References of "Lejeune, Philippe"
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See detailUse of Unmanned Aerial System to assess wildlife (Sus scrofa) damage to crops (Zea mays)
Michez, Adrien ULg; Morelle, Kevin; Lehaire, François et al

in Journal of Unmanned Vehicle Systems (in press)

Damage caused by ungulates to agricultural areas are difficult to evaluate because the real extent of the damage remains usually poorly described and potentially arising conflicts. Recent advances in ... [more ▼]

Damage caused by ungulates to agricultural areas are difficult to evaluate because the real extent of the damage remains usually poorly described and potentially arising conflicts. Recent advances in unmanned aerial system (UAS) provide new versatile mapping and quantification possibilities in a wide range of applications. We used crop fields (Zea mays) damaged by wild boar (Sus scrofa) and compared the extent of the damage by means of three methods: i) traditional ground-based assessment ii) UAS orthoimages with operator delineation and iii) UAS Crop Height Model with automatic delineation based on height threshold. We showed for the first time that UAS could be applied for assessing damage of ungulates to agriculture. The two methods using UAS imagery provide coherent and satisfactory results and trended to underestimate the damage area when compared to in-use ground-based field expertise. However we suggest that performance of UAS should further be tested in variable conditions in order to assess the broad application of this tool. Our study describes the potential of UAS as a tool for estimating more accurately the damage area and subsequently the compensation costs for wildlife damage. The proposed approach can come in support of local and regional policies for the definitions of compensation for farmers. [less ▲]

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See detailCaractérisation des forêts à l’aide de la technologie lidar
Michez, Adrien ULg; Bauwens, Sébastien ULg; Bonnet, Stéphanie ULg et al

in Baghdadi, Nicolas; Zribi, Mehrez (Eds.) Observation des Surfaces Continentales par Télédétection: Agriculture et Forêt (in press)

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See detailQuantification of anthropogenic effects in the landscape of Lubumbashi
Andre, Marie ULg; Vranken, Isabelle ULg; Boisson, Sylvain ULg et al

in Mahy, Grégory; Colinet, Gilles; Bogaert, Jan (Eds.) Anthropisation au Katanga (in press)

In order to understand the dynamic of the (sub)urbanisation and so, to quantify the anthropogenic effects of the rapid growth of tropical cities, it is crucial to find and apply valuable methods. In this ... [more ▼]

In order to understand the dynamic of the (sub)urbanisation and so, to quantify the anthropogenic effects of the rapid growth of tropical cities, it is crucial to find and apply valuable methods. In this contribution, the transferability of the Rüdisser et al. (2012) «Distance to Nature» hemeroby assessment method to the landscape surrounding the city of Lubumbashi (DRC) is evaluated. That methodology has the advantage of taking structural connectivity into account by computing the distance to natural habitats. As it had never been applied to an African city before, some adjustments (fitting of the local land uses types into the hemeroby levels designed to Austria) and amendments (suppression of the final classification into hemeroby level simplification) are proposed. Moreover, an analysis of the decanal (2002-2013) hemeroby dynamics is presented. Results suggest that the Distance to Nature methodology is transferable but requires good field knowledge to define reference habitats and identify them in the Landsat classified images. There was a dramatic decrease of the «natural» and «near-natural» levels in the study extent during the studied period. In addition, 32% of the land underwent anthropisation increase, mostly around cities and following a ribbon development. [less ▲]

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See detailCharacterization of Forests with LiDAR Technology
Michez, Adrien ULg; Bauwens, Sébastien ULg; Bonnet, Stéphanie ULg et al

in Baghdadi, Nicolas; Zribi, Mehrez (Eds.) Land Surface Remote Sensing in Agriculture and Forest (2016)

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See detailBack on Track... in 3D
Marchal, Antoine ULg; Lejeune, Philippe ULg; De Bruyn, Nico

Poster (2016, September 04)

