Annals of Forest Research is a semestrial open access journal, which publishes research articles and notes and critical review papers. Articles are peer-reviewed and should be original, of high scientific quality and of international interest. The journal scope is to cover aspects of both basic and applied research of all domain of forestry sciences and other related sciences, which contribute to forest sustainable management.
"Marin Drăcea" National Research-Development Institute in Forestry
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Sirococcus smithogilvyi: haplotype diversity in Basilicata Region (Southern Italy)
Chestnut phytosanitary emergencies are rising in recent years also due to climate changes, which allow new treats to find favourable environmental conditions in previously unsuitable places and the rapidity of movements which aids their survival. Among the emerging fungal pathogens, Sirococcus smithogilvyi the causal agent of chestnut brown rot (CBR), a very damaging chestnut disease, stands out. Between 2023-2024, S. smithogilvyi was frequently isolated from 1200 nuts collected randomly in three chestnut locations of Basilicata region (Southern Italy) and initially identified based on morphology features. Other fungal taxa were less frequently isolated: Alternaria alternata, Botrytis cinerea, Penicillium sp., Neofusicoccum parvum, Mucor sp., Cladosporium sp. and Trichoderma sp. Sequencing of two common fungal barcodes, the Internal Transcribed Spacer (ITS) region of ribosomal DNA and the β-tubulin (tub2) gene confirmed the morphological identification. Furthermore, phylogenetic analyses of S. smithogilvyi isolates, based on tub2 nucleotide sequences, showed the occurrence of two separate evolutionary lineages in Basilicata, previously recognized as haplotypes A and B. The haplotype A, was predominant registering 86% frequency while the haplotype B registered only a 14% frequency. The prevalent presence of S. smithogilvyi haplotype A (reported to be more aggressive) along with other additional factors could explain the serious damage and the chestnut production losses recorded for the past years in Basilicata, which urges to find and implement suitable measures to control this emerging and very damaging chestnut pathogen.
Copyright (c) 2026 Annals of Forest Research
When native meets exotic: Uncovering hybridization between Cuban and introduced mahogany using chloroplast and nuclear microsatellites
The introduction of closely related species can threaten the genetic integrity of endemic taxa through hybridization and introgression. In Cuba, Swietenia macrophylla was widely planted in the 1970s for its fast growth and high-value timber, raising concerns about its potential genetic impact on the native S. mahagoni and the emergence of hybrids. This study investigates the genetic consequences of introducing S. macrophylla to Cuba by analysing 357 individuals from five populations, including two naturally regenerated S. mahagoni populations, a pure S. macrophylla remnant, and two mixed stands containing both species and morphologically intermediate forms. The two predominant cpDNA haplotypes were shared across all five populations, whereas one mixed stand exhibited the highest diversity, with nine chloroplast DNA haplotypes—suggesting that its establishment involved seeds from multiple sources. cpDNA markers didn't reveal clear species-level differentiation. In contrast, nuclear microsatellites indicated moderate genetic differentiation (mean FST= 0.15±0.02) and substantial within-population variability, with expected heterozygosity (He) ranging from 0.46 to 0.85. At the same time, S. mahagoni showed a higher number of alleles (Na = 12.4–13.3) and expected heterozygosity (He = 0.73–0.78) than the remnant S. macrophylla population (Na = 5.75; He = 0.59), likely reflecting the smaller size of the existing S. macrophylla plantation in Cuba. Based on discriminant analysis of principal components and STRUCTURE results, the two parental species were clearly separated into distinct genetic clusters, while putative hybrid individuals were mainly concentrated in the two mixed stands. Leaf morphological and molecular classifications were highly concordant in parental populations (≈91%), confirming the phenotypic identifiability of S. mahagoni and S. macrophylla. The estimated proportion of hybrids varied: STRUCTURE (7.8–15.1%), whereas NewHybrids (36.1–39.2%). These findings provide a genetic framework for conservation-oriented management of native tree species, which is a tool for implementing long-term genetic monitoring and consolidating certified germplasm banks to safeguard the native Cuban mahogany.
Overstory stability, growth and regeneration across ten years after shelterwood cuts in Nothofagus pumilio stands from Tierra del Fuego (Argentina)
Nothofagus pumilio is a native tree from the Andean Patagonia, including Tierra del Fuego archipelago, with exceptional timber quality. In N. pumilio natural forests, harvesting generates changes in structure, which in combination with natural disturbances, particularly windthrown, modify the recovery pathways to face management proposals. Overstory stability and diameter growth of remnant trees (>5 cm diameter), and density and height of natural regeneration (<5 cm) were analysed in stands managed with shelterwood after preparatory cuts (PC), final cuts (FC), and thinning (T) in Tierra del Fuego (Argentina). Overstory stability measured as fallen basal area of remnant trees was evaluated across 10 years-after-harvesting (YAH), diameter growth was evaluated during 2012-2018 and 2019-2022, and regeneration was evaluated before harvesting and 10 YAH. PC (fallen basal area 6.0%) and FC (8.4%) promoted greater stability than T (21.0%), in which higher instability was recorded during the first 4 YAH. Diameter growth did not show significant differences between shelterwood cuts (3.6-4.2 mm yr-1) and thinning (3.7-4.6 mm yr-1). PC and FC showed abundant regeneration (21.8 and 17.0 x 103 ind ha-1, respectively). Our study showed that shelterwood cuts (PC and FC) in N. pumilio forests promoted greater tree stability and natural regeneration while thinning generated greater growth values at stand level.
