References of "Piqueray, Julien"
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See detailIdentification of flower functional traits affecting abundance of generalist predators in perennial multiple species wildflower strips
Hatt, Séverin ULiege; Uyttenbroeck, Roel; Lopes, Thomas et al

in Arthropod-Plant Interactions (2019)

In agricultural fields, wildflower strips can be sown to enhance conservation biological control of insect pests. However, issues remain regarding the composition of flower mixtures to effectively attract ... [more ▼]

In agricultural fields, wildflower strips can be sown to enhance conservation biological control of insect pests. However, issues remain regarding the composition of flower mixtures to effectively attract and support large communities of natural enemies. Trait-based approaches are promising for this purpose. In the present study, conducted in an agricultural field of Belgium in 2014 and 2015, 15 flower mixtures were considered to explore the relation between the abundance of trapped generalist predators (i.e. lacewings [Neuroptera: Chrysopidae], ladybeetles [Coleoptera: Coccinellidae] and hoverflies [Diptera: Syrphidae]) and the community-weighted means of seven flower traits. Through a redundancy analysis, it was found that the presence/absence of flower ultra-violet pattern and the morphology of the corolla (that determines the accessibility of floral resources) were the traits that significantly affected the abundance of the generalist predators in the flower mixtures. The ladybeetles Harmonia axyridis and Propylea quatuordecimpunctata as well as the lacewings Chrysoperla carnea were more abundant in mixtures with a high cover of flowers showing an ultra-violet pattern, while the opposite was observed for the ladybeetle Coccinella septempunctata. As for hoverflies, Episyrphus balteatus and Eupeodes corollae were more abundant in mixtures with a high cover of flowers with open nectar. These results bring new knowledge regarding how a range of natural enemy species reacts to flower cues in diversified plant communities and should help in elaborating flower mixtures that enhance conservation biological control. [less ▲]

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See detailIdentification of flower functional traits affecting abundance of generalist predators in perennial multiple species wildflower strips
Hatt, Séverin ULiege; Uytenbroeck, Roel; Lopes, thomas et al

in Arthropod-Plant Interactions (2019), 13

In agricultural fields, wildflower strips can be sown to enhance conservation biological control of insect pests. However, issues remain regarding the composition of flower mixtures to effectively attract ... [more ▼]

In agricultural fields, wildflower strips can be sown to enhance conservation biological control of insect pests. However, issues remain regarding the composition of flower mixtures to effectively attract and support large communities of natural enemies. Trait-based approaches are promising for this purpose. In the present study, conducted in an agricultural field of Belgium in 2014 and 2015, 15 flower mixtures were considered to explore the relation between the abundance of trapped generalist predators (i.e. lacewings [Neuroptera: Chrysopidae], ladybeetles [Coleoptera: Coccinellidae] and hoverflies [Diptera: Syrphidae]) and the community-weighted means of seven flower traits. Through a redundancy analysis, it was found that the presence/absence of flower ultra-violet pattern and the morphology of the corolla (that determines the accessibility of floral resources) were the traits that significantly affected the abundance of the generalist predators in the flower mixtures. The ladybeetles Harmonia axyridis and Propylea quatuordecimpunctata as well as the lacewings Chrysoperla carnea were more abundant in mixtures with a high cover of flowers showing an ultra-violet pattern, while the opposite was observed for the ladybeetle Coccinella septempunctata. As for hoverflies, Episyrphus balteatus and Eupeodes corollae were more abundant in mixtures with a high cover of flowers with open nectar. These results bring new knowledge regarding how a range of natural enemy species reacts to flower cues in diversified plant communities and should help in elaborating flower mixtures that enhance conservation biological control. [less ▲]

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See detailEffect of flower traits and hosts on the abundance of parasitoids in perennial multiple species wildflower strips sown within oilseed rape (Brassica napus) crops
Hatt, Séverin ULiege; Uyttenbroeck, Roel ULiege; Chevalier Mendes Lopes, Thomas et al

in Arthropod-Plant Interactions (2018)

Reducing the use of insecticides is an important issue for agriculture today. Sowing wildflower strips along field margins or within crops represents a promising tool to support natural enemy populations ... [more ▼]

