Herbivory on the pedunculate oak along an urbanization gradient in Europe : Effects of impervious surface, local tree cover, and insect feeding guild

Urbanization is an important driver of the diversity and abundance of tree-associated insect herbivores, but its consequences for insect herbivory are poorly understood. A likely source of variability among studies is the insufficient consideration of intra-urban variability in forest cover. With the help of citizen scientists, we investigated the independent and interactive effects of local canopy cover and percentage of impervious surface on insect herbivory in the pedunculate oak (Quercus robur L.) throughout most of its geographic range in Europe. We found that the damage caused by chewing insect herbivores as well as the incidence of leaf-mining and gall-inducing herbivores consistently decreased with increasing impervious surface around focal oaks. Herbivory by chewing herbivores increased with increasing forest cover, regardless of impervious surface. In contrast, an increase in local canopy cover buffered the negative effect of impervious surface on leaf miners and strengthened its effect on gall inducers. These results show that-just like in non-urban areas-plant-herbivore interactions in cities are structured by a complex set of interacting factors. This highlights that local habitat characteristics within cities have the potential to attenuate or modify the effect of impervious surfaces on biotic interactions.Peer reviewe

Herbivory on the pedunculate oak along an urbanization gradient in Europe : Effects of impervious surface, local tree cover, and insect feeding guild

Urbanization is an important driver of the diversity and abundance of tree-associated insect herbivores, but its consequences for insect herbivory are poorly understood. A likely source of variability among studies is the insufficient consideration of intraurban variability in forest cover. With the help of citizen scientists, we investigated the independent and interactive effects of local canopy cover and percentage of impervious surface on insect herbivory in the pedunculate oak (Quercus robur L.) throughout most of its geographic range in Europe. We found that the damage caused by chewing insect herbivores as well as the incidence of leaf-mining and gall-inducing herbivores consistently decreased with increasing impervious surface around focal oaks. Herbivory by chewing herbivores increased with increasing forest cover, regardless of impervious surface. In contrast, an increase in local canopy cover buffered the negative effect of impervious surface on leaf miners and strengthened its effect on gall inducers. These results show that – just like in non-urban areas – plant-herbivore interactions in cities are structured by a complex set of interacting factors. This highlights that local habitat characteristics within cities have the potential to attenuate or modify the effect of impervious surfaces on biotic interactions.Agence Nationale de la Recherche, Grant/Award Number: ANR-10--LABX-45; Fondation BNP Paribas.info:eu-repo/semantics/publishedVersio

Herbivory on the pedunculate oak along an urbanization gradient in Europe: Effects of impervious surface, local tree cover, and insect feeding guild

Urbanization is an important driver of the diversity and abundance of tree-associated insect herbivores, but its consequences for insect herbivory are poorly understood. A likely source of variability among studies is the insufficient consideration of intra-urban variability in forest cover. With the help of citizen scientists, we investigated the independent and interactive effects of local canopy cover and percentage of impervious surface on insect herbivory in the pedunculate oak (Quercus robur L.) throughout most of its geographic range in Europe. We found that the damage caused by chewing insect herbivores as well as the incidence of leaf-mining and gall-inducing herbivores consistently decreased with increasing impervious surface around focal oaks. Herbivory by chewing herbivores increased with increasing forest cover, regardless of impervious surface. In contrast, an increase in local canopy cover buffered the negative effect of impervious surface on leaf miners and strengthened its effect on gall inducers. These results show that-just like in non-urban areas-plant-herbivore interactions in cities are structured by a complex set of interacting factors. This highlights that local habitat characteristics within cities have the potential to attenuate or modify the effect of impervious surfaces on biotic interactions

PHENOTOOLS : un suivi continue de la croissance assistée par capteur pour comprendre la phénologie et physiologie d'espèces exotiques "acclimatées" au climat méditerranéen

International audienceLes mesures continues des variations de diamètre des arbres ont été utilisées comme marqueur de la phénologie et de physiologie de quelques espèces exotiques acclimatées au climat méditerranéen du Jardin Thuret au Cap d'Antibes. ces mesures sont comparées aux mesures classiques de phénologie et mises en regard des données climatique. différentes stratégies de croissance face au risque de séchresse sont ainsi observées et montrent que la mesure continue de variations de diamètre est un outil performant de phénologie et physiologie

Study of the adaptation of the trees to the drought, by the growth phenology follow-up in the botanical garden of the Villa Thuret

Communication orale de C. Ducatillon + résuméStudy of the adaptation of the trees to the drought, by the growth phenology follow-up in the botanical garden of the Villa Thuret. 7th European botanic gardens congress. EUROGARD VII 201

Impact of early insect herbivory on the invasive oak lace bug (Corythucha arcuata Say, 1832) in different oak species

Insect herbivores co-occurring on the same host plant interact in various ways. In particular, early-season insect herbivory triggers a wide range of plant responses that can determine the performance of herbivores colonizing the plant later in the course of the season. But the strength and direction of such effects are debated, and virtually unknown in the case of novel interactions involving exotic insects in their introduction range. We conducted an observational field study in SW France, a region recently invaded by the Oak Lace Bug (OLB, Corythucha arcuata Say). We measured early chewing damage and subsequent OLB damage in four oak species (Quercus robur, Q. pubescens, Q. cerris and Q. ilex). We set up a complementary non-choice experiment in the laboratory, feeding OLB with leaves with or without prior herbivory. The four oak species differed in their sensitivity to OLB damage, Q. ilex being broadly resistant. Prior herbivory promoted OLB damage in the laboratory experiment, but not in the field. However, prior herbivory did not alter the rank of oak resistance to the OLB. Our results suggest possible synergistic effects between spring defoliators and the OLB. This study brings insight into herbivore-herbivore interactions and their possible implications for forest management

Study of the adaptability of trees to drought:phenological monitoring of assisted growth sensors, in the Botanical Garden of Villa Thuret.

Theme E : Botanic Gardens & Climate ChangeEuroGard VII was held in Paris, France from 6-10 July 2015 at the National Museum of Natural History. It was organised in partnership with the European Botanic Gardens Consortium, BGCI and the Jardins botaniques de France and pays francophones (JBF). The Proceedings of the EuroGard VII Congress are now available online on the current page and on the European Botanic Gardens Consortium website The first part of the Proceedings is dedicated to the Congress and the second part presents the 51 full papers, classified into the themes A to G of the Congress

PHENOTOOLS : le dispositif expérimental

National audienceLa Villa Thuret rassemble des collections dendrologiques exotiques adaptées au climat méditerranéen. Originaires de pays à climats variés, méditerranéens ou non, ces arbres tolèrent les aléas du climat d’accueil, en particulier chaleur et sécheresse estivales. Ils présentent des modalités de croissance et des phénologies diverses. Un échantillon d’arbres appartenant à différents taxons représente cette diversité ; ils sont équipés de capteurs et font l’objet d’observations phénologiques