silviculture, stand stability, stand recovery, forest structure, Patagonia
Timber as a low-carbon material strategy: A systematic review of substitution effects and mitigation potential in building systems
The building sector is a major contributor to global greenhouse gas emissions. Substituting carbon-intensive materials with timber presents a significant, yet not fully quantified, climate mitigation opportunity. This systematic review synthesizes three decades of global research to quantify the timber substitution effect in the built environment. Its primary objectives are to: (1) consolidate displacement factors and emission reduction ranges from life-cycle assessments, (2) evaluate systemic barriers and enablers for adoption, and (3) provide actionable insights for policy and research. A structured literature search (1990–2024) was performed using Web of Science and Google Scholar. From 12,526 initial records, 12,320 unique studies were screened. Following a full-text review, 80 studies were included in the qualitative synthesis, with 68 providing quantitative data for meta-analysis. A mixed-methods framework combined bibliometric and thematic synthesis. The analysis confirms a robust substitution effect. Replacing steel with wood avoids 2.3 kg of CO₂ per kg of wood, while substituting concrete saves 1.4 kg CO₂/kg. In whole-building systems, emission reductions range from 36 to 530 kg CO₂-equivalents per m³ of wood. When sourced sustainably, timber serves as a long-term carbon store, with life-cycle assessments showing 34–84% lower climate impact in multi-story applications. Scaling timber use could reduce sector emissions by 20–30% by 2050. Key barriers include prescriptive building codes, fire safety perceptions, and uneven forest governance. Timber substitution is a viable, scalable mitigation pathway. Realizing its potential requires updated building codes, carbon pricing mechanisms, and certified sustainable forestry. Future research must standardize life-cycle assessment methods and address geographic literature gaps. This transition can simultaneously advance climate goals, circular economy principles, and green job creation.
timber substitution, cross-laminated timber (CLT), embodied carbon, displacement factor, systematic review, low-carbon construction, carbon sequestration.
Forest structure and its changes from multi-temporallidar data: a homogeneously derived database forpeninsular Spain
Monitoring forest structure across large and heterogeneous landscapes is essential to understanding ecosystem dynamics, carbon stocks, and the impacts of global change. This study leverages lidar surveys from Spain's national airborne laser scanning (ALS) program to produce harmonized, high-resolution maps of canopy height, canopy cover, and aboveground biomass (AGB) across peninsular Spain over two periods: 2008-2016 and 2015-2021. We developed a consistent processing workflow to overcome challenges posed by heterogeneous lidar acquisitions, and integrate the resulting metrics with National Forest Inventory (NFI) data to model AGB using machine learning algorithms. Validation against field data demonstrated high accuracy for canopy height (R² > 0.8; RMSE < 3 m in some regions) and acceptable performance for AGB estimation (RMSE: 23–44 t ha⁻¹). Between the two lidar surveys, forests exhibited structural development in forest canopies, with average annual increases of 0.2 m in height and 0.9% in canopy cover, particularly pronounced in the Atlantic regions. Species-level analysis highlighted the structural and functional contrast between biomes: high-biomass Atlantic species such as Fagus sylvatica and Pinus radiata reached up to 188 t ha⁻¹ and 126 t ha⁻¹ AGB, respectively, while Mediterranean species like Quercus ilex and P. halepensis remained under 35 t ha⁻¹. Comparisons with global and regional satellite-derived products revealed that airborne lidar offers superior spatial detail and accuracy, especially in structurally complex forests. ALS-based height estimates showed significantly lower mean absolute error (MAE: 1.6–3.7 m) than global products (MAE: 2.9–7.8 m), and the GEDI dataset consistently overestimated canopy height, 5.9 m on average, across the peninsular Spain. This work highlights the critical role of harmonized lidar datasets for robust forest monitoring, and provides a valuable baseline for future ecological assessments, carbon accounting, and validation of satellite products across the peninsular Spain.
Shocks, strategies and socio-economic determinants of rural households coping mechanisms: Case study of Kakamega Forest, Kenya
Rural forest communities in developing countries face multiple and compounding shocks that increase their vulnerability and reliance on limited coping options. While many studies have examined how socio-economic factors shape coping strategies, few have explored the combined and interacting effects of these factors on strategy selection across diverse shock types. This study investigates the types of shocks experienced by communities surrounding the Kakamega Forest Ecosystem (KFE) in western Kenya, the coping strategies employed, and how socio-economic characteristics and their interactions influence these responses. Using participatory approaches, primary data were collected from 453 households through focus group discussions, key informant interviews, and a structured household survey. Data were analysed using Chi-square tests, ANOVA, poisson, and negative binomial regression models. Economic distress and illness emerged as the most widely acknowledged shocks. Significant differences were found across wealth categories and Community Forest Association (CFA) membership for illness, unemployment, animal disease outbreaks, and economic shocks. Only animal disease shocks varied significantly by gender of household head. Forest harvesting was the most frequently adopted coping strategy, used in response to 78% of shocks, underscoring the forest’s buffering role. Consumption reduction was common among poor households during unemployment and economic distress, while productive asset sales were triggered by economic and health-related shocks. Rich CFA members and male headed households were less likely to adopt costly or asset-depleting strategies. The paper demonstrates that forest resources serve primarily as short-term safety nets, underscoring the importance of reducing socio-economic disparities and enhancing forest governance to avoid poverty traps and foster resilient, context-specific policies.
forest-dependent communities, coping strategies, socio-economic vulnerability, multiple shocks, ecosystems
Optimizing forest-dominated campus environment: The impact of campus green and blue spaces on well-being and institutional per-formance
The built environment of a campus is characterized by forest-dominated landscapes, which may determine the competitiveness of host university by influencing the emotional perceptions of experiencers. Relevant evidence has been derived from studies in parks and neighborhood landscapes but less is known about the emotions of experiencers in indoor and outdoor settings. In this study, 50 top universities were randomly chosen from a list of highly competitive rankings along a competition gradient, with campuses distributed over a wide geographical range from mainland China. Volunteers were recruited from indoor and outdoor locations (either number of 50 individuals per campus) to collect facial photos as a source of data used for analyzing expression scores for happy, sad, and neutral emotions (n = 4824). The positive response index (PRI) and emotional nonparametric relation index (ENRI) were calculated to comprehensively assess emotions. The neutral score decreased with an increase in university competition evaluated using the A+ discipline number. The blue space area benefited presentations of PRI and ENRI in the cohort mainly at outdoor places, and the green space area increased the exposure of happy scores for the indoor population. The campuses of top universities with more competitive disciplines were built with larger areas of blue and green spaces and larger cohorts with less calm facial emotions. It is recommended that top universities aiming to enhance competitiveness prioritize incorporating well-designed green and blue spaces with size and distribution tailored to campus usage patterns.