Reducing the use of insecticides is an important issue for agriculture today. Sowing wildflower strips along field margins or within crops represents a promising tool to support natural enemy populations in agricultural landscapes and, thus, enhance conservation biological control. However, it is important to sow appropriate flower species that attract natural enemies efficiently. The presence of prey and hosts may also guide natural enemies to wildflower strips, potentially preventing them from migrating into adjacent crops. Here, we assessed how seven flower traits, along with the abundance of pollen beetles (Meligethes spp., Coleoptera: Nitidulidae) and true weevils (Ceutorhynchus spp., Coleoptera: Curculionidae), affect the density of parasitoids of these two coleopterans in wildflower strips sown in an oilseed rape field in Gembloux (Belgium). Only flower traits, not host (i.e. pollen beetles and true weevils) abundance, significantly affected the density of parasitoids. Flower colour, ultraviolet reflectance and nectar availability were the main drivers affecting parasitoids. These results demonstrate how parasitoids of oilseed rape pests react to flower cues under field conditions. Similar analyses on the pests and natural enemies of other crops are expected to help to develop perennial flower mixtures able to enhance biological control throughout a rotation system. [less ▲]

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See detailNaturally recruited herbaceous vegetation in abandoned Belgian limestone quarries: towards habitats of conservation interest analogues?
Pitz, Carline ULiege; Piqueray, Julien; Monty, Arnaud ULiege et al

in Folia Geobotanica (2018)

We examined if naturally recruited herbaceous vegetation in abandoned Belgian limestone quarries tend towards plant communities analogous to semi-natural habitats of conservation interest. We studied ... [more ▼]

We examined if naturally recruited herbaceous vegetation in abandoned Belgian limestone quarries tend towards plant communities analogous to semi-natural habitats of conservation interest. We studied taxon-based assemblages (using two-dimensional non-metric multidimensional scaling ordination) and functional patterns (relative to Grime’s competitor, stress tolerator and ruderal plant strategies (CSR) classification) of plant communities (n = 360 plots) among three different time periods after quarry abandonment (< 3 y, 3–20 y, > 20 y). We compared those successional assemblages with those of habitat of conservation interest plant communities (n = 53 plots): lowland hay meadows and rupicolous, xerophilous and mesophilous calcareous grasslands. Our results indicate that naturally recruited herbaceous vegetation compositionally resembled mesophilous grassland, even though initial substrate conditions were more similar to rupicolous or xerophilous grasslands. The specific successional pathway we found in CSR state-space differs from Grime's predictions because there was a functional shift in plant assemblages from dominance by ruderals to dominance by stress-tolerant species. The differences in successional trajectories we found on different types of rock substrate suggest that conservation management should adopt a site-specific approach, recognizing that the highest probabilities of success on hard limestone will be restoration to calcareous grassland analogues. [less ▲]

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See detailIncreasing plant functional diversity is not the key for supporting pollinators in wildflower strips
Uyttenbroeck, Roel ULiege; Piqueray, Julien; Hatt, Séverin ULiege et al

in Agriculture, Ecosystems and Environment (2017), 249

Intensification of agriculture has been one of the major drivers for biodiversity loss in recent decades. Pollinators, which serve an important role in pollinating crops as well as wild plants, have shown ... [more ▼]

Intensification of agriculture has been one of the major drivers for biodiversity loss in recent decades. Pollinators, which serve an important role in pollinating crops as well as wild plants, have shown a decline in species richness. Flower strips can be used to support pollinators in agro-ecosystems, however the question remains as to how their design can be optimized in order to best benefit pollinators. Increasing plant species diversity has been shown to be beneficial for pollinators, and it is often suggested that functional traits are driving this relationship. Therefore, increasing plant functional diversity could be a tool to support pollinator abundance and diversity. As experimental evidence on this relationship is scarce, we developed a field study with experimental sown flower strips with four functional diversity levels, based on multiple flower traits and with equal plant species richness. We monitored vegetation development, as well as the flower-visiting pollinator community and their interaction networks with flowers. We were able to create a functional diversity gradient while controlling for plant species richness and evenness. However, in contrast to our expectations, pollinator species richness and evenness were not influenced by functional diversity, and increasing functional diversity even resulted in lower flower visitation rates. Network stability metrics showed no effect or negative relationships with functional diversity. We conclude that increasing functional diversity was not the key for supporting pollinators in wildflower strips. Our results also suggest that, for a constant amount of flower resources, increasing plant functional diversity and thus decreasing redundancy of potential pollinator feeding niches, decreases the amount of flower resources present per feeding niche. As pollinator species tended to have less overlap in their feeding niches in flower strips with increased functional diversity, this may lead to a reduction of flower resources available for pollinator species with a more specialized feeding niche. [less ▲]

