In planted forest landscapes, semi-natural forest remnants constitute essential habitats for forest biodiversity. However, modifying forest cover to restore these stands and enhance the connectivity among them remains a logistical challenge for forest managers. While hedgerows have been widely studied for their role in promoting biodiversity in agricultural landscapes (i.e., “bocage”), it remains unclear to what extent these interstitial elements, would enhance biodiversity in planted forest landscapes. To address this question, we conducted our study in a homogeneous and monospecific pine plantation landscape in southwestern France, where we compared the diversity of six taxonomic groups in broadleaved hedgerows vs. pine stand edges. We also analysed the effect of the connectivity of hedgerows to semi-natural broadleaved stands and the proportion of broadleaved stands in the landscapes. Beyond species richness and community composition of each taxon, we calculated multidiversity indexes across all groups (using dominant, rare, or forest specialist species). Multidiversity was significantly higher in hedgerows than in pine stand edges. Hedgerows were home to communities with a distinct composition, including a greater abundance of rare species and forest specialist species. Increasing broadleaved cover in the landscape had a negative effect on multidiversity but altered community composition in three out of six groups. The connectivity of hedgerows to broadleaved stands had no significant effect on biodiversity. Preserving or planting broadleaved hedgerows therefore emerges as an effective and practical management method for enhancing biodiversity, particularly of forest specialist species, in pine plantation landscapes.

Mixed forests exhibit greater resistance to pests compared to monospecific forests. However, stand-level diversification is challenging for managers. An alternative approach is to enhance tree diversity at the landscape scale. Building on the agricultural landscapes with hedgerows, we hypothesized that in a pine plantation landscape broadleaved hedgerows along pine stands locally increase tree diversity, while broadleaved stands increase landscape level diversity. According to the associational resistance concept, both methods should reduce pest damage. We tested these hypotheses in a pine plantation landscape (dominated by Pinus pinaster), by counting nests of the pine processionary moth (Thaumetopoea pityocampa, hereafter “PPM”) along 36 pine edges adjacent or not to broadleaved hedgerows, in landscapes with low or high broadleaved cover. PPM bird and bat predators activities were assessed using acoustic devices. At the local level, PPM nests were 42

In forested landscapes, compositional and configurational heterogeneity have been shown to enhance biodiversity. However, changing the type of land cover to improve landscape heterogeneity remains a logistical challenge for forest managers. While hedgerows and forest patches have been widely studied for their role in promoting biodiversity in agricultural landscapes (i.e., “bocage”), it remains unclear to what extent increasing the share of these interstitial elements would enhance the diversity of different taxonomic groups in plantation landscapes. To address this question, we conducted our study in a homogeneous and monospecific pine plantation landscape in southwestern France, where we compared the diversity of six taxonomic groups in broadleaved hedgerows vs pine stand edges. We also analysed the effect of the connectivity of hedgerows to broadleaved stands and the proportion of broadleaved stands in the landscapes. Beyond species richness and community composition of each taxon, we calculated multidiversity indexes across all groups (using dominant, rare, or forest specialist species). Multidiversity was significantly higher in hedgerows than in pine stand edges. Hedgerows were home to communities with a distinct composition, including a greater abundance of rare species and forest specialist species. Increasing broadleaved cover in the landscape had a negative effect on multidiversity but altered community composition in three out of six groups. The connectivity of hedgerows to broadleaved stands had no significant effect on biodiversity. Preserving or planting broadleaved hedgerows therefore emerges as an effective and practical management method for enhancing biodiversity, particularly of forest specialist species, in pine plantation landscapes.