built environment; sustainable university; higher education; campus construction; building and human emotion
Copyright (c) 2025 Annals of Forest Research
Leaf litter decomposition in Pinus massoniana monoculture and mixed plantation with Castanopsis fissa in a subtropical area of China
We measured the rates of Pinus massoniana needle litter decomposition mixed with different proportions of Castanopsis fissa leaf litter in P. massoniana monoculture and P. massoniana mixed with C. fissa forests, which are the typical forest of the subtropical zone of China. The broadleaved species on sites could naturally promote the degradation of litter and mineralization of carbon and nitrogen, which results in faster nutrient return and enhanced productivity. But it is not well known how specific species influence the decomposition processes of each other in mixtures. In this paper, there were 4 types of litter mixtures, which referred to the mass ratio of P. massoniana leaf to C. fissa leaf in the mixtures: 1:1, 3:2, 7:3, and 1:0. We placed 4 types of litterbags in the two forest types for an over 12-month experiment. We applied the litterbag technique for this experiment. The main results were: 1. P. massoniana leaf litter (1:0) decomposed faster in the mixed forest than in monoculture. 2. The mixed leaf litter (1:1, 3:2, 7:3) decomposed faster than the monoculture P. massoniana litter, moreover, the 1:1 type decomposed the fastest. 3. The mixture effects on needle litter decomposition changed during decomposition process, the antagonistic mixture effects of 1:1 and 7:3 could be found in the first six months in the mixed and monoculture stands, the non-additive synergistic litter mixture effects dominated after 9 months. The results showed that broadleaff litter could promote the decomposition of conifer litter, and the decomposition of litter was faster in the mixed forest than in the monoculture coniferous forest. It also shows that keeping a suitable proportion of broad-leaved tree species in coniferous monoculture forest is beneficial to the nutrient cycle and the tree’s growth.
Twenty years of temperate montane forest progression in the oldest Polish national park
The historical fragmentation of forest ecosystems led to a significant spatial reduction in natural forest biomes. After centuries of exploitation for various purposes, the fragments remaining as national parks have been systematically monitored. This provides a wide range of field data and allows an in-depth understanding of processes responsible for short- and long-term forest dynamics. The existing monitoring systems should be considered unique and worth maintaining because they spanned before the era of remote sensing data acquisition in sufficient spatial and temporal resolution. We explored tree monitoring data from the oldest national park in Poland – Pieniny National Park (PNP) in the Western Carpathians, established in 1932. We assessed stand aboveground increment, recruitment, and mortality for 44 monitoring plots with field observations obtained in 1987, 1998, and 2009. Using a linear mixed-effects model, we assessed differences in stand biomass among sampling years and determined the drivers of biomass dynamics. For relative values of increment, recruitment, and mortality, we developed generalized linear mixed-effects models with a Beta distribution of the dependent variable. We found that stand composition was only slightly affected across 22 years. The mean aboveground biomass increased evenly and significantly (from 168 to 237 Mg/ha). Stand dynamics were mostly affected by stand structure characteristics, especially basal area (BA) and density, while other factors (geomorphometric and climatic characteristics) modified these relationships. The importance of climatic and geomorphometric factors shows local responses of stand dynamics, which can be utilized for fine-scale sites. We found twice higher relative increments in SW than in NE exposition, which can be related to higher insolation (sunlight and temperature) on SW-exposed hillslopes. The aboveground tree biomass change caused by mortality was partly controlled by several variables, among which the most important was BA. With increasing BA, mortality increased and was also slightly related to steeper slopes. Species-specific trends were dominated by species proportion. Fagus sylvatica had higher relative increment and mortality in plots with its dominance, while Abies alba absolute increment decreased. Studying the mountain forest dynamics is crucial for biodiversity, soil and groundwater protection, and tourism. Ground measurements are an accurate way to estimate biomass.
Abies alba, aboveground biomass, Fagus sylvatica, increment, monitoring, mortality, recruitment
Forest recreation and well-being - a survey of sanatorium patients' opinions
Numerous studies provide evidence of the positive effects of forest recreation on well-being. However, there is a lack of research conducted among sanatorium patients. Some sanatoria organize various exercises for patients, supervised by instructors in the forests surrounding the health resort. This study examined the opinions of patients in these sanatoria regarding the impact of such forest exercises on their well-being. An additional objective was to gain knowledge about the type of exercises held in the forest, as well as their frequency and duration. A total of 293 patients participated in the individual questionnaire interview. Ninety-five percent of respondents declared that forest exercises took place several times a week, while 5% indicated a frequency of 1-2 times a week. Seventy-five percent of patients spent 1 to 2 hours during individual forest exercises, 23% spent more than 2 hours, and 2% less than 1 hour. The most frequently organized forms of forest activities for sanatorium patients were walking (40%) and Nordic walking (31%), followed by exercising in the outdoor gym (17%) and gymnastics (12%). Almost all patients reported improved well-being after forest exercises. Additionally, 92% of patients also visited the forest during their leisure time. The results may pave the way for the potential development of forest bathing as an effective method to enhance the well-being of sanatorium patients, thereby positively influencing the process of improving their health. Considering health promotion, sanatorium management is encouraged to implement various forms of forest recreation, including forest bathing, into sanatorium treatment programs. It is essential to ensure that the form of forest recreation and the duration of sessions (1-2 hours) are tailored to the capabilities of sanatorium patients.
