Clément Tisseuil | Université libre de Bruxelles (original) (raw)

Papers by Clément Tisseuil

Parameters, standard deviation and significance for the best Core (zero inflated negativ... more Parameters, standard deviation and significance for the best Core (zero inflated negative binomial model; zeroinf-nb), Init (GLM negative binomial model; glm-nb) and Max models (GLM negative binomial model; glm-nb).</p

a) according to the monitoring week of the year and b) according to the week of model in... more a) according to the monitoring week of the year and b) according to the week of model initialization.</p

Statistical model selection for the Core, Init and Max modeling components, based on bas... more Statistical model selection for the Core, Init and Max modeling components, based on based on Akaike information criterion (AIC), Spearman correlation coefficient (COR), root mean square error (RMSE) and dispersion parameter (DISP).</p

The darker the color the more projected abundance by the model.</p

Journal of Animal Ecology, 2012

1. Whereas global patterns and predictors of species diversity are well known for numerous terres... more 1. Whereas global patterns and predictors of species diversity are well known for numerous terrestrial taxa, our understanding of freshwater diversity patterns and their predictors is much more limited. 2. Here, we examine spatial concordance in global diversity patterns for five freshwater taxa (i.e. aquatic mammals, aquatic birds, fishes, crayfish and aquatic amphibians) and investigate the environmental factors driving these patterns at the river drainage basin grain. 3. We find that species richness and endemism patterns are significantly correlated among taxa. We also show that cross-taxon congruence patterns are often induced by common responses of taxa to their contemporary and historical environments (i.e. convergent patterns). Apart from some taxa distinctiveness (i.e. fishes), the 'climate/productivity' hypothesis is found to explain the greatest variance in species richness and endemism patterns, followed by factors related to the 'history/dispersion' and 'area/environmental heterogeneity' hypotheses. 4. As aquatic amphibians display the highest levels of congruency with other taxa, this taxon appears to be a good 'surrogate' candidate for developing global freshwater conservation planning at the river drainage basin grain.

La dermatose nodulaire contagieuse des bovins (DNCB), maladie virale enzootique en Afrique sub-sa... more La dermatose nodulaire contagieuse des bovins (DNCB), maladie virale enzootique en Afrique sub-saharienne et classee comme danger sanitaire de categorie I, a ete detectee pour la premiere fois en Turquie en novembre 2013. Elle s'est ensuite etendue a l'Europe : tout d'abord dans la partie europeenne de la Turquie en mai 2015, puis dans les Balkans. Au 31 juillet 2016, elle touchait la Grece, la Bulgarie, la Macedoine (ARYM), le Montenegro, l'Albanie et la Serbie, avec 747 foyers notifies au total. La diffusion du virus se poursuit depuis son introduction en Europe, malgre les mesures de lutte mises en place dans les pays touches (restrictions de mouvements, abattages, vaccinations…). La vigilance quant a la diffusion de l'infection en Europe ainsi que les propositions de mise en oeuvre d'une surveillance dediee sur le territoire national s'exercent dans le cadre de la Plateforme ESA. Cet article fait le point sur la situation epidemiologique de la DNCB da...

L'objectif etait d'evaluer l'impact du changement global sur les ecosystemes aquatiqu... more L'objectif etait d'evaluer l'impact du changement global sur les ecosystemes aquatiques au cours du 21eme siecle, dans le bassin Adour Garonne (S-O France). Une approche de " downscaling " a ete developpee a l'interface entre les sciences du climat, de l'hydro-chimie et de l'ecologie. Les resultats suggerent une augmentation globale des debits hivernaux ainsi que des debits d'etiages plus faibles. Les concentrations en nitrate pourraient augmenter, de meme que la distribution des especes de poissons les plus thermophiles. Toutefois, une diminution des gaz a effet de serre ainsi qu'une modification des pratiques agricoles (ex. diminution des fertilisants azotes) pourraient limiter l'intensite des perturbations ecologiques. Cette these offre une contribution originale, notamment pour la gestion future des ressources hydriques et ecologiques.

