This research presents the development of a reliable system for predicting the total stem volume of Scots pine (Pinussylvestris L.) trees by building models for estimating the mean diameter reduction factor (alpha). Using easily measured in-field variables as independent variables, the construction of regression models that best fit a representative sample of trees from the mountainous complex of the Pieria Mountains was investigated. The evaluation of these models was based on a set of fit criteria, including R-adj(2), SEE, Bias,AIC, BIC, VIF, and residual distribution.The results showed that the proposed model estimates (alpha) with acceptable accuracy (SEE = 0.187, R-adj (2)= 0.839). Ultimately, the proposed system for predicting total stem volume will support more effective and sustainable forest management. By providing accurate estimates of standing wood volume based solely on stump diameter, it offers a practical, efficient tool for reliable volumetric assessment.
The forest based bioeconomy has become a strategic priority in the European Union (EU); however, substantial disparities persist among Member States. This study eva luates Greece's performance in the forestry sector of the bioeconomy over the period 2008-2023, using harmonized data from the European Commission's Bioeconomy Country Dashboard. Three core economic indicators-turnover, value added at fac tor cost, and employment-are analyzed, with turnover and value added additionally expressed on a per employee basis to enhance comparability. The results indicate a persistent and widening performance gap between Greece and the EU27 average. Turnover per employee in the forestry sector declined by almost 45% between 2008 and 2023, while value added per employee decreased by more than 50%, contrasting sharply with strong upward trends observed at the EU level. Although total employ ment in the forestry sector of bioeconomy in Greece increased over the period, the sector's contribution to total bioeconomy employment remained limited, reaching only 1.43% in 2023, compared with approximately 2.6-3.1% in the EU27. These outcomes reflect longstanding structural and institutional constraints, including fragmented forest ownership, low timber mobilization, outdated technologies, and limited innovation capacity, which have been exacerbated by external shocks such as the 2008 financial crisis and the COVID19 pandemic. Comparative evidence from Northern European countries highlights the importance of coherent national strate gies, technological upgrading, and coordinated policy frameworks. The study conclu des that the development of a National Bioeconomy Strategy, supported by impro ved monitoring mechanisms and targeted investments, is essential for enhancing the contribution of the forest sector to sustainable regional development in Greece and for strengthening the competitiveness of the forest based bioeconomy.
Paulownia tomentosa is a fast-growing broadleaf species of increasing interest for timber and bioenergy production. This study examined the interactions between the microscopic structure of the wood - specifically the vessel element size, wood density, and growth ring width - in samples collected from a five-year-old plantation in Vasilika, Thessaloniki. The results indicated significant variability in anatomical characteristics across growth rings. Vessel diameter increased toward the outer growth rings, while it consistently decreased from earlywood to latewood.The average wood density was 0.285 g/cm3, and it was negatively correlated with vessel diameter. In conclusion, vessels play a critical role in determining the wood quality of Paulownia tomentosa, a ring-porous species that displays semi-diffuse porosity in its early developmental stages.