forest bathing, forest therapy, public health, shinrin-yoku, spas, wellness
Genetic parameters of Abies alba progenies from seed orchards and natural populations in Romania
A total of 204 silver fir open-pollinated families from four first-generation seed orchards and 12 natural stands were tested in a nursery experiment. The performances and genetic parameters of the seed orchards (SO) and natural populations progenies (NP) were determined and compared at ages from 3 to 6 years old. Several traits were assessed such as: the total height, the annual height increment, the root collar diameter, the branch length, the number of branches, and the bud burst evaluated during spring 2015-2016. On average, progenies derived from seed orchards outperformed those from natural stands, exhibiting 8–14% greater height and 4–6% greater diameter. Estimates of genetic variance components indicated that most of the variation was attributable to additive genetic effects. Total height and annual height increment showed the highest proportions of additive variance, ranging from 42 to 91% in NP progenies and from 41 to 78% in SO progenies. Narrow-sense individual heritability estimates were generally higher than those previously reported for silver fir, ranging from 0.12 to 0.83 for SO progenies and from 0.23 to 0.91 for NP progenies. Family heritability exceeded individual heritability in both progeny types investigated. Among the studied traits, total height exhibited the highest heritability for both progenies. Heritability of total height increased moderately from ages 3 to 6, whereas heritability for root collar diameter declined and remained relatively stable for branch-related traits. Phenotypic and genetic correlations between growth traits were relatively high, while those between bud burst and growth traits were positive and weak for both progenies. The correlations between growth traits and branch traits were positive but nonsignificant. A significant correlation was obtained between bud burst in 2016 and elevation of populations. The phenotypic correlations were higher than the genetic ones for both progenies. Genetic gain differed depending on the selection method, intensity, and traits examined. Across all selection methods, total height showed greater genetic gain than root collar diameter. Recurrent selections based on the parental genetic values will bring the greatest genetic gain in the next breeding generation. The genetic gains that could be achieved if the backwards selection will be used at the level of the first-generation seed orchards are between 19–27% for total height, 9–27% for diameter and 40–48% for current height increment. If the backward selection is used in natural populations, a genetic gain of 21–32% for total height, 13–22% for diameter and 42–55% for current height increment could be obtained. The results are discussed linking them to their implications for the development of a silver fir breeding strategy and also for the second-generation seed orchards establishment.
silver fir, open-pollinated progenies, early testing, quantitative traits, genetic parameters
Integrating ARKit 6 (Arboreal Forest app) in woodland mensuration: A case study in the Zagros woodlands, Iran
As augmented reality (AR) technology continues to evolve, its application in forestry measurement is gaining increasing attention. While previous research has largely focused on diameter at breast height (DBH) measurements, expanding AR-based tools to other tree parameters is essential for assessing forest structure, biomass, and growth. This study evaluates the effectiveness of ARKit 6 (Arboreal Forest app, AF), a LiDAR-integrated mobile tool, for measuring tree height and crown diameter, by comparing its measurements with those of TruPulse 360B (TP), a professional-grade laser rangefinder. A statistical framework employing probability and cumulative distribution functions was applied to 215 broadleaved and coniferous trees, with goodness-of-fit tests (Kolmogorov-Smirnov and Anderson-Darling) indicating that Weibull and Log-Normal distributions best described the measurements. Agreement between tools was assessed using Bland-Altman analysis and error metrics including bias, mean absolute error (MAE), and root mean square error (RMSE). For height, the bias was -0.01 m, MAE 0.125 m, and RMSE 0.211 m, while for crown diameter, bias -0.59 m, MAE 2.02 m, and RMSE 2.70 m, indicating strong agreement between AF and TP. Descriptive statistics indicated similar means, standard deviations, and skewness values, suggesting that AF provides measurements comparable to TP. Minor differences in kurtosis and skewness suggest how each tool handles extreme values. These findings highlight AF as a cost-efficient and reliable alternative to professional-grade tools for tree height and crown diameter estimation. As AR technology evolves, its role in forestry is expected to expand toward real-time data integration, modeling, and ecological assessments.
crown diameter, cumulative distribution functions (CDFs), height, LiDAR, probability density functions (PDF), TruPulse 360B
Wood measurement at the factory gate: a comparison study to evaluate the accuracy of a state-of-the-art digital truckload measurement system
Precise wood measurement and traceability are important for increasing supply chain efficiency and guaranteeing legal compliance in the forest industry. Digitalization has emerged as a transformative trend globally, offering significant potential to address current challenges associated with wood transportation. This study investigates the accuracy of the CIND’s Timspec ® system in measuring the roundwood solid volume at the factory gate. It compares the system's performance using data from a number of 1,300 truckloads, of which 1,292 were retained after outlier removal, and were compared to data sourced by manual measurements performed in the forest and Microtec® measurements carried out in the sawmill yard. The study followed a comprehensive methodological framework from outlier removal using the DBSCAN (Density-Based Spatial Clustering of Applications with Noise) algorithm to statistical analysis and heteroskedasticity tests to assess the reliability of the system. The results indicate a high degree of agreement among the used measurement systems. However, it highlights the differences in volume estimations produced by these systems, revealing that while the Timspec system tends to overestimate wood volumes by approximately 0.5 m³ overall, which is likely attributed to operational factors such as truckload gaps and moving speed, Microtec system underestimates by about 0.8 m³ overall, primarily due to observable factors such as bark loss during mechanical handling in the sawmill yard. Based on the findings, Timspec® system can be used to effectively check the conformity regarding the quantity of wood delivered to the processing industry by those in charge with tactical and strategic decision making, mainly due to speed, effectiveness, and coverage of measurements. Following improvements, this digital system may stand as an effective tool for the wood supply chain, allowing for fast and accurate estimates of the truckload-based wood deliveries, as well as automation of the measurement processes at the factory gate.
transportation, supply chain, estimates, agreement, digital systems, traceability, decision making
Assessing spatial dynamics of GEDI biomass prediction in managed versus unmanaged tropical forest ecosystems in Kenya
Above ground biomass (AGB) estimation is vital for monitoring carbon storage and ecosystem fluxes, especially in tropical forests for climate mitigation in the Global South. The Global Ecosystem Dynamics Investigation (GEDI) instrument offers high resolution forest monitoring; however, field measurements are crucial to enhance spatial accuracy. This study assessed the limitations of using machine learning models trained on GEDI data to estimate AGB for two distinct forest ecosystems in Kenya: Kakamega National Forest Reserve (KNFR) and Karura Forest Reserve (KFR). Our specific objectives were (i) developing Random Forest (RF) machine learning model using GEDI data for training, (ii) comparing GEDI estimates with field measurements, and (iii) quantifying the limitations of using integrated GEDI-RF model. Plots were coincided with GEDI beams for comparison to assess variability and bias in AGB estimates. The p-value of 0.005 for heteroskedasticity in KNFR indicated high variability and bias of the GEDI-RF model relative to the field measured model. In contrast, p-value of 0.195 for heteroskedasticity in KFR indicated low variability and bias of the GEDI-RF model relative to the field measured model. 55% of plots which coincided with GEDI had less than 10% relative difference in AGB estimates between models. Plots outside of GEDI had a relative difference in AGB estimates between models greater than 10%. Relative to the field measured model, the GEDI-RF model overestimated AGB values less than 100 Mg ha⁻¹ and underestimated greater than 200 Mg ha⁻¹. This study contributes to effective forest monitoring, carbon accounting, and conservation in heterogeneous forests.
