Maintaining forest resilience under climate change depends on understanding genetic adaptation and preserving diversity. Long-term common garden networks are essential for revealing how species and populations perform across life stages and environments. When strategically designed and deployed across diverse sites, including suboptimal ones, these networks provide critical empirical insights into adaptive capacity of forest tree species under future climate conditions.
A new database of forest stand characteristics from forest sites (583 sites) within the French Soil Quality Monitoring Network (RMQS) is now available. Covering two campaigns (2006–2007 and 2024), it includes descriptive stand-level data (forest structure, density, diversity, aboveground biomass) as well as forest management data and a record of silvicultural practices from 1995 to 2024. This dataset should improve the interpretation of soil analyses across this systematic national network. As the majority of RMQS forest sites also belong to the ICP Forests Level I network, it should further contribute to forest monitoring studies at the European scale. The database is available at: https://doi.org/10.57745/HE78QT , and the metadata at: https://metadata-afs.nancy.inra.fr/geonetwork/srv/fre/catalog.search#/metadata/6be8da55-9c80-42bf-afec-5c042c9e5ef1 .
Despite the strong legal framework provided by the European Union (EU) Plant Health Regulation, its implementation by Member States remains constrained by gaps in biological and epidemiological knowledge, as well as by insufficient information for the reliable diagnosis of several quarantine pathogens. By outlining these challenges, we identify scientific needs and promising avenues for improvement, providing guidance to strengthen early detection, risk-based surveillance, and diagnostic reliability across the EU.
Climate change narrows viable management alternatives in the Landes de Gascogne Forest. By testing a wide range of management regimes under contrasting climate and risk scenarios, we show that the capacity of timber damage varies across the landscape. Identifying where flexible, low-risk regimes can still sustain carbon sequestration helps decision-makers select robust strategies that reconcile local limits with regional planning needs. Regional forest management integrates diverse forest types and objectives, yet the impacts of climate change at sub-regional scales and identifying suitable management regimes for mitigation require further investigation. We align regional strategies with site-specific constraints by assessing how maritime pine (Pinus pinaster Ait.) management in the Landes de Gascogne Forest can reconcile local climatic limitations with regional production goals. We aim to identify local management flexibility and quantify the resulting trade-offs with regional carbon sequestration and carbon export under contrasted scenarios. Our cross-scale framework integrated 8 × 8 km climate projections with process-based forest simulations. Using multi-objective optimization, we explored how the set of feasible management alternatives changes across space under different climate scenarios and disturbance risks. Climate change consistently reduced service provision supply across scenarios. Under the most worst-case scenario, regional outcomes depended on the ability of local management regimes to mitigate risk, up to thresholds beyond which no current regimes remained viable. Climate effects amplified spatial disparities, reinforcing productivity in the southwest while increasing water limitations in eastern areas. Sub-regional flexibility emerged as a key lever to buffer losses in carbon-related services. This framework links local decision-making capacity with regional constraints, supporting adaptive, climate-informed forest planning.
The Index of Biodiversity Potential (IBP) can differentiate between management regimes in a context of semi-natural, mature, close-to-nature managed and set-aside temperate lowland forests. Under optimal tree-growing conditions, thresholds within the capped IBP are frequently and largely exceeded. Application of an uncapped IBP or adjustment of the scoring systems can increase the discriminating power of the index for maturity-related factors. The Index of Biodiversity Potential (IBP) is a tool used by forest managers for fast and cost-efficient assessment of the biodiversity potential in forest stands. The index is based on a set of easy-to-assess structural attributes linked to forest biodiversity. In this study, we want to assess whether the IBP can discriminate between close-to-nature managed and recently set-aside mature lowland temperate forests. We use the Benelux version of the IBP to assess differences between 42 managed and unmanaged forest patches in Belgium. The IBP was measured in at least one circular plot of 1 ha per 10 ha for each forest patch. We find that the IBP increases with time since set-aside in most forests. This can be mainly attributed to increases in deadwood, very large trees and tree-related microhabitats. Overshoot of the threshold leading to maximum scores for IBP factors occurred in both managed and unmanaged forests, but is larger in unmanaged forests, implying that the capped IBP underestimates the actual difference between management types. The IBP can be used in mature lowland temperate forest. However, depending on the required level of detail or stand maturity, an uncapped IBP or adjustment of the scoring system is advised.
