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Human impacts on Earth’s ecosystems have greatly intensified in the last decades. This is reflected in unexpected disturbance events, as well as new and increasing socio-economic demands, all of which are affecting the resilience of forest ecosystems worldwide and the provision of important ecosystem services. This Anthropocene era is forcing us to reconsider past and current forest management and silvicultural practices, and search for new ones that are more flexible and better at dealing with the increasing uncertainty brought about by these accelerating and cumulative global changes. Here, we briefly review the focus and limitations of past and current forest management and silvicultural practices mainly as developed in Europe and North America. We then discuss some recent promising concepts, such as managing forests as complex adaptive systems, and approaches based on resilience, functional diversity, assisted migration and multi-species plantations, to propose a novel approach to integrate the functionality of species-traits into a functional complex network approach as a flexible and multi-scale way to manage forests for the Anthropocene. This approach takes into consideration the high level of uncertainty associated with future environmental and societal changes. It relies on the quantification and dynamic monitoring of functional diversity and complex network indices to manage forests as a functional complex network. Using this novel approach, the most efficient forest management and silvicultural practices can be determined, as well as where, at what scale, and at what intensity landscape-scale resistance, resilience and adaptive capacity of forests to global changes can be improved.

An increase in the frequency and magnitude of drought events threatens the health of forests and the economic, ecological, and societal services they provide. It has been widely demonstrated that trees undergoing a succession of stresses may accumulate lesions that in turn lead to a decrease in their vigor and eventually to death. However, recent studies have shown that a nonlethal stress should also initiate a stress memory, which triggers a faster and stronger plant defensive response when a new stress occurs. Although this mechanism is well understood in many herbaceous plants, a better understanding in trees is needed. The aim of our study was to explore the capacity of two forest tree species to develop a stress memory. A greenhouse experiment was conducted to evaluate the tree seedlings' vigor after one or two consecutive droughts separate from a rehydration period during the same growing season. No stress memory pattern was observed for the two tree species as, on the contrary, we even observed a stress accumulation pattern in sugar maple. It remains possible that some individuals in our study developed stress memory, but that we were not able to detect it. The fine‐tuning of experimental parameters and the conducting of longitudinal studies would be helpful to detect individual capacity in stress memory activation.

Forests face an escalating threat from the increasing frequency of extreme drought events driven by climate change. To address this challenge, it is crucial to understand how widely distributed species of economic or ecological importance may respond to drought stress. In this study, we examined the transcriptome of white spruce ( Picea glauca (Moench) Voss) to identify key genes and metabolic pathways involved in the species’ response to water stress. We assembled a de novo transcriptome, performed differential gene expression analyses at four time points over 22 days during a controlled drought stress experiment involving 2-year-old plants and three genetically distinct clones, and conducted gene enrichment analyses. The transcriptome assembly and gene expression analysis identified a total of 33,287 transcripts corresponding to 18,934 annotated unique genes, including 4,425 genes that are uniquely responsive to drought. Many transcripts that had predicted functions associated with photosynthesis, cell wall organization, and water transport were down-regulated under drought conditions, while transcripts linked to abscisic acid response and defense response were up-regulated. Our study highlights a previously uncharacterized effect of drought stress on lipid metabolism genes in conifers and significant changes in the expression of several transcription factors, suggesting a regulatory response potentially linked to drought response or acclimation. Our research represents a fundamental step in unraveling the molecular mechanisms underlying short-term drought responses in white spruce seedlings. In addition, it provides a valuable source of new genetic data that could contribute to genetic selection strategies aimed at enhancing the drought resistance and resilience of white spruce to changing climates.

As the Anthropocene tightens its grip on the world, forests are facing escalating disturbance rates, tree mortality, degradation and risks of catastrophic collapses. A popular and controversial proposition is to enhance forests’ response diversity by adding novel tree species with missing functional traits through forest assisted migration (FAM). Beyond tests of the survival and growth of southern species or provenances in colder regions and studies of the socio-ecological challenges facing FAM, little interest has been paid to the silvicultural system for FAM implementation. Yet, the topic could influence its biological success, social acceptability, and economic feasibility. For example, southern light-intolerant tree species introduced into northern uneven-aged forests may experience a lack of light availability. Likewise, implementing FAM in clearcuts raises social acceptability issues. The patch-cut system combines advantages of even- and uneven-aged systems useful for FAM; however, perhaps due to the difficulty of its operationalization, it is rarely used. We propose a new way to implement the patch-cut system, enabling from the get-go to plan the location and timing of treatment of each patch in a stand. We discuss the advantages that this revisited patch-cut system presents for FAM: (i) the testing of various planting environments, (ii) easy monitoring in an adaptative management context where each patch is a replicate of a repeated-measure experiment and (iii) low intensity planting for efficient future dispersion of species adapted to a changing climate. We end with a call for the development of an international network of FAM trials within the revised patch-cut system.

