To understand the roles of charcoal and ectomycorrhizal fungi (ECMF) on tree growth, which relates to the rehabilitation of forest ecosystems after forest fires, two experiments were set up in this study, the first was to determine the correct amount of charcoal for Japanese larch (Larix kaempferi Sarg.) seedling growth by applying oak charcoal to basic soil medium at ratios of 1:1, 1:2, 1:4 and 1:8 by volume. The second experiment investigated the combined effects of four types of charcoal: derived from oak wood, husks of buckwheat, rice and activated charcoal of larch wood, and two types of ECMF: Pt (Pisolithus tinctorius Pers.) and Ec (Pt + Rhizopogon spp. + Laccaria spp. + Scleroderma spp.) on the growth of Japanese larch seedlings. Our results show that growth was significantly stressed by large amounts charcoal applications. There were significant variations among the four types of charcoal on growth. We concluded that the addition of charcoal was the critical factor that influenced larch growth and ECMF formation. Rice charcoal and Ec stimulates the growth and nitrogen uptake of Japanese larch seedlings, thus the most suitable fungus and charcoal for practices is Ec-rice charcoal (1: 8 charcoal to basic soil).

Climate change is the most severe ecological challenge faced by the world today. Forests, the dominant component of terrestrial ecosystems, play a critical role in mitigating climate change due to their powerful carbon sequestration capabilities. Meanwhile, climate change has also become a major factor affecting the sustainable management of forest ecosystems. Climate-Smart Forestry (CSF) is an emerging concept in sustainable forest management. By utilizing advanced technologies, such as information technology and artificial intelligence, CSF aims to develop innovative and proactive forest management methods and decision-making systems to address the challenges of climate change. CSF aims to enhance forest ecosystem resilience (i.e., maintain a condition where, even when the state of the ecosystem changes, the ecosystem functions do not deteriorate) through climate change adaptation, improve the mitigation capabilities of forest ecosystems to climate change, maintain high, stable, and sustainable forest productivity and ecosystem services, and ultimately achieve harmonious development between humans and nature. This concept paper: (1) discusses the emergence and development of CSF, which integrates Ecological Forestry, Carbon Forestry, and Smart Forestry, and proposes the concept of CSF; (2) analyzes the goals of CSF in improving forest ecosystem stability, enhancing forest ecosystem carbon sequestration capacity, and advocating the application and development of new technologies in CSF, including artificial intelligence, robotics, Light Detection and Ranging, and forest digital twin; (3) presents the latest practices of CSF based on prior research on forest structure and function using new generation information technologies at Qingyuan Forest, China. From these practices and reflections, we suggested the development direction of CSF, including the key research topics and technological advancement.

Exotic tree species, though widely used in forestry and restoration projects, pose great threats to local ecosystems. They need to be replaced with native species from natural forests. We hypothesized that natural forests contain large, fast-growing, dominant native tree species that are suitable for specific topographic conditions in forestry. We tested this hypothesis using data from a 50-ha forest dynamics plot in subtropical China. We classified the plot into the ridge, slope, and valley habitats and found that 34/87 species had significant associations with at least one topographic habitat. There were 90 tree species with a maximum diameter ≥ 30 cm, and their abundances varied widely in all habitat types. In all habitat types, for most species, rate of biomass gain due to recruitment was < 1% of its original biomass, and rate of biomass gain due to tree growth was between 1 and 5% of its original biomass. For most species, biomass loss due to tree mortality was not significantly different than biomass gain due to recruitment, but the resulting net biomass increment rates did not significantly differ from zero. The time required to reach a diameter of 30 cm from 1 cm diameter for Altingia chinensis in the slope habitat, for Quercus chungii and Morella rubra in the ridge habitat and for Castanopsis carlesii in all habitats could be as short as 30 years in our simulations based on actual distributions of tree growth observed in the forest. Principal component analyses of maximum diameter, abundance and net biomass increment rates suggested several species were worthy of further tests for use in forestry. Our study provides an example for screening native tree species from natural forests for forestry. Because native tree species are better for local ecosystems, our study will also contribute to biodiversity conservation in plantations.

Pinewood nematode is a devastating forest pathogen and is considered a quarantine organism worldwide. First identified in China 40 years ago, the disease has been spreading since. In response, Chinese authorities have introduced new requirements for preventing and controlling the disease. This paper proposes a new and highly effective preventive drug, a trunk injection agent usable at normal temperatures. Its use is suggested for localized epidemic areas to reduce diseased and dead trees and as a preventive measure in adjacent non-epidemic areas to prevent the infection from spreading, particularly protecting important and ancient pine trees.Kindly check and verify corresponding affiliation is correctly identified.Checked

Pinus koraiensis (Sieb. et Zucc.) is a coniferous tree species naturally distributed in northeastern China. However, the effects of gene flow on its genetic diversity and structure remain unclear. This study investigates these dynamics in seven populations using ten microsatellite markers. The results show a high level of genetic diversity within the populations (Ho = 0.633, He = 0.746). In addition, molecular analysis of variance (AMOVA) shows that 98% of genetic diversity occurs within populations, with minimal differentiation between populations (Fst = 0.009–0.033). Gene flow analysis shows significant migration rates between specific population pairs, particularly C-TH (87%), LS-Y (69%) and TH-LS (69%), suggesting genetic homogenization. Bayesian clustering (STRUCTURE) supports admixture and weak population differentiation. Environmental factors, especially temperature-related variables, significantly influence genetic patterns. Partial Mantel tests and multiple matrix regression show strong correlations between genetic distance and adaptations to cold temperatures (bio6 and bio11). Overall, this study emphasizes the robust genetic diversification and high migration rates in the populations of P. koraiensis and highlights their resilience. These results emphasize the importance of incorporating genetic and ecological factors into conservation strategies for sustainable forest management. This research provides valuable insights into the complex interplay of genetic variation, gene flow and environmental influences in forest tree species and improves our understanding of their adaptive mechanisms.

Photodegradation is considered as a universal contributing factor to litter decomposition and carbon (C) cycling within the Earth’s biomes. Identifying how solar radiation modifies the molecular structure of litter is essential to understand the mechanism controlling its decomposition and reaction to shifts in climatic conditions and land-use. In this study, we performed a spectral-attenuation experiment following litter decomposition in an understory and gap of a temperate deciduous forest. We found that short-wavelength visible light, especially blue light, was the main factor driving variation in litter molecular structure of Fagus crenata Blume, Quercus crispula Blume, Acer carpinifolium Siebold & Zuccarini and Betula platyphylla Sukaczev, explaining respectively 56.5%, 19.4%, 66.3%, and 16.7% of variation in its chemical composition. However, the variation also depended on canopy openness: Only in the forest gap was lignin aromatic C negatively associated with C-oxygen (C–O) bonding in polysaccharides receiving treatments containing blue light of the full spectrum of solar radiation. Regardless of species, the decomposition index of litter that explained changes in mass and lignin loss was driven by the relative content of C–O stretching in polysaccharides and lignin aromatic C. The results suggest that the availability of readily degradable polysaccharides produced by the reduction in lignin aromatic C most plausibly explains the rate of litter photodegradation. Photo-products of photodegradation might augment the C pool destabilized by the input of readily degradable organic compounds (i.e., polysaccharides).