Ecological monitoring provides basic information on population status and distribution that is crucial for conservation, research and management strategies. Studies using tracks are controversial due to ... [more ▼]

Ecological monitoring provides basic information on population status and distribution that is crucial for conservation, research and management strategies. Studies using tracks are controversial due to past misuses tainted with subjectivity. Advances in photogrammetry literally add another dimension to the recording techniques, and geometric morphometrics provides an appropriate approach for the study of track shape variation. Tracks are back on track in conservation! [less ▲]

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See detailForest Inventory with Terrestrial LiDAR: A Comparison of Static and Hand-Held Mobile Laser Scanning
Bauwens, Sébastien ULg; Bartholomeus, Harm; Calders, Kim et al

in Forests (2016), 7(6), 127

The application of static terrestrial laser scanning (TLS) in forest inventories is becoming more effective. Nevertheless, the occlusion effect is still limiting the processing efficiency to extract ... [more ▼]

The application of static terrestrial laser scanning (TLS) in forest inventories is becoming more effective. Nevertheless, the occlusion effect is still limiting the processing efficiency to extract forest attributes. The use of a mobile laser scanner (MLS) would reduce this occlusion. In this study, we assessed and compared a hand-held mobile laser scanner (HMLS) with two TLS approaches (single scan: SS, and multi scan: MS) for the estimation of several forest parameters in a wide range of forest types and structures. We found that SS is competitive to extract the ground surface of forest plots, while MS gives the best result to describe the upper part of the canopy. The whole cross-section at 1.3 m height is scanned for 91% of the trees (DBH > 10 cm) with the HMLS leading to the best results for DBH estimates (bias of 0.08 cm and RMSE of 1.11 cm), compared to no fully-scanned trees for SS and 42% fully-scanned trees for MS. Irregularities, such as bark roughness and non-circular cross-section may explain the negative bias encountered for all of the scanning approaches. The success of using MLS in forests will allow for 3D structure acquisition on a larger scale and in a time-efficient manner. [less ▲]

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See detailApport des nuages de points LiDAR et photogrammétriques pour le monitoring de 12000 km de cours d’eau en Wallonie (Belgique)
Michez, Adrien ULg; Piégay, Hervé; Desteucq, Olivier et al

Conference (2016, June 10)

Sous l’impulsion de son administration, la Wallonie a entamé un processus de révision complète des modalités de la gestion des cours d’eau, notamment à travers le projet des Programmes d’Actions sur les ... [more ▼]

Sous l’impulsion de son administration, la Wallonie a entamé un processus de révision complète des modalités de la gestion des cours d’eau, notamment à travers le projet des Programmes d’Actions sur les Rivières par une approche Intégrée et Sectorisée (PARIS). Les PARIS ont pour but l'intégration dans le temps et dans l’espace de l’ensemble des mesures de gestion spécifiques au linéaire des cours d'eau en fonction d'enjeux prioritaires identifiés à l’échelle d’unités de gestion homogènes, les secteurs (6185 secteurs de gestion de 2 km de long en moyenne). La mise en place et le suivi de ces plans de gestion impliquent de facto le développement d'outils de suivi efficaces, permettant d'établir les états des lieux pour la planification des actes de gestion et à terme, d'évaluer l'efficacité desdits plans de gestion. Ces opérations doivent se réaliser sur près de 12000 km de cours d’eau et de bandes riveraines associées sur une base objective et commune à l’ensemble des gestionnaires de cours d’eau. Des données fines de télédétection étant disponibles et acquises de manière régulière par l’administration wallonne, des solutions dérivées de ces sources de données permettront de répondre partiellement aux besoins réguliers en information des plans de gestion PARIS pour un budget réduit. Pour atteindre cet objectif, un protocole a été établi sur base de nuages points LiDAR (densité ≈ 1 point « sol » / m²) complétés par des nuages de points photogrammétriques dérivés des images individuelles des couvertures ortho du territoire. Ces données ont été utilisées afin de caractériser la structure spatiale des bandes riveraines associées à l’ensemble du réseau hydrographique wallon (> 12 000 km) à travers 6 paramètres. Ces paramètres peuvent être d’ordre hydromorphologique (hauteur des berges, largeur et sinuosité du lit mineur), ou décrire la structure des forêts riveraines (hauteur moyenne, continuité longitudinale et ombrage du lit mineur). Une évaluation des patrons spatiaux de ces différents paramètres en lien avec les caractéristiques des territoires wallons (occupation du sol, régions naturelles) peut être ainsi réalisée. Différentes formes de visualisations de l’information peuvent ainsi appuyer le processus décisionnel des gestionnaires, de l’échelle locale (secteurs d’une masse d’eau DCE - Directive ‘Cadre-Eau’) à l’échelle régionale (354 masse d’eau DCE). L’acquisition des données sur l’ensemble du territoire wallon (15000 km²) a été sous-traitée à différentes compagnies privées, pour des montants approximatifs de 17 et 10 € / km² respectivement pour la donnée LiDAR et ortho. Une plateforme en ligne a récemment été lancée par la Direction des Cours d’Eau Non-Navigables du Service Public de Wallonie (DCENN) en tant que support du projet de plans de gestion PARIS. Les paramètres extraits dans le cadre de ce projet seront prochainement intégrés au sein de cette plateforme permettant leur visualisation à différentes échelles ainsi que l’encodage des actions par les gestionnaires. [less ▲]

