Climate change is impacting forests in Central Europe, causing increased mortality and degradation of forest ecosystem services (FES). As global warming intensifies, these effects are likely to worsen, particularly through more severe droughts and increased biotic disturbances. Understanding how forests respond to different levels of warming is essential for adaptation planning. Therefore, this study analyzed changes in forest structure and FES, including timber production, climate change mitigation, recreation, and structural diversity, under three global warming scenarios. Using the LandClim model, we compared warming levels of 1.5, 2, and 3 ​°C above pre-industrial temperatures, based on 30-year periods from RCP data, to historical climate. Our research focused on Freiburg's forests in southwestern Germany, characterized by diverse tree species and an elevation range of 200–1,250 ​m a.s.l. A warming of 1.5 ​°C could temporarily increase productivity, but at 2 ​°C, biomass losses of up to 10% would occur below elevations of 450 ​m due to drought mortality. Under 3 ​°C, losses would intensify below 650 ​m up to 40%, with even drought-resistant species like pedunculate oak experiencing mortality. At higher elevations, bark beetle outbreaks caused mortality of Norway spruce, while European beech capitalized on the changing ecological conditions. Higher warming levels significantly deteriorated FES, particularly timber production, climate change mitigation, and structural diversity, while recreation was less affected. These findings emphasize the urgency of meeting Paris Agreement targets, as limiting warming below 2 ​°C can reduce severe impacts. If warming exceeds this critical threshold, even species presently considered drought-resistant, such as native sessile and pedunculate oaks and non-native red oak, could face serious threats at lower elevations. This would undermine the effectiveness of current management strategies, as these tree species are key to providing multiple FES.

Floristic diversity and forest structure in two protected miombo woodlands: Insights from permanent plots in Gilé and Niassa, Mozambique

Forests in the Himalaya occur across a huge elevational range up to the tree-line ecotone. Precipitation also varies strongly; it is usually high at the windward side and low at the leeward side of the central mountain chain. Our objectives were (a) to compare forest structures in the tree-line ecotones at the wind and leeward side, and (b) to test the predictability of forest structural complexity by topographic and climatic variables from lower elevations to the tree-line. The study was conducted in the Annapurna range with 90 plots in the tree-line ecotones and an additional 69 plots at lower elevations. Forest structure was assessed by mobile laser scanning. On the windward side, the tree-line ecotone forest was mainly composed of broad-leaved species such as Rhododendron campanulatum. The stands had a high number of stems, small crowns, low vertical stratification, and dense canopy cover. On the leeward side, the tree-line ecotone forest was predominantly composed of needle-leaved species, including Pinus wallichiana. The stands had a low number of stems, large crowns, greater vertical stratification, and an open canopy. Forest structural complexity, measured by the box dimension (Db) was similar at the tree-line on both sides. For all available plots (n = 159), generalized additive models explained up to 83% of the variation in Db with the variable elevation, precipitation, slope, and aspect. Shapley additive explanations (SHAP) analysis underlined the dominant influence of elevation, followed by precipitation on both Db and forest height. Overall, Db remained relatively stable up to 3,600 m a.s.l. and then abruptly declined. This contrasts with forest height, which had already declined earlier. Overall, our study highlights the differences between precipitation regimes and underscores the importance of topography and precipitation in shaping forest height and structural complexity differently in the Himalaya.

Forest plant diversity is threatened by global change, highlighting the importance of long-term monitoring to disentangle short-term fluctuations from directional changes of communities. We investigate changes in understory vascular plant communities over 25 years (1999-2023) in 31 Italian permanent ICP Forests plots across four forest biomes. We assessed temporal dynamics of alpha diversity with respect to climate, forest structure and soil parameters. Analysing the two components of beta diversity (turnover and nestedness) at two temporal scales, we distinguish between interannual variations and long-term trends. Richness loss occurred in alpine coniferous and temperate deciduous forests, driven by increased canopy closure and climatic extremes. In these forests, species decline corresponded to long-term trends in both turnover and nestedness. Conversely, Mediterranean (i.e., sclerophyllous evergreen forests) forests exhibited stable richness, characterized by interannual species turnover. Species filtering and replacement have increased in alpine coniferous and temperate deciduous forests, reflecting shifts from initial environmental conditions. Our results underscore changes in forest understory diversity over time, particularly in forests impacted by historic management practices and climatic extremes. Conversely, Mediterranean drought-prone forests with steady canopy cover appear more stable. Continued long-term monitoring is essential to assess how canopy stabilization and climate change interact in shaping future dynamics.

Experiments uncover forest management effects on deadwood fungi.