Leptocybe invasa is an invasive pest, native to Australia, which causes serious damage to Eucalyptus all over the world. Here, we monitored gall development in resistant and susceptible Eucalyptus clones to determine whether plant genotype affects the durations of the different gall stages. Gall development varied among six Eucalyptus clones that differed in susceptibility to L. invasa viz., PE-5, 316, 3011, PE-11, 3020 and P-13 in Punjab in a nethouse. In susceptible clones PE-5 and 316, L. invasa emerged from both green and pink galls. Five stages of gall formation were found: Stage 1 (tissue disruption), Stage 2 (gall development), Stage 3 (glossy pink), Stage 4 (dull pink) and Stage 5 (exit hole) in susceptible clones when adults emerged from pink galls. However, in resistant clones, adults emerged only from green galls, and galls formed in three stages. In the susceptible clones, when adults emerged from pink galls, the life cycle was 105–115 d; however, when adults emerged from green galls, the duration was significantly shorter (81–87 d). In the most-resistant clone, P-13, corky tissue formed after oviposition, and galls did not develop further. In the resistant clones (3020, PE-11 and 3011), adults emerged from green galls, and the life cycle lasted 90–96 d. When adults emerged from green galls in susceptible and resistant clones, Stage 1 lasted longer in resistant clones than in the susceptible; however, in susceptible clones, Stage 5 was longer. When adults emerged from pink galls in susceptible clones and from green galls in resistant clones, the life cycle was longer in susceptible clones. In susceptible clones, the number of emergence holes was significantly higher than resistant clones. Gall width and gall length also differed significantly between susceptible and resistant clones. The results showed that the Eucalyptus genotype had a significant effect on gall development induced by gall wasps.

Biological invasions, driven mainly by human activities, pose significant threats to global ecosystems and economies, with fungi and fungal-like oomycetes playing a pivotal role. Ink disease, caused by Phytophthora cinnamomi and P. × cambivora, is a growing concern for sweet chestnut stands (Castanea sativa) in Europe. Since both pathogens are thermophilic organisms, ongoing climate change will likely exacerbate their impact. In this study, we applied species distribution modeling techniques to identify potential substitutive species for sweet chestnut in the light of future climate scenarios SSP126 and SSP370 in southern Switzerland. Using the presence-only machine learning algorithm MaxEnt and leveraging occurrence data from the global dataset GBIF, we delineated the current and projected (2070–2100) distribution of 28 tree species. Several exotic species emerged as valuable alternatives to sweet chestnut, although careful consideration of all potential ecological consequences is required. We also identified several native tree species as promising substitutes, offering ecological benefits and potential adaptability to climatic conditions. Since species diversification fosters forest resilience, we also determined communities of alternative species that can be grown together. Our findings represent a valuable decision tool for forest managers confronted with the challenges posed by ink disease and climate change. Given that, even in absence of disease, sweet chestnut is not a future-proof tree species in the study region, the identified species could offer a pathway toward resilient and sustainable forests within the entire chestnut belt.

Rhododendron micranthum Turcz. is a shrub esteemed for its ornamental and medicinal attributes within the Changbai Mountain range of China. We selected 3-year saplings and subjected them to four distinct light conditions: full light (CK), 70% light (L1), 50% light (L2), and 30% light (L3) to investigate variations in morphology, photosynthetic responses, stomatal ultrastructure as well as the mechanisms through which these saplings adapt to differing lighting environments. The results indicate that L2 leaves exhibit significantly greater length, width, and petiole development compared to other treatments across varying intensities. Over time, chlorophyll content and PSII levels in L2-treated saplings surpass those observed in other treatments; Proline (PRO), malondialdehyde (MDA), and soluble protein (SP) contents are markedly lower under L2 treatment. Catalase (CAT) and superoxide dismutase (SOD) demonstrate significant correlations across various light conditions but respond differently among treatments, indicating distinct species sensitivities to light intensity while both contribute to environmental stress resistance mechanisms. Findings reveal that R. micranthum saplings at 50% light intensity benefit from enhanced protection via antioxidant enzymes, and shading reduces osmotic adjustment substances yet increases chlorophyll content. Stomatal length/width along with conductance rates and net photosynthesis rates for L2 exceed those of CK, suggesting an improved photosynthetic structure conducive to efficient photosynthesis under this condition. Thus, moderate shading represents optimal growth at 50% illumination, a critical factor promoting sapling development. This research elucidates the ideal environment for R. micranthum adaptation to varying light conditions supporting future conservation initiatives.

Human activities contribute to elevated nitrogen input in terrestrial ecosystems, influencing the composition of soil nutrients and microbial diversity in forest ecosystems. In this study, we built four addition treatments (0, 20, 40, and 80 kg ha⁻¹ a⁻¹ N for 6 a) at a Korean pine plantation of different soil horizons (organic (O) horizon, ranging from 0 to 10 cm, and organomineral (A) horizon, extending from 10 to 20 cm) to evaluate responses of the structure of saprophytic fungal communities. Here, 80 kg ha⁻¹ a⁻¹ N treatment significantly decreased the community richness in soil A horizon with the Chao1 index decreasing by 12.68%. Nitrogen addition induced changes in the composition of saprophytic fungi community between the different soil horizons. The co-occurrence network and its associated topological structure were utilized to identify mycoindicators for specific fungi to both soil horizons and nitrogen addition levels. In soil O horizon, the mycoindicators included Penicillium, Trichoderma, Aspergillus, and Pseudeurotium across control, low, medium, and high nitrogen treatments. In soil A horizon, Geomyces, Cladophialophora, Penicillium, and Pseudeurotium were identified as mycoindicators. Structural equation modeling determined NH₄ ⁺-N as the key factor driving changes in saprotrophic fungal communities. Our study aimed to screen mycoindicators that can respond to the increasing global nitrogen deposition and to assess the roles of these mycoindicators in the saprophytic fungal community structure within Korean pine plantations in northeast China.

To better understand the effects of ground-level ozone (O₃) on nutrients and stoichiometry in different plant organs, urban tree species Celtis sinensis, Cyclocarya paliurus, Quercus acutissima, and Quercus nuttallii were subjected to a constant exposure to charcoal-filtered air (CF), nonfiltered air (NF), or NF + 40, 60, or 80 nmol O₃ mol^–1 (NF40, NF60, and NF80) starting early in the summer of the growing season. At the end of summer, net CO₂ assimilation rate (A), stomatal conductance (g_s), leaf mass per area (LMA), and/or leaf greenness (SPAD) either were not significantly affected by elevated O₃ or were even higher in some cases during the summer compared with the CF or NF controls. LMA was significantly lower in autumn only after the highest O₃ exposures. Compared to NF, NF40 caused a large increase in g_s across species in late summer and more K and Mn in stems. At the end of the growing season, nutrient status and stoichiometric ratios in different organs were variously altered under O₃ stress; many changes were large and often species-specific. Across O₃ treatments, LMA was primarily associated with C and Mg levels in leaves and Ca levels in leaves and stems. NF40 enriched K, P, Fe, and Mn in stems, relative to NF, and NF60 enhanced Ca in leaves relative to CF and NF40. Moreover, NF resulted in a higher Ca/Mg ratio in leaves of Q. acutissima only, relative to the other O₃ regimes. Interestingly, across species, O₃ stress led to different nutrient modifications in different organs (stems + branches vs leaves). Thus, ambient and/or elevated O₃ exposures can alter the dynamics and distribution of nutrients and disrupt stoichiometry in different organs in a species-specific manner. Changes in stoichiometry reflect an important defense mechanism in plants under O₃, and O₃ pollution adds more risk to ecological stoichiometries in urban areas.

The increasing frequency of extreme weather events raises the likelihood of forest wildfires. Therefore, establishing an effective fire prediction model is vital for protecting human life and property, and the environment. This study aims to build a prediction model to understand the spatial characteristics and piecewise effects of forest fire drivers. Using monthly grid data from 2006 to 2020, a modeling study analyzed fire occurrences during the September to April fire season in Fujian Province, China. We compared the fitting performance of the logistic regression model (LRM), the generalized additive logistic model (GALM), and the spatial generalized additive logistic model (SGALM). The results indicate that SGALMs had the best fitting results and the highest prediction accuracy. Meteorological factors significantly impacted forest fires in Fujian Province. Areas with high fire incidence were mainly concentrated in the northwest and southeast. SGALMs improved the fitting effect of fire prediction models by considering spatial effects and the flexible fitting ability of nonlinear interpretation. This model provides piecewise interpretations of forest wildfire occurrences, which can be valuable for relevant departments and will assist forest managers in refining prevention measures based on temporal and spatial differences.