To understand the resilience of aquatic ecosystems to environmental change, it is important to de... more To understand the resilience of aquatic ecosystems to environmental change, it is important to determine how multiple, related environmental factors, such as near-surface air temperature and river flow, will change during the next century. This study develops a novel methodology that combines statistical downscaling and fish species distribution modeling, to enhance the understanding of how global climate changes (modeled by global climate models at coarse-resolution) may affect local riverine fish diversity. The novelty of this work is the downscaling framework developed to provide suitable future projections of fish habitat descriptors, focusing particularly on the hydrology which has been rarely considered in previous studies. The proposed modeling framework was developed and tested in a major European system, the Adour-Garonne river basin (SW France, 116,000 km(2)), which covers distinct hydrological and thermal regions from the Pyrenees to the Atlantic coast. The simulations suggest that, by 2100, the mean annual stream flow is projected to decrease by approximately 15% and temperature to increase by approximately 1.2 °C, on average. As consequence, the majority of cool- and warm-water fish species is projected to expand their geographical range within the basin while the few cold-water species will experience a reduction in their distribution. The limitations and potential benefits of the proposed modeling approach are discussed.

PLoS neglected tropical diseases, Feb 1, 2018

The increasing spread of the Asian tiger mosquito, Aedes albopictus, in Europe and US raises publ... more The increasing spread of the Asian tiger mosquito, Aedes albopictus, in Europe and US raises public health concern due to the species competence to transmit several exotic human arboviruses, among which dengue, chikungunya and Zika, and urges the development of suitable modeling approach to forecast the spatial and temporal distribution of the mosquito. Here we developed a dynamical species distribution modeling approach forecasting Ae. albopictus eggs abundance at high spatial (0.01 degree WGS84) and temporal (weekly) resolution over 10 Balkan countries, using temperature times series of Modis data products and altitude as input predictors. The model was satisfactorily calibrated and validated over Albania based observed eggs abundance data weekly monitored during three years. For a given week of the year, eggs abundance was mainly predicted by the number of eggs and the mean temperature recorded in the preceding weeks. That is, results are in agreement with the biological cycle of...

Preventive veterinary medicine, 2018

Several epidemics caused by different bluetongue virus (BTV) serotypes occurred in European rumin... more Several epidemics caused by different bluetongue virus (BTV) serotypes occurred in European ruminants since the early 2000. Studies on the spatial distribution of these vector-borne infections and the main vector species highlighted contrasted eco-climatic regions characterized by different dominant vector species. However, little work was done regarding the factors associated with the velocity of these epidemics. In this study, we aimed to quantify and compare the velocity of BTV epidemic that have affected different European countries under contrasted eco-climatic conditions and to relate these estimates to spatial factors such as temperature and host density. We used the thin plate spline regression interpolation method in combination with trend surface analysis to quantify the local velocity of different epidemics that have affected France (BTV-8 2007-2008, BTV-1 2008-2009), Italy (BTV-1 2014), Andalusia in Spain (BTV-1 2007) and the Balkans (BTV-4 2014). We found significant di...

Ecography, 2015

Early View (EV): 1-EV contagion between populations of susceptible hosts and vectors through the ... more Early View (EV): 1-EV contagion between populations of susceptible hosts and vectors through the use of transmission kernels .

Science of The Total Environment, 2014

The scale dependence of ecological phenomena remains a central issue in ecology. Particularly in ... more The scale dependence of ecological phenomena remains a central issue in ecology. Particularly in aquatic ecology, the consideration of the accurate spatial scale in assessing the effects of landscape factors on stream condition is critical. In this context, our study aimed at assessing the relationships between multi-spatial scale land cover patterns and a variety of water quality and diatom metrics measured at the stream reach level. This investigation was conducted in a major European river system, the Adour-Garonne river basin, characterized by a wide range of ecological conditions. Redundancy analysis (RDA) and variance partitioning techniques were used to disentangle the different relationships between land cover, water-chemistry and diatom metrics. Our results revealed a top-down &amp;amp;amp;amp;amp;amp;amp;amp;amp;quot;cascade effect&amp;amp;amp;amp;amp;amp;amp;amp;amp;quot; indirectly linking diatom metrics to land cover patterns through water physico-chemistry, which occurred at the largest spatial scales. In general, the strength of the relationships between land cover, physico-chemistry, and diatoms was shown to increase with the spatial scale, from the local to the basin scale, emphasizing the importance of continuous processes of accumulation throughout the river gradient. Unexpectedly, we established that the influence of land cover on the diatom metric was of primary importance both at the basin and local scale, as a result of discontinuous but not necessarily antagonist processes. The most detailed spatial grain of the Corine land cover classification appeared as the most relevant spatial grain to relate land cover to water chemistry and diatoms. Our findings provide suitable information to improve the implementation of effective diatom-based monitoring programs, especially within the scope of the European Water Framework Directive.