Ground-level habitat microstructures are critical yet overlooked drivers of forest biodiversity, offering resources for diverse forest organisms. While canopy gaps, tree-related microhabitats (TreMs), and coarse woody debris are widely studied, small-scale features such as ground-level dead wood, micro-pools, and topographic irregularities remain poorly documented in Turkiye. This study presents the first systematic, plot-based quantitative assessment of such features in the ancient Belgrade Forest, a historically protected woodland near Istanbul. 40 randomly selected 10x10 m plots were surveyed across 5,400 ha, assessing seven microstructure categories: dead wood elements (logs, snags, stumps), perennially wet micro-pools, mounds, depressions, branch/brash piles, stone piles, and ant mounds. Frequencies were evaluated using a standardized four-tier scale. Results revealed severe microhabitat simplification. Ecologically valuable dead wood (>= 10 cm) occurred in only 7.5% of plots; smaller snags (<10 cm) appeared in 25%. Micro-pools were nearly absent (2.5%), large Mounds (>50 cm) were rare (5%), and deep depressions (>50 cm) were scarce (7.5%). Branch/brash piles and ant mounds each occurred in <10% of plots. Stumps (>= 10 cm) were widespread (82.5%), but excluded from the ecological rating due to anthropogenic origin. No category reached "High" status; most were "Low" or "Very Low." Shannon's H' ranged from 2.05 to 2.31; Simpson's index (1-D) ranged from 0.82 to 0.86, indicating no spatial dominance. Jaccard similarity (mean = 0.31) reflected high spatial heterogeneity. Principal Component Analysis (PCA) results demonstrated that no individual structural element exerted a dominant effect; rather, small structural elements contributed to forest habitat heterogeneity along different axes, providing relatively modest but complementary contributions. Rarefaction curves plateaued near 12 types, confirming sampling sufficiency. Chi-square (chi(2) = 321.0, df = 39, p < 0.001) and Kruskal-Wallis tests (H = 10.35, p = 0.016) indicated significant variation in frequency and richness. These findings highlight the scarcity of essential microhabitats for saproxylic insects, amphibians, and other taxa, even in a legally protected forest, demonstrating that passive conservation alone cannot maintain ecological integrity. By focusing on ground-level microstructures (distinct from TreMs), this study reveals a structurally degraded but spatially heterogeneous mosaic. Restoration should prioritize dead wood enrichment, perennial micro-pools, and fine-scale topography, implemented proactively in historically protected forests such as Belgrade forest, once safeguarded under imperial edicts but now ecologically simplified. Similar degradation patterns may occur in other peri-urban forests such as Berlin's Grunewald, Vienna's Wienerwald, and Paris's Bois de Boulogne. Thus, Belgrade Forest provides an instructive model for biodiversity-oriented forest policy and restoration, emphasizing recognition, protection, and artificial creation of ground-level habitat microstructures.To our knowledge, this is the first systematic forest inventory worldwide focusing specifically on these features, addressing a gap in forest biodiversity monitoring.
This study analyses whether and how the amount of total timber from salvage logging has an impact on the shares of assortments of domestic timber supply as well as on the relationship between thinnings and final cuts in Austria. The main data source for this study are the annual ,,Timber Felling Reports" of the (currently labeled) ,,Federal Ministry Agriculture and Forests, Climate and Environment Protection, Regions and Water Management". Correlation analysis and analysis of variance (ANOVA) are the main statistical methods used, based on the time-series data 2006-2023. The results show, that the annual fluctuations of total timber from salvage logging are much more volatile than those of the assortments, the shares of which harvests are only moderately affected by the amount of salvage logging. For coniferous as well as non-coniferous wood, the share of sawlogs is not significantly decreasing and the shares of pulpwood and wood for energy are not significantly increasing when storm damage is increasing; rather it is the other way around. When the damage caused by other reasons than storm (e.g. bark beetles, snow-break) is increasing, then there generally is a decrease in the share of sawlogs. For coniferous wood the impact of damage other than storm is mainly and (partly) significantly positive on the supply of wood for energy, while for non-coniferous wood the main and (partly) significantly positive impact is on pulpwood supply. The supply of timber from salvage logging is above the average in final cuts (larger dimensions) and below average in thinnings (smaller dimensions). The correlation analyses show that increasing calamities affect final cuts more than thinnings, therefore the supply of sawlogs in general tends to increase slightly. Although the underlying data on timber harvests allow detailed analyses due to the differentiation by ownership categories, assortments, coniferous and non-coniferous timber as well as reasons for the damage (e.g. storms, bark beetles), the interpretation of the results is limited, because the data situation does not allow the inclusion of assortment qualities and assortment prices. In addition, the length of the time-series (2006-2023) is quite short. Several suggestions for potential follow-up research activities are presented.
