Strength of forest edge effects on litter-dwelling macro-arthropods across Europe is influenced by forest age and edge properties

International audienceAim: Forests are highly fragmented across Western Europe, making forest edges im ‐portant features in many agricultural landscapes. Forest edges are subject to strong abiotic gradients altering the forest environment and resulting in strong biotic gradi ‐ents. This has the potential to change the forest's capacity to provide multiple eco ‐system services such as nutrient cycling, carbon sequestration and natural pest control. Soil organisms play a key role in this perspective; however, these taxa are rarely considered in forest edge research.Location: A latitudinal gradient of 2,000 km across Western Europe.Methods: We sampled six dominant taxa of litter‐dwelling macro‐arthropods (car ‐abid beetles, spiders, harvestmen, centipedes, millipedes and woodlice) in forest edges and interiors of 192 forest fragments in 12 agricultural landscapes. We related their abundance and community composition to distance from the edge and the inter ‐action with forest age, edge orientation and edge contrast (contrast between land use types at either side of the edge).Results: Three out of six macro‐arthropod taxa have higher activity‐density in forest edges compared to forest interiors. The abundance patterns along forest edge‐to‐in‐terior gradients interacted with forest age. Forest age and edge orientation also influ ‐enced within‐fragment compositional variation along the forest edge‐to‐interior gradient. Edge contrast influenced abundance gradients of generalist predators. In general, older forest fragments, south‐oriented edges and edges along structurally more continuous land use (lower contrast between forest and adjacent land use) re ‐sulted in stronger edge‐to‐interior gradients while recent forests, north‐oriented edges and sharp land use edges induced similarity between forest edge and interior along the forest edge‐to‐interior gradients in terms of species activity‐density and composition.Main conclusions: Edge effects on litter‐dwelling macro‐arthropods are anticipated to feedback on important ecosystem services such as nutrient cycling, carbon se ‐questration and natural pest control from small forest fragments

High ecosystem service delivery potential of small woodlands in agricultural landscapes

Global forest loss and fragmentation have strongly increased the frequency of forest patches smaller than a few hectares. Little is known about the biodiversity and ecosystem service supply potential of such small woodlands in comparison to larger forests. As it is widely recognized that high biodiversity levels increase ecosystem functionality and the delivery of multiple ecosystem services, small, isolated woodlands are expected to have a lower potential for ecosystem service delivery than large forests hosting more species. We collected data on the diversity of six taxonomic groups covering invertebrates, plants and fungi, and on the supply potential of five ecosystem services and one disservice within 224 woodlands distributed across temperate Europe. We related their ability to simultaneously provide multiple ecosystem services (multiservice delivery potential) at different performance levels to biodiversity of all studied taxonomic groups (multidiversity), forest patch size and age, as well as habitat availability and connectivity within the landscape, while accounting for macroclimate, soil properties and forest structure. Unexpectedly, despite their lower multidiversity, smaller woodlands had the potential to deliver multiple services at higher performance levels per area than larger woodlands of similar age, probably due to positive edge effects on the supply potential of several ecosystem services. Biodiversity only affected multiservice delivery potential at a low performance level as well as some individual ecosystem services. The importance of other drivers of ecosystem service supply potential by small woodlands in agricultural landscapes also depended on the level of performance and varied with the individual ecosystem service considered. Synthesis and applications. Large, ancient woodlands host high levels of biodiversity and can therefore deliver a number of ecosystem services. In contrast, smaller woodlands in agricultural landscapes, especially ancient woodlands, have a higher potential to deliver multiple ecosystem services on a per area basis. Despite their important contribution to agricultural landscape multifunctionality, small woodlands are not currently considered by public policies. There is thus an urgent need for targeted policy instruments to ensure their adequate management and future conservation in order to either achieve multiservice delivery at high levels or to maximize the delivery of specific ecosystem services

High ecosystem service delivery potential of small woodlands in agricultural landscapes