Old-growth forest structures in small-scale private forests are strongly shaped by landscape context and can be reliably predicted using freely available spatial data. Remnant forest patches within mixed cultural landscapes act as important reservoirs and connectivity elements for forest biodiversity and should be prioritized in conservation and management planning. Many forest species of high conservation concern depend on old-growth structures, which are often rare in contemporary production forests. In small-scale private forests, these structures are fostered by inactive owners and influenced by parcel topography. We attempt to quantify the abundance of old-growth structures in small-scale private forests in Lower Saxony, Germany. Landscape-related predictors are employed to model spatial distribution patterns. The Parcel Index of Conservation Attributes (PICA) was calculated from forest structural data and modeled using a gradient boosting tree model. Independent survey data was used to evaluate its performance externally. The predictions are shown in the form of a spatial distribution map. The prediction identified parcels with a high abundance of old-growth structures. These were mostly found outside of large, more intensively managed forest regions and consisted of stands rich in broadleaf trees situated in semi-open, mixed-use cultural landscapes. Predictions about the spatial distribution of valuable habitats can be made using freely available landscape-scale data. Verifying these predictions using small samples increases the trustworthiness of the model. Forest patches in fragmented agricultural landscapes can act as islands of old-growth structures. These patches are vital for rare forest species and must be urgently protected.
Field experiments in South Korea show that warming alters the seedling phenology of Pinus densiflora Siebold and Zucc.. Spring needle unfolding was accelerated by spring warming and influenced by elevated daily maximum temperatures. Cumulative high-temperature exposure strongly accelerated lammas shoot development, highlighting extreme heat as a key driver of climate impacts on lammas shoot occurrence and needle unfolding. Climate warming is reshaping plant phenology worldwide; however, the specific effects of seasonal and extreme temperature accumulation on seedling development remain poorly understood. We investigated the phenological responses of Pinus densiflora Siebold and Zucc. seedlings to seasonal warming in an open-field experiment in South Korea. One hundred eight 1-year-old seedlings were subjected to four treatments: spring–fall warming (WSF), summer warming (WS), consistent warming (W), and control (C). We assessed spring needle unfolding and lammas shoot development, including occurrence and needle elongation stages. Elevated spring temperatures advanced spring needle unfolding in WSF and W with 80
Increasing crown transparency shortens phloem production in co-occurring Pinus sylvestris L. and Juniperus communis L. and shifts carbon allocation from growth to defense metabolism in Pinus sylvestris L.. Climate warming intensifies drought stress in temperate forests, altering carbon allocation and tree vitality. Crown transparency (CT) is a widely used indicator of canopy decline, but its relationship with secondary phloem development and metabolism remains unclear. We examined how CT influences intra-annual phloem phenology in Pinus sylvestris L. and Juniperus communis L., and metabolomic profiles in P. sylvestris, at a drought-prone submontane site (Tyrol, Austria), testing whether increasing CT alters phloem phenology and metabolomic profiles. We combined microcore sampling, Gompertz modeling, and untargeted GC–MS metabolomics across CT classes, linking anatomical development with biochemical composition. Phloem onset was CT-independent in P. sylvestris but delayed in J. communis with higher CT. Increasing CT shortened phloem formation and reduced cell production in both species. In P. sylvestris, xylem-to-phloem ratios decreased with CT. Low-CT trees showed higher hexoses, arabinose, and redox-active metabolites, whereas high-CT trees accumulated phenolics and showed reduced metabolic flexibility, indicating a shift toward stress-related metabolism. CT links structural and metabolic stem responses and coordinates phloem phenology with carbon allocation strategies.