Mistletoe species are part of the biodiversity of cities, forests and other tree-covered areas, but as a hemiparasite they are also a possible threat to trees, in particular in view of increasing drought stress as a consequence of climate change. The distribution of mistletoe largely depends on the woody host species and their growing density. The tree cadasters of the Austrian cities Vienna and Graz were analysed, as well as the data of the Austrian National Forest Inventory around Vienna for the inventory cycles 2000-2002, 2007-2009 and 2016-2021. Fieldwork and visual assessments of the trees were conducted to determine the prevalence of mistletoe infection. The most common host trees for mistletoe in Vienna and Graz (Acer, Tilia, Populus) and Austrian forests (Pinus, Quercus) were identified and the distribution of the various mistletoe species is described. The factors determining the presence of mistletoes within urban areas and surrounding forests were analysed. Our results allow to predict the spread of particular mistletoe species to adjacent areas. Our study also identified mistletoe-resistant trees, that remain healthy and live longer and may help mitigate the effects of climate change.
The purpose of this research is to conduct a performance assessment of forestry operations across counties in Sweden. We employed a two-stage double bootstrap data envelopment analysis (DEA) approach to evaluate the efficiency of production units. The first stage examines the technical efficiency scores by a variable returns-to-scale slack-based DEA model. In the second stage, we applied the double bootstrap DEA model to determine the impact of explanatory variables that affect the efficiency of forested counties. To the best of our knowledge, this is the first attempt to forestry technical efficiency assessment in Sweden by using double Bootstrap two-stage data envelopment analysis model. Overall, this study highlights the superiority of the bootstrap DEA approach in identifying inefficiencies and evaluating efficiency under uncertainty, providing valuable insights for forestry practices. Our results indicated that approximately 43% of the counties studied are fully efficient, reflecting the high overall efficiency score of 0.8512 in the Swedish forest sector. We show that the two contextual variables, regional density and deadwood, have a negative influence. In contrast, precipitation and gross domestic product have positive coefficients, indicating a positive relationship with efficiency. To address uncertain measurement bias, a double bootstrap DEA model is employed, resulting in an adjusted overall efficiency score of 0.7480. The estimation results have varying degrees of uncertainty for contextual variables, emphasizing the robustness of the influences on the true efficiency of forested counties in Sweden.
Accurate prediction of dead fuel moisture content (FMC) is critical for wildfire management, particularly in the Hyrcanian forests of Iran. This study evaluates the performance of machine learning models-Random Forest (RF), Support Vector Machine (SVM), Gradient Boosting (GBoost), and Convolutional Neural Network (CNN) versus traditional linear regression methods in predicting FMC for three fuel classes (1-hr, 10-hr, and litter) over Golestan province, NE Iran. Using data collected from 235 plots between March and November 2023, we incorporated meteorological variables including temperature (T), relative humidity (RH), and wind speed (WS), along with topographic features, into the models. The results showed that multivariable models considerably outperformed the univariate models, and machine learning models were more accurate than the linear regression models. The most accurate model was RF reaching an adjusted coefficient of determination (R2adj) of 97.08 and a relative RMSE of 5.93%, considering the training data. Meanwhile, with the test data, RF obtained an R2adj of 87.99, with a relative RMSE of 10.44%. Furthermore, the performance of the SVMs is very good, with an R2adj of 85.40 for the training data and 86.86 for the test data. In contrast, the linear regression models had lower accuracy, with the best performance, from univariate models being RH with a R2adj of 66.70 and a relative RMSE of 18.90%. Multivariable regression models combining RH,Tand vapor pressure deficit (VPD) improved their performance, but still fell short of machine learning models. The results show that RH and VPD were the most important variables for FMC prediction, especially for fine fuels. The machine learning models showed excellent performance due to their capabilities for describing nonlinear relationships and performing well with high-dimensional data enhancing FMC predictions by up to 31% over traditional methods. This study advances the understanding of FMC dynamics by demonstrating the enhanced accuracy of machine learning models in FMC prediction, here studied for complex temperate forest ecosystems. By highlighting the importance of RH and VPD as critical predictors, the findings contribute to the growing body of knowledge on wildfire risk assessment. Still these results underscore the need for further research to refine models and explore their applicability in diverse environments and under varying climatic conditions.