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See detailNouvelles normes sylvicoles pour les peuplements purs équiennes d'épicéa et de douglas
Perin, Jérôme ULg; Hebert, Jacques ULg; Lejeune, Philippe ULg et al

E-print/Working paper (2016)

Ces documents rassemblent les tables de production (version 2016) représentant les nouvelles normes sylvicoles recommandées pour les peuplements purs équiennes d'épicéa commun et de douglas. Un ensemble ... [more ▼]

Ces documents rassemblent les tables de production (version 2016) représentant les nouvelles normes sylvicoles recommandées pour les peuplements purs équiennes d'épicéa commun et de douglas. Un ensemble de 10 tables de production est présentée pour chaque essence, associant deux densités de plantation (2.5 x 2 m et 2 x 2 m) et 5 classes de productivité (0 à IV). [less ▲]

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See detailThe determinants of tropical forest deciduousness: disentangling the effects of rainfall and geology in central Africa
Ouedraogo, Dakis-Yaoba ULg; Fayolle, Adeline ULg; Gourlet-Fleury, Sylvie et al

in Journal of Ecology (2016)

1. Understanding the environmental determinants of forests deciduousness i.e. proportion of deciduous trees in a forest stand, is of great importance when predicting the impact of ongoing global climate ... [more ▼]

1. Understanding the environmental determinants of forests deciduousness i.e. proportion of deciduous trees in a forest stand, is of great importance when predicting the impact of ongoing global climate change on forests. In this study, we examine (i) how forest deciduousness varies in relation to rainfall and geology, and (ii) whether the influence of geology on deciduousness could be related to differences in soil fertility and water content between geological substrates. 2. The study was conducted in mixed moist semi-deciduous forests in the northern part of the Congo basin. We modelled the response of forest deciduousness to the severity of the dry season across four contrasting geological substrates (sandstone, alluvium, metamorphic and basic rocks). For this, we combined information on forest composition at genus level based on commercial forest inventories (62 624 0.5 ha plots scattered over 6 million of ha), leaf habit, and rainfall and geological maps. We further examined whether substrates differ in soil fertility and water-holding capacity using soil data from 37 pits in an area that was, at the time, relatively unexplored. 3. Forest deciduousness increased with the severity of the dry season, and this increase strongly varied with the geological substrate. Geology was found to be three times more important than the rainfall regime in explaining the total variation in deciduousness. The four substrates differed in soil properties, with higher fertility and water-holding capacity on metamorphic and basic rocks than on sandstone and alluvium. The increase in forest deciduousness was stronger on the substrates that formed resource-rich clay soils (metamorphic and basic rocks) than on substrates that formed resource-poor sandy soils (sandstone and alluvium). 4. Synthesis. We found evidence that tropical forest deciduousness is the result of both the competitive advantage of deciduous species in climates with high rainfall seasonality, and the persistence of evergreen species on resource-poor soils. Our findings offer a clear illustration of wellknown theoretical leaf carbon economy models, explaining the patterns in the dominance of evergreen versus deciduous species. And, this large-scale assessment of the interaction between climate and geology in determining forest deciduousness may help to improve future predictions of vegetation distribution under climate change scenarios. In central Africa, forest is likely to respond differently to variation in rainfall and/or evapotranspiration depending on the geological substrate. [less ▲]