No induced herbivory effect under defoliation by Eastern spruce budworm (Choristoneura fumiferana Clemens) was detected in young conifer saplings, but a marked difference among species—balsam fir (Abies balsamea (L.) Mill.), white spruce (Picea glauca [Moench] Voss), and black spruce (Picea mariana [Mill.])—in monoterpene compositions. Terpenoids are among the most common defensive compounds in conifers, found in foliage, wood, and bark. Induction of terpenoids by chewing folivorous insects is less understood than stem-feeding xylophagous insects. This study examined whether three conifers —balsam fir (Abies balsamea (L.) Mill.), white spruce (Picea glauca [Moench] Voss), and black spruce (Picea mariana [Mill.])— induce terpenoid variation in response to Eastern spruce budworm (Choristoneura fumiferana Clemens) defoliation. A total of 360 4-years-old saplings from three coniferous species were grown in a greenhouse for a 2-years-long experiment, with half exposed to defoliation and half as controls. Buds and larvae phenology were monitored, and foliage was collected throughout the growing season. Terpenoid compounds from needles were analysed using static headspace gas chromatography (HS-GC). Statistical analyses were performed on the 14 most common compounds that were found. A total of 43 terpenoids were identified, of which 67
Pine plantations of Pinus radiata and Pinus pinaster in the Atlantic regions of north-western Spain exhibit sufficient genetic diversity to ensure sustainable forests and to establish future breeding programs, although they show lower levels of variation than populations in their native ranges and in other countries. Exotic Monterey and native maritime pines are two of the most abundant conifers in north-western Spain and have been widely used for productive objectives. However, the sustainability of these two species has been altered by diseases caused by fungi and insects along with ongoing abiotic stresses. Genetic diversity is a key factor in adaptability as it brings a greater range of functional responses and thus a greater likelihood for a population to resist or recover from a perturbation. Forest management practices may affect the genetic dynamics of tree populations, and therefore European and national regulations are implemented to ensure the long-term sustainability of forest plantations. This research aimed to assess the genetic diversity in Monterey and maritime pines productive plantations across north-western regions of Spain. The goal is to support the adoption of effective management practices to enhance adaptation and breeding potential. In this study, we analyzed the genetic diversity and structure of 52 Monterey and 56 maritime pines plantations spread across north-western Spain, using 12 and 11 nuclear microsatellites, respectively. Results exhibited a unique genetic group for Monterey pine plantations, which were genetically uniform and consistent with a single importation provenance in Spain. Conversely, some maritime pine plots were found to be differentiated, suggesting multiple origins. Genetic diversity in both species was slightly lower than reported for their original distribution ranges and for plantations in other countries. The relatively small differences in genetic diversity compared with natural populations and other international plantations may indicate sufficient genetic resources to ensure future sustainable management and establish breeding programs. Nonetheless, introducing new genetic material from other provenances to increase overall diversity could broaden the adaptive and productive potential of these two species.
Radial growth is a fitness related trait that is expected to vary among forest tree populations when habitat conditions change. Yet, the genetic variability of ring-width and radial growth–climate relationships among geographic origins within species is rarely investigated. This is what we analyzed in the European black pine, Pinus nigra J.F. Arnold (1785), a forest tree species widely but patchily distributed. Using four partially replicated common gardens in France, we show that late spring minimum temperatures affect radial growth negatively and early summer precipitations positively across all provenances. In contrast, there was a strong provenance effect on mean ring-widths, as well as high phenotypic plasticity and significant genotype by environment interactions in most provenances and all subspecies. Provenances of the subspecies P.n. subsp. salzmannii often displayed the smallest mean ring widths except in the least fertile common garden. A few provenances of P.n. subsp. pallasiana, P.n. subsp. laricio and P.n. subsp. nigra performed equally well in all common gardens. Climate smart forestry should consider provenance and not just subspecies recommendations for plantations where black pine is not native, either for ecological restoration or timber production. Pinus nigra J.F. Arnold (1785), the European black pine, is a forest tree species widely but patchily distributed throughout southern Europe, from isolated locations in North Africa to the Black Sea and Western Asia. While it has been widely used as a plantation species since the mid-nineteenth century because of its rapid growth even on rather poor soils, the effect of geographic origin within genetic lineage on radial growth and climate sensitivity has not yet been assessed. We analyze the effects of geographic origin on radial growth variability and radial growth–climate relationships within four subspecies of the European black pine. Using a tree-ring to climate relationship approach and a 40-year-long chronology, we first estimated how variable the effect of monthly climate was on radial growth, among 16 provenances within four subspecies, in four bioclimatically contrasted common gardens in France. We then used the tree-ring data to estimate genetic and plasticity effects and to test for the existence of genotype by environment interactions. Lastly, we ranked the growth performance of the different subspecies and provenances measured in each common garden. There were few differences in climate effects among provenances and subspecies. Late spring minimum temperatures affect radial growth negatively and early summer precipitations positively. The provenance effect on ring-widths was stronger than the subspecies effect. Radial growth phenotypic plasticity was high across the four common gardens and so were genotype by environment interactions in most subspecies. Provenances of the subspecies P.n. subsp. salzmannii often displayed the smallest mean ring widths except in the least fertile test site. Provenance, in addition to subspecies variability should be considered in climate-smart forestry practice, whether for ecological restoration and timber production.