Journal of Applied Ecology, 2013

1. Current models estimating impact of habitat loss on biodiversity in the face of global climate... more 1. Current models estimating impact of habitat loss on biodiversity in the face of global climate change usually project only percentages of species 'committed to extinction' on an uncertain timescale. Here, we show that this limitation can be overcome using an empirically derived 'background extinction rate-area' curve to estimate natural rates and project future rates of freshwater fish extinction following variations in river drainage area resulting from global climate change. 2. Based on future climatic projections, we quantify future active drainage basin area losses and combine them with the extinction rate-area curve to estimate the future change in extinction rate for each river basin. We then project the number of extinct species in each river basin using a global data base of freshwater fish species richness. 3. The median projected extinction rate owing to climate change conditions is c. 7% higher than the median background extinction rate. A closer look at the pattern reveals great geographical variations highlighting an amplification of aridity by 2090 and subsequent increase in extinction rates in presently semi-arid and Mediterranean regions. Among the 10% mostimpacted drainage basins, water availability loss will increase background extinction rates by 18Á2 times (median value). 4. Projected numbers of extinct species by 2090 show that only 20 river basins among the 1010 analysed would experience fish species extinctions attributable to water availability loss from climate change. Predicted numbers of extinct species for these rivers range from 1 to 5. 5. Synthesis and applications. Our results strongly contrast with previous alarming predictions of huge surface-dependent climate change-driven extinctions for riverine fishes and other taxonomic groups. Furthermore, based on well-documented fish extinctions from Central and North American drainages over the last century, we also show that recent extinction rates are, on average, 130 times greater than our projected extinction rates from climate change. This last result implies that current anthropogenic threats generate extinction rates in rivers far greater than the ones expected from future water availability loss. We thus argue that conservation actions should be preferentially focused on reducing the impacts of present-day anthropogenic drivers of riverine fish extinctions.

Global Ecology and Biogeography, 2012

Diversity and Distributions, 2013

ABSTRACT Aim: Species inhabiting fresh waters are severely affected by climate change and other a... more ABSTRACT Aim: Species inhabiting fresh waters are severely affected by climate change and other anthropogenic stressors. Effective management and conservation plans require advances in the accuracy and reliability of species distribution forecasts. Here, we forecast distribution shifts of Salmo trutta based on environmental predictors and examine the effect of using different statistical techniques and varying geographical extents on the performance and extrapolation of the models obtained. Location: Watercourses of Ebro, Elbe and Danube river basins (c. 1,041,000 km 2 ; Mediterranean and temperate climates, Europe). Methods: The occurrence of S. trutta and variables of climate, land cover and stream topography were assigned to stream reaches. Data obtained were used to build correlative species distribution models (SDMs) and forecasts for future decades (2020s, 2050s and 2080s) under the A1b emissions scenario, using four statistical techniques (generalised linear models, generalised additive models, random forest, and multivariate adaptive regression). Results: The SDMs showed an excellent performance. Climate was a better predictor than stream topography, while land cover characteristics were not necessary to improve performance. Forecasts predict the distribution of S. trutta to become increasingly restricted over time. The geographical extent of data had a weak impact on model performance and gain/loss values, but better species response curves were generated using data from all three basins collectively. By 2080, 64% of the stream reaches sampled will be unsuitable habitats for S. trutta, with Elbe basin being the most affected, and virtually no new habitats will be gained in any basin. Main conclusions: More reliable predictions are obtained when the geographical data used for modelling approximate the environmental range where the species is present. Future research incorporating both correlative and mechanistic approaches may increase robustness and accuracy of predictions.

Preventive veterinary medicine, 2018

Journal of Hydrology, 2010

s u m m a r y An extensive statistical 'downscaling' study is done to relate large-scale climate ... more s u m m a r y An extensive statistical 'downscaling' study is done to relate large-scale climate information from a general circulation model (GCM) to local-scale river flows in SW France for 51 gauging stations ranging from nival (snow-dominated) to pluvial (rainfall-dominated) river-systems. This study helps to select the appropriate statistical method at a given spatial and temporal scale to downscale hydrology for future climate change impact assessment of hydrological resources. The four proposed statistical downscaling models use large-scale predictors (derived from climate model outputs or reanalysis data) that characterize precipitation and evaporation processes in the hydrological cycle to estimate summary flow statistics. The four statistical models used are generalized linear (GLM) and additive (GAM) models, aggregated boosted trees (ABT) and multi-layer perceptron neural networks (ANN). These four models were each applied at two different spatial scales, namely at that of a single flow-gauging station (local downscaling) and that of a group of flow-gauging stations having the same hydrological behaviour (regional downscaling). For each statistical model and each spatial resolution, three temporal resolutions were considered, namely the daily mean flows, the summary statistics of fortnightly flows and a daily 'integrated approach'. The results show that flow sensitivity to atmospheric factors is significantly different between nival and pluvial hydrological systems which are mainly influenced, respectively, by shortwave solar radiations and atmospheric temperature. The non-linear models (i.e. GAM, ABT and ANN) performed better than the linear GLM when simulating fortnightly flow percentiles. The aggregated boosted trees method showed higher and less variable R 2 values to downscale the hydrological variability in both nival and pluvial regimes. Based on GCM cnrm-cm3 and scenarios A2 and A1B, future relative changes of fortnightly median flows were projected based on the regional downscaling approach. The results suggest a global decrease of flow in both pluvial and nival regimes, especially in spring, summer and autumn, whatever the considered scenario. The discussion considers the performance of each statistical method for downscaling flow at different spatial and temporal scales as well as the relationship between atmospheric processes and flow variability.