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See detailPotentiel des véhicules aériens sans pilote dans la détection des activités humaines illégales dans les aires protégées en République Démocratique du Congo
Semeki Ngabinzeke, Jean; Linchant, Julie ULg; Quevauvillers, Samuel ULg et al

in Journal of Unmanned Vehicle Systems (2016), 4

The recent advent of unmanned aerial vehicles (UAVs) in natural resource management opens new opportunities to help protected area managers fighting against various human pressures. The Falcon UAV was ... [more ▼]

The recent advent of unmanned aerial vehicles (UAVs) in natural resource management opens new opportunities to help protected area managers fighting against various human pressures. The Falcon UAV was used for 15 missions to help detect human activities in Garamba National Park and its surrounding game reserves (Gangala na Bodio, Mondo Missa) in the North-Eastern Democratic Republic of Congo. A Sony Block camera coupled with a Tamarisk thermal camera was used to record videos, whereas photos were acquired with a Sony Nex7 digital camera. Tests showed that it was possible to detect precise objects using the Falcon UAV. Houses, fields, bare ground patches, burned areas, roads and tracks were easily detectable and identified in the videos at a flight altitude of up to 250 m AGL. Artisanal gold mining sites (size ≤ 0.21 ha) are also recognizable on the video and still images. Improvements are needed, notably in photo overlap and georeferencing, but the system shows great potential to ensure detection and continuous surveillance of human activities within protected areas. [less ▲]

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See detailSupporting integrated and systemic management of windthrow crises by public decision-makers
Riguelle, Simon ULg; Hebert, Jacques ULg; Lejeune, Philippe ULg et al

Poster (2016, April 21)

This poster presents the development of an integrated framework for systemic management of storm damage risk in Wallonia (Belgium) and how it can be implemented throughout the risk management cycle with ... [more ▼]

This poster presents the development of an integrated framework for systemic management of storm damage risk in Wallonia (Belgium) and how it can be implemented throughout the risk management cycle with user-friendly tools and suitable methodologies. [less ▲]

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See detailTaller trees, denser stands and greater biomass in semi-deciduous than in evergreen lowland central African forests
Fayolle, Adeline ULg; Loubota Panzou, Grâce Jopaul ULg; Drouet, Thomas et al

in Forest Ecology & Management (2016), 374

Accurate height-diameter allometry is crucial for the estimation of forest biomass and carbon stocks. Tree height measurements over a large range of diameters and species are urgently needed in the ... [more ▼]