Increasing extreme events that are related to global change are expected to affect the dynamics of forest ecosystems. If disruptive stressors (e.g., insects, drought) affect tree vigor without causing mortality, the ecological effects may be subtle, making subsequent ecosystem dynamics more difficult to predict than in the case of disturbances causing death. Based on the literature and our personal observations, we expected that such a subtle change could have occurred in the dynamics between sugar maple and American beech. We implemented a targeted paired‐sampling design (1) to verify whether a change occurred (gradual or abrupt, recovered or not) in the growth dynamics between the two species over a 57‐yr period, (2) to identify the likely causes of this change, and (3) to investigate whether such changes could trigger other long‐time ecological consequences. We found that sugar maple growth was negatively affected by an extreme event (or a few events) between 1986 and 1989, while American beech was not affected. Twenty years after the 1986–1989 abrupt growth decrease, sugar maple (1) had a slower growth than American beech, although it was previously similar, (2) did not respond to monthly climatic variations as it did prior to the abrupt growth decrease, and (3) had lower resilience when faced with a new stress event. Overall, our study, besides showing that extreme events with subtle effects may change the dynamics of an ecosystem, also illustrates that these events may accelerate ecosystem misadaptation to climate. Fine‐scale targeted monitoring is essential to complement broad‐scale monitoring to detect such misadaptations in a global change context.

With an increasing pressure on forested landscapes, conservation areas may fail to maintain biodiversity if they are not supported by the surrounding managed forest matrix. Worldwide, forests are managed by one of two broad approaches—even‐ and uneven‐aged silviculture. In recent decades, there has been rising public pressure against the systematic use of even‐aged silviculture (especially clear‐cutting) because of its perceived negative esthetic and ecological impacts. This led to an increased interest for uneven‐aged silviculture. However, to date, there has been no worldwide ecological comparison of the two approaches, based on multiple indicators. Overall, for the 99 combinations of properties or processes verified (one study may have evaluated more than one property or process), we found nineteen (23) combinations that clearly showed uneven‐aged silviculture improved the evaluated metrics compared to even‐aged silviculture, eleven (16) combinations that showed the opposite, and 60 combinations that were equivocal. Furthermore, many studies were based on a limited study design without either a timescale (44 of the 76) or spatial (54 of the 76) scale consideration. Current views that uneven‐aged silviculture is better suited than even‐aged silviculture for maintaining ecological diversity and processes are not substantiated by our analyses. Our review, by studying a large range of indicators and many different taxonomic groups, also clearly demonstrates that no single approach can be relied on and that both approaches are needed to ensure a greater number of positive impacts. Moreover, the review clearly highlights the importance of maintaining protected areas as some taxonomic groups were found to be negatively affected no matter the management approach used. Finally, our review points to a lack of knowledge for determining the use of even‐ or uneven‐aged silviculture in terms of both their respective proportion in the landscape and their spatial agency. We reviewed 76 papers worldwide that compared the two approaches regarding their effects on species/structural diversity and ecological processes. Current views that uneven‐aged silviculture is better suited than even‐aged silviculture for maintaining ecological diversity and processes are not substantiated by our analyses.