In forestry, thinning operations place considerable cognitive demands on harvester operators. The operators are responsible not only for tree selection but also for manoeuvring the harvester head between the remaining trees without causing damage on them. Consequently, crane work accounts for approximately 90% of total time consumption during thinnings. Assistance systems facilitating crane work, such as boom-tip control (BTC), allow for improved productivity during thinning. With BTC, the operator controls the movement of the boom tip directly, rather than manipulating individual crane joints. We conducted a standardised field experiment simulating crane movement between remaining trees, as in thinning operations. The harvester used was a midsized (18-tonne) Komatsu 911, equipped with Smart Crane, i.e. Komatsu's version of BTC. The operators (n = 18) were students enrolled in a threeyear forest machine operator education programme. Each experimental run involved visiting and gripping 13 standing stems with the harvester head. None of the stems were felled, allowing them to be reused throughout the experiment. We applied re-peated-measures analysis of covariance to compare conventional boom control with Smart Crane. On average, operators completed the task 9.5% faster when they used Smart Crane. Based on our findings and current literature, BTC appears to offer grea-ter time-saving potential in thinnings than during clearcutting. Furthermore, as most operators benefitted from BTC, we recommend full implementation of BTC on all new forest machines.
The aim of this study was to investigate the influence of tree species characteristics on the occurrence and diversity of tree-related microhabitats in the mixed beech-silver fir Dinaric old-growth forest of Ravna Vala, located on Bjela & scaron;nica Mountain. We evaluated microhabitats in living trees of silver fir (Abies alba Mill.), European beech (Fagus sylvatica L.), Norway spruce (Picea abies Karst) and sycamore (Acer pseudoplatanus L.) with diameters at breast height (dbh) exceeding 40 cm. The microhabitats were systematically recorded using circular concentric plots distributed throughout the forest. Our findings revealed that deciduous tree species support a higher abundance and diversity of microhabitats per living tree compared to coniferous species. Sycamore and beech trees harbored a greater number and variety of microhabitats than silver fir and Norway spruce, consistently exhibiting higher amounts and diversity of microhabitat types per tree. In particular, even sycamore trees in the smaller dbh class (40-60 cm) exhibited microhabitat diversity comparable to larger trees (>80 cm dbh) of other species. These results underscore the significant role of sycamore as an auxiliary species in mixed beech and silver fir forests, which contributes substantially to the occurrence and diversity of microhabitats. Based on these findings, we suggest that forest management practices should prioritize the conservation and promotion of deciduous species such as sycamore and beech to enhance the diversity of the microhabitat. Maintaining a heterogeneous forest structure with a mix of species and tree sizes can serve as an effective strategy for biodiversity conservation, using old-growth forests like Ravna Vala as a blueprint for sustainable management.
The intensification of heat waves and extreme temperatures in recent years has negatively affected trees, reducing their growth processes and diminishing their capacity to withstand thermal stress. In this context, identifying the physiological and biochemical recovery processes in ecologically and economically valuable species is essential for sustainable forest management. This study investigated two forests dominated by Quercus petraea and by Q. robur located in the Plaiul Fagului Nature Reserve (Republic of Moldova). Detached leaves of F. sylvatica, Q. petraea, Q. robur and Fraxinus excelsior were collected and incubated under controlled conditions for ten days following natural exposure of the trees to thermal stress. The research assessed recovery processes based on functional parameters (photosynthetic pigment content, effective quantum yield of photosystem II), antioxidant activity (catalase and phenolic compounds), and leaf water retention capacity. F. sylvatica exhibited the highest tolerance to thermal stress, maintaining both photosynthetic function and leaf hydration. Q. petraea showed an intermediate response, characterized by elevated antioxidant activity. In contrast, F. excelsior recorded the lowest physiological and biochemical values, indicating increased vulnerability to thermal stress. Additionally, the physiological condition of Quercus robur trees revealed greater tolerance in individuals with green foliage compared to those with yellow-brown leaves. These findings suggest species-specific and condition-dependent differences in physiological adaptation mechanisms linked to foliar functional status.