Abstract Forest structure is shaped by forest management practices, land‐use changes, and natural disturbances, including droughts, fires, storms, and insect outbreaks that drive species‐specific and size‐specific mortality. By modifying the carbon‐water‐energy exchanges with the atmosphere, it influences a stand's capacity to buffer against or succumb to extreme weather events, which in turn determines the long‐term stability of the terrestrial carbon stocks. Given the importance of forest structure for forest land sink, land surface models are moving toward explicit representations of forest structure and management strategies. We present a new procedure to initialize forest diameters over Europe and document its implications for simulations of future forest carbon sinks. The simulated diameters for each grid cell covered by forests are initialized toward the diameter from a forest inventory. To this end, a 300‐year semi‐analytical spinup was carried out to bring the soil carbon pools into equilibrium. A lookup table with the simulated diameter and plant functional type as its entries was built by clearcutting all forests followed by a 200‐year simulation over Europe. For each grid point, the year associated with the simulated diameter that is the closest to the observation is selected, enabling the production of new initial state files over Europe. The new initialization procedure makes the initial state of forest more realistic and therefore significantly modifies the evolution of the forest carbon sink. The method could be further extended to initialize other forest state variables such as height or aboveground biomass.

Feedbacks between vegetation and soil in global Forest degradation: a meta-analysis

Deforestation reshuffles communities across landscapes with myriad consequences for ecosystem function. Following deforestation, rapid exposure to novel microclimates can act as a strong environmental filter, favoring warm-adapted species and decoupling trophic interactions. Forest restoration may partly reverse this process through increased food resources, structural complexity of habitat, and buffering of microclimates-each potentially modified by tree diversity. Despite growing evidence that tree diversity and cool microclimates help maintain animal diversity in natural forests, less is known about how these factors shape species assemblages or multi-trophic dynamics in restoration areas. Here, using surveys and two field experiments within a long-term tree planting experiment, we assessed the relative effects of tree diversity, forest structure, and associated microclimate on fine-scale space use by birds and their top-down impacts on insects. Surveys showed that the probability of occurrences of birds increased in cooler plots, which were associated with higher tree diversity and vertical complexity. The strength of microclimate effects on bird occurrences was strongest for species that are forest specialists. To assess risk to insect herbivores from avian predation, we used a sentinel prey experiment and found that predation risk increased in warmer plots, counter to our expectations based on bird surveys. Last, we examined top-down effects of bird exclusion on leaf herbivory, finding that skeletonizing patterns of herbivory increased in exclosures and in cooler plots. Taken together, these results suggest that microclimate resulting from variation in forest structure shapes the space use of birds at fine scales with complex outcomes for bird-herbivore-tree interactions in planted forests. Active restoration methods that enhance below-canopy cooling may improve biodiversity outcomes and help maintain species interactions that underlie many ecosystem functions.

Background: Understanding the biotic factors that drive aboveground biomass, including species and structural diversity, is essential for improving forest productivity and informing management under climate change. Hypotheses: We evaluated whether species diversity and structural diversity positively influence aboveground biomass in a temperate forest of northwestern Mexico, hypothesizing that structural diversity would exert a stronger and more consistent effect. Data description / Mathematical model: Aboveground biomass was estimated using species- and genus-specific allometric equations. Species diversity indices (richness, Shannon, and evenness) and structural metrics (tree density, number of diameter and height classes, and tree-size diversity indices) were calculated. Partial correlations guided variable selection, followed by linear regression relating diversity metrics to plot-level aboveground biomass. Study site and dates: The study was conducted in the El Brillante ejido, Sierra Madre Occidental, Durango, Mexico (~2,500 m elevation), using data collected in 2023 from 40 randomly distributed plots. Methods: Pearson and partial correlations evaluated bivariate and independent relationships between predictors and aboveground biomass. The final model included tree density, number of diameter classes, and the Shannon index of height classes; assumptions were verified using residual diagnostics and variance inflation factor. Results: Mean aboveground biomass was 82 Mg ha⁻¹. Species richness showed weak and non-significant relationships, whereas structural variables explained 82% of biomass variation. Conclusions: Structural diversity is a strong predictor of aboveground biomass, while species richness plays a limited role.

How artificial drought generated by the Balbina hydropower dam has transformed the floristic structure of downstream floodplain forests

Old-growth mixed beech-dominated forests continue accumulating carbon with advancing age

TLNet: A deep learning framework for tree detection in forest point clouds using multi-layered forest structure

Wildfire alters forest structure while belowground multifunctionality remains unchanged in a karst Pinus massoniana forest

Physical, rather than chemical soil properties influence tree community structure and functional composition in forests and savannas.