Evapotranspiration (ET), vapor pressure deficit (VPD) and water use efficiency (WUE) are crucial components of the hydrological cycle in forest ecosystems, serving as indicators that reflect the intricate coupling of carbon and water fluxes within the ecosystem. The cold temperate zone, being ecologically fragile and sensitive to climate change, accentuates the significance of exploring the variation characteristics of the dynamics of hydrological processes of a Larix gmelinii forest ET, VPD and WUE were measured in the June to August growing season and the April, May, September and October freeze–thaw period from 2011 to 2016. A structural equation model (SEM) quantitatively analyzed the impact of environmental factors on ecohydrological variables. The results reveal that: (1) Daily average ET in the growing season was significantly higher than in the freeze–thaw period. WUE showed the opposite. Peaks for both ET and VPD occurred in July. In contrast, the freeze–thaw period saw maximum ET and VPD, and minimum WUE in May. July and May emerged as the most active months for hydrological processes in the ecosystem; (2) During the growing season, VPD was influenced by relative humidity (RH) and temperature (T_a), ET responded negatively to solar radiation, and WUE negatively to VPD. Throughout the freeze–thaw period, the ecosystem experienced heat stress, and ecohydrological processes were influenced by T_a. This study provides valuable references for further research on hydrological cycles in forest systems within cold temperate zones.

Studying the reproductive system of the pine wood nematode, Bursaphelenchus xylophilus (Steiner & Buhrer) Nickle, will identify its characteristics and life cycle. This is crucial for developing more targeted control strategies. In this study, the development of the gonads and reproductive organs were observed using microscopy, gonad dissection, and DAPI staining techniques. Second-stage juveniles (J2) had gonads composed of four primordial germ cells (Z1, Z2, Z3, and Z4) that form the adult gonads by proliferation within 72 h at 25 °C. There were subtle differences in somatic gonad cell morphology between males and females, which developed from Z1 and Z4 in third-stage juveniles (J3). These differences became more pronounced at fourth-stage juveniles (J4) and adult stages. Z2 and Z3 germ cells underwent mitosis and two rounds of meiosis, ultimately developing into male and female gametes. Female vulval precursor cells and male cloacal cells developed rapidly during the J4 stage. These results provide a basis for identifying the expression sites and biological functions of key genes regulating reproductive system development. Based on this, in situ hybridization and RNA interference (RNAi) were used to determine the function of the Bxy-glp-1 gene to show that it is involved in vulval formation and spermatogenesis. The results of this study will lay the foundation for disrupting critical stages in the reproduction of B. xylophilus.

As part of the global effort to mitigate climate change effects, New Zealand’s Climate Change Commission has recommended the establishment of 300,000 ha of native trees across the country by 2035. To achieve this goal, significant improvement in seedling production and field establishment is needed. Across New Zealand, there is a trade-off between seedling size and early seedling establishment success; plants grown in large pots are more resistant to weeds, pests and frost; however, they are more expensive and take longer to grow. We tested this trade-off between cost and establishment success by raising seedlings of twelve key native species in three container grade sizes: small, large, and revegetation grade, and tracking their success across five sites around Rotorua, in the Central North Island of New Zealand. After two-year post-planting, we found that high-quality sites and larger container systems tended to promote higher survival and faster early growth (plant height and root collar diameter). Some species, such as Kunzea ericoides and Leptospermum scoparium, survived and grew well (> 75%) even when raised in small container sizes. Other species such as Sophora microphylla had very low survival (< 25%) even when raised in revegetation container grade sizes. If the quality of the planting site is high, the container size seems to be less important for most species. Other species such as Aristotelia serrata, Cordyline australis, Plagianthus regius and Podocarpus totara appear to depend more on site quality. In conclusion, nursery container systems for raising New Zealand native plants should be chosen based on the biology of the species, nursery management practices, quality of the planting site, and a balance between cost and benefit for each situation.

Snowpack in the Northern Hemisphere is gradually disappearing due to rising global temperatures. Snowmelt water is a critical water resource for vegetation in the arid areas of the Northeast Tibetan Plateau. We used a random forest model to analyze the main factors influencing tree growth and using structural equation modelling to examine the pathways through which snowpack affected vegetation growth. The results show that soil moisture, controlled by snowmelt water, dominates the radial growth of Qinghai spruce (Picea crassifolia Kom.). At the same time, snow melt on vegetation is affected by both elevation and land cover. Atmospheric circulation patterns regulated by North Atlantic sea surface temperatures determine spring snowpack variability in this area. In future scenarios based on the Coupled Model Intercomparison Project Phase 6 (CMIP6) simulations, snowpack will continue to decrease, presenting significant constraints to the growth of vegetation.

Nitrogen and phosphorus (NP) deposition can change the nutrient input of forest ecosystems. The effects of NP deposition on soil aggregate need to be analyzed to propose effective environmental management strategies. In this study, representative Korean pine mixed forests and Korean pine plantations in northeastern China were selected. Soil samples were sieved to obtain four different particle sizes of soil aggregates (> 2, 2–0.25, 0.25–0.053, and  < 0.053 mm). Four NP treatments were applied to simulate N and P deposition, and an indoor incubation experiment was conducted over a period of 360 d. Total nitrogen, microbial nitrogen, dissolved organic nitrogen, hydrolyzed nitrogen, NH₄⁺–N, NO₃⁻–N content, and extracellular enzyme activities of NAG, LAP, and AP were determined. Different fractions of N responded differently to NP addition. Lower NP addition had a greater promoting effect on aggregate N compared to higher NP addition. NAG was the main extracellular enzyme affecting N in both forest types. NP addition had a greater effect on the extracellular enzyme activities of the soil aggregates from the Korean pine plantations. These results enhance our understanding of the effects of NP addition on soil nitrogen within temperate forest ecosystems.

Climate change is a global phenomenon that has profound impacts on ecological dynamics and biodiversity, shaping the interactions between species and their environment. To gain a deeper understanding of the mechanisms driving climate change, phenological monitoring is essential. Traditional methods of defining phenological phases often rely on fixed thresholds. However, with the development of technology, deep learning-based classification models are now able to more accurately delineate phenological phases from images, enabling phenological monitoring. Despite the significant advancements these models have made in phenological monitoring, they still face challenges in fully capturing the complexity of biotic-environmental interactions, which can limit the fine-grained accuracy of phenological phase identification. To address this, we propose a novel deep learning model, RESformer, designed to monitor tree phenology at a fine-grained level using PhenoCam images. RESformer features a lightweight structure, making it suitable for deployment in resource-constrained environments. It incorporates a dual-branch routing mechanism that considers both global and local information, thereby improving the accuracy of phenological monitoring. To validate the effectiveness of RESformer, we conducted a case study involving 82,118 images taken over two years from four different locations in Wisconsin, focusing on the phenology of Acer. The images were classified into seven distinct phenological stages, with RESformer achieving an overall monitoring accuracy of 96.02%. Furthermore, we compared RESformer with a phenological monitoring approach based on the Green Chromatic Coordinate (GCC) index and ten popular classification models. The results showed that RESformer excelled in fine-grained monitoring, effectively capturing and identifying changes in phenological stages. This finding not only provides strong support for monitoring the phenology of Acer species but also offers valuable insights for understanding ecological trends and developing more effective ecosystem conservation and management strategies.

Tropical forests, critical for global carbon storage and biodiversity, are failing to adapt at the pace required by accelerating climate change. A comprehensive study by Aguirre-Gutiérrez et al. (Science 387:eadi5414, 2025) analyzing four decades of data from 415 forest plots and 250,000 trees across the Americas reveals significant mismatches between functional trait shifts (e.g., leaf area, wood density, photosynthetic capacity) and climatic pressures. Survivor trees tracked climatic changes at less than 8% of the necessary rate, while recruits achieved only 22%, leaving ecosystems increasingly vulnerable. Lowland forests exhibited stronger trait responses compared to nutrient-limited montane forests, but neither aligned with future climate projections. By 2100, projected temperature rises (~ 4 °C) and precipitation declines (~ 20%) may push forests into “no-analog” climates, surpassing adaptive thresholds. These lags threaten carbon sequestration, biodiversity, and ecosystem stability, underscoring the urgent need for emissions reduction, conservation of climate refugia, and assisted migration strategies to mitigate irreversible biome transitions.