In the interest of facilitating the reintroduction of Swiss stone pine (Pinus cembra L.) in the Lotrului and Sureanu mountains (Southern Carpathians), where the species naturally existed in the past, two half-sib comparative trials were conducted at Cugir and Voineasa. In total, 71 and respectively 65 families were tested (41 common in both trials), which belong to 7 provenances (4 common) originating from two countries (Romania and France) and three mountain divisions (French Alps, Eastern and Southern Carpathians). This study aims to analyze genetic variability by examining testing site influences, inheritance rates, and trait correlations in two 27-year-old half-sib trials with the goal of identifying the best-performing families and developing an optimal breeding strategy to enhance desired characteristics in future generations At the trial's 27 years of age, measurements and evaluations of the breast height diameter, tree height, branch diameter and finess of branches, stem straightness, and survival were performed, while the trait-trait, trait-origin, and inheritance rate were estimated. The high level of genetic variance and heritability (especially for tree height), along with the significant correlations among traits, and the large number of families, ensures the success of the breeding program. The MGIDI index (multi-trait genotype-ideotype distance) allowed us to select ten to eleven families in each trial that could be promoted in the Southern Carpathians and under similar ecological conditions to those in the trial where they were performed. A forward selection of the top 30% of individual trees from the best selected families, based on tree height, could be applied in each trial. Given the strong effects of the testing site and site x family interaction, extreme attention is required when transferring reproductive materials. Our findings provide a constructive approach for management plans, as we recommend transition from Norway spruce monocultures to structurally more diverse stands with codominant Swiss stone pine, at the upper altitudinal limit of the Southern Carpathian forests.
The net timber revenue (NTR) or contribution margin is a key variable in economics of primary forestry production. The article discusses definitions and methodological aspects. The potential variety of key figures is shown. Out of the four possible economic levels, the focus of this study lies on the cost accounting approach. The importance of the NTR in the context of management accounting and for corporate management is explained. Possible pitfalls and misinterpretations are also discussed. The results of an online survey among forest experts addressing NTR provides an indicative picture of the industry's opinion on the subject. Empirical findings are presented and methodological aspects discussed based on information from the accountancy data network of bigger forest enterprises in Austria. The data accumulated over decades allow analyzing long-term developments, which is particularly important in forestry with its extremely long production periods. Using the most recent data (accounting year 2023), alternative input variables and the key figures derived from them are quantified by way of example. Finally, cost elements are analyzed which, with respect to the NTR, can be of significance in determining the calamity profit.
Awareness of the ecological importance of deadwood as a key structural component of forest ecosystems is steadily increasing. Consequently, forest managers' acceptance of deadwood retention in managed forests is becoming more frequent. This study investigates the quantitative and qualitative characteristics of deadwood and natural regeneration within a 25-hectare protected lowland forest located in northern Iran. On three transects measuring 50 m x 750 m all types of deadwood, that is, snags, logs, and stumps, were recorded. Each deadwood item was classified by decay stage (classes 1 to 4) and tree and shrub species was identified. 1000 m(2) sample plots on a grid system of 150 m x 200 m were established to examine forest structure. Within each 1000 m(2) sample plot, four subplots measuring 5 m x 4 m were placed at the inner corners to record natural regeneration, taking into account species and growth stage. Our results show, that Carpinus betulus represent the highest number and volume of deadwood.The total deadwood volume was on average 9.8 m(3)/ha, representing 4.9% of the volume of living trees. Among the three deadwood types, logs had the highest volume at 6.8 m(3)/ha.The majority of deadwood occurred in the more advanced decay classes (Classes 3 and 4), while the lowest frequency and volume were recorded in the least decayed class (Class 1). Total natural regeneration was 1,593 individuals per hectare, with 1,038 per hectare and 501 per hectare in the sapling and thicket stages, respectively. Parrotia persica was most frequent in the natural regeneration, but its share was not significantly different from that of Carpinus betulus. For both species, regeneration was most abundant at the seedling stage compared to the sapling and thicket stages. The abundance of deadwood, the composition of tree and shrub species, and the degree of decay may significantly influence forest structure and the establishment of natural regeneration. It is recommended that the management of such protected forests not only focus on stand structure and volume accumulation, but also consider species admixture regulation, the promotion of natural regeneration, and the preservation and appropriate spatial distribution of deadwood across the landscape.