3D laser scanning is a cornerstone of modern forest and ecological research, allowing detailed insight into forest structures and dynamics. Although point cloud processing and noise management are crucial steps in the exploitation of LiDAR data, traditional denoising methods are usually based on the assumption of a Gaussian noise distribution, whereas many factors (including structural complexity of forest environments) lead to the opposite By overlooking the complexity of noise distribution within point clouds, these methods often fail to distinguish noise correctly, resulting in a loss of relevant information and introducing potential biases. This is particularly problematic in areas with smaller stems and branches, where their pronounced curvature leads to light diffraction, complicating reliable detection. To address these issues, we propose a new noise compression method designed to better distinguish noise from information‐bearing points within MLS‐point clouds. By self‐optimizing its parameters against ground‐truth data, our method significantly enhances the accuracy and reliability of MLS‐derived metrics while preserving essential structural details. Compared to previous denoising methods, our approach minimizes data loss and ensures a more accurate representation of forest structures across diverse conditions (including small stems and branches), widening the potential contributions of 3D mapping to other ecological spheres. La cartographie 3D constitue un pilier de la recherche forestière et écologique moderne, en offrant une représentation fine et détaillée des structures et de la dynamique des écosystèmes forestiers. Bien que la gestion du bruit soit une étape essentielle dans l'exploitation des données LiDAR, les méthodes classiques de débruitage reposent généralement sur l'hypothèse d'une distribution gaussienne du bruit, alors que de nombreux facteurs (notamment la complexité structurale des environnements forestiers) conduisent à des distributions bien plus hétérogènes. En négligeant cette complexité, ces approches peinent souvent à distinguer correctement le bruit des structures, entraînant une perte de l'information pertinente et l'introduction de biais potentiels. Ce problème est particulièrement marqué dans les zones caractérisées par de petites tiges ou branches fines, dont la courbure prononcée provoque des phénomènes de diffraction lumineuse, réduisant la fiabilité de leur détection. Pour répondre à ces limitations, nous proposons une nouvelle méthode de compression du bruit permettant de mieux discriminer le bruit des points porteurs d'informations dans les nuages captés par LiDAR mobile terrestre (LMT). En optimisant automatiquement ses paramètres à partir de mesures terrain, notre méthode améliore significativement la précision et la robustesse des métriques dérivées du LMT, tout en préservant les détails structuraux essentiels. Comparée aux méthodes traditionnelles, la compression limite la perte de données et fournit une représentation plus fidèle des structures forestières (y compris les structures fines) dans des contextes variés, élargissant ainsi le potentiel d'application de la cartographie 3D à d'autres domaines de l'écologie.

Despite recent advances in understanding tree species sensitivities to climate change, ecological knowledge on different species remains scattered across disparate sources, precluding their inclusion in vulnerability assessments. Information on potential sensitivities is needed to identify tree species that require consideration, inform changes to current silvicultural practices and prioritize management actions. A trait-based approach was used to overcome some of the challenges involved in assessing sensitivity, providing a common framework to facilitate data integration and species comparisons. Focusing on 26 abundant tree species from eastern Canada, we developed a series of trait-based indices that capture a species’ ability to cope with three key climate change stressors—increased drought events, shifts in climatically suitable habitat, increased fire intensity and frequency. Ten indices were developed by breaking down species’ response to a stressor into its strategies, mechanisms and traits. Species-specific sensitivities varied across climate stressors but also among the various ways a species can cope with a given stressor. Of the 26 species assessed, Tsuga canadensis (L.) Carrière and Abies balsamea (L.) Mill are classified as the most sensitive species across all indices while Acer rubrum L. and Populus spp. are the least sensitive. Information was found for 95% of the trait-species combinations but the quality of available data varies between indices and species. Notably, some traits related to individual-level sensitivity to drought were poorly documented as well as deciduous species found within the temperate biome. We also discuss how our indices compare with other published indices, using drought sensitivity as an example. Finally, we discuss how the information captured by these indices can be used to inform vulnerability assessments and the development of adaptation measures for species with different management requirements under climate change.

Two concomitant phenomena currently affect the dynamics of sugar maple-American beech (AB) stands in northeastern North America: beech bark disease (BBD), and increased AB understory density. Many studies suggest a causal link between the two phenomena, i.e., BBD favouring beech regeneration. But this link has yet to be experimentally demonstrated. To address the question, we compared regeneration composition between recently BBD-affected and -unaffected stands. A total of 109 stands were sampled; half were affected by BBD. Seedling and sapling density were assessed, together with the origin (seedling or sprout). While BBD affects stands in the eastern part of the study region, AB was observed in the understory across the entire region. No clear difference in AB sprout density between BBD-affected and -unaffected stands was observed while AB seedling density—as well as pooled AB seedling and sprout density were higher in unaffected stands. Findings suggests that BBD, in its early stage, is not a necessary trigger of AB understory establishment. Yet, AB sapling basal area generally was higher in stands affected by BBD, likely indicating a greater rate of AB understory development due to increased light availability beneath a more open crown canopy. That development can lead to AB understory dominance. This distinction—BBD not necessarily triggering AB root sucker establishment but favoring AB advance regeneration development—also questions the generalized perception that dense AB thickets necessarily originate from root suckers.