GEDI, forest monitoring, remote sensing, tropical forest, carbon storage
Evaluation of gene diversity and gain in Eucalyptus camaldulensis seed orchards of two generations
This paper is a comparative synthesis of the gene diversity and gain based on published results of two Eucalyptus camaldulensis breeding programmes (BP 1&2) in India. The dynamics and genetic gain of four first generation (F1) seedling seed orchards (SPA) of BP1 were compared with three second generation (F2) SPAs and two clonal seed orchards (CSO) of BP2. Three F1 orchards (F1 SPAs 1,3&4) of BP1 had low flowering (30%) and high fertility variation (sibling coefficient, Ψ = 5-11) whereas F1 SPA2 had 73% fertile trees (Ψ = 2.27). No significant gain was obtained in BP1 when the four F1SPA seed crops were evaluated at two locations in genetic gain trials - to estimate the gain obtained in comparison to native provenance and commercial clone checks. For infusing improved seed from BP1 to BP2, three F2SPAs were developed, of which two (F2 SPA 1-2) were thinned genetic gain trials that incorporated bulked seed lots from four F1 SPAs of BP1, and the third (F2 SPA 3) originated from bulked seed of only one F1SPA. Two clone trials of F1 progeny selections were converted to clonal seed orchards (F2 CSO 1&2). Flowering was low (26%) in the F2 SPAs also with high fertility variation (Ψ, 9-14). The CSOs had high flowering (81%) but fertility was highly skewed in CSO2 (Ns = 2) compared to CSO1 (Ns = 11). The F2 SPAs 1&2, which originated from four F1 SPAs in genetic gain trials, had higher effective population size (Ns, 95 and 74) than the F2 SPA3 (Ns = 39) and CSOs, and better progeny performance than the native provenance at 3 years. CSO2 had the lowest gene diversity and survival than the other taxa. Genetic composition and fertility status of the orchards affected the performance and genetic diversity of progeny.
clonal seed orchard, fertility, provenance, breeding programme, progeny trial
Bee-inspired Radial Basis Function network to estimate tree aboveground wood volume in Brazilian Savanna
Forest variables such as aboveground wood volume are usually estimated by applying regression analysis. Nevertheless, in the past decades, new alternatives have been used, for example, artificial neural networks. In this sense, our study aimed to evaluate the efficiency of the Radial Basis Function (RBF) neural network in estimating aboveground wood volume for the Brazilian savanna using the cOptBees training algorithm. We fitted 18 allometric models and trained three Multilayer Perceptron (MLP) networks and two RBF networks using two different algorithms: k-means and cOptBees. We selected the MLP and RBF networks, as well as the allometric model with the best accuracy, for comparison. We verified the methods’ accuracy by analysing the statistics of bias, root mean square error (RMSE), and Pearson’s correlation coefficient. The lowest bias value was presented by the RBF network using the cOptBees algorithm (5.90 x 10-5). The Näslund model showed the highest correlation (9.45 x 10-1), as well as the lowest RMSE (2.07 x 10-3). The aboveground wood volume estimates provided by the artificial neural networks showed similar results to those provided by classical regression models. Overall, we may infer that RBF networks trained using the cOptBees algorithm can be used to estimate aboveground wood volume in the Brazilian savanna, being as accurate as MLP or RBF networks trained with the k-means algorithm and allometric models. Finally, all methods showed similar aboveground wood volume estimates. However, neural networks offer advantages in optimizing field surveys because they require less sampling effort.
A case study on forest practitioners' perspectives on climate extremes: consensus on impacts and conflicts in responses
Climate extremes present significant challenges to the German forestry sector, impacting forest ecosystems, biodiversity, and overall forest health. This study examines the perspectives of forest practitioners regarding the impacts of climate extremes, such as drought, heat waves, storms, and heavy rainfall, as well as their proposed responses and potential conflicts. Utilizing a transdisciplinary approach, semi-structured interviews were conducted with 28 forest practitioners. The findings reveal that over 89% of practitioners acknowledge drought as the most significant climate extreme affecting forests, highlighting its detrimental impacts on tree health and forest ecosystems. Drought-related damage since 2018 has also resulted in significant economic losses and necessitates large-scale reforestation. Notably, two divergent management approaches were identified: those prioritizing wood production (FWP) tend to focus on economic viability and timber management strategies, while those emphasizing protection and recreation (FPR) concentrate on ecological sustainability and biodiversity conservation. There is a broad consensus on the impacts of climate change, but responses remain contested. Both groups agree on the importance of promoting mixed, multi-layered forest stands to enhance resilience to climate extremes. However, important differences remain: the FWP group advocates active interventions and favors conifer species such as spruce for economic reasons, while the FPR group emphasizes natural processes and prefers native species like beech. Although climate adaptation serves as a shared rationale, their underlying priorities differ considerably. These insights underscore the need for integrating diverse perspectives in forest management to effectively address the complexities of climate change, facilitating collaborative approaches that address both economic aspects and environmental co-benefits through integrated forest management.
forest management, resilience, stakeholder engagement, adaptive strategies, climate extremes, drought, storms, transdisciplinarity, sustainable forestry
Sentinel-2 and environmental data as predictors of the spatiotemporal dynamics of bark beetle (Coleoptera: Scolytinae) - induced tree mortality in natural spruce forests
Biotic and abiotic disturbances affect forest ecosystems. Unlike sudden disturbances, bark beetle outbreaks are a gradual process. Bark beetle outbreak triggered by windstorm in Norway spruce (Picea abies) forests was analysed over a 6-year period (2016-2021) in mountainous conditions (890-2,100 m a.s.l.) with deep valleys and high ridges. The disturbance extent and dynamics were assessed via remote sensing (Sentinel-2 imagery) using a supervised maximum likelihood classification. Topographical variables, bark beetle-related spatial metrics and spectral indices were assessed for predictor importance for their influence on bark beetle-caused disturbance dynamics by boosted regression trees. The overall accuracy of the classification ranged from 87-92% (Kappa 0.84-0.89). Bark beetle spots were initiated mainly at relatively high altitudes and preferentially on exposed terrain. Spectral indices, such as the red-edge normalized difference vegetation index (RENDVI), played a consistent role across various years in predicting spot initiation. With respect to the spread of bark beetle spots, distance emerged as the most influential predictor across all years. Additionally, elevation and RENDVI had notable impacts on spot spreading. In the case of bark beetle spot initialization, the importance of different factors varied among years whereas for spot spreading distance was the most influential for each year.