Accurate height-diameter allometry is crucial for the estimation of forest biomass and carbon stocks. Tree height measurements over a large range of diameters and species are urgently needed in the tropics, specifically in central Africa, for the development of locally derived height-diameter allometric equations and the conversion of forest inventory data into biomass estimates, and for the validation of remotely sensed canopy height that mostly rely on a few specific field sites. In this study, we aimed to identify the variation in height-diameter allometry of tropical trees between forest types and among species in central Africa, and we examined the consequences for biomass estimation. Height and diameter were measured for a total of 521 trees over a large range of diameters in two forest types in southern Cameroon, 10–240 cm in the evergreen forest and 11–182 cm in the semi-deciduous forest. A total of ten allometric models including asymptotic and non-asymptotic models were fitted to the heightdiameter data. Measured tree diameters, grouped into 10 cm wide diameter classes up to 150, from commercial forest inventory data (0.5 ha plots, n = 2101 and n = 5152, respectively in the evergreen and in the semi-deciduous forests) were converted into biomass estimates using general allometric models with and without including our site-specific height-diameter allometry. Though debated in the literature, our results supported a saturation of tree height with tree diameter both at site and species level, with asymptotic models better depicting the height-diameter allometry. Height-diameter allometry significantly differed between forest types and these local height-diameter equations also differed from published equations. For a given diameter, trees tended to be taller in the semi-deciduous forest than in the evergreen forest, as already reported between moist and wet forests in pantropical studies. Similar trends were reported within species for the three species shared by both forest types, suggesting an environmental control of tree allometry. Because of the low performance of the bioclimatic stress variable to predict tree height and of the slight soil differences between the two forest types, the environmental determinants of height-diameter allometry remain to be explored. In addition to tree allometry variation, structural differences (basal area and density) were also identified between the two forest types using commercial forest inventory data at genus level, and both allometry and forest structure (taller trees and denser stands) contributed to the greater biomass per hectare of the semi-deciduous forest. [less ▲]

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See detailFoot identification from digital 3D models of lion tracks and paws
Marchal, Antoine ULg; Lejeune, Philippe ULg; De Bruyn, Nico

Conference (2016, March 15)

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See detailUtilisation dans QGIS des Web Map Services (WMS) du Géoportail de Wallonie
Lejeune, Philippe ULg; Handerek, Daphné

Cartographic material (2016)

Note technique expliquant comment accéder aux Webservices du géoportail de Wallonie avec le logiciel QGIS. Ce guide est accompagné d'un projet QGIS rassemblant les WMS les plus utiles (ortho-images ... [more ▼]

Note technique expliquant comment accéder aux Webservices du géoportail de Wallonie avec le logiciel QGIS. Ce guide est accompagné d'un projet QGIS rassemblant les WMS les plus utiles (ortho-images, cadastre, fond topographique, plans de secteurs) [less ▲]

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See detailMapping of riparian invasive species with supervised classification of Unmanned Aerial System (UAS) imagery
Michez, Adrien ULg; Piégay, Hervé; Lisein, Jonathan ULg et al

in International Journal of Applied Earth Observation and Geoinformation (2016), 44

Riparian zones are key landscape features, representing the interface between terrestrial and aquatic ecosystems. Although they have been influenced by human activities for centuries, their degradation ... [more ▼]

Riparian zones are key landscape features, representing the interface between terrestrial and aquatic ecosystems. Although they have been influenced by human activities for centuries, their degradation has increased during the 20th century. Concomitant with (or as consequences of) these disturbances, the invasion of exotic species has increased throughout the world’s riparian zones. In our study, we propose a easily reproducible methodological framework to map three riparian invasive taxa using Unmanned Aerial Systems (UAS) imagery: Impatiens glandulifera Royle, Heracleum mantegazzianum Sommier and Levier, and Japanese knotweed (Fallopia sachalinensis (F. Schmidt Petrop.), Fallopia japonica (Houtt.) and hybrids). Based on visible and near-infrared UAS orthophoto, we derived simple spectral and texture image metrics computed at various scales of image segmentation (10,30, 45, 60 using eCognition software). Supervised classification based on the random forests algorithm was used to identify the most relevant variable (or combination of variables) derived from UAS imagery for mapping riparian invasive plant species. The models were built using 20% of the dataset, the rest of the dataset being used as a test set (80%). Except for H. mantegazzianum, the best results in terms of global accuracy were achieved with the finest scale of analysis (segmentation scale parameter = 10). The best values of overall accuracies reached 72%, 68%, and 97% for I. glandulifera, Japanese knotweed, and H. mantegazzianum respectively. In terms of selected metrics, simple spectral metrics (layer mean / camera brightness) were the most used. Our results also confirm the added value of texture metrics (GLCM derivatives) for mapping riparian invasive species. The results obtained for I. glandulifera and Japanese knotweed do not reach sufficient accuracies for operational applications. However, the results achieved for H. mantegazzianum are encouraging. The high accuracies values combined to relatively light model-inputs needed (delineation of a few umbels) make our approach a serious contender as a cost-effective tool to improve the field management of H. mantegazzianum. [less ▲]