Both abiotic conditions and management influence the success of forest restoration. Despite growing interest and practical effort in restoring degraded forest landscapes, understanding of how disparate factors, such as terrain, soil conditions, climate and silvicultural treatments, directly or collectively control species performance and shape community recovery remains limited. In this study, we assessed how topography and management intervention affect seedling survival and growth in the early stages of restoration. To do so, we established seven experimental plots, each measuring 20 m × 20 m (400 m²) subdivided into 48 subplots, in coarse, anthropogenic grassland on a mid-elevation mountain slope in Hong Kong, and planted a total of 3975 native tree seedlings belonging to 12 tree species within them. To characterise topography, we modelled the elevation, slope, convexity and aspect of each subplot. Two types of tree guard (enclosed blue plastic sleeve and open yellow mesh), two types of fertiliser (organic and inorganic) and cardboard weeding mats were used to assess the impact of management interventions on the establishment of the seedlings. Survivorship, height and basal diameter were measured at 1, 2 and 4 years after planting. We used generalised linear models to examine the effect of these factors and their interactions on seedling survival, and we applied linear models and hierarchical partitioning to explore their relative importance in determining the relative growth rate (RGR) of each species. The most parsimonious models were selected using the Akaike Information Criterion. Survivorship was 98.1%, 95.2% and 86.4% across all plots in the first, second and fourth year, respectively. On average, topographic and management variables explained 1.48–3.34% of total variation in RGR, respectively, for all species. The models revealed that type of tree guard, aspect and elevation were the most important factors explaining RGR and survival. Results of hierarchical partitioning by species and growth period showed that the key determinants of performance vary by species and shift over the course of early seedling establishment, emphasising the importance of both spatial and temporal scales in the restoration of degraded tropical forests. Our findings support the use of enclosed tree guards and fertiliser to improve survivorship and growth across a range of broadleaved Asiatic species. All potential limiting factors pertaining to both site factors and management, as well as their interactions, should be considered in restoration planning to maximise restoration success.

Soil microbial communities play a crucial role in forest ecological processes, but the differences between rhizosphere and non-rhizosphere soils, as well as their variations with stand ages remain unclear. We collected rhizosphere and non-rhizosphere soils in Castanopsis hystrix plantations at ages (6, 10, 15, 25, 30 and 34 years) in the southern subtropics and analyzed soil microbial communities using the phospholipid fatty acid (PLFA) method. There were significant differences in microbial communities between the two. Rhizosphere soils had higher total PLFAs and fungal to bacterial (F:B) ratios, and lower arbuscular mycorrhizal fungi to ectomycorrhizal fungi (AMF:EMF) ratios in the 34-year-old stand but microbial communities in non-rhizosphere soils showed no changes with stand age. Rhizosphere soils had higher total PLFAs and F:B ratios but lower AMF:EMF ratios. Further analysis revealed a strong correlation between fine root nutrients and rhizosphere soil PLFAs, indicating a closer interaction between root exudates and microbial communities. In contrast, non-rhizosphere soil PLFAs appeared to be more influenced by soil nitrogen availability. Overall, soil microbial communities exhibited significant differences between rhizosphere and non-rhizosphere soils over various stand ages. A strong correlation was observed between rhizosphere soil PLFAs and fine root nutrients, which may improve our understanding of forest management strategies.

Texas experienced the worst drought in its 100-year history in 2011, resulting in the death of approximately 300 million trees. The high number of sudden deaths had a significant impact on forest ecosystems. This study aimed to gain insight into the long-term and combined impacts of drought-induced forest tree deaths and their effects on biomass. This study used data obtained from 1797 National Forest Inventory (NFI) plots to analyze trends and major causes of changes in tree biomass at the sample plot level in East Texas forests over the past 20 years (2000 − 2019). In this study, forest trees in East Texas were divided into diameter at breast height (dbh), height, stand types, latitude, elevation, ecological zones, and FIA Unit. Principal component analysis (PCA) was also performed using drought intensity, drought duration, the four competing factor indicators, and the biomass loss rate of forest trees to better understand r drought impacts on forest trees. The results showed the lowest biomass loss rate of Pine species. Similarly, trees with shorter height and smaller dbh experienced a higher biomass loss rate. A higher biomass loss rate was observed in natural forests, West Gulf Coastal Plain and Plain and Southern East Texas ecoregion experienced higher biomass loss. Principal component analyses of drought intensity, drought duration, and the four competing metrics revealed that overall drought was the main contributor to biomass loss rates, and that drought intensity and drought duration had comparable effects on biomass loss rates.

While the fire protection function of tree bark has been extensively documented, other critical functions, including storage and mechanical support, have received less attention. In this study we examined: (1) the allometry of bark thickness (and biomass) against wood radius (and biomass) at a disc level, (2) differences in bark allocation between the ratio and the regression approaches, (3) differences between bark thickness and biomass as metrics of bark allocation, and (4) how bark allocation is associated with the evolution of wood from non-porous to diffuse-porous and ring-porous types. Thickness and biomass of bark and wood were measured using trunk discs of 88 individual trees of 36 species in a temperate forest characterized by a long fire interval. Allometric relationships of bark thickness (and biomass) against wood radius (and biomass) explained why both relative bark thickness and biomass decreased with increasing stem diameter. Variations in both among species varied by factors of 3.5 to 7.5 depending on the measurement methods. The ratio approach produced higher estimates of both relative bark thickness and biomass compared to the regression approach, while relative bark thickness was significantly lower than relative bark biomass. Ring-porous species exhibited higher bark thickness based on the ratio approach, which might reflect evolutionary adaptations where ring-porous species have developed thicker bark as protection: thermal insulation against freeze–thaw embolism coupled with carbohydrate reservoirs for hydraulic repair. The regression slope of bark allocation against wood density increased along the wood porosity gradient, demonstrating evolutionary biomechanical coordination between bark and wood. These findings highlight systematic coupling between bark and xylem multifunctionality.

The duration of snow cover has shortened in the boreal region, and the amount of seasonal snow decreased. This affects the coupling between soil and air temperatures and may thus lead to colder soil and deeper soil frost. We prevented snow reaching the forest floor for two winters in mature boreal forest and studied how that affects tree and forest floor processes. The studied species were Scots pine, Norway spruce, silver birch, and a dwarf shrub bilberry. Decreased soil temperature, due to the lack of snow cover, decreased forest floor respiration in winter and spring. Simultaneously, response of respiration to temperature seemed to increase, perhaps due to the exposure of forest floor vegetation to cold air temperature. Indeed, lack of snow cover induced mortality of bilberry, but the remaining ramets grew more in height and their average leaf size was larger likely to compensate for the lost plant biomass. Lack of snow cover also affected tree hydraulics as tree water uptake was decreased in spring, and the start of the sap season delayed in birch. Pine and birch tended to grow less in the snow exclusion treatment (differences not statistically significant), whereas spruce grew more. Coarse root traits, e.g. water content and cellular frost damages, were not affected by the snow exclusion treatment. The results of this case study increase our understanding on the effects of changing snow cover on spring-time tree and forest floor processes in mature boreal forest, but also reveal the need for further studies on mature trees.