This study shows how climate change profoundly reshapes forest planning routines. Based on a French state forest case study, it demonstrates a shift from rigid, long-term planning toward adaptive planning built on shorter cycles, continuous monitoring through remote sensing, and renewed governance that strengthens coordination within forest administrations and with external stakeholders. Climate change fundamentally challenges the foundations of traditional forest planning, which has long relied on stable ecological baselines, long-term predictability, and deterministic planning cycles. Increasing disturbances such as droughts, pests, and large-scale dieback undermine these assumptions and create conditions of prolonged uncertainty, rendering conventional planning increasingly ineffective. We explored how forest planners adapt their practices to cope with this prolonged uncertainty and provide emerging alternatives, through the theoretical framework of organizational routines to analyze both stability and change. We conducted an in-depth single-case study of a French state forest, combining interviews, field observations, and analysis of management documents. Using an abductive and processual approach, we traced the sequencing of actions, actors, and artifacts to understand how forest planning routines evolve in practice. We identify three major shifts: the shortening of planning cycles to reduce long-term obsolescence; the integration of continuous monitoring enabled by remote sensing technologies; and the redesign of governance arrangements to enhance internal coordination and stakeholder engagement. Forest planning is transitioning from a fixed long-term roadmap toward an adaptive, continuously updated process designed to cope with persistent uncertainty.
The arbitrary 8-degree scale of dead wood decomposition is an excellent tool for studying changes in the flora of lichens and plants on decaying logs in forest ecosystems. With this scale, we showed that species turnover closely resembles the relay floristics scenario in the most species-rich forests. The succession of saproxylic organisms colonizing deadwood is commonly assessed using wood_decay scales with four to eight classes. We applied McCullough’s (1948) eight-class decay scale to determine whether the succession of lichens, liverworts, mosses, and vascular plants aligns more closely with relay floristics or initial floristic composition. We surveyed 630 logs across four montane forest types in southern Poland, assessing log traits, species richness, cover, and beta-diversity. Principal component analysis and multifuzzy set ordination were used to identify environmental factors affecting species composition. Species richness patterns differed among groups: liverworts, mosses, and vascular plants displayed a humped-back relationship with decay, while lichens declined along the gradient. Species turnover resulted from shifts between epiphytic and epixylic taxa and varied among forest types. Decay stage correlated strongly with soil contact and moisture, and the combined effects of decay and altitude showed the highest cumulative correlation with species composition (r = 0.65). Several taxa were significantly confined to the eighth decay class, confirming the usefulness and non-redundancy of all eight classes. McCullough’s eight‑class decay scale effectively captures successional changes in epixylic flora and provides sufficient resolution for ecological analyses. High species turnover—particularly in lichens—suggests that successional trajectories are more consistent with relay floristics than with initial floristic composition, whereas vascular plants act as late‑stage colonizers with low turnover. Forest type and altitude strongly shaped species composition along the decay continuum.