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See detailEnsuring consistency of tools dedicated to biodiversity and ecosystem services : case studies
Pécheur, Emilie ULiege; Maebe, Laura ULiege; Piqueray, Julien

Conference (2017, May 04)

Public awareness regarding key issues of biodiversity and ecosystem services gave rise to several policies aiming at their consideration in human activities. These policies led to a bunch of legal ... [more ▼]

Public awareness regarding key issues of biodiversity and ecosystem services gave rise to several policies aiming at their consideration in human activities. These policies led to a bunch of legal constraints and incentives that are as many tools to preserve and restore both biodiversity and ecosystem services. However, these tools are often activated in a punctual way, following private initiatives or opportunities and without much reflection about the stakes beyond the actors’ own interests. This results in scattered actions, a lack of cohesion in land planning and sometimes conflicts between stakeholders. Yet biodiversity and ecosystem services need a collaborative management, beyond the individualist approach, to ensure the success and continuity of launched projects. Two case studies illustrate the collaborative and structured application of diverse tools by and for a variety of stakeholders willing to respond to specific needs. The first case is biodiversity-oriented, as it concerns the conservation of Bromus grossus, a plant species listed in Annex II of the Natura 2000 “Habitat” directive, which only grows in agroecosystems. The second case study worked on land multi-functionality in three Walloon municipalities, using ecosystem services as a tool for a land consolidation plan. These two examples highlight: 1° the key actors for the launching and cohesion of the projects, 2° the strengthening steps for short and mid-term success and 3° some conflicting elements interfering with coherent development plans. [less ▲]

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See detailDo flower mixtures with high functional diversity enhance aphid predators in wildflower strips?
Hatt, Séverin ULiege; Uyttenbroeck, Roel ULiege; Chevalier Mendes Lopes, Thomas ULiege et al

in European Journal of Entomology (2017), 114

Among semi-natural elements in agricultural landscapes, wildflower strips sown at field margins or within fields represent potential habitats for the natural enemies of insect pests. As insects are ... [more ▼]

Among semi-natural elements in agricultural landscapes, wildflower strips sown at field margins or within fields represent potential habitats for the natural enemies of insect pests. As insects are sensitive to a variety of flower traits, we hypothesised that mixtures with high functional diversity attract and support a higher abundance and species richness of aphid flower visiting predators compared to mixtures with low functional diversity. During a field experiment, repeated over two years (2014 and 2015) in Gembloux (Belgium), aphid predators (i.e., lacewings, ladybeetles and hoverflies) were pan-trapped in five sown flower mixtures (including a control mixture, with three replicates of each mixture) of low to high functional diversity based on seven traits (i.e., flower colour, ultra-violet reflectance and pattern, blooming start and duration, height and flower class, primarily based on corolla morphology). In both years, flower species in the sown mixtures (i.e., sown and spontaneous flowers) were listed, and the realised functional diversity of each plot was calculated. Over the two years, an increase in functional diversity did not result in an increase in the abundance and richness of aphid predators. Moreover, ladybeetles, representing the majority of trapped predators, were more abundant in mixtures with very low or intermediary functional diversity at sowing, especially in 2014. We hypothesise that certain flower species, which were abundant in certain mixtures (and not in those exhibiting the highest functional diversity), attracted predators and were sufficiently represented to support them. Our results present novel information that could be used to the development of flower mixtures that provide effective ecosystem services, such as pest control. [less ▲]

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See detailPlant functional trait diversity in wildflower strips: the key to promote pollinators in agricultural landscapes?
Uyttenbroeck, Roel ULiege; Piqueray, Julien; Monty, Arnaud ULiege

Conference (2016, October 27)

Creating wildflower strips is often suggested as a tool to support pollinator diversity in agricultural landscapes and to promote crop pollination service. The choice of the plant species to sow in flower ... [more ▼]