Forest ecosystems are among the most important and play a vital role in maintaining ecological balance and supporting biodiversity. Integrated forest management (IFM) has gained prominence in European countries as a strategy to meet human needs for ecosystem services while ensuring biodiversity conservation. Given the complementary strengths of China and the European Union (EU) in forestry and the potential for collaboration, it is beneficial to compare and analyze the research status of both in IFM-related fields to provide insights into key areas and future directions for cooperation. This study employs bibliometric analysis to systematically evaluate IFM-related research status and trends between China and the EU. By examining publication trends, collaborative networks, prominent scholars, keyword co-occurrence patterns, research hotspots, and thematic clusters, providing a comprehensive overview of IFM-related research. The findings reveal that core research areas—such as forest management practices, ecosystem services, biodiversity conservation, and data-driven assessment methods—remain central to IFM-related research. In contrast, frontiers in climate change mitigation, disturbance and restoration dynamics, and multi-stakeholder governance represent critical areas for future exploration and collaboration. Our results provide areas for enhancing China-EU collaboration in future research in IFM.

The restoration of severely fragmented forests requires urgent guidance from succession theory. New theories and methods in plant functional ecology offer novel perspectives on the mechanisms that drive forest succession and productivity. Here, we established a restoration gradient of seven forest logging periods in temperate forests in China, and conducted systematic surveys on the leaf functional traits of all observed plant species, plant community structure, and soil properties. Inspired by the new concept of two-dimensional plant community traits (i.e., efficiency and quantity traits) and plant trait networks (PTNs), we explored the adaptation mechanisms of forest communities along a restoration succession and their relationship to productivity. Efficiency and quantity traits initially increased and then stabilized, whereas multi-trait relationships (MR) exhibited fluctuations, with community resource utilization efficiency increasing initially before stabilization. As expected, productivity is poorly explained by either efficiency or quantity traits alone but is substantially better explained by their joint consideration as two-dimensional community traits. Among these, the efficiency and quantity traits of leaf area and leaf dry weight can explain up to 43% of productivity. Furthermore, MR exhibit a time-lag effect on productivity. A structural equation model (SEM) with time-lag analysis showed that efficiency traits, quantity traits, MR, and soil properties explained 64% of the spatial variation in productivity during forest succession. Efficiency and quantity traits directly regulated productivity, whereas soil properties and MR indirectly regulated productivity. Our findings are the first to demonstrate the regulation mechanisms between forest succession and productivity from the framework of efficiency traits–quantity traits-MR, providing theoretical guidance and a reference for ecological restoration, and predicting the spatial variation of forest productivity, especially at small scale.

Planting genetically improved, fast-growing tree seedlings is gaining importance as a strategy to enhance forest productivity and reduce labor requirements during plantation establishment. In this study, we evaluated the early growth and survival of advanced-generation Cryptomeria japonica seedlings compared to conventional stock, under varying planting densities and cultivation methods. A field experiment was conducted over 5 years using container-grown and bare-root seedlings derived from first- and second-generation plus trees, alongside traditional seedlings. The results showed that advanced-generation seedlings exhibited higher growth in tree height, stem diameter, and crown development than traditional seedlings, particularly when planted as container stock. These seedlings also had higher survival rates, likely due to their rapid initial height growth, which reduced the risks of accidental damage during weeding operations. Wider planting intervals increased the risk of man-made injury and seedling mortality, while faster-growing seedlings were more likely to escape from competing vegetation. Our findings highlight the potential of improved seedling stock to enhance early plantation success and reduce management inputs in the critical establishment phase of forestry.

Nitrogen (N) deficiency is a critical factor limiting natural regeneration in coastal shelterbelt forests, but the influence of different N forms on seedling establishment under varying light conditions remains poorly understood. This study investigated the effects of N forms and N concentrations on Ligustrum compactum seedlings under simulated canopy gap conditions using a three-factor design: N form (NO₃^⁻-N, NH₄⁺-N, mixed N), N concentration (30 and 60 kg ha^⁻1 a^⁻1), and light intensity (30%, 60%, and 90% full sunlight). Results showed that N addition significantly promoted seedling growth, net photosynthesis rate, and water use efficiency; however, the effects varied among N forms and concentrations. Overall, NO₃⁻-N or mixed N were more favored by L. compactum seedlings; however, the N preference was altered by light intensity and N concentration. For instance, L. compactum showed greater NO₃⁻-N or mixed N preference under low and medium light intensities, while displaying more NH₄⁺-N preference under high light intensity. N concentration also affected the growth and N preference of L. compactum seedlings, but the variance explained by N concentration was lower than that of light intensity. Leaf C, N, P stoichiometry exhibited stronger correlations with seedling’s morphological trait plasticity than those of leaf gas exchange, and further analysis demonstrated that leaf C:P and N:P were the top two critical factors affecting seedling growth, indicating that the coordination and balance among C, N, P elements were more important in explaining the seedling growth under N addition. Therefore, our results clarified that the N preference of L. compactum seedlings could be altered by light intensity and revealed that leaf C, N, P ratios were stronger predictors than leaf gas exchange parameters for explaining the N effects on seedling performance. These findings demonstrated the mechanisms of light-N interactions affecting seedling performance, providing practical guidance for optimizing N fertilization and improving natural regeneration in canopy gaps of degraded coastal shelterbelt forests.

Radial growth of trees is highly sensitive to environmental changes, but the effect of climate on tree rings in Qinghai spruce (Picea crassifolia), a widely distributed endemic conifer in western China, is more complex than in many other conifers. A comprehensive understanding of the spatiotemporal climatic responses of its rings is needed to develop theoretical basis for designing strategies for its conservation and management. Here, our synthesis of the literature on responses of radial growth of Qinghai spruce to monthly climate variables in different environmental conditions by meta-analysis showed that precipitation and drought severity are the main limiting factors for Qinghai spruce radial growth in the semiarid region of northwestern China. In warmer and drier areas, radial growth of Qinghai spruce is mainly limited by drought. In the areas north of the 600-mm annual precipitation isoline, the tree-ring width (TRW) was significantly positively correlated with precipitation and significantly negatively correlated with temperature during the growing season (June–August). The limiting effect of drought on Qinghai spruce is also gradually increasing from southeast to northwest, to the west of 103° E and within 37° N–39° N.

Forest ecosystems are critical to ecological stability, yet their functionality is increasingly threatened by the growing frequency of drought, particularly in arid and semi-arid regions. While afforestation enhances forest cover in these areas, the capacity of planted forests to adapt to climate change is poorly understood. This study examines the drought resistance and adaptive capacity of planted and naturally growing Schrenk spruce (Picea schrenkiana Fisch. & C. A. Mey.) in the Ili River Basin, Xinjiang, China using tree-ring analysis. The results indicate that natural stands have a stronger correlation with meteorological factors than plantations. Over the past 50 years, significant growth declines occurred during 1995–1997, 2007–2009, and 2012–2014, with natural forests showing a greater frequency and severity of declines compared to plantations. Planted stands demonstrated greater resistance to drought, whereas natural forests had higher resilience and recovery. Over time, natural forests have shown declining resistance to drought but increased resilience and recovery. Conversely, plantations showed declines in resistance and recovery but an increased capacity for recovery. Older natural forests are more prone to growth decline, while structurally simpler planted forests show stronger drought resistance. However, following periods of drought, natural forests demonstrated a stronger capacity for recovery. These findings provide valuable insights into the response of P. schrenkiana to climate change and offer support for the sustainable management and conservation of forest ecosystems in the Xinjiang region of China.

Norway spruce (Picea abies (L.) Karst.) in the Harz Mountains National Park (Germany) has experienced widespread mortality (> 97% of trees in the study stands) due to infestation with the large spruce bark beetle (Ips typographus L.). The dead trees (snags) remain standing in the forest for 2–5 years before harvesting. It is important to identify trees that can still produce quality timber, which may be achieved by examining their outer appearance using selected characteristics. The aim of this study was to identify possible correlations between the standing storage duration and defined external characteristics of the snags. The mean tree height at compartment level was calculated using a vegetation height model, based on light detection and ranging data from 2018, to derive the stem breakage proportion. The condition of the crown and the bark and presence of fungi, wood rot, stem cracks and bark stripping damage were also assessed. The majority of the snags were broken at least once. Windthrows were less likely compared to living spruce trees because of reduced resistance to the wind as a result of needle loss and breakage. The mean stem breakage proportion increased significantly with the duration of the standing storage; however, prolonged storage durations did not always lead to complete breakage. The occurrence of fungal fruiting bodies was significantly correlated with a higher proportion of stem breakage, and the longer the storage, the more snags had fungal fruiting bodies. The condition of the crown, assessed by the presence of branchlets, was a good indicator of the duration of the standing storage. If trees had few or no branchlets, they had been standing for at least 4 years. Overall, this initial description of the external appearance of spruce trees that have been stored standing for many years suggests that time significantly influences the tree condition and breakage intensity, which is reflected by certain tree characteristics. Future studies should examine these aspects in greater depth, particularly with regard to utilization options and safety during timber harvesting.