Sentinel-2, bark beetle, disturbances, Ips typographus, Norway spruce, Picea abies
Temporal variation of macrofungal communities in forest stands afforested on former agricultural land
Our study aimed to assess inter-annual (2016–2020) temporal variability in macromycete species richness, diversity, abundance, and community composition for saprotrophic (SAP) and ectomycorrhizal (ECM) fungi in Norway spruce-dominated stands of different ages (21, 31 and 51 years; a proxy for succession) afforested on former agricultural land (locality Vrchdobroč, central Slovakia). We observed significant inter-annual variability in macromycete species richness, diversity, and abundance, depending on ecotrophic fungal groups. Year had a greater influence than fungal group on all characteristics except species richness, where both factors had similar importance. Stand age affected only macromycete abundance, with differences between ecotrophic groups. The models explained more variability in species richness and abundance than in diversity. Inter-annual variability in fungal community composition exceeded the variability attributable to stand age, with ECM macromycete communities exhibiting greater inter-annual variability than SAP macromycete communities. No direct interaction effects between stand age and sampling year were detected, suggesting that macromycete communities may be shaped by processes operating at broader spatial or temporal scales than those captured by the study plots (416.16 m2) and sampling period. Consequently, in short-term studies, high inter-annual variability in macromycete species richness, diversity, abundance, and community composition could obscure the influence of other factors of interest.
afforested agricultural land, macromycetes, Picea abies, temporal variability
Mapping the monetary value of forest-based recreation: a case study in the Italian Carnic Prealps
In the last decades, ecosystem services are increasingly of interest to the scientific community and policy makers, due to their ability to improve people's physical and mental well-being. To better target forest management interventions, it is important to assign a spatially explicit monetary value to ecosystem services provided by forests. This study aims to defined a procedure to assess and map the monetary values of outdoor recreational in a case study in the north-east of Italy (Cansiglio Orientale forest). For that purpose, a zonal Travel Cost Method and a spatial analysis were implemented in order to map the outdoor recreation value in different forest areas. During the summer 2023, 118 questionnaires were collected through face-to-face administration on the site. The results showed an annual consumer surplus of 13,961,789 € that corresponds to 15.36 € per visit per person. According to the spatial analysis, accommodation facilities, points of interest, and roads and paths network are the elements that most affect the distribution of the outdoor recreation value.
ecosystem services; user perception; economic value; spatial analysis; Cansiglio Orientale forest (Italy)
Litter nutrient dynamics under different tree plantations of humid subtropical region of Uttarakhand, India
Litter plays a vital role in forest ecosystems, significantly contributing to nutrient cycling through litter production and decomposition. Understanding these processes is crucial for forest management and conservation, especially in the face of global environmental changes. This research is important because it provides insights into the litterfall patterns and nutrient dynamics of different tree species, which are essential for maintaining forest health and productivity. The present study aimed to determine the quantity and pattern of litterfall and nutrient return to the forest floor of Pinus roxburghii, Shorea robusta, and Bambusa tulda. We collected litterfall monthly over two years in three different plantations of P. roxburghii, S. robusta, and B. tulda, and measured the nutrient content of the litter. The mean annual litter production recorded in these plantations was greatest in B. tulda (4652.15 kg ha-1yr-1), followed by S. robusta (3731.4 kg ha-1yr-1) and P. roxburghii (2588.85 kg ha-1yr-1). The plantations included both the main species and associated understory vegetation, such as herbs and shrubs. Leaf litter from the main species accounted for the highest total litterfall in April. During this period, leaf litter accounted for approximately 24% of the total in S. robusta, 16% in P. roxburghii, and 15% in B. tulda. Minimum mean monthly litterfall was recorded in September and November for P. roxburghii and S. robusta, and in November and December for B. tulda. There was significant monthly variation in nutrient content between the species. Maximum nitrogen (N) was measured during June for P. roxburghii, December for S. robusta, and January for B. tulda, and phosphorus (P) and potassium (K) concentrations also varied significantly. Annual patterns of nutrient return followed the order N > K > P. Maximum nutrient return was observed during April in all species due to higher litter production during that month. There was greater variability in litter quality in the broadleaved forest (S. robusta) than in the coniferous forest (P. roxburghii), indicating the more dynamic functioning of broad-leaved plantations compared to coniferous ones.. This research highlights the critical role of litterfall in nutrient cycling within forest ecosystems and underscores the importance of considering species-specific litter dynamics in forest management and conservation strategies.
litter dynamics, nutrient return, Pinus roxburghii, Shorea robusta, Bambusa tulda.
How dynamic are structural and compositional changes at different scales? An example from the strictly protected forests of Roztocze National Park in Poland
In certain instances, forest managers are expected to emulate the structural patterns and disturbance regimes of primary forests. In this context, the forest cycle theory, established during the 20th century and widely adopted by many forest researchers and practitioners with little or no critique, suggests that particular patches (groups of trees) within an old-growth stand develop unidirectionally, progressing through stages from regeneration and initial growth to optimal and, finally, breakdown stage. However, due to the lack of long-term observations with detailed tree position data, little research has been conducted on this subject. Our study focused on proxy small-scale spatial dynamics based on patches of living trees for which exact positions and diameters were recorded from 1993 to 2023. First, we analyzed changes at the stand level in terms of diameter distributions and tree species composition over three decades. The distributions of European beech and silver fir remained relatively stable, while the cumulative distribution changed significantly due to a noticeable decrease in young trees of minor species. Secondly, we investigated the dynamics of basal area (BA) changes at the sub-stand level on small patches ranging from 0.01 ha to 0.0625 ha for each decade and over the entire observation period. At the decadal level, the values of Clark-Evans index indicated spatially random single-tree mortality as the predominant disturbance pattern. However, over a longer period, some of these small disturbances repeatedly occurred and concentrated at the same microlocations within the forest, which eventually resulted in spatially aggregated losses of BA by the end of the observation period. Another important finding from this study was that patches with non-directional BA dynamics were more common than those with continual positive BA accretion and/or continual negative BA trajectories. This finding significantly challenges the premises of unidirectional patch development.