Creating wildflower strips is often suggested as a tool to support pollinator diversity in agricultural landscapes and to promote crop pollination service. The choice of the plant species to sow in flower strips can influence the effectivity of the strips in supporting pollinators. While it has already been shown that increasing plant species diversity is beneficial for ecosystem services, it is often suggested that plant functional traits and functional trait diversity are the key for this relationship. We created a replicated field experiment with different levels of plant functional diversity in wildflower strips in Belgium to test the effect on the flower-visiting pollinator community. We sampled plant-pollinator interaction networks during 2 years and assessed how the plant functional diversity affected the network structure. Plant functional diversity did not have a clear effect on visiting pollinator species richness, however a different interaction pattern was observed with different functional diversity level. Pollinators in wildflower strips with higher functional diversity had less overlap in their ecological niche, while network stability and robustness for secondary extinctions were not affected. We discuss implications for wildflower strip design. [less ▲]

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See detailLandscape diversity, better for biodiversity? - hoverflies and butterflies in different agri-environment schemes
Pécheur, Emilie ULiege; Piqueray, Julien; Dopagne, Claude ULiege et al

Conference (2016, August 31)

In Europe, agri-environment schemes (AES) are designed to give credit to environmental issues in agricultural practices. Among the different Walloon AES, some are dedicated to enhance and preserve ... [more ▼]

In Europe, agri-environment schemes (AES) are designed to give credit to environmental issues in agricultural practices. Among the different Walloon AES, some are dedicated to enhance and preserve biodiversity linked to the agroecosystems. This study wishes to explore, at a landscape scale, how do different AES perform regarding butterflies and syrphidae diversity. Data collection occurred in five categories of ecological infrastructures (EI): four types of agri-environmental schemes (grassy strips, wildflower strips, bird-feeding margins, species-rich meadows) and cereal crops. Five replicates were selected for each category. Syrphidae were collected in water traps once per month, from May to July. Butterflies were monitored along transects from May to Augustus. Plant species were identified in every plot, within a 1-m radius around the traps and along a transect through every plot. Preliminary results show that abundance and species diversity of butterflies is significantly higher in parcels with floral resources. Moreover, hosts plants for larvae and foraging plants for adults are significantly more present in two types of AES: the wildflower strips and the species-rich meadows. Regarding the identified plant species, categories are divided in three groups (crops apart): bird-feeding margins; species-rich meadows and grassy strips; wildflower strips (Fig.1). Concerning hoverflies, a significantly higher abundance is observed in the wildflower strips compared to the crops in June (p= 0.008). Other abundance values in May and July show no difference. These results suggest that wildflower strips are performing infrastructures for biodiversity conservation in agroecosystems. As the presence of floral resources seem to be an important factor for the presence of foraging of adults, attention should be paid to the provisioning of food resources for the larval stages, especially butterflies, at a landscape scale in order to assure a sustainable approach in biodiversity support. [less ▲]

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See detailPros and cons of flowers strips for farmers. A review
Uyttenbroeck, Roel ULiege; Hatt, Séverin ULiege; Paul, Aman ULiege et al

in Biotechnologie, Agronomie, Société et Environnement (2016), 20(s1), 225-235

Description of the subject. To counteract environmental problems due to agricultural intensification, European farmers can apply agri-environmental schemes in their fields. Flower strips are one example ... [more ▼]

Description of the subject. To counteract environmental problems due to agricultural intensification, European farmers can apply agri-environmental schemes in their fields. Flower strips are one example of these schemes, with the aim of supporting biodiversity, leading to an increase in “useful” species groups such as pollinators for crop pollination and natural enemies for pest control. However, to our knowledge, a complete appraisal of the pros and cons of flower strips, from a farmer’s point of view, does not yet exist. It is proposed that better and more complete information could increase the adoption and implementation of such agri-environmental schemes. Objectives. This study aims 1) to assess the pros and cons of flower strips, from a farmer’s point of view, and 2) to highlight the knowledge gaps that exist in the scientific literature, for the different types of pros and cons. Method. We listed the different components of the appraisal of pros and cons and conducted a systematic screening of the scientific literature on flower strips and these components. Results. The largest part of the 31 selected studies was concerning agronomical and ecological processes, such as pollination and animal pest control. Most of them indicated positive effects of flower strips. For many components of the appraisal, mostly economic and social ones, few or no studies were found. Conclusions. While a positive balance of pros and cons, from a farmer’s point of view, came from our literature screening, large research gaps still remain and more research is required, especially in the economic and social components of the evaluation. [less ▲]