This study looks at the impact of climate change on the future distribution of Taxus baccata L., a species under threat. It examines how altitudinal changes may influence distribution, projecting scenarios to 2100 using the SSPs 585 SSPs 245 scenarios in 20-year intervals. The results show a contraction in distribution in areas such as in Iceland and the United Kingdom, with certain extreme points disappearing. Simultaneously, new suitable areas are expected to emerge in select regions of Asia. The study underscores the significant changes anticipated in the distribution of T. baccata due to global climate change. It suggests that the threshold for addressing climate change on this particular species has been exceeded, and emphasizes the need for concerted efforts to mitigate and adapt to climate change impacts on ecosystems and organisms. As climate change affects various aspects of life, the study advocates for sector-wide plans. These would include efficient resource utilization, selecting genotypes for afforestation of this species with lower water requirements, incorporating climate change predictions into management plans, conserving biological and genetic diversity, and developing in-situ and ex-situ conservation strategies. Anticipation of future climate changes and corresponding measures in response are crucial to minimizing the impact on this species. The study recommends establishing mixed forests composed of species resilient to a range of climate scenarios, thereby enhancing forest continuity across regions with varying degrees of climate impact. Genetic diversity is an important defense mechanism important to preserving it. Global climate change will result in significant alterations in the distribution of certain species, potentially causing population declines. Intervention is required to support the adaptation of vulnerable species, necessitating forward-looking strategies that anticipate shifts in their habitat suitability. This study emphasizes the implications of climate change for T. baccata and underscores the urgency of targeted conservation efforts to protect its populations and ensure long-term persistence.

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Corresponding editor: Tao Xu.

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Tree plantations in the tropical-subtropical transition zone (TSTZ) represent crucial ecological regions where diverse biomes converge. Investigating the carbon sequestration potential and dynamic changes within these plantation ecosystems is of considerable ecological significance. However, the spatial distribution, driving factors, and underlying mechanisms of carbon sequestration in plantations in this region are poorly understood, thereby limiting accurate assessments of their carbon sequestration potential. This study examines four types of plantation forests located within the TSTZ on the Puwen forest farm of Xishuangbanna, China. Two slope gradients were established to quantify and compare the rate of carbon sequestration across these ecosystems. Using random forest modeling and structural equation modeling, the study identifies key environmental factors influencing the rate of carbon sequestration in the plantations. The results reveal substantial variation in DBH growth rates, biomass carbon sequestration, and soil organic carbon sequestration rates (R_SOC) among the four forest types. Critical factors affecting R_SOC include leaf nitrogen and phosphorus concentrations (LP), total soil nitrogen (STN), total soil phosphorus (STP), soil available phosphorus, and nitrogen concentration in ground surface litter. Among these, STN and STP exerted positive effects on R_SOC, while LP is exerted negative. Overall, the concentration of soil carbon, nitrogen and phosphorus, along with the nitrogen and phosphorus levels in leaves, under different species and topographic slopes, play decisive roles in regulating soil carbon sequestration rates in tropical and subtropical plantations. This research provides support for vegetation protection and restoration in ecologically sensitive areas and watersheds, contributing to the enhancement of regional forest carbon sequestration capacity.

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Corresponding editor: Tao Xu.

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Although Quercus mongolica is a widely distributed, economically and ecologically important deciduous tree in northern China, models to accurately predict stand growth at a regional scale are limited. The physiological process model (3-PG) has the potential to predict stand growth dynamics under varying site conditions and climate change scenarios. Here, we used field inventory, tree ring sampling, and Bayesian calibration to parameterize a model for Q. mongolica. Stand volume and productivity were then predicted under present conditions and three future climate scenarios (RCP26, RCP45 and RCP85). Our results demonstrated that after Bayesian calibration, the posterior ranges of the sensitivity parameters aphaCx, wSx1000 and pRn accounted for 34%, 45% and 65%, respectively, of their prior range. Calibration and validation results revealed a strong correlation between predicted and measured values (R² > 0.87, P < 0.01), with < 20% bias for all growth indicators. Stand volume was projected to increase by 145% and productivity by 80% by the year 2100 under the RCP85 scenario, although these projections may vary across regions. The present study developed a tailored set of 3-PG model parameters for Q. mongolica, based on a comprehensive range of climate conditions, stand structure, and age classes. These parameters offer a scientific basis to accurately predict growth of other monospecific oak or mixed-species stands.

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Corresponding editor: Tao Xu

The online version contains supplementary material available at https://doi.org/10.1007/s11676-025-01892-1.

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Biodiversity has always been valued by ecology, Diversity is generally believed to lead to stability, and biodiversity is an important condition for ecosystems to maintain health. So what factors are related to forest ecosystem biodiversity, and what kind of forest structure affects and determines the size of biodiversity. This study proposes the concept of contained uniformity based on the theory of uniformity, and uses the convergence of contained uniformity to obtain the judgment model of the forest station pattern type. At the same time, it proposes the concept of forest ecosystem distance diversity, and uses the judgment model of the stand pattern type to derive the mathematical definition of forest ecosystem distance diversity. Combining the ecological characteristics of different stand patterns and measurement indicators of forest ecosystem biodiversity, the connection between forest ecosystem distance diversity and biodiversity is derived, and this is used as an indicator to evaluate forest ecosystem biodiversity. Forest ecosystem distance diversity, as an indicator of biodiversity, can not only conduct early assessment and prediction of the biodiversity of immature forests (forests in the early succession or recovery stage), but also provide a quantitative basis for forest structure optimization. Ultimately realize the sustainable development of forestry production and operation and biodiversity protection.

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Corresponding editor: Lei Yu.

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Stress in plants refers to adverse changes in their functioning. The occurrence and intensity of a stress can be assessed by alterations in plant traits, termed stress indicators. The ultimate goal of this study was to test whether six morpho-physiological plant traits, frequently used as stress indicators, respond consistently across species to various environmental stressors, with the aim of detecting universal stress indicators in forest tree species. We examined changes in vertical increment, leaf/needle size, shoot length, needle longevity, photosynthetic efficiency and fluctuating asymmetry in three common European tree species, mountain birch (Betula pubescens var. pumila), Norway spruce (Picea abies) and Scots pine (Pinus sylvestris) along three environmental gradients (elevation, pollution and seashore) from forests to stressful open environments. Data were collected in 2003, 2004 and 2005 from 297 trees growing naturally across 36 sites in north-western Russia. Fluctuating asymmetry was the only trait that did not vary among sites with differing levels of environmental stress. Leaf/needle size and shoot length occasionally changed along stress gradients, but the magnitude and direction of these changes differed by gradient type and species, resulting in no significant overall stress effect for either trait. In contrast, photosynthetic efficiency, vertical increment and needle longevity consistently decreased from low-stress to high-stress sites. The overall effect was significant for each of these three traits despite the magnitudes of these decreases differed depending on the gradient type and location, species, study year and individual tree. Replication at spatial, temporal and taxonomic levels ensured the robustness and reliability of our results that photosynthetic efficiency, vertical growth and needle longevity reliably captured a general stress syndrome and may serve as stress indicators in forest species.

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Corresponding editor: Tao Xu

The online version contains supplementary material available at https://doi.org/10.1007/s11676-025-01891-2.