Stone Pine (Pinus cembra L.) grows preferentially in the higher elevations of the European Alps and Carpathians with a slow juvenile growth but exhibits a strong economic potential. This study provides an insight to the altitudinal distribution of Stone Pine in the Styrian Alps as indication for forest management concepts to increase the stability and resilience of alpine mountain forests in the context of a changing climate. In the FORSITE project (Dynamic Forest Site Classification), data concerning relief, soil, ground vegetation, tree-and stand characteristics were gathered at 1803 forest site investigation plots and analyzed as basis for creating a forest site classification system for the Austrian province of Styria. Out of the total plots Stone Pine was found on 98 forest sites ranging between 1250 m and 2050 m asl. Stone Pine is typically dominant in the forest stands within the upper forest vegetation zones (very cold, cold and moderately cold) with shares >50 %. The subdominant admixture of Stone Pine in the cool forest vegetation zones (very cool, cool and moderately cool) is emphasized. A tendency for increasing productivity (Site Index 100) related to decreasing elevation was found. The potential drivers for the current distribution of Stone Pine in Styria, the economic use, silvicultural measures to enhance the resilience of mountain forests and potential risks are discussed.
Trees absorb CO2 from the atmosphere via their stomata and store C using photosynthesis as carbohydrates in wood. This leads to a reduction of CO2 concentration - an important greenhouse gas - in the atmosphere and represents an important contribution to mitigating the climate crisis, especially if CO2 remains stored in wood for a long time. This long-term storage can be fulfilled by durable wood products in the construction sector. Although this carbon storage is temporary and eventually CO2 is emitted back to the atmosphere by burning or depositing wood in landfills, it still avoids direct emissions and thus facilitates medium- to long-term CO2 reduction targets. However, current methods of life cycle assessment of construction products and buildings, provided by EN 15804+A2 and EN 16485, cannot quantify this effect. This issue has already been encountered and led to the inclusion of dynamic life cycle assessment in the 2024 annual Union work programme for European standardization. Here we developed a comprehensible model for mapping the temporary CO2 storage of durable wood products. Essential parameters for quantifying the effect of temporary carbon storage were the degradation rate of greenhouse gases in the atmosphere and the net carbon uptake in the forest during the lifetime of the construction product.The latter, amongst others, depends on the rotation times of the tree species and the effects of climate change on growth and mortality. We used a dynamic climate-sensitive forest growth model to derive the input parameters for the dynamic wood product model for a hypothetical yet typical forest stand in Austria. The adequate consideration of reuse or recycling as well as innovative approaches to end of life treatment of timber products were included in this model as input parameters. The combination of several different modelling approaches with different outputs (forest growth model, LCA wood product model, greenhouse gas decay model and end of life model) was challenging. The result is a modelling approach for a holistic quantification of the CO2 sink of constructive timber, considering all relevant input parameters in different scenarios which vary over the time of 300 years. One key finding was identifying the minimum storage time of carbon in building products, to ensure a positive climate effect as well as the impact of different harvesting methods with related implications on carbon stock in the forest. Equally important are end of life decisions, which seem to be crucial for a positive climate mitigation effect of building products made of wood, implicating the need for intensifying research on this aspect.