We evaluated the seed storability of three native Korean Rhododendron species (Rhododendron micranthum Turcz., R. mucronulatum Turcz., and R. schlippenbachii Maxim.) under storage seed bank conditions. Although the three species were classified as bearing orthodox seeds, our analysis revealed a profound interspecific divergence in storability trends. These results highlight the need for species-specific storage protocols, even within the same genus or storage category. Rhododendron micranthum, R. mucronulatum, and R. schlippenbachii are representative native Rhododendron species in Korea. They differ genetically and ecologically. Conservation of each species is becoming critical under climate change conditions, and reliable long-term data on seed storability are essential for effective conservation planning. This study aimed to obtain long-term germination data for the three species across various storage periods (>10 years) to statistically evaluate the interspecific differences in longevity and storability during seed bank storage. Seeds were collected from wild populations in Korea and processed according to standardized seed bank protocols. Changes in germination were assessed using periodic germination tests. Seed longevity varied significantly among species (p < 0.001), and R. micranthum exhibited a rapid decline in germination beyond 10 years. R. mucronulatum showed a more gradual decline. In contrast, R. schlippenbachii maintained a consistently high germination rate throughout the storage. Probit-based P50 estimates supported these patterns for species exhibiting significant slopes of deterioration, whereas the longevity of highly persistent seeds remained statistically uncertain. The GLM analysis revealed a highly significant Time × Species interaction (χ2 = 142.01, df = 2, p < 0.001), demonstrating fundamentally different rates of germination loss despite identical storage conditions. These findings demonstrate a strong interspecific variation in seed storability among Korean Rhododendron species. The results underscore that categorical storage designations (i.e., “orthodox”) may mask substantial differences in actual storage potential.
A large European forest monitoring dataset reveals a pattern of reduced foliar nitrogen (N) and phosphorus (P) concentrations following drought conditions in spruce and pine, and, in the case of P, beech and oak, often exhibiting N:P imbalances. Gradual nutritional imbalance and nutrient deficiency during droughts raise concern for tree vitality and forest carbon sequestration under climate change. Nitrogen (N) and phosphorus (P) are essential nutrients for tree metabolism, forest growth, and carbon sequestration, yet the drivers of their availability to trees are often complex to untangle. In this study, we investigated environmental controls of foliar N, P, and N:P based on > 4100 N and P measurements in foliage samples of main tree species (beech, oak, spruce, and pine) across 279 European monitoring sites by applying mixed regression models. We found overall nutritional declines over the past three decades that ranged from − 1.8
Chemistry-based tracing techniques are increasingly used for combating illegal timber trade, but they are currently limited by the small and fragmented reference datasets available. We introduce a model that integrates data from multiple tree genera while accounting for statistical differences between them. Our model accurately predicts the harvest location even when relevant data are unavailable in some areas, by leveraging data from other genera. Our approach could lower reference sampling costs and enable tracing in situations where new samples cannot be collected, such as during armed conflict. Chemistry-based techniques for identifying the harvest location of timber are becoming increasingly important for enforcing timber trade regulations. However, their application has been limited by the need for reference samples from all species across all areas of interest. We investigate whether combining reference data from multiple taxonomic groups can improve timber harvest location determination in regions where reference data is scarce by using the shared natural variability in isotopic composition across species. We extend the harvest location model of Mortier et al. to jointly model isotope ratios and trace element concentrations in wood from different genera. This is achieved by a new covariance function that accounts for shared patterns of spatial variation between genera. We evaluate our approach on 1020 tree samples from four economically important genera (Betula, Fagus, Pinus, Quercus) across 12 Eastern European countries. The multi-genus model substantially outperforms the single-genus model when little or no data for that genus is available in the focus area. When data from all genera are available across the study area, the multi-genus model achieves similar performance to the single-genus model. Our approach strengthens the applicability of timber tracing methods by enabling accurate predictions in areas where sample collection is not currently feasible due to political, logistical and/or security-related challenges, provided that pre-existing samples from other genera are available.