Hydrology and Earth System Sciences Discussions, 2011

Potential evaporation (PET) is one of the main inputs of hydrological models. Yet, there is limit... more Potential evaporation (PET) is one of the main inputs of hydrological models. Yet, there is limited consensus on which PET equation is most applicable in hydrological climate impact assessments. In this study six different methods to derive global scale reference PET time series from CFSR reanalysis data are compared: Penman-Monteith, Priestley-Taylor and original and modified versions of the Hargreaves and Blaney-Criddle method. The calculated PET time series are (1) evaluated against global monthly Penman-Monteith PET time series calculated from CRU data and (2) tested on their usability for modeling of global discharge cycles. The lowest root mean squared differences and the least significant deviations (95 % significance level) between monthly CFSR derived PET time series and CRU derived PET were obtained for the cell specific modified Blaney-Criddle equation. However, results show that this modified form is likely to be unstable under changing climate conditions and less reliable for the calculation of daily time series. Although often recommended, the Penman-Monteith equation did not outperform the other methods. In arid regions (e.g., Sahara, central Australia, US deserts), the equation resulted in relatively low PET values and, consequently, led to relatively high discharge values for dry basins (e.g., Orange, Murray and Zambezi). Furthermore, the Penman-Monteith equation has a high data demand and the equation is sensitive to input data inaccuracy. Therefore, we preferred the modified form of the Hargreaves equation, which globally gave reference PET values comparable to CRU derived values. Although it is a relative efficient empirical equation, like Blaney-Criddle, the equation considers multiple spatial varying meteorological variables and consequently performs well for different climate conditions. In the modified form of the Hargreaves equation the multiplication factor is uniformly increased from 0.0023 to 0.0031 to overcome the global underestimation of CRU derived PET obtained with the original equation. It should be noted that the bias in PET is not linearly transferred to actual evapotranspiration and runoff, due to limited soil moisture availability and precipitation. The resulting gridded daily PET time series provide a new reference dataset that can be used for future hydrological impact assessments or, more specifically, for the statistical downscaling of daily PET derived from raw GCM data.

Journal of Environmental Quality, 2008

Whereas global patterns and predictors of species diversity are well known for numerous terrestri... more Whereas global patterns and predictors of species diversity are well known for numerous terrestrial taxa, our understanding of freshwater diversity patterns and their predictors is much more limited. 2. Here, we examine spatial concordance in global diversity patterns for five freshwater taxa (i.e. aquatic mammals, aquatic birds, fishes, crayfish and aquatic amphibians) and investigate the environmental factors driving these patterns at the river drainage basin grain. 3. We find that species richness and endemism patterns are significantly correlated among taxa. We also show that cross-taxon congruence patterns are often induced by common responses of taxa to their contemporary and historical environments (i.e. convergent patterns). Apart from some taxa distinctiveness (i.e. fishes), the 'climate/productivity' hypothesis is found to explain the greatest variance in species richness and endemism patterns, followed by factors related to the 'history/dispersion' and 'area/environmental heterogeneity' hypotheses. 4. As aquatic amphibians display the highest levels of congruency with other taxa, this taxon appears to be a good 'surrogate' candidate for developing global freshwater conservation planning at the river drainage basin grain.

The darker the color the more projected abundance by the model.</p

Journal of Animal Ecology, 2012

PLoS neglected tropical diseases, Feb 1, 2018

Preventive veterinary medicine, 2018

Ecography, 2015

Science of The Total Environment, 2014

Journal of Applied Ecology, 2013

Global Ecology and Biogeography, 2012

Diversity and Distributions, 2013

Preventive veterinary medicine, 2018

Journal of Hydrology, 2010

Hydrology and Earth System Sciences Discussions, 2011

Journal of Environmental Quality, 2008