Global forest loss and fragmentation have strongly increased the frequency of forest patches smaller than a few hectares. Little is known about the biodiversity and ecosystem service supply potential of such small woodlands in comparison to larger forests. As it is widely recognized that high biodiversity levels increase ecosystem functionality and the delivery of multiple ecosystem services, small, isolated woodlands are expected to have a lower potential for ecosystem service delivery than large forests hosting more species. We collected data on the diversity of six taxonomic groups covering invertebrates, plants and fungi, and on the supply potential of five ecosystem services and one disservice within 224 woodlands distributed across temperate Europe. We related their ability to simultaneously provide multiple ecosystem services (multiservice delivery potential) at different performance levels to biodiversity of all studied taxonomic groups (multidiversity), forest patch size and age, as well as habitat availability and connectivity within the landscape, while accounting for macroclimate, soil properties and forest structure. Unexpectedly, despite their lower multidiversity, smaller woodlands had the potential to deliver multiple services at higher performance levels per area than larger woodlands of similar age, probably due to positive edge effects on the supply potential of several ecosystem services. Biodiversity only affected multiservice delivery potential at a low performance level as well as some individual ecosystem services. The importance of other drivers of ecosystem service supply potential by small woodlands in agricultural landscapes also depended on the level of performance and varied with the individual ecosystem service considered. Synthesis and applications. Large, ancient woodlands host high levels of biodiversity and can therefore deliver a number of ecosystem services. In contrast, smaller woodlands in agricultural landscapes, especially ancient woodlands, have a higher potential to deliver multiple ecosystem services on a per area basis. Despite their important contribution to agricultural landscape multifunctionality, small woodlands are not currently considered by public policies. There is thus an urgent need for targeted policy instruments to ensure their adequate management and future conservation in order to either achieve multiservice delivery at high levels or to maximize the delivery of specific ecosystem services

Habitat properties are key drivers of Borrelia burgdorferi (s.l.) prevalence in Ixodes ricinus populations of deciduous forest fragments

Background: The tick Ixodes ricinus has considerable impact on the health of humans and other terrestrial animals because it transmits several tick-borne pathogens (TBPs) such as B. burgdorferi (sensu lato), which causes Lyme borreliosis (LB). Small forest patches of agricultural landscapes provide many ecosystem services and also the disservice of LB risk. Biotic interactions and environmental filtering shape tick host communities distinctively between specific regions of Europe, which makes evaluating the dilution effect hypothesis and its influence across various scales challenging. Latitude, macroclimate, landscape and habitat properties drive both hosts and ticks and are comparable metrics across Europe. Therefore, we instead assess these environmental drivers as indicators and determine their respective roles for the prevalence of B. burgdorferi in I. ricinus. Methods: We sampled I. ricinus and measured environmental properties of macroclimate, landscape and habitat quality of forest patches in agricultural landscapes along a European macroclimatic gradient. We used linear mixed models to determine significant drivers and their relative importance for nymphal and adult B. burgdorferi prevalence. We suggest a new prevalence index, which is pool-size independent. Results: During summer months, our prevalence index varied between 0 and 0.4 per forest patch, indicating a low to moderate disservice. Habitat properties exerted a fourfold larger influence on B. burgdorferi prevalence than macroclimate and landscape properties combined. Increasingly available ecotone habitat of focal forest patches diluted and edge density at landscape scale amplified B. burgdorferi prevalence. Indicators of habitat attractiveness for tick hosts (food resources and shelter) were the most important predictors within habitat patches. More diverse and abundant macro- and microhabitat had a diluting effect, as it presumably diversifies the niches for tick-hosts and decreases the probability of contact between ticks and their hosts and hence the transmission likelihood.[br/] Conclusions: Diluting effects of more diverse habitat patches would pose another reason to maintain or restore high biodiversity in forest patches of rural landscapes. We suggest classifying habitat patches by their regulating services as dilution and amplification habitat, which predominantly either decrease or increase B. burgdorferi prevalence at local and landscape scale and hence LB risk. Particular emphasis on promoting LB-diluting properties should be put on the management of those habitats that are frequently used by humans. In the light of these findings, climate change may be of little concern for LB risk at local scales, but this should be evaluated further

Environmental drivers of Ixodes ricinus abundance in forest fragments of rural European landscapes

Background: The castor bean tick (Ixodes ricinus) transmits infectious diseases such as Lyme borreliosis, which constitutes an important ecosystem disservice. Despite many local studies, a comprehensive understanding of the key drivers of tick abundance at the continental scale is still lacking. We analyze a large set of environmental factors as potential drivers of I. ricinus abundance. Our multi-scale study was carried out in deciduous forest fragments dispersed within two contrasting rural landscapes of eight regions, along a macroclimatic gradient stretching from southern France to central Sweden and Estonia. We surveyed the abundance of I. ricinus, plant community composition, forest structure and soil properties and compiled data on landscape structure, macroclimate and habitat properties. We used linear mixed models to analyze patterns and derived the relative importance of the significant drivers. Results: Many drivers had, on their own, either a moderate or small explanatory value for the abundance of I. ricinus, but combined they explained a substantial part of variation. This emphasizes the complex ecology of I. ricinus and the relevance of environmental factors for tick abundance. Macroclimate only explained a small fraction of variation, while properties of macro- and microhabitat, which buffer macroclimate, had a considerable impact on tick abundance. The amount of forest and the composition of the surrounding rural landscape were additionally important drivers of tick abundance. Functional (dispersules) and structural (density of tree and shrub layers) properties of the habitat patch played an important role. Various diversity metrics had only a small relative importance. Ontogenetic tick stages showed pronounced differences in their response. The abundance of nymphs and adults is explained by the preceding stage with a positive relationship, indicating a cumulative effect of drivers. Conclusions: Our findings suggest that the ecosystem disservices of tick-borne diseases, via the abundance of ticks, strongly depends on habitat properties and thus on how humans manage ecosystems from the scale of the microhabitat to the landscape. This study stresses the need to further evaluate the interaction between climate change and ecosystem management on I. ricinus abundance