Organic farming is a promising but still debated option to ensure sustainable agriculture. However, whether organic farming fosters synergies or mitigates tradeoffs between biodiversity, ecosystem services and crop production has rarely been quantified. Here, we investigate relationships between multitrophic diversity (14 taxa above and belowground), yield, natural pest control and soil quality (14 proxies of ecosystem services) in organic and conventional vineyards along a landscape gradient. Organic farming enhanced biodiversity and pest control, but decreased wine production. Compared to conventional systems, multitrophic diversity was 15 % higher, and pest control services were 9 % higher in organic systems, while wine production was 11 % lower. Regardless of management type, we found a strong tradeoff between wine production and pest control, but not between wine production and biodiversity. The landscape context was not a strong moderator of organic farming effects across taxa groups and ecosystem services, but affected specific taxa and ecosystem services, especially natural pest control. Our study reveals that wine production and biodiversity conservation do not necessarily exclude each other, which implies the existence of a safe operating space where biodiversity and wine production can be combined. We conclude that organic farming can contribute to improve the sustainability of viticulture, but needs to be complemented by management options at the local and landscape scales in order to fully balance biodiversity conservation with the simultaneous provision of multiple ecosystem services.

Faced with current health and environmental challenges, viticulture is directly concerned with the need to reduce pesticide use. Natural pest control services provided by bats have been demonstrated in other crops and is regularly mentioned as a way to reduce pesticide use. However, the trophic link between bats and grape pests as well as the effect of pest presence on bat activities remain largely unknown. To investigate the functional role of bats in vineyard landscapes, we used two independent approaches. We monitored the activities of bats and of the European grapevine moth (Lobesia botrana) in 23 vineyards located in the Bordeaux region (France). In parallel, we developed DNA primers to examine bat faeces from two regions, Bordeaux and Burgundy, for the presence of the three main species of grapevine moths. Our results demonstrate that bats significantly increase their hunting activity when European grapevine moths are present in vineyards. In addition, our molecular analysis of the faeces provides robust evidence that at least 10 species of bats predate the three grapevine moth species. Our results therefore suggest that bats can be natural enemies of grape pests in vineyard landscapes. Further research is now needed to investigate the consequences of predation of pests by bats on crop production as well as the effect of some management options at both the local and landscape scale to increase the level of pest control services provided by bats.

Plant diversity is an important driver of diversity at other trophic levels, suggesting that cascading extinctions could reduce overall biodiversity. Most evidence for positive effects of plant diversity comes from grasslands. Despite the fact that forests are hotspots of biodiversity, the importance of tree diversity, in particular its relative importance compared to other management related factors, in affecting forest‐associated taxa is not well known. To address this, we used data from 183 plots, located in different forest types, from Mediterranean to Boreal, and established along a climatic gradient across six European countries (FunDivEUROPE project). We tested the influence of tree diversity, tree functional composition (i.e. functional trait values), forest structure, climate and soil on the diversity and abundance/activity of nine taxa (bats, birds, spiders, microorganisms, earthworms, ungulates, foliar fungal pathogens, defoliating insects and understorey plants) and on their overall diversity and abundance/activity (multidiversity, multiabundance/activity). Tree diversity was a key driver of taxon‐level and overall forest‐associated biodiversity, along with tree functional composition, forest structure, climate and soil. Both tree species richness and functional diversity (variation in functional trait values) were important. The effects of tree diversity on the abundance/activity of forest‐associated taxa were less consistent. Nonetheless, spiders, ungulates and foliar fungal pathogens were all more abundant/active in diverse forests. Tree functional composition and structure were also important drivers of abundance/activity: conifer stands had lower overall multidiversity (although the effect was driven by defoliating insects), while stands with potentially tall trees had lower overall multiabundance/activity. We found more synergies than tradeoffs between diversity and abundance/activity of different taxa, suggesting that forest management can promote high diversity across taxa. Our results clearly show the high value of mixed forest stands for multiple forest‐associated taxa and indicate that multiple dimensions of tree diversity (taxonomic and functional) are important.