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See detailChanges in the vegetation of hay meadows under an agri-environment scheme in South Belgium
Piqueray, Julien; Rouxhet, Serge ULiege; Hendrickx, Sébastien ULiege et al

in Conservation Evidence (2016)

We monitored five-year changes in the vegetation of 31 hay meadows under an agri-environment scheme in Wallonia, Southern Belgium. Management included delayed mowing (in July) and fertilizer prohibition ... [more ▼]

We monitored five-year changes in the vegetation of 31 hay meadows under an agri-environment scheme in Wallonia, Southern Belgium. Management included delayed mowing (in July) and fertilizer prohibition. It resulted in increasing cover of characteristic forbs (such as Leucanthemum vulgare, Lotus corniculatus, Centaurea jacea) and oligotrophic grasses (Avenula pubescens, Festuca rubra), while the competitive grasses, such as Holcus lanatus, Phleum pratense and Alopecurus pratensis, tended to decrease. We interpreted this as a vegetation shift from typical hay meadow to oligotrophic grasslands due to soil impoverishment following the current management. Both habitats are of conservation value. Despite these changes in the meadow plant communities, only one of the four criteria used by the Walloon administration to indicate hay meadow conservation status changed significantly over the six-year period. This was a decrease in the cover of species indicating high grazing intensity. The number and cover of characteristic plant species, and the cover of nitrophilous species, did not change significantly. [less ▲]

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See detailWildflowers sown at field margins have positive and negative effects on pests and parasitoids
Hatt, Séverin ULiege; Uyttenbroeck, Roel ULiege; Chevalier Mendes Lopes, Thomas ULiege et al

Conference (2015, September 03)

Wildflower strips are sown at field margins throughout Europe to support insect conservation in agricultural areas. Among other insects, parasitoids may favor a biological regulation of pests. On an ... [more ▼]

Wildflower strips are sown at field margins throughout Europe to support insect conservation in agricultural areas. Among other insects, parasitoids may favor a biological regulation of pests. On an experimental field of the research platform AgricultureIsLife in Gembloux (University of Liège, Belgium), three replications of five wildflower seed mixtures were sown in strips adjacent to crops in spring 2013. Insect pests and their parasitoids were pan-trapped in spring 2014 in both wildflower strips and oilseed rape crops and identified at the species level. Flower species and cover were monitored in the strips using 1 m² quadrats, before mowing. Meligethes spp. were found abundantly in crops when oilseed rape was blooming. Meligethes’ parasitoids occurred later and their abundance was positively correlated with that of Meligethes in the flower strips. At the crop ripening stage, weevils Ceutorhynchus spp. occurred and were followed by an increase in abundance of their parasitoids in both crops and flowers. Positive as well as negative correlations were found between the abundance of these pests, their parasitoids and different flower species blooming at this time. The link between these results with flower species’ functional traits will be discussed. [less ▲]

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See detailChallenges for the restoration of dry calcareous grasslands in quarries: does nature need help?
Pitz, Carline ULiege; Piqueray, Julien; Harzé, Mélanie ULiege et al

Conference (2015, August 26)

In order to maximize the biodiversity potential of dry calcareous grasslands in former quarries two options are available to managers: (i) allow species to spontaneously recolonize the site, (ii ... [more ▼]

In order to maximize the biodiversity potential of dry calcareous grasslands in former quarries two options are available to managers: (i) allow species to spontaneously recolonize the site, (ii) implement technical support for ecosystem restoration. This study aimed at characterizing the spontaneous communities established in dry area of unexploited quarries and at comparing communities encountered to the succession panel of dry grasslands. To evaluate the ecological succession in quarries, three successional stages where defined: (i) less than three years; (ii) three to 20 years; and (iii) more than 20 years after exploitation. For each successional stage, six parcels were selected and 20 1m2 plots were randomly marked in each parcel. All selected parcels presented dry grasslands abiotic conditions: filtering and stony soils and south orientation. During the 2014 vegetation period, percentage cover of higher plant species was recorded in each plot. Explaining environmental variables including coordinates, altitude, slope (degrees), soil depth, exposure, maximum vegetation height, bare ground cover, moss cover, and shrub cover (%) were measured. Our main results showed that, over decades of time, the ecological succession in dry area of unexploited quarries does not approach a typical formation of dry calcareous grassland. Most recolonizations tended to form meadows communities, except for three sites belonging to a specific landscape context. Potential implications for future quarries restoration will be discussed. [less ▲]