Use of Lidar Technology for Archaeological and Geo-historical Knowledge. French Examples

International audienceThe airborne laser or lidar (Light Detection and Ranging) is a technology in full development. For about fifteen years it has presented applications in geography and archeology. In particular, it makes it possible to obtain a high-resolution digital terrain model under the forest canopy. In France, lidar has been used in many forests such as those of Haye, Rouen, Fontainebleau or Verdun. This article presents the applications of the lidar tool to the Compiegne national forest, north of Paris (department of Oise). It offers some image processing, applied to the study of plots and old game parks

Use of Lidar Technology for Archaeological and Geo-historical Knowledge. French Examples

International audienceThe airborne laser or lidar (Light Detection and Ranging) is a technology in full development. For about fifteen years it has presented applications in geography and archeology. In particular, it makes it possible to obtain a high-resolution digital terrain model under the forest canopy. In France, lidar has been used in many forests such as those of Haye, Rouen, Fontainebleau or Verdun. This article presents the applications of the lidar tool to the Compiegne national forest, north of Paris (department of Oise). It offers some image processing, applied to the study of plots and old game parks

Predicting the effects of sea level rise on salt marsh plant communities: does vegetation age matter more than sea level?

Background and aims – Salt marsh plant communities will be among the first to be exposed to the predicted increase in sea level and to the associated environmental changes. The objectives of this study were to evaluate the influence of three major environmental variables (elevation above sea level, distance from the sea, vegetation age) on vegetation diversity in salt marshes and to predict vegetation changes in the year 2100 according to different scenarios of sea level rise. Methods – Plant communities were sampled in 1257 plots of 1 m 2 distributed along transects randomly positioned perpendicular to the shoreline in the Bay of Somme (Picardy, France). Digital elevation model data were used to determine the plot elevation and the distance between the plots and the shoreline. Three centuries of changes in the vegetation cover were reconstructed using historical maps and aerial photographs to estimate the vegetation age. We investigated the relationships between elevation above sea level, distance from the sea, vegetation age and vegetation richness and composition using mixed models. Predictive models of species richness and cover of dominant halophytes were built using the parameter estimates of the previous mixed models and the projections of the explanatory variables in 2100 according to the different sea level scenarios from +0.5 m to +2.5 m. Key results – Mixed models showed that species richness mainly increased with vegetation age. The halophytes exhibited contrasting patterns along elevation and age gradients. Sedimentation rates may counteract the sea level rise until the latter reaches a critical rate that drowns the marsh vegetation. Conclusions – Because the proportions of ancient vegetation will be higher in the bay, mean plant species richness may be higher in predicted communities in 2100 than in recently sampled communities

Predicting the effects of sea level rise on salt marsh plant communities: does vegetation age matter more than sea level?

Background and aims – Salt marsh plant communities will be among the first to be exposed to the predicted increase in sea level and to the associated environmental changes. The objectives of this study were to evaluate the influence of three major environmental variables (elevation above sea level, distance from the sea, vegetation age) on vegetation diversity in salt marshes and to predict vegetation changes in the year 2100 according to different scenarios of sea level rise. Methods – Plant communities were sampled in 1257 plots of 1 m 2 distributed along transects randomly positioned perpendicular to the shoreline in the Bay of Somme (Picardy, France). Digital elevation model data were used to determine the plot elevation and the distance between the plots and the shoreline. Three centuries of changes in the vegetation cover were reconstructed using historical maps and aerial photographs to estimate the vegetation age. We investigated the relationships between elevation above sea level, distance from the sea, vegetation age and vegetation richness and composition using mixed models. Predictive models of species richness and cover of dominant halophytes were built using the parameter estimates of the previous mixed models and the projections of the explanatory variables in 2100 according to the different sea level scenarios from +0.5 m to +2.5 m. Key results – Mixed models showed that species richness mainly increased with vegetation age. The halophytes exhibited contrasting patterns along elevation and age gradients. Sedimentation rates may counteract the sea level rise until the latter reaches a critical rate that drowns the marsh vegetation. Conclusions – Because the proportions of ancient vegetation will be higher in the bay, mean plant species richness may be higher in predicted communities in 2100 than in recently sampled communities