Bats and birds are key providers of ecosystem services in forests. How climate and habitat jointly shape their communities is well studied, but whether biotic predictors from other trophic levels may improve bird and bat diversity models is less known, especially across large bioclimatic gradients. Here, we achieved multi-taxa surveys in 209 mature forests replicated in six European countries from Spain to Finland, to investigate the importance of biotic predictors (i.e. the abundance or activity of defoliating insects, spiders, earthworms and wild ungulates) for bat and bird taxonomic and functional diversity. We found that nine out of 12 bird and bat diversity metrics were best explained when biotic factors were added to models including climate and habitat variables, with a mean gain in explained variance of 38% for birds and 15% for bats. Tree functional diversity was the most important habitat predictor for birds, while bats responded more to understorey structure. The best biotic predictors for birds were spider abundance and defoliating insect activity, while only bat functional evenness responded positively to insect herbivory. Accounting for potential biotic interactions between bats, birds and other taxa of lower trophic levels will help to understand how environmental changes along large biogeographical gradients affect higher-level predator diversity in forest ecosystems.

Forest ecosystem functioning generally benefits from higher tree species richness, but variation within richness levels is typically large. This is mostly due to the contrasting performances of communities with different compositions. Evidence-based understanding of composition effects on forest productivity, as well as on multiple other functions will enable forest managers to focus on the selection of species that maximize functioning, rather than on diversity per se. We used a dataset of 30 ecosystem functions measured in stands with different species richness and composition in six European forest types. First, we quantified whether the compositions that maximize annual above-ground wood production (productivity) generally also fulfil the multiple other ecosystem functions (multifunctionality). Then, we quantified the species identity effects and strength of interspecific interactions to identify the "best" and "worst" species composition for multifunctionality. Finally, we evaluated the real-world frequency of occurrence of best and worst mixtures, using harmonized data from multiple national forest inventories. The most productive tree species combinations also tended to express relatively high multifunctionality, although we found a relatively wide range of compositions with high- or low-average multifunctionality for the same level of productivity. Monocultures were distributed among the highest as well as the lowest performing compositions. The variation in functioning between compositions was generally driven by differences in the performance of the component species and, to a lesser extent, by particular interspecific interactions. Finally, we found that the most frequent species compositions in inventory data were monospecific stands and that the most common compositions showed below-average multifunctionality and productivity. Synthesis and applications. Species identity and composition effects are essential to the development of high-performing production systems, for instance in forestry and agriculture. They therefore deserve great attention in the analysis and design of functional biodiversity studies if the aim is to inform ecosystem management. A management focus on tree productivity does not necessarily trade-off against other ecosystem functions; high productivity and multifunctionality can be combined with an informed selection of tree species and species combinations.

Humans require multiple services from ecosystems, but it is largely unknown whether trade-offs between ecosystem functions prevent the realisation of high ecosystem multifunctionality across spatial scales. Here, we combined a comprehensive dataset (28 ecosystem functions measured on 209 forest plots) with a forest inventory dataset (105,316 plots) to extrapolate and map relationships between various ecosystem multifunctionality measures across Europe. These multifunctionality measures reflected different management objectives, related to timber production, climate regulation and biodiversity conservation/recreation. We found that trade-offs among them were rare across Europe, at both local and continental scales. This suggests a high potential for 'win-win' forest management strategies, where overall multifunctionality is maximised. However, across sites, multifunctionality was on average 45.8-49.8% below maximum levels and not necessarily highest in protected areas. Therefore, using one of the most comprehensive assessments so far, our study suggests a high but largely unrealised potential for management to promote multifunctional forests.