forest dynamics, fine-scale patches, basal area trajectories, primary forests
Development of acorn discrimination model for warm-temperature evergreen oaks using hyperspectral analysis
We used hyperspectral analysis to distinguish between acorns of Japanese red oak (Quercus acuta Thunb.) and ring-cup oak (Quercus glauca Thunb.), two closely related species of the evergreen oaks. To accomplish this, 631 Japanese red oak acorns and 505 ring-cupped oak acorns were collected from the seed orchard in Jeju Island, Korea, and hyperspectral imaging was performed. Two types of hyperspectral devices, Corning and Korea Spectral Products (KSP), were used to calibrate images and extract regions of interest. Average spectra were obtained from the extracted regions of interest, and morphological variables were added to the Corning data to form a dataset. Partial least square (PLS) was used as the learning model, Standard normal variate, Multiplicative scatter correction, and Savitzky-Golay filtering were applied as preprocessing techniques, and competitive adaptive reweighted sampling and successive projection algorithm were applied as variable selection techniques ; and the combination of preprocessing method, the number of PLS components, and the number of selected variables were optimized.. The lightweight model was generated from the selected variables, and the performance was improved by combining the morphological variables. As a result, the lightweight model based on Corning dataset showed 45~85% accuracy, and the lightweight model based on the KSP dataset showed 75~90% accuracy. The model utilizing morphological variables in the Corning-based lightweight model showed a high accuracy of 98-100%, so we were able to discriminate the acorns of evergreen oaks between Q. acuta and Q. glauca. The results of this study are expected to serve as a basis for future model development for seed classification of hybrid oak acorns.
hyperspectral analysis; seed identification; variable selection; evergreen oak; species classification
Field assessment of synthetic attractants and traps for the cerambycid beetles Tetropium castaneum L. and Tetropium fuscum (F.) in the Eastern Carpathians, Romania
Tetropium species, significant forest pests in some countries, are expected to pose an even more significant threat in the context of climate change and biological invasions. The potential impact is substantial, making detecting their presence and monitoring their populations crucial. The research presented in the paper aimed to test the response of adults of Tetropium castaneum (Linnaeus,1758) and Tetropium fuscum (Fabricius, 1787) to synthetic attractants similar to those used in other countries (two experiments) and to verify the effectiveness of three types of traps in their capture (one experiment). The experiments were conducted in six freshly clear-cutting areas located in spruce or mixed stands in the northern part of the Eastern Carpathians. In the first two experiments, carried out between 2015 and 2016, we investigated the response to fuscumol, both alone and in combination with host tree volatiles (monoterpenes and ethanol) released at different rates. We also tested a combination of (-)-alpha-pinene, ethanol, and aggregative pheromone of Ips typographus (C.Linnaues, 1758). Barrier traps were used in these initial experiments. The third experiment, conducted in 2017, evaluated the effectiveness of Crosstrap, Barrier, and MultiWit traps, all baited with lures of fuscumol, (-)-alpha-pinene, and ethanol. Numerous specimens of both species were caught in all experiments, namely 7,824-10,466 T. castaneum and 1,041-1,215 T. fuscum. The sex ratio (M/F) varied from 1:1.02 to 1.36:1 for the first species and from 1:1.03 to 1.55:1 for the second. All the baits tested were found to be significantly attractive to the adults of both species. The differences in average catches recorded in traps baited with fuscumol or combinations of attractants were statistically significant compared to those in unbaited traps. Additionally, the catches from traps baited with fuscumol and host volatiles differed significantly from those baited with fuscumol alone. However, there were no significant differences in the average catches of traps baited only with fuscumol compared to those baited with (-)-alpha-pinene, ethanol, and synthetic I. typographus pheromone. Baits containing fuscumol primarily attracted female insects, but when baits with host volatiles were added to those containing fuscumol, the proportion of males in the total catches increased. The Crosstrap and Barrier traps captured significantly more specimens of T. castaneum and T. fuscum than the MultiWit traps, with capture rates 3.20 to 5.57 times higher for T. castaneum and 4.81 to 8.56 times higher for T. fuscum. However, the differences between the Crosstrap and Barrier traps were not statistically significant. Fuscumol baits, whether used independently or alongside host tree volatiles, demonstrate significant attractiveness to beetles of both Tetropium species in Romania. Adding monoterpenes and ethanol lures creates a powerful synergistic effect, remarkably enhancing the allure of fuscumol, particularly for T. fuscum compared to T. castaneum. Moreover, a combination of (-)-alpha-pinene, ethanol, and aggregative pheromone of Ips typographus matches the attractiveness of fuscumol lures, making it an effective alternative. For effective detection and monitoring of Tetropium native or exotic species, fuscumol lures in conjunction with host volatile baits and Crosstrap or Barrier traps are recommended. This approach improves population monitoring and ensures reliable results.
black spruce beetle, brown spruce longhorn beetle, fuscumol, (-)-alpha-pinene, monoterpenes, ethanol, Ips typographus aggregation pheromone, Crosstrap, Barrier trap, MultiWit trap.
Fertility variability among clones and genetic diversity of seed crops at seed orchards of Chamaecyparis obtusa in South Korea
Chamaecyparis obtusa (Siebold & Zucc.) Endl., commonly known as Japanese cypress or hinoki cypress, is widely cultivated for its high-quality timber and ornamental use. Despite its economic and ecological importance, the species faces challenges in adapting to various climates, necessitating the distribution of high-quality seeds and seedlings. This study aims to enhance the genetic improvement and stability of seed production by analyzing fertility characteristics and genetic traits from two clonal seed orchards of C. obtusa in two locations (Gochang and Seogwipo), South Korea. We examined patterns of strobilus and cone production from 2020 to 2022, assessed effective parent numbers, genetic diversity, and heritability estimates, and analyzed parental contribution for the reproductive traits. Results indicated significant annual variation in strobilus and cone production among clones, with higher male fertility variance than female parents. The effective parent number and genetic diversity were generally maintained sustainably, though Seogwipo showed slightly lower diversity. The study underscores the need for management practices to balance clonal contributions, and sustain long-term productivity and genetic diversity in the seed orchards of C. obtusa. Future research should focus on understanding environmental influences on clonal contributions and refining selection criteria for superior clones in the advanced generation breeding program.