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See detailDes bandes fleuries pour la lutte biologique : état des lieux, limites et perspectives en Wallonie – Une synthèse bibliographique.
Hatt, Séverin ULiege; Uyttenbroeck, Roel ULiege; Bodson, Bernard ULiege et al

in Entomologie Faunistique (2015), 68

Managing field margins takes part of the Agri-Environmental Measures supported by the European Union in Wallonia. Among possible infrastructures, wildflower strips are known to conserve a wide diversity ... [more ▼]

Managing field margins takes part of the Agri-Environmental Measures supported by the European Union in Wallonia. Among possible infrastructures, wildflower strips are known to conserve a wide diversity of insects, including natural enemies that can be mobilized to biologically control pests. However, the efficiency of pest control is not guaranteed. It depends mainly on the ability of flowers to attract natural enemies at the right time and to keep them in this environment while favoring their migration into adjacent crops. A reflection on the composition of the floral mixtures may optimize their capacity in biological control. In this context, this review paper put forward the interest of considering functional traits of flowers and presents the concept of functional diversity. Furthermore, the sown perennial wildflower strips should be maintained by regular mowing. However, mowing affects both insect and plant populations due to momentary destruction of the habitat. An appropriate management of field margins is therefore needed to optimize the pest control service provided. [less ▲]

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See detailEtude de la flore spontanée de la carrière de Loën (Belgique) pour de futures restaurations
Pitz, Carline ULiege; Monty, Arnaud ULiege; Piqueray, Julien et al

Conference (2015, March 04)

Afin de maximiser le potentiel de biodiversité d’une carrière en fin d’exploitation deux options s’offrent au gestionnaire : (1) laisser les espèces recoloniser spontanément le site, (2) mettre en œuvre ... [more ▼]

Afin de maximiser le potentiel de biodiversité d’une carrière en fin d’exploitation deux options s’offrent au gestionnaire : (1) laisser les espèces recoloniser spontanément le site, (2) mettre en œuvre des appuis techniques à la restauration d’écosystèmes. Une méthode hybride associant une recolonisation naturelle et une assistance technique peut également être une opportunité pour le gestionnaire. La recolonisation spontanée des carrières peut, dans certains cas, créer une mosaïque d’habitats diversifiés pour des coûts faibles par rapport à des projets de réhabilitation ou de restauration couteux. Toutefois, l’intérêt biologique des habitats issus de successions spontanées peut fortement varier d’un site à l’autre en fonction de l’historique de gestion, des conditions climatiques et édaphiques locales, de l’isolement du site dans le paysage et du pool régional d’espèces présentes. Afin d’évaluer la nécessité ou non de mise en œuvre d’une restauration active d’habitats en carrière, il est nécessaire de caractériser les habitats issus de la succession spontanée ainsi que leur valeur biologique. L’évaluation de l’intérêt biologique d’un habitat prend en compte à la fois la diversité biologique locale (diversité alpha) et l’originalité des communautés présentes par rapport à un référentiel paysager (diversité béta). Ce projet a pour objectif de caractériser la flore recolonisant spontanément les zones xériques non exploitées dans une carrière située en Belgique (Loën, en région wallonne), du point de vue de la diversité spécifique et de la fonctionnalité écologique. Les communautés végétales ont été caractérisées au sein du site de Loën (diversité alpha) et d’un ensemble d’autres carrières représentatives de la diversité des contextes géographiques des carrières calcaires en Région wallonne (diversité béta). [less ▲]

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See detailWildflower strips for crop protection: What do we know ? What should we know ?
Hatt, Séverin ULiege; Uyttenbroeck, Roel ULiege; Bodson, Bernard ULiege et al