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See detailDealing with paralogy in RADseq data: in silico detection and single nucleotide polymorphism validation in Robinia pseudoacacia L.
Verdu, C. F.; Guichoux, E.; Quevauvillers, Samuel ULg et al

in Ecology and Evolution (2016)

The RADseq technology allows researchers to efficiently develop thousands of polymorphic loci across multiple individuals with little or no prior information on the genome. However, many questions remain ... [more ▼]

The RADseq technology allows researchers to efficiently develop thousands of polymorphic loci across multiple individuals with little or no prior information on the genome. However, many questions remain about the biases inherent to this technology. Notably, sequence misalignments arising from paralogy may affect the development of single nucleotide polymorphism (SNP) markers and the estimation of genetic diversity. We evaluated the impact of putative paralog loci on genetic diversity estimation during the development of SNPs from a RADseq dataset for the nonmodel tree species Robinia pseudoacacia L. We sequenced nine genotypes and analyzed the frequency of putative paralogous RAD loci as a function of both the depth of coverage and the mismatch threshold allowed between loci. Putative paralogy was detected in a very variable number of loci, from 1% to more than 20%, with the depth of coverage having a major influence on the result. Putative paralogy artificially increased the observed degree of polymorphism and resulting estimates of diversity. The choice of the depth of coverage also affected diversity estimation and SNP validation: A low threshold decreased the chances of detecting minor alleles while a high threshold increased allelic dropout. SNP validation was better for the low threshold (4×) than for the high threshold (18×) we tested. Using the strategy developed here, we were able to validate more than 80% of the SNPs tested by means of individual genotyping, resulting in a readily usable set of 330 SNPs, suitable for use in population genetics applications. [less ▲]

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See detailTerrestrial photogrammetry: A non-destructive method for modeling irregularly shaped tropical tree trunks
Bauwens, Sébastien ULg; Fayolle, Adeline ULg; Gourlet-Fleury, Sylvie et al

Computer development (2016)

1. Irregularly shaped trees including trees with buttresses, flutes or stilt roots are frequent in tropical forests. The lack of an international standard to measure the diameter of such trees leads to ... [more ▼]

1. Irregularly shaped trees including trees with buttresses, flutes or stilt roots are frequent in tropical forests. The lack of an international standard to measure the diameter of such trees leads to high uncertainties in biomass estimation, tree growth and carbon budget monitoring. 2. In this study, we developed a new method based on terrestrial close range photogrammetry for measuring and modeling irregular stems. This approach is cheap and easy to implement in the field as it only requires a camera and a graduated rod. We validated the approach with destructive cross section measurements along the stem of three buttressed trees. To demonstrate the broader utility of this method, we extended the validated approach to 43 additional trees belonging to two species: Celtis mildbraedii (Ulmaceae) and Entandophragma cylindricum (Meliaceae). Based on the 3D models, we computed shape indices for each tree, and we analyzed the stem morphology of the two species. Finally, we analyzed some standardized predictors for the estimation of above-ground biomass. 3. We found a high concordance between diameters derived from the photogrammetric process and destructive diameter measurements along the stem for the three calibration trees. We found that C. mildbraedii develop much stronger irregularities than E. cylindricum. We also identified a large intra-specific variation in trunk morphology for E. cylindricum. The basal area at 1.3m height (Darea130), seems to be a more robust predictor for biomass estimates (lowest AIC and RSE) than diameter measured above buttresses (DAB) or DBH estimated from available taper model. Finally, Darea130 might be estimated with a good precision (RMSE < 5 %) with linear model based on the field measurements DAB and the perimeter of the convex hull of the buttresses at 1.3 m height (Dconvhull130). 4. In this study, we showed the high potential of the photogrammetry for measuring and modeling irregular stems. Photogrammetry could then be used as a non destructive measurement tool to produce correction factors for standardizing the diameter of irregular stems at a reference height which is a key issue in tree growth monitoring and biomass change estimation. [less ▲]