Spring phenology is one of the most sensitive ecological indicators of forest responses to climate warming. Understanding the precise climatic drivers of bud break in keystone species is crucial for developing robust phenological models and predicting future ecological and economic impacts. In this study, spring bud phenology was recorded 2020–2022 of 42 provenances of sugar maple (Acer saccharum Marsh.) originating from the northern range of the species in Quebec, Canada. The effect of temperature on budburst timing was assessed, and based on the observed linear relationship, we reconstructed the budburst timings of maple forests located between 45° and 49°N latitude and –70° and –76°W longitude over the past two decades. In the common garden the entire bud break process lasted between 20 and 40 d. Bud swelling occurred mid-April to mid-May, on average 5 d earlier in the southern and warmer stands. A strong correlation was observed between bud swelling dates and mean temperatures in the last two weeks of April, with temperature explaining 90% of the variance. An increase of 1 °C in mean temperature during this period advanced budburst by 4 d. At the northern limit of sugar maple, late April had an average temperature between 1.6 and 8.7 ℃ during 2003–2022, resulting in an estimated variability of 28 d in bud swelling from early April to early May. Our findings confirm that late April temperatures play a major role in the reactivation of sugar maple at its northern range. The earlier onset of leaf development under warming conditions could increase the risk of late frost damage, with consequences for maple syrup production and species distribution.

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Corresponding editor: Tao Xu.

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Upper Andean tropical forests are renowned for their extraordinary biodiversity and heterogeneous environmental conditions. Despite the critical role of litter decomposition in carbon and nutrient cycles, its dynamics in this region remains unexplored at finer scales. This study investigates how microsite conditions influence litter decomposition of 15 upper Andean species over time. A reciprocal translocation field experiment was conducted over 18 months in 14 permanent plots within four sites in Colombian Andean mountain forests. Each plot contained three litterbeds (microsites), each with the 15 species, harvested at 3, 6, 12 and 18 months, totaling 2520 litterbags. Different forest variables, including canopy openness, leaf area index, slope and depth of litter, were measured in each litterbed. ANOVAs and linear mixed models were used to assess variation between sites and plots respectively, while multiple linear regression analyses evaluated the effects of forest variables on decay rates over time at the microsite scale. Results showed differences in absolute decay rates between sites but consistent relative decay rates, indicating varying magnitudes of decomposition, yet maintaining the same order based on their litter quality. Decay rates varied between species, with more variation in labile species compared to recalcitrant ones. Despite substantial variation in forest characteristics within sites, their influence on litter decomposition was minimal and declined over time. This suggests that, at finer spatial scales, the forest microenvironment plays a lesser role in litter decomposition, with litter quality emerging as the primary driver. This study is a step towards understanding the fine-scale dynamics of litter decomposition in upper Andean tropical forests, highlighting the intricate interplay between microenvironmental factors and decomposition processes.

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Corresponding editor: Shuxuan LI

The online version contains supplementary material available at https://doi.org/10.1007/s11676-025-01887-y.

Xishui National Forest Park in Heilongjiang Province hosts China’s most pristine temperate forests and serves as a key site for ecotourism and forest therapy. However, the emission patterns of phytoncides (key bioactive compounds) remain poorly understood, limiting their therapeutic application. This study provides the first comprehensive characterization of spatiotemporal dynamics in airborne phytoncides and their synergistic interactions with environmental factors throughout the autumn-early spring seasonal transition in a temperate forest ecosystem. We analyzed the compositional dynamics of phytoncides and terpenoid content variations using thermal desorption-gas chromatography-mass spectrometry (TD-GC-MS) from September 2024 to March 2025. This period encompassed seasonal transitions from autumn to early spring, including diurnal variations in September and snowfall events in November. The method demonstrated detection limits (LODs) ranging from 1.35 to 5.33 ng m⁻³ and quantification limits (LOQs) from 4.09 to 16.15 ng m⁻³. Our results revealed pronounced seasonal fluctuations in phytoncide composition. In September, terpenoids, esters, alcohols, and alkanes displayed a diurnal “decrease-increase” trend, whereas aldehydes and ketones peaked at midday. Notably, esters and alcohols were undetectable in November and January. By January, terpenoids reached their lowest proportion (0.17 ± 0.02%) at noon. Five terpenoids (α-pinene, myrcene, D-limonene, camphene, p-cymene) were detected in September, four (α-pinene, D-limonene, camphene, p-cymene) in November, two (D-limonene, p-cymene) in January, and only p-cymene in March. The total concentration and emission rate of the five terpenoids peaked in September afternoons at 1961.58 ± 106.67 ng m⁻³ and 653.86 ± 35.56 ng m⁻³ h⁻¹, respectively. Nocturnal emissions (32131.95 ± 2522.21 ng m⁻³) significantly surpassed daytime levels (14473.04 ± 958.49 ng m⁻³), with emission rates escalating from 1447.30 ± 95.85 ng m⁻³ h⁻¹ (day) to 5355.33 ± 420.37 ng m⁻³ h⁻¹ (night), marking a 3.7-fold increase. Snowfall dramatically elevated terpenoid concentrations (pre-snowfall: 158.58 ± 14.12 ng m⁻³; post-snowfall: 1080.57 ± 57.76 ng m⁻³) and emission rates (pre-snowfall: 52.86 ± 4.71 ng m⁻³ h⁻¹; post-snowfall: 360.19 ± 19.25 ng m⁻³ h⁻¹), reflecting a 6.8-fold surge. This study underscores the profound influence of light intensity, seasonal shifts, and climatic conditions on airborne phytoncide levels, offering a scientific foundation for optimizing forest therapy and ecotourism strategies.

The online version is available at https://link.springer.com/.

Corresponding editor: Lei Yu.

Cryptorhynchus lapathi L., a globally distributed wood-boring pest, significantly threatens poplar (Populus spp.) and willow (Salix spp.) trees. Entomopathogenic fungi (EPFs), particularly Beauveria bassiana (Bals.-Criv.) Vuilla, play a crucial role in integrated pest management because of their broad-spectrum insecticidal properties. This study clarifies the pathogenic mechanisms of B. bassiana CFCC81428 treatment and its oil-based formulation against male and female C. lapathi adults, alongside their impacts on cumulative mortality, enzyme activity and nutrient metabolism. The results indicated that the oil-based formulation significantly enhanced B. bassiana pathogenicity, achieving cumulative mortality rates of 91.7% and 83.8% for male and female adults, respectively, with LT₅₀ values of 7.9 and 8.7 d, markedly outperforming the B. bassiana treatment. Scanning electron microscopy revealed that the oil-based formulation improved spore adhesion to the insects’ cuticle, accelerated spore germination and hyphal growth, and significantly improved cuticular penetration efficiency. Within the host, the activities of detoxification enzymes (GST and CarE) were upregulated, whereas the activities of catalase and peroxidase enzymes were suppressed. Superoxide dismutase activity remained elevated throughout most of the observation time points. Polyphenol oxidase activity significantly increased between 24 and 120 h postinfection, indicating its critical role in preventing B. bassiana invasion. The infection also triggered substantial shifts in the host’s nutrient metabolism, with time-dependent changes observed in carbohydrates, free fatty acids, and soluble proteins. The oil-based formulation exacerbated the depletion of these nutrients, ultimately leading to metabolic collapse. This study indicates that the oil-based formulation optimizes spore germination conditions and accelerates infection, thereby significantly increasing B. bassiana pathogenicity in C. lapathi males, whereas female adults exhibited stronger physiological and metabolic responses, providing new insights for the application of B. bassiana in the biological control of pests.

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Corresponding editor: Tao Xu.