Forest management, especially in regions with diverse socio-economic and environmental challenges, is crucial for promoting sustainable livelihoods. The absence of effective participatory forest management strategies has led to deficits in both forest resource conservation and the enhancement of local livelihoods. This research investigates participatory forest land management by identifying and prioritizing key factors and proposing strategic management approaches. Data were collected through interviews and questionnaires in Qazvin Province, Iran. The data was analyzed using an integrated SWOT-AHP model. The SWOT matrix underscored critical aspects of forest resource management in the study area: "soil conservation and erosion prevention" emerged as a key strength, while "economic stability, improvement and diversity of livelihood of dependent communities" were highlighted as significant opportunities. Conversely, "weak enforcement of laws, policies, and strategies" was identified as a notable weakness and "reduction of forests area" was a concerning threat. The prioritization of SWOT factors revealed that opportunities hold the highest priority. Specifically, "economic stability, improvement, and diversification of livelihoods for dependent communities" and "collaborative forestry" were assigned top priorities, with final weights of 0.1665 and 0.1095, respectively. Furthermore, the AHP method indicated that "program-oriented management with stakeholder participation" is the most crucial strategy, with a relative weight of 0.21. The study underscores this strategy as an effective approach to achieving sustainable forest management, emphasizing its potential to align stakeholder interests and enhance forest conservation efforts.
Forests represent important carbon pools among terrestrial ecosystems and play an important role in mitigating the impact of global warming. Changes in land use and forest planning systems affect the spatiotemporal distribution of forest carbon stocks. In this study, the total carbon stocks of the forest stands were calculated, and spatial and temporal changes of the carbon stock were investigated for the 1996, 2009, and 2018 planning periods in Ilgaz Forest Enterprise, T & uuml;rkiye. Growing stock volume (GSV) was obtained from the forest management plans of Ilgaz Forest Enterprise. GSV-based carbon conversion coefficients were used to calculate the total carbon stock of the forest stands. Mapping the total carbon stock of forest stands was done using stand maps from forest management plans. Our results indicate that changes in land use contributed to enhanced forest carbon stock in the study region. Forest stands stored a total of 7.56, 9.65, and 10.22 MtC over the planning periods of 1996, 2009, and 2018, respectively. While the forest carbon stocks per hectare was 113.4 tC ha(-1) in the planning period of 1996, it was 125.1 tC ha(-1) in 2018. This was an increase of +11.7 tC ha(-1) over 22 years. In the 22 year planning period covering 1996 and 2018, the increase in productive forest areas, expansion of protection oriented functions, and the moderate silvicultural treatments applied to the forest stands positively affected on the carbon stock increase in the study region.
Sampling surveys are broadly employed in forest inventories due to their efficiency in quantifying forest characteristics. To this end, selecting an appropriate sampling method is essential. This study introduces a new application of horizontal point sampling (HPS). We assess the statistical properties of HPS with variations in crown basal area factor (CBAF) and sample sizes (n). The study further conducts a comparative analysis between HPS and fixed-radius (FR) plot sampling methods. The study was done in an actual open coppice forest and in a simulated forest, using sampling simulations with a large number of repetitions. In HPS, a greater CBAF for a given sample size lead to a higher relative standard error (RSE %). Multiple regression model showed that both n and CBAF influence RSE %. There was an inverse relationship between n and RSE%, whereas a positive relationship was found between CBAF and RSE %. A combination of HPS and crown relascope is easily applicable in forest inventories. This combined method demonstrates efficiency, when compared to the traditional FR for estimating crown cover area in open coppice forests.
The primary aim of this investigation was to examine the morphological diversity of leaves in naturally occurring populations of common hornbeam (Carpinus betulus L.) in Turkiye. Twelve common hornbeam populations, distributed over four distinct watersheds in the Eastern Black Sea Region, were sampled from three altitude levels, ranging from sea level to 1200 meters. Nine morphological characteristics of the leaves were analyzed biometrically. We found a high degree of phenotypic heterogeneity both within and among the investigated populations. The eco-geographic principle's classification of populations was disclosed. Altitude appeared to be the primary factor influencing variation in the majority of leaf attributes from the Camlihemsin, Caykara, and Espiye watersheds. Compared to trees at lower altitude, trees at higher altitudes were characterized by smaller leaves. The populations in the Trabzon-Macka watershed, however, did not show this trend. Largest leaves were observed for trees from the Trabzon-Macka watershed region at the second altitude level. Overall, our findings support the notion that the Eastern Black Sea area is a hotspot of biodiversity and that the intricate evolutionary process leading to leaf morphological variability may be a consequence of adaptation and plasticity.