Japanese cypress, gene diversity, fertility variation, genetic parameter, effective parent number, cone production
Structural features of Peleș Park Forest: managing for ecosystem services provision
The Peleș Park Forest (PPF), a semi-natural peri-urban forest near Sinaia, Romania, is essential in providing ecological benefits and improving human well-being through recreation. As the urban population grows and stress-related health problems increase, green spaces are increasingly recognised for their restorative functions, including air purification, temperature regulation and mental health improvement. This study aims to develop a sustainable management framework that reconciles forest conservation with recreational value use by assessing forest structure, evaluating tourism-related stressors, and proposing adaptive management strategies. We assessed forest structure through tree diameter, height, volume, and crown health measurements, applying principal component analysis (PCA) to identify the main structural drivers. The results revealed a strong correlation between tree diameter and height, modulated by species composition and site conditions. They showed pronounced crown defoliation in the upper canopy layers, particularly among trees of lower wood quality. The findings suggest that uneven-aged stand structures, which support biodiversity and ecological resilience, are subject to tourism-related pressures such as soil compaction and vegetation damage.
Forest Park, ecological functions, recreational value, forest structure, sustainable management.
Tree stem mean diameter reduction factor prediction through advanced modeling approaches
Sustainable management of natural resources relies on accurate modelling of forest attributes to prevent degradation. This study explores advanced modelling techniques, including Artificial Neural Networks (ANN) and Support Vector Regression (SVR), for estimating the mean stem diameter reduction factor (taper) of standing fir trees (Abies x borisii-regis Matff.). These methods are compared against traditional non-linear regression model (NLR), developed using the Levenberg-Marquardt optimization algorithm. The ANN models employ cascade correlation, generalized regression, and Bayesian regularization back-propagation architectures, while the ε-SVR approach is assessed for its robustness. The results show that support vector regression (ε-SVR) achieved the lowest relative errors in model fitting, improving by 0.60% over cascade correlation and generalized regression and by 0.67% over Bayesian regularization. Regarding generalization ability, the ε-SVR model performed best, with a relative error of 4.90%, which was slightly lower than cascade correlation (by 0.1%), generalized regression (by 0.01%), and Bayesian regularization (by 0.04%). A comparative analysis between machine learning approaches and standard regression revealed that the ε-SVR model had the lowest mean error (0.0715), while the non-linear regression (NLR) model showed a higher mean error of 0.0955, which means 1.35 times greater. These findings highlight the strong capability of machine learning methods in accurately estimating and predicting the diameter reduction factor of trees, effectively capturing its non-linear behaviour compared to traditional regression models. Overall, this study underscores the potential of advanced machine learning techniques to enhance accuracy and adaptability in sustainable forest management.
mean diameter reduction factor, cascade correlation, generalized regression, Bayesian regularization, support vector regression
Insights into fallow deer population dynamics: Juvenile mortality in Arad County
The fallow deer (Dama dama) is one of the main species of large herbivores in Romania, with a fluctuating presence over time, particularly during the last century. Population fluctuations have been driven by a combination of factors including climate, habitat quality, interspecific competition, predation, and human activities. While mortality represents a key component in the population dynamics, this study aims to quantify juvenile mortality in fallow deer during their first year of life, representing one of the first investigations of this type conducted in Romania. The study examines juvenile mortality rate in a fallow deer population from the Western Plain of Romania over the period June 2020-May 2021. Population structure was analyzed by age classes, and temporal variation in reproductive performance was evaluated by examining the number of calves per mature female over one year. The results indicate a juvenile mortality rate of approximately 50% during the first year of life. This level of mortality is considered typical for natural habitats supporting free-ranging ungulate populations in the presence of substantial mesocarnivores populations. The age-class structure of female fallow deer, together with the population dynamics of mesocarnivores, particularly the golden jackal (Canis aureus) and the red fox (Vulpes vulpes), suggests that predation plays a significant role in juvenile mortality within the study area. These findings highlight the importance of continuous monitoring of reproductive indicators and predator populations to ensure more effective wildlife management strategies.
fallow deer, mortality rate, age structure
Structure and dynamics of deadwood in the mixed beech-conifers Frakto virgin forest of Greece
Virgin forests are considered valuable reference areas for studying forest ecosystem structures and functions as they have been naturally grown with no human interventions. In the Mediterranean region there are few such areas and even scarcer data on deadwood which is a key element for multi-functional forest management. Data regarding the amount and variety of standing and lying deadwood were recorded in the core zones of the Frakto virgin forest in the central Rodopi Mountains in eight square plots of 0.25 ha each. The average deadwood volume accounted for 175.71 m3 ha-1 with lying deadwood consisting mainly of conifers and representing over 60% of the total deadwood. The deadwood distribution showed a decreasing trend towards larger size classes while in terms of quality deadwood it was represented by all stages of decay, thus showing high variability. The research outcomes contribute to knowledge standards when adopting management regimes in mixed beech forests aiming at sustainable forest ecosystem management.
coarse woody debris, snags, logs, stumps, decay stages
The inevitable role of the oil market: Does its price really matter for forestry investment in China?
Delving into the intricate roles of oil prices holds the key to attaining sustainable growth of forestry investment in China. Utilising the full- and sub-sample approaches, this article aims to reveal the dynamically evolving relationships between oil price (OP) and forest investment (FI) in China. The quantitative outcomes underscore the complex interplay between OP and FI, highlighting favourable and unfavourable impacts. Notably, the findings indicate that a substantial surge in oil prices could potentially pose obstacles to forestry investment in China, whereas a decline in OP could serve as a stimulus. Nevertheless, it is imperative to acknowledge that this inference is not uniformly applicable when the effect turns positive, primarily influenced by sluggish economic conditions resulting from the global trade wars. Conversely, FI positively influences OP, underscoring that the decline in forestry investment in China could drive down oil prices through psychological and environmental factors. Amid escalating economic and energy uncertainties globally, essential policy suggestions will be proffered to China, aiming to ensure the robust development of the oil market and forestry investment.
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