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Allometric equations are fundamental tools in ecological research and forestry management, widely used for estimating above-ground biomass and production, serving as the core foundations of dynamic vegetation models. Using global datasets from Tallo (a tree allometry and crown architecture database encompassing thousands of species) and TRY (a plant traits database), we fit Bayesian hierarchical models with three alternative functional forms (power-law, generalized Michaelis–Menten (gMM), and Weibull) to characterize how diameter at breast height (DBH), tree height (H), and crown radius (CR) scale with and without wood density as a species-level predictor. Our analysis revealed that the saturating Weibull function best captured the relationship between tree height and DBH in both functional groups, whereas the CR–DBH relationship was best predicted by a power-law function in angiosperms and by the gMM function in gymnosperms. Although including wood density did not significantly improve predictive performance, it revealed important ecological trade-offs: lighter-wood angiosperms achieve taller mature heights more rapidly, and denser wood promotes wider crown expansion across clades. We also found that accurately estimating DBH required considering both height and crown size, highlighting how these variables together distinguish trees of similar height but differing trunk diameters. Our results emphasize the importance of applying saturating functions for large trees to improve forest biomass estimates and show that wood density, though not always predictive at broad scales, helps illuminate the biomechanical and ecological constraints underlying diverse tree architectures. These findings offer practical pathways for integrating height- and crown-based metrics into existing carbon monitoring programs worldwide.

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Corresponding editor: Lei Yu.

The online version contains supplementary material available at https://doi.org/10.1007/s11676-025-01898-9.

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Tree plantations are globally significant, and therefore, growth-related challenges cannot be ignored. Canopy structure and light environment influence the growth of plantations, but the precise relationship remains unclear. We selected seven-year-old poplar plantations of varying cultivars planted various densities and measured their growth, canopy structure, and light environment. The findings indicate that poplar plantations of different cultivars and at different planting densities showed variations in leaf area index (LAI), average leaf angle (ALA), crown length (CL), length ratio (CLR), roundness (CR) and surface area (CSA), which directly or indirectly affect growth, resulting in disparities in their growing conditions. Crown roundness directly impacted growth, while LAI, CLR and ALA influenced growth indirectly by affecting intercellular carbon dioxide concentration. LAI and CLR had a positive effect; ALA had a negative one. Crown length and surface area directly and indirectly influenced growth by affecting photosynthetically active radiation and net photosynthetic rate, with direct impacts being more pronounced. This research has clarified the regulatory role of canopy structure in plantations growth, providing valuable insights for developing more effective management strategies.

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Corresponding editor: Shuxuan Li.

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Peri-urban plantations in the Mediterranean are often degraded due to human inactivity and climate change, leading to a loss of ecosystem services and biodiversity. This study investigates the impact of different thinning practices on carbon sequestration and tree stability in a degraded peri-urban plantation in the Italian Apennines, six years after thinning. Three treatments were compared: (a) moderate thinning from below (− 25% biomass), representing the typical practice; (b) intense selective thinning (-35% biomass), representing an innovative approach; and (c) no management as the control. Growth projections were used to estimate carbon recovery for these treatments, based on site-specific models calibrated with real data. The results show that both thinning approaches increased carbon sequestration over time, with the innovative thinning achieving a 7% higher annual carbon sequestration rate than traditional thinning and 8% more than the control. Estimated payback times were 9 years for recovering the harvested volume in both thinning approaches, 10 years for innovative thinning to surpass traditional thinning, 17 years for innovative thinning to surpass the control, and 24 years for traditional thinning to surpass the control. Additionally, tree mechanical stability improved significantly in both thinning treatments after two years, with further increases observed in the innovative thinning group after six years. These results suggest that selective thinning can accelerate forest recovery and carbon sequestration, especially in areas with high stem density, where it can reduce the negative impacts of tree mortality and deadwood accumulation. However, careful planning is required to mitigate potential short-term stability issues, particularly in challenging environments (e.g., windy conditions, steep slopes). Forest management strategies should therefore aim to balance growth, carbon storage, and tree stability, considering both long-term sustainability and local environmental conditions. The findings are particularly relevant for current climate change mitigation strategies, emphasizing that thinning should be carefully tailored to forest type and conditions to maximize benefits in carbon credit generation and sustainable forest management practices.

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Corresponding editor: Lei Yu.

Springer Nature or its licensor (e.g. a society or other partner) holds exclusive rights to this article under a publishing agreement with the author(s) or other rightsholder(s); author self-archiving of the accepted manuscript version of this article is solely governed by the terms of such publishing agreement and applicable law.

Evaluating the effectiveness of forest restoration projects is crucial for designing adaptive restoration strategies. However, existing studies have primarily focused on ecological outcomes while overlooking cost inputs. This gap can lead to increased uncertainties in restoration planning. Here we investigated forest dynamics in China’s Upper Yangtze River Basin (UYRB) using kernel Normalized Difference Vegetation Index (kNDVI), Leaf Area Index (LAI), Gross Primary Productivity (GPP), Ku-band Vegetation Optical Depth (Ku-VOD) time series and climate data from 1982 to 2020. Subsequently, we employed a residual trend analysis integrating temporal effects to determine the relative contributions of climate change and human activities to forest dynamics before and after the implementation of forest restoration engineering in 1998. Additionally, we developed an Afforestation Efficiency Index (AEI) to quantitatively assess the cost efficiency of afforestation projects. Results indicated that forest in the UYRB showed sustained increases during 1982–2020, with most areas experiencing greater growth after 1998 than before. Temporal effects of climatic factors influenced over 42.7% of the forest, and incorporating time-lag and cumulative effects enhanced climate-based explanations of forest variations by 1.61–24.73%. Human activities emerged as the dominant driver of forest dynamics post 1998, whereas climate variables predominated before this period. The cost-effectiveness of forest restoration projects in the UYRB typically ranges from moderate to high, with higher success predominantly observed in the northeastern and eastern counties, while the central, western, and northwestern counties mainly showed relatively low efficiency. These findings stress the need for assessing forest restoration outcomes from both ecological and cost perspectives, and can offer valuable insights for optimizing the layout of forest restoration initiatives in the UYRB.

The online version is available at https://link.springer.com/.

Corresponding editor: Lei Yu.

Springer Nature or its licensor (e.g. a society or other partner) holds exclusive rights to this article under a publishing agreement with the author(s) or other rightsholder(s); author self-archiving of the accepted manuscript version of this article is solely governed by the terms of such publishing agreement and applicable law.

Soil fertility and forest structure influence tree carbon stocks. However, it remains unclear how tree mycorrhizal types affect these relationships. This study addressed the question of how aboveground and belowground tree carbon stocks in soils with different mycorrhizal types are affected by soil fertility and forest structure. Tree demographic data were used from a 21.12-ha study area collected over a ten-year period (2009–2019), covering 43 species of woody plants and more than 50,000 individuals. Relationships between tree carbon stock, soil fertility and forest structure (stand density, diameter variation, species diversity and spatial distribution) were examined, as well as whether these relationships differed between arbuscular mycorrhiza and ectomycorrhizal mycorrhiza groups in a typical temperate conifer and broad-leaved mixed forest. We found that total tree carbon stock was positively impacted by variations in stand density and tree diameter but negatively influenced by soil fertility, tree species diversity and uniform angle index. Soil fertility promoted carbon stock of trees associated with arbuscular mycorrhiza (AM) but inhibited the carbon stock of trees with ectomycorrhizal mycorrhiza fungi (EcM). Carbon stock of AM trees was mainly influenced by soil fertility, while carbon stock of EcM trees was influenced by stand density. Our findings show that mycorrhizae types mediate the impact of stand structure and soil fertility on tree carbon stocks and provides new evidence on how forest tree carbon stocks may be enhanced based on the types of mycorrhizal associations. Tree species with different mycorrhizal types can be managed in different ways.

The online version is available at https://link.springer.com/.

Corresponding editor: Tao Xu.

The online version contains supplementary material available at https://doi.org/10.1007/s11676-025-01908-w.

Springer Nature or its licensor (e.g. a society or other partner) holds exclusive rights to this article under a publishing agreement with the author(s) or other rightsholder(s); author self-archiving of the accepted manuscript version of this article is solely governed by the terms of such publishing agreement and applicable law.