Species assemblages are shaped by local and continental-scale processes that are seldom investigated together, due to the lack of surveys along independent gradients of latitude and habitat types. Our study investigated changes in the effects of forest composition and structure on bat and bird diversity across Europe. We compared the taxonomic and functional diversity of bat and bird assemblages in 209 mature forest plots spread along gradients of forest composition and vertical structure, replicated in 6 regions spanning from the Mediterranean to the boreal biomes. Species richness and functional evenness of both bat and bird communities were affected by the interactions between latitude and forest composition and structure. Bat and bird species richness increased with broadleaved tree cover in temperate and especially in boreal regions but not in the Mediterranean where they increased with conifer abundance. Bat species richness was lower in forests with smaller trees and denser understorey only in northern regions. Bird species richness was not affected by forest structure. Bird functional evenness increased in younger and denser forests. Bat functional evenness was also influenced by interactions between latitude and understorey structure, increasing in temperate forests but decreasing in the Mediterranean. Covariation between bat and bird abundances also shifted across Europe, from negative in southern forests to positive in northern forests. Our results suggest that community assembly processes in bats and birds of European forests are predominantly driven by abundance and accessibility of feeding resources, i.e., insect prey, and their changes across both forest types and latitudes.

Significance Numerous studies have demonstrated the importance of biodiversity in maintaining multiple ecosystem functions and services (multifunctionality) at local spatial scales, but it is unknown whether similar relationships are found at larger spatial scales in real-world landscapes. Here, we show, for the first time to our knowledge, that biodiversity can also be important for multifunctionality at larger spatial scales in European forest landscapes. Both high local (α-) diversity and a high turnover in species composition between locations (high β-diversity) were found to be potentially important drivers of ecosystem multifunctionality. Our study provides evidence that it is important to conserve the landscape-scale biodiversity that is being eroded by biotic homogenization if ecosystem multifunctionality is to be maintained.

Context In heterogeneous landscapes, habitat complementation is a key process underlying the distribution of mobile species able to exploit non-substitutable resources over large home ranges. For instance, insectivorous bats need to forage in a diversity of habitat patches offering varied compositions and structures within forest landscape mosaics to fulfill their life cycle requirements. Objectives We aimed at analyzing the effects of forest structure and composition measured at the stand and landscape scales on bat species richness, abundance and community composition in pine plantation forests of south-western France. Methods We sampled bat communities at different periods of the summer season using automatic ultrasound recorders along a tree composition gradient from pine monocultures to pure oak stands. We analyzed bat species activity (as a proxy for bat abundance) and species richness with linear mixed models. Distance-based constrained ordinations were used to partition the spatio-temporal variation in bat communities. Results Deciduous tree cover increased bat activity and modified community composition at both stand and landscape scales. Changes in bat communities were mostly driven by landscape-scale variables while bat activity responded more to stand-scale predictors. Conclusions The maintenance of deciduous trees at both stand and landscape scales is likely critical for bat communities living in fast-growing conifer plantations, by increasing the availability and diversity of prey and roosting sites. Our study suggests that bats respond to forest composition at both stand and landscape scales in mosaic plantation landscapes, mainly through a resource complementation process.

There is considerable evidence that biodiversity promotes multiple ecosystem functions (multifunctionality), thus ensuring the delivery of ecosystem services important for human well-being. However, the mechanisms underlying this relationship are poorly understood, especially in natural ecosystems. We develop a novel approach to partition biodiversity effects on multifunctionality into three mechanisms and apply this to European forest data. We show that throughout Europe, tree diversity is positively related with multifunctionality when moderate levels of functioning are required, but negatively when very high function levels are desired. For two well-known mechanisms, ‘complementarity’ and ‘selection’, we detect only minor effects on multifunctionality. Instead a third, so far overlooked mechanism, the ‘jack-of-all-trades’ effect, caused by the averaging of individual species effects on function, drives observed patterns. Simulations demonstrate that jack-of-all-trades effects occur whenever species effects on different functions are not perfectly correlated, meaning they may contribute to diversity–multifunctionality relationships in many of the world’s ecosystems.

