by real-time PCR with similar overall flea infection rate in Laos (76.6%, 69/90) and Borneo (74.4%, 268/360). Both of the encountered flea vectors . Ctenocephalides orientis and . Ctenocephalides felis felis were infected with . R. felis. The degrees of similarity of partial . gltA and . ompA genes with recognized species indicate the rickettsia detected in two . Boophilus spp. ticks collected from a cow in Laos may be a new species. Isolation and further characterization will be necessary to specify it as a new species. . Bartonella clarridgeiae was detected in 3/90 (3.3%) and 2/360 (0.6%) of examined fleas from Laos and Borneo, respectively. Two fleas collected in Laos and one flea collected in Borneo were co-infected with both . R. felis and . B. clarridgeiae. Further investigations are needed in order to isolate these agents and to determine their epidemiology and aetiological role in unknown fever in patients from these areas. © 2011 Elsevier Ltd.

Wells K.,Biodiversity and Climate Research Center Bik F | Wells K.,University of Ulm | Beaucournu J.-C.,University of Monastir | Durden L.A.,Georgia Southern University | And 3 more authors.
Parasitology Research | Year: 2012

Domestic dogs, Canis lupus, have been one of the longest companions of humans and have introduced their own menagerie of parasites and pathogens into this relationship. Here, we investigate the parasitic load of 212 domestic dogs with fleas (Siphonaptera) chewing lice (Phthiraptera), and ticks (Acarina) along a gradient from rural areas with near-natural forest cover to suburban areas in Northern Borneo (Sabah, Malaysia). We used a spatially-explicit hierarchical Bayesian model that allowed us to impute missing data and to consider spatial structure in modelling dog infestation probability and parasite density. We collected a total of 1,968 fleas of two species, Ctenocephalides orientis and Ctenocephalides felis felis, from 195 dogs (prevalence, 92 %). Flea density was higher on dogs residing in houses made of bamboo or corrugated metal (increase of 40 % from the average) compared to timber or stone/compound houses. Host-dependent and landscape-level environmental variables and spatial structure only had a weak explanatory power. We found adults of the invasive chewing louse Heterodoxus spiniger on 42 dogs (20 %). The effect of housing conditions was opposite to those for fleas; lice were only found on dogs residing in stone or timber houses. We found ticks of the species Rhipicephalus sanguineus as well as Haemaphysalis bispinosa gp., Haemaphysalis cornigera, Haemaphysalis koenigsbergi, and Haemaphysalis semermis on 36 dogs (17 %). The most common tick species was R. sanguineus, recorded from 23 dogs. Tick infestations were highest on dogs using both plantation and forest areas (282 % increase in overall tick density of dogs using all habitat types). The infestation probability of dogs with lice and ticks decreased with elevation, most infestations occurred below 800 m above sea level. However, the density of lice and ticks revealed no spatial structure; infestation probability of dogs with these two groups revealed considerable autocorrelation. Our study shows that environmental conditions on the house level appeared to be more influential on flea and lice density whereas tick density was also influenced by habitat use. Infestation of dogs with Haemaphysalis ticks identified an important link between dogs and forest wildlife for potential pathogen transmission. © Springer-Verlag 2012.

Schmidt M.,Senckenberg Institute | Schmidt M.,Goethe University Frankfurt | Schmidt M.,Biodiversity and Climate Research Center Bik F | Konig K.,Goethe University Frankfurt | And 6 more authors.
Ecotropica | Year: 2011

We combined grass (Poaceae) occurrence data from the Sahelian parts of Burkina Faso, West Africa, with data on the photosynthetic type of these species. Occurrence data were compiled from relevfa and collections of the Herbarium Senckenbergianum, and the assignment of photosynthetic types was taken from the literature and completed by leaf anatomical observations of our own. We used the occurrence data to model species distributions using GARP (Genetic algorithm of rule-set production) and high-resolution satellite data (Landsat ETM+) as environmental predictors. In a subsequent step we summarized the distributions of single species for each photosynthetic type. The resulting distribution patterns reflect the ecological preferences connected with photosynthetic pathways. The only C3 species is strictly bound to watercourses and temporary lakes, C4 MS species mainly occur on the dunes, C4 PS-PCK species are mainly from dunes and watercourses, C4 PS-NAD type species dominate the drier peneplains.

Schneider J.V.,Senckenberg Institute | Schneider J.V.,Goethe University Frankfurt | Schneider J.V.,Biodiversity and Climate Research Center Bik F | Zizka G.,Senckenberg Institute | And 2 more authors.
Systematic Botany | Year: 2012

A taxonomic revision of the Neotropical dioecious genus Lacunaria (Quiinaceae / Ochnaceae s. l.) is presented including keys to the species and subspecies, descriptions, illustrations, nomenclature, typification, and geographical distribution of each species. Seven species are recognized within the genus, one subspecies, L. jenmanii subsp. subsessilis, is described newly, and the status of Lacunaria decastyla has been changed, transferring it to Lacunaria crenata subsp. decastyla. Leaf pubescence, number of secondary veins, and petal, stamen, and carpel number, although all quite variable, are the most important characters to distinguish the species. © Copyright 2012 by the American Society of Plant Taxonomists.

Pachzelt A.,Biodiversity and Climate Research Center Bik F | Rammig A.,Potsdam Institute for Climate Impact Research | Higgins S.,Goethe University Frankfurt | Hickler T.,Biodiversity and Climate Research Center Bik F | Hickler T.,Goethe University Frankfurt
Ecological Modelling | Year: 2013

Large grazers have played a fundamental role in grassland and savannah ecosystems since these vegetation types formed in the late Miocene, but the feedback loops between vegetation and large grazers are still not well understood. Modern dynamic global vegetation models (DGVMs) lack the explicit impact of herbivory, but are calibrated to benchmarks including herbivory. We coupled a generalized model for the population dynamics of large mammalian grazers, based on animal physiology, with a plant-physiological model for vegetation dynamics and ecosystem processes, applicable at local to global scales (LPJ-GUESS). To our knowledge, this is the first attempt to combine process-based grazer population and vegetation modelling in a single generalized modelling framework, applicable at regional to continental scales. The capability of the coupled model to reproduce real-world grazer densities was tested by comparing modelled biomass densities with empirical data from African game parks, where semi-natural grazer populations still exist. The model reproduced inter-park differences in long-term average grazer biomass densities and yielded similar dependencies between major environmental drivers (e.g. precipitation, annual net primary productivity (NPP), dry season length) and grazer population densities as found in other more empirical studies. Amongst the potential environmental drivers, modelled NPP and dry season length were most strongly correlated with empirical and modelled biomass densities. Major discrepancies between modelled and empirical densities occurred for individual parks, but this was expected because the model did not include all factors that influence grazer populations (e.g. nutrient dynamics and poaching). The generalized flexible framework of the coupled model makes it possible to apply the model to other regions, to include further processes (if data for parameterizing them is available) and to parameterize other types of grazers. It could become a useful tool for investigating interactions between grazers and vegetation in a process-based framework. © 2013 Elsevier B.V.

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