Abstract The impact of lightning in tropical forests remains uncertain. Specifically, the factors that influence the spatial distribution of lightning damage within forests remain unknown. Here, we investigate the distribution of direct lightning‐caused damage across different spatial scales in two Central African forests: a montane forest in Uganda and a lowland forest in the Democratic Republic of the Congo. We surveyed a total of 134 km of forest transects and identified 121 lightning strike locations. First, we investigated at the landscape scale how topography and elevation relate to lightning‐caused damage using generalized linear mixed models. Second, we investigated at the stand scale how trees' relative size and species identity affect strike patterns. For this, we compared focal trees (those directly struck) to their immediate neighbours using generalized linear models, testing how relative canopy height, relative crown area and species explained likelihood of showing evidence of strikes. At the landscape scale, we found that trees on ridges were significantly more likely to show lightning‐caused damage than those in valleys ( β = −1.44, p = 0.008). At the stand level, greater relative canopy height increased lightning damage probability, particularly in the lowland forest ( β = 1.62, p = 0.001). Crown area also increased lightning damage likelihood in the montane forest, though not in the lowland forest. Species differed in their likelihood to show lightning damage, independent of size. Our findings suggest that ridges shield lower‐lying areas, leading to spatially uneven disturbance. In addition, larger and more exposed trees and certain tree species show lightning‐caused damage more frequently, suggesting that lightning is a selective phenomena, potentially shaping forest structure and composition. Read the free Plain Language Summary for this article on the Journal blog.

Abstract. Dash A, Mishra RK, Patra BK, Dash A, Sahu A, Biswal AK, Upadhyay VP. 2026. Vegetation dynamics of canopy tree species of Lendrikia Reserve Forest, Kandhamal, Odisha, India. Biodiversitas 27 (2): d270217. https://doi.org/10.13057/biodiv/d270217. Sustainable management of forests, especially tropical forests, is essential to comprehend how the phytosociological attributes and diversity indices of canopy tree species affect forest structure and to propose forest management options. The moist deciduous forest covers of Lendrikia Reserve Forest (LRF), an ecologically sensitive and biodiverse area in Phulbani Forest Division, Kandhamal, Odisha, India, have not yet been assessed, though numerous studies have been conducted in various tropical forest covers of India and Odisha. To address this knowledge gap, we examined phytosociological attributes of canopy tree species in the tropical moist deciduous forests of LRF in Phulbani Forest Division. Forty quadrats (20 m × 20 m) were randomly laid within the reserve forest for the study. A total of 70 canopy tree species from 55 genera and 23 families was recorded. Across species, the basal area of the species ranged from 0.233 to 2.66 m² ha-¹, totalling to 27.6 m² ha-¹, and the density from 0.625 to 43.75 individuals ha⁻¹, totalling to 575 individuals ha-¹. The Shannon wiener diversity, evenness, richness, concentration of dominance, and beta diversity of species were 3.92, 0.92, 10.11, 0.26, and 6.65, respectively, indicating the heterogeneous nature of the reserve forest. In terms of Importance Value Index (IVI), Shorea robusta (17.74) was the most dominant tree species, followed by Ficus religiosa (10.51), Terminalia anogeissiana (9.24), Schleichera oleosa (8.67), Melia azedarach (8.41), and Lannea coromandelica (8.31) as co-dominants. The conservation status of tree species of the reserve, as per the IUCN Red list category, includes vulnerable (04), critically endangered (01), endangered (01), and near-threatened species (02). The present study emphasizes that the combined knowledge of phytosociological characters, along with documentation of the conservation status of canopy tree species, is essential for prioritizing conservation efforts for managing resources and ensuring the long-term sustainability of both the plant species and the forest ecosystem.

Stochastic processes drive the soil fungal community structure in boreal forests

Abstract Habitat suitability models are widely used to estimate the potential distribution of species under current and future environmental conditions. In this study, the IPSL-CM6A-LR model and climate scenarios from the CMIP6 were employed to simulate future climate conditions. Using MaxEnt modeling, the future distributions of five dominant tree species ( Pinus nigra , Abies nordmanniana , Fagus orientalis , Quercus spp., and Pinus sylvestris ) in the Western Black Sea region were projected for the years 2030, 2050, 2070, and 2090 under the Shared Socioeconomic Pathways SSP 2-4.5 and SSP 5-8.5. Results under the SSP 2-4.5 scenario indicated a general loss of suitable habitats for all species, with Quercus spp. showing the highest reduction (6.1%), whereas very suitable zones increased for most species except Pinus nigra , which declined by 4.3%. Under the SSP 5-8.5 scenario, only Abies nordmanniana exhibited an increase (5%) in suitable habitat, while other species experienced contractions, resulting in a net loss of 12.3%; nevertheless, very suitable areas increased overall by 7.3%. In addition, this study assessed both current and future potential species mixtures by identifying stand-type combinations derived from overlapping suitable habitats. While Fagus orientalis and Quercus spp. currently dominate mixed stands, future projections suggest increasing overlap between Abies nordmanniana and Pinus sylvestris , particularly under SSP 5-8.5. Overall, species exhibited distinct and contrasting responses to future climate conditions across both scenarios. Variable importance analyses revealed that temperature seasonality, precipitation of the driest month, and isothermality were the primary environmental drivers shaping the current and future distributions of the studied tree species. Such analysis of dynamic species associations has not been previously addressed in the literature at this scale. By integrating spatial species distribution modeling with forest stand-type composition analysis, this study provides novel insights into how climate change may reshape forest structure and biodiversity, offering critical guidance for adaptive forest planning, conservation strategies, and the sustainable management of forest ecosystems under changing climatic conditions.