Global change is expected to modify the frequency and magnitude of defoliating insect outbreaks in forest ecosystems. Bats are increasingly acknowledged as effective biocontrol agents for pest insect populations. However, a better understanding is required of whether and how bat communities contribute to the resilience of forests to man-and climate-driven biotic disturbances. We studied the responses of forest insectivorous bats to a major pine defoliator, the pine processionary moth pityocampa, which is currently expanding its range in response to global warming. We used pheromone traps and ultrasound bat recorders to estimate the abundance and activity of moths and predatory bats along the edge of infested pine stands. We used synthetic pheromone to evaluate the effects of experimentally increased moth availability on bat foraging activity. We also evaluated the top-down regulation of moth population by estimating T. pityocampa larval colonies abundance on the same edges the following winter. We observed a close spatio-temporal matching between emergent moths and foraging bats, with bat activity significantly increasing with moth abundance. The foraging activity of some bat species was significantly higher near pheromone lures, i.e. in areas of expected increased prey availability. Furthermore moth reproductive success significantly decreased with increasing bat activity during the flight period of adult moths. These findings suggest that bats, at least in condition of low prey density, exhibit numerical and functional responses to a specific and abundant prey, which may ultimately result in an effective top-down regulation of the population of the prey. These observations are consistent with bats being useful agents for the biocontrol of insect pest populations in plantation forests.

AimThe role of bird-insect interactions in shaping bird distribution patterns at the landscape scale has been seldom investigated. In mosaic landscapes, bird functional diversity is considered to be an important driver of avian insectivory, but depends on forest fragmentation and edge effects from adjacent, non-forest habitats. In a transcontinental experiment, we investigated edge and landscape effects on bird functional diversity and insectivory in mosaic landscapes of mixed forests and open habitats.LocationNew Zealand and France.MethodsWe paired edge and interior plots in native forest fragments in New Zealand and native plantation forests in France. We sampled bird communities using point-counts and linear transects respectively and simultaneously quantified avian insectivory as the rate of bird attacks on plasticine models mimicking tree-feeding Lepidoptera larvae. The same seven life traits and attributes were compiled for French and New Zealand birds, including biogeographic origin, body mass, mobility, foraging method, adult diet, nest location and clutch size. Bird functional diversity was quantified on this multitrait basis by four indices: functional richness, evenness, divergence and dispersion. We used mixed models to test for the effects of forest edges, study area, surrounding landscape diversity and native forest cover on bird functional diversity and insectivory.ResultsWe found higher bird functional richness at forest edges than interiors in New Zealand and lower functional richness at edges in France. However, bird functional evenness and divergence were significantly higher at forest edges in the two countries. Functional evenness and dispersion both increased with landscape diversity and evenness increased with native forest cover. Moreover, bird insectivory increased at forest edges with functional evenness, irrespective of the study area.Main conclusionsWe suggest that intermediate levels of forest fragmentation and edge effects increase avian insectivory in mosaic landscapes, through enhanced functional evenness and trait complementation within predatory bird assemblages.

1 Little is known about the relative effect of different mortality factors triggering the population dynamics of outbreaking Lepidoptera (e.g. climate, natural enemies, habitat diversity), especially at the egg stage.2 The presence of broadleaved hedgerows bordering pine stands has been shown to reduce infestation by Thaumetopoea pityocampa (Denis & Schiffermuller, Lepidoptera). This effect of habitat diversity has been proposed to result from the disruption of visual and chemical cues that the female moth uses to locate its host. In the present study, we further hypothesized that egg mortality was higher behind broadleaved hedgerows because of higher predation or parasitism, or as a result of harsher microclimatic conditions.3 A total of 120 egg masses obtained from laboratory rearing were exposed under three exclusion treatments (large predators, predators and parasitoids, no exclusion). Overall egg mortality was 35%. Predation was the main cause of mortality (22%). Mortality as a result of abiotic factors (abortion) was only 12%. Almost no parasitoids were observed.4 Overall mortality did not differ between pines bordered (or not) by deciduous hedgerows, nor did mortality differ as a result of predation or abortion.5 Despite an important contribution of predation to mortality in T. pityocampa eggs, the effect of deciduous hedgerows on tree infestation by this pest is more likely to result from disruption of female moth behaviour than from differential mortality.