This study provides new equations to estimate crown width and percent crown cover of cork oak (Quercus suber L.), helping forest managers understand forest structure and making informed decisions on understory management and thinning operations. These equations can either be used as standalone solutions or help adapt existing tools, such as the Physiological Processes Predicting Growth (3PG) model, thereby supporting better decisions to protect Mediterranean woodlands facing environmental changes. Tree crown width and canopy cover are key variables that influence forest productivity, regeneration, and ecosystem functioning. In cork oak stands, low regeneration and sparse canopy cover are common challenges. There is no established consensus on the optimal stand density, and research on this topic remains limited. This study aims to develop robust models to estimate tree crown width and canopy cover at the stand level, designed for both standalone application and integration with the outputs of the widely used 3PG model. In addition, the proposed models can be used to evaluate alternative methods for estimating light interception in the 3PG model. The first step involved the development of a crown width model based on stand variables, computed with all trees in the stand, including trees with DBH < 7.5 cm, which is really important in young even-aged stands and in close-to-nature management. This model was then used to calculate missing crown widths, followed by the development of new models to estimate canopy cover based on stand variables and some biomass component(s). Several formulations of allometric and monomolecular functions were tested to produce alternatives both for general use as a decision-support tool and use within the 3PG model. The monomolecular function was preferred for its broad applicability across stand ages. Three final formulations, one using basal area and the other two using leaf biomass as the main predictor, showed strong predictive performance (EFpred. = 0.88, 0.91 and 0.91, respectively) and maintained biological relevance. The model based on leaf biomass and tree density enables canopy cover estimation independent of stand age and uses variables directly provided by the 3PG model. Improved estimates of crown width and canopy cover allow for more accurate assessments of the relationship between the tree canopy and the understory vegetation, which enables the use of canopy cover as thinning criteria. Therefore, the equations developed in this study are valuable tools for supporting sustainable forest management. Furthermore, one of the canopy cover models was specifically designed for direct integration into the 3PG model, and the set of equations developed open new avenues to test alternative methods for estimating light interception within this framework.
The described database provides environmental information about a case study of post-mining slopes in northern Spain. It characterizes soil physicochemical properties (including first mineral horizon thickness), plant community attributes (diversity indexes and cover by species, by family, by Raunkiær’s life-form and by life cycle) and the topography (slope steepness and altitude) of two vegetation patches—grassland and shrubland—on the same mine slope restored 11 years ago, and the close native forest. The database is available at https://doi.org/10.5281/zenodo.17523269, and the associated metadata at: https://metadata-afs.nancy.inra.fr/geonetwork/srv/fre/catalog.search#/metadata/ec2be8d2-dbb2-4d7b-a8f3-7aabe30e6517.
Forests in Europe are changing unevenly. Recovery dominates parts of Northern and Central Europe, while disturbance, degradation, and loss intensify in Southern and Eastern regions, and urbanization-driven fragmentation is spreading widely. A pan-European expert survey shows that climate and market pressures matter everywhere, but forest change outcomes depend most on governance capacity—enforcement, coordination, and regionally adapted incentives. European forests are central to climate change mitigation, biodiversity conservation, and ecosystem service provision, yet they are undergoing rapid and uneven change under climatic, economic, and land-use pressures. While inventories and remote sensing document large-scale trends, they provide limited understanding into governance changes and context-specific drivers affecting forest change across regions. This study examines expert opinions on what forest changes are occurring across the EU, where they are concentrated, why they are taking place, and who the key actors moving these changes forward are. A structured expert survey was conducted across all 27 EU Member States, collecting assessments on forest change types, spatial patterns, drivers, and governance arrangements. Responses were aggregated at the country level and analyzed using descriptive statistics and thematic coding within a PESTEL framework. Afforestation and reforestation dominate in Northern Europe and parts of Central Europe, while degradation, disturbance-driven losses, and deforestation pressures intensify in Southern and Eastern regions. Forest fragmentation linked to urbanization is increasingly pan-European. Climate change and market pressures were universally recognized, but forest change outcomes consistently depended on governance capacity, enforcement, and institutional coherence. National policymakers and the agricultural sector were identified as the most influential actors, with conflicts reported across all regions. The findings indicate that European forest change trajectories are determined not only by changes in forest area but also by differences in governance capacity and institutional coherence. These results emphasize the importance of considering governance context when interpreting forest change patterns and designing regionally adapted policy responses.
In the study area around Yacuiba, Bolivia, four field inventory plots were established. The associated plots cover a total of 16 ares of Chaco forest, distributed across zones of high and low photosynthetic activity. This dataset supports the assessment of climate impacts and provides field-based data for biomass analysis. The dataset can be accessed at https://doi.org/10.5281/zenodo.14710238. Associated metadata are available at: https://metadata-afs.nancy.inra.fr/geonetwork/srv/fre/catalog.search#/metadata/f5c18250-89d4-46fc-bda5-bb7e88bff873.