Abstract. Mapping vegetation is required for monitoring the condition of forest resources. Satellite data provide information on land cover and change; however, forest structural attributes are difficult to model without additional measurements from ground plots or airborne laser scanning (ALS, also known as airborne light detection and ranging or lidar) instruments. Over large and inaccessible areas, such as Canada's northern and predominantly unmanaged forests, ground plots are expensive, difficult to install, and unlikely to form a statistically valid probability sample. An alternative means to obtain information regarding forest structure in these situations is samples of ALS (hereafter lidar plots). Transect-based samples of ALS data can be used to provide structural information for the calibration and validation of spatially explicit predictive modelling for wide-area mapping of forest attributes. Here we describe and share data from the recent acquisition and processing of ALS transects across Canada's northern forests. Approximately 55 000 km of ALS transects have been acquired in 2023, 2024, and 2025. Acquisition specifications included minimum swath widths of 500 m (year 2023) or 800 m (2024 and 2025), with a minimum pulse density of 12 pulses m−2. Acquisition flight lines were designed to sample a range of northern forest conditions and to correspond with a concurrent ground plot sampling campaign. Airborne laser scanning data were processed into height-normalized point clouds and reprojected to a custom Lambert conformal conic projection to align with existing national satellite information products. More than 15 million 900 m2 lidar plots were generated from the 2023 transect dataset with point cloud metrics (i.e., area-based statistical summaries of the ALS point cloud) calculated for each 30 m by 30 m cell. Presently, the 2023 lidar plots and their associated point cloud metrics are stored in openly available SQLite GeoPackages, with additional annual transect collections to be added as available. To accommodate a wide range of users and applications, both comprehensive and abridged versions of the metric databases, with 369 metrics and 40 metrics, respectively, are shared. The framework underlying this dataset is fully transferable to other regions with comparable information needs. The flexible data structure used allows seamless integration of additional open-access ALS transect data as new acquisitions and processing become available. By providing detailed, scalable measurements that bridge the gap between ground observations and wall-to-wall satellite information products, this open-access resource empowers both the scientific and operational forestry communities. These data will drive the development of enhanced wildfire fuels maps, comprehensive forest inventories, and robust carbon products, supporting informed decision making and advancing sustainable forest management. The 2023 lidar plots and point cloud metrics described here are available at https://doi.org/10.5281/zenodo.16782860 on Zenodo (Bater et al., 2025).

Tree canopy height is one of the most important indicators of aboveground biomass density, productivity and ecosystem structure in forests. The newest released global canopy height models as of 2023 are the 10 m spatial resolution High Resolution Canopy Height Model of the Earth (HRCH) and the first Global Map of Tree Canopy Height (GMTCH) at 1 m spatial resolution. The accuracy of both maps was mostly assessed with independent airborne laser scanning (ALS) data in boreal and temperate forests of the USA, Europe and Oceania, with limited validation datasets in tropical regions. This study aimed to provide an accuracy assessment of high and very high spatial resolution global canopy height maps in Andean Patagonian forests by comparing them with independent unmanned aerial vehicle (UAV)-mounted LiDAR datasets. The mean error of HRCH showed a positive vertical offset within a 2.7–6.6 m range, and the root mean square error (RMSE) values varied from 4.4 m to 8.8 m. In the more complex broadleaf native forests with dense canopies and steep slopes, HRCH underestimated canopy heights. Mean errors of GMTCH indicated a negative vertical offset from −2.1 m to −13.3 m at all study sites, and RMSE values ranged from 4.0 m to 14.9 m. HRCH tended to overestimate the height of low canopies and underestimate the tall ones, whereas GMTCH strongly underestimated the height of all canopies, regardless of their height. Global canopy height models represent a significant advancement in mapping forest attributes and offer new opportunities to obtain deeper insight into forests worldwide. According to the findings, we recommend using both global maps for height estimates as ancillary information at a regional level. The increased availability of ALS and UAV-mounted LiDAR databases in poorly surveyed areas, especially in South America and Africa, will strengthen the robustness of accuracy assessments for global canopy height models.