Poster (2015, January 30)

Wildflower strips (WFS) are known to support the conservation of a large diversity of insects and thus natural enemies (i.e. predators and parasitoids) that can control pests. However, the conclusions of ... [more ▼]

Wildflower strips (WFS) are known to support the conservation of a large diversity of insects and thus natural enemies (i.e. predators and parasitoids) that can control pests. However, the conclusions of studies looking at the efficiency of WFS to control pests are not unanimous. Indeed, the enhancement of pest control seems to depend on (1) the ability of flowers to attract the natural enemies at the right moment and (2) the capacity of natural enemies to migrate into the adjacent crops to attack pests. Therefore, constituting appropriate flower mixes may be an essential lever to enhance the efficiency of pest control. In this context, using functional diversity is promising. To our knowledge, few studies have tested the impact of the functional diversity of a flower mix on insect abundance and diversity and the control of pests. Through this contribution, the insect diversity and abundance found to be associated with the different kinds of WFS and management applied will be discussed, as well as the further research needed. [less ▲]

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See detailDo wildflower strips favor insect pest populations at field margins ?
Hatt, Séverin ULiege; Uyttenbroeck, Roel ULiege; Chevalier Mendes Lopes, Thomas ULiege et al

in Agriculture and Agricultural Science Procedia (2015)

Reducing pesticide use is one the major issues of today’s agriculture. Among other possibilities, attracting and conserving pest natural enemies in agricultural landscapes by providing them habitats is ... [more ▼]

Reducing pesticide use is one the major issues of today’s agriculture. Among other possibilities, attracting and conserving pest natural enemies in agricultural landscapes by providing them habitats is promising. Wildflower strips (WFS) sown at field margins are one of these potential habitats. They are known to attract and conserve a large diversity of insects, as they provide them food resources such as pollen and nectar, as well as shelter and overwintering sites. However, the risk of attracting insect pests at field margins may represent an obstacle to their adoption by farmers. Conversely, it would be interesting if such WFS could play the role of pest trap crops. In an experimental field sown with WFS intercropped with oilseed rape (OSR) (Brassica napus L.), its coleopteran pests were trapped in both WFS and OSR using yellow pan traps between April and June 2014. More than 130 000 Meligethes spp., Ceutorhynchus spp. and Psylliodes chrysocephalla (L.) adults were trapped. Meligethes spp., Ceutorhynchus spp. were significantly more abundant in the OSR compared with WFS when adults emerged and populations reached their abundance peak. Before and between these periods, the few adults trapped were significantly more abundant in the WFS compared with the OSR. Concerning P. chrysocephala, too few individuals were caught for analysis. Results showed that OSR was more attractive than WFS when coleopteran pests were abundant. In this study, WFS sown for insect conservation may neither favour insect pest conservation at field margin, nor be considered as trap crops. [less ▲]

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See detailCREATING PERENNIAL FLOWER STRIPS: THINK FUNCTIONAL!
Uyttenbroeck, Roel ULiege; Hatt, Séverin ULiege; Piqueray, Julien et al

in Agriculture and Agricultural Science Procedia (2015), 6

In last decades, farmland biodiversity came under large threat. To counteract farmland biodiversity loss and other environmental impacts of intensive agriculture, European farmers can apply Agri ... [more ▼]

In last decades, farmland biodiversity came under large threat. To counteract farmland biodiversity loss and other environmental impacts of intensive agriculture, European farmers can apply Agri-environmental schemes. One of these is the creation of flower strips, a part of the cropping field where flowers are sown or naturally settled. Flower strips are known to increase biodiversity in the agricultural landscape, notably attracting specific insects groups, such as pollinators and natural enemies that can provide valuable pollination and biocontrol services to the crop. However, the plant species composition and management of the strips can have a large influence on the identity and amount of useful insects present in the strips, suggesting the need to develop tailored flower strips to maximize the services delivered. Functional diversity (FD) is sometimes proposed as a promising approach, focusing on plant functional traits rather than plant species itself. Yet, it is not certain that sowing a set of plant species results in the desired vegetation with the desired functional trait composition. Species from soil seed bank or dispersing from neighboring vegetation can settle in the strip, while sown species might not always be equally adapted to local conditions. To test this, we developed seed mixtures with four different levels of FD, based on flower traits, and sew them as flower strips in a conventional arable field. We monitored the vegetation to calculate the FD of the realized vegetation. While the absolute FD values of the realized vegetation were lower than the expected FD values, the realized vegetation showed the same FD gradient as expected from the sown mixtures, indicating that it is possible to manipulate FD in flower strips. [less ▲]