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See detailOn the distance travelled for woodland leisure via different transport modes in Wallonia, south Belgium
Li, Sen; Colson, Vincent; Lejeune, Philippe ULg et al

in Urban Forestry and Urban Greening (2016), 15

Based on an extensive survey of woodland visitors in Wallonia, south Belgium, we examined a widerange of individual-, residential- and destination-level variables for their associations with the ... [more ▼]

Based on an extensive survey of woodland visitors in Wallonia, south Belgium, we examined a widerange of individual-, residential- and destination-level variables for their associations with the distancetravelled for woodland leisure on foot, by bicycle and by car. For each transport mode, explanatorybivariate analyses were conducted firstly to identify potential correlates of the distances travelled. Then,cross-classified multilevel analysis was performed to build estimation models for the trip distance. Theresults showed that, amongst the multilevel variables selected, walking trip distance was only associatedwith individual trip behaviour, while cycling and car-borne trip distance could also be associated withindividual socio-economic profile as well as a large range of residential and destination attributes onland use, land cover and visitor support services. The final estimation model for (i) walking trip distanceincluded trip duration as the only explanatory variable, for (ii) cycling trip distance included variables ontrip duration, proportion of woodland area at residence and presence of service facilities at destination,and for (iii) car-borne trip distance included variables on trip duration, visitor’s employment status,whether the trip is on weekend or in summer, proportion of woodland area at residence and remotenessof destination from urban area. Despite being simple in form, all multilevel estimation models showa satisfactory explanatory power and a better performance than the ordinary single-level models. Ourresults add new empirical evidences on the key factors associated with the transport mode-specific traveldistance, in particular, for woodland leisure. The cross-classified multilevel analysis used in our studyprovides new methodological insights for the estimation of individual trip distance, which could benefitfuture modelling of woodland recreation demand. [less ▲]

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See detailInvading or recolonizing? Patterns and drivers of wild boar population expansion into Belgian agroecosystems
Morelle, Kévin; Fattebert, Julien; Mengal, Coralie ULg et al

in Agriculture, Ecosystems & Environment (2016), 222

Native species can also exhibit invasive-like spreading patterns, and identifying mechanisms driving spread of native species is a recent but essential challenge in ecology. In Europe, wild boar Sus ... [more ▼]

Native species can also exhibit invasive-like spreading patterns, and identifying mechanisms driving spread of native species is a recent but essential challenge in ecology. In Europe, wild boar Sus scrofa populations and range increased for decades. While patterns of population growth are well studied, those related to range expansion are still poorly understood. In this study, we aimed to understand patterns and mechanisms that promoted wild boar population expansion in agricultural landscapes of Southern Belgium between 1981 and 2010. Using hunting-based knowledge on colonization history and an information-theoretic approach, we evaluated support to four a priori hypotheses explaining mechanisms of wild boar colonisation in an agro-ecosystem: natural forested landscape as recolonization mechanism, and cultivated landscape, propagule pressure and climate change as invasion mechanisms. We found that wild boar population expansion in Belgian agroecosystems was a relatively slow process driven by the natural landscape, propagule pressure, and climatic changes. This suggests a combination of invasive and recolonization mechanisms was in play in the expansion of wild boar over the last three decades. Our study provides insights in the mechanisms that enable the species’ recovery in Europe since the mid-20th century, and underline the need for adapted management strategies taking into account the invasive components of wild boar population expansion. [less ▲]

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