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See detailPlant functional traits as a promising tool for the ecological restoration of degraded tropical metal-rich habitats and revegetation of metal-rich bare soils: A case study in copper vegetation of Katanga, DRC
Ilunga wa Ilunga, Edouard; Mahy, Grégory ULiege; Piqueray, Julien et al

in Ecological Engineering (2015), 82

Ecological restoration of degraded metal-rich habitats and bare metal-rich soils created by mining activities has nowadays become a major environmental issue to reduce mining impacts on the erosion of ... [more ▼]

Ecological restoration of degraded metal-rich habitats and bare metal-rich soils created by mining activities has nowadays become a major environmental issue to reduce mining impacts on the erosion of biodiversity and the degradation of landscape, soil and water.Studies based on species identification for restoration purposes without reference to plant trait are limited only to local pool of species which makes the interpretation and applications in various ecological contexts rather difficult. This study aims at trait analysis of metal-rich habitats in order to test the differences in plant traits in degraded primary habitat and along a successional gradient in secondary habitats. In this context, investigation of the existence of resilience or the need for ecological restoration is attempted. A second aim of this work is also the identification of traits candidates for appropriate species selection for revegetation of metal-rich bare soils purposes.Results showed that the cover of xylopodia trait values decreases according to the intensity of degradation among habitats, and can be considered an indicator of habitat degradation. Differences of traits values among primary and old secondary habitats highlighted that the absence of resilience of degraded primary steppic savanna was not explained by 14 soil factors measured.The main plant traits for revegetation of metal-rich bare soils are the following: annual life cycle, growth phenology in wet season, depth 0-10. cm of underground system. , bud bank by seeds, dispersule size <2. mm. ×. 2. mm and dispersal mode by adhesion.Future challenge would be to develop new functional ecosystem on metal-rich bare soils promoting biodiversity conservation and ecosystem services related to water and soil protection. This would require the association of species selected for revegetation and phytostabilization from plant traits occurring in secondary metalliferous habitats and species selected from plant traits specific to primary habitats. © 2015 Elsevier B.V. [less ▲]

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See detailSpecialist plant species harbour higher reproductive performances in recently restored calcareous grasslands than in reference habitats
Harzé, Mélanie ULiege; Mahy, Grégory ULiege; Bizoux, Jean-Philippe ULiege et al

in Plant Ecology and Evolution (2015), 148(2),

Background and aims_Calcareous grasslands are local biodiversity hotspots in temperate regions that suffered intensive fragmentation. Ecological restoration projects took place all over Europe. Their ... [more ▼]

Background and aims_Calcareous grasslands are local biodiversity hotspots in temperate regions that suffered intensive fragmentation. Ecological restoration projects took place all over Europe. Their success has traditionally been assessed using a plant community approach. However, population ecology can also be useful to assess restoration success and to understand underlying mechanisms. Methods_We took advantage of three calcareous grassland sites in Southern Belgium, where reference parcels coexist with parcels restored in the late twentieth century and with more recently restored parcels. We evaluated the colonization stage of three specialist species (Sanguisorba minor, Potentilla neumanniana and Hippocrepis comosa) using occurrence data. We also measured the reproductive traits of 120 individuals per species and compared components of fitness between recent restorations, old restorations and reference habitats. Key results_We found that the occurrence of H. comosa was similar in the different restoration classes, whereas both P. neumanniana and S. minor occurrences decreased from reference grasslands to recent restorations. In contrast, these two latter species exhibited a much higher reproductive output in recent restorations, thanks to an increased production of flowers and seeds. Conclusions_Our results suggest that, during colonization of recently restored calcareous grasslands, favourable environmental conditions, low competition and sufficient genetic mixing may lead to an increased fitness of individuals and a faster population growth than in the reference habitat. These results demonstrate how population processes can increase ecological resilience and highlight the interest of a population-based approach to assess the success of ecological restoration. [less ▲]

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