https://www.ijf-isaforestry.ir/ Iranian Journal of Forest en daily 1 Mon, 15 Jan 2024 00:00:00 +0330 Mon, 15 Jan 2024 00:00:00 +0330 https://www.ijf-isaforestry.ir/article_187611.html Introduction and Objective: ALS data has been widely used to describe the 3D canopy structure due to collection of 3D point clouds with high spatial resolution and accuracy. Individual tree detection using LiDAR data is an efficient method for extracting the structural characteristics of the forest such as tree height, diameters at breast height and above-ground biomass. Accurate estimation of these parameters is of key importance in the management of forest resources.Material and Methods: So far, different methods have been developed to detect single trees, which have different limitations and capabilities and show different reactions to changes in forest tree species and canopy vertical structure. Therefore, in this research, a quantitative approach was developed in order to evaluate the scientific-technical performance of six single tree detection algorithms from ALS data. These methods include two raster-based methods, two point-based methods and two combined methods. Due to lack of access to LiDAR and ground data from Iran's forests, the unique dataset of the NEWFOR project was used, which covers different forests of the Alpine region with a variety of tree species and different canopy structures.Results: The results showed that the vertical structure of the canopy plays a significant role in detection accuracy of ITD methods and its effect is greater than the composition of forest tree species. The highest detection rate is related to the combined method in single-layered coniferous forests with a value of 0.91 and the lowest detection rate is related to raster-based method in multi-layered mixed forests with a value of 0.45. The detection rates of the studied methods in the highest height layer vary from 66% to 91% and in the lowest height layer (2-5 meters) from 13% to 52%. Conclusion: Although the understory trees cannot be extracted with the same accuracy as the dominant trees, the results showed that the hybrid method of marker-controlled watershed segmentation with K-means clustering algorithm was able to detect 91% of the trees in the highest height layer and the highest number of understory trees with a detection rate of 52% in the lowest height layer. This method has the highest values of detection rate, detection accuracy and overall accuracy with values of 0.83, 0.91 and 0.87 respectively, the lowest amount of commission and omission errors with values of 9.03% and 17.36% respectively and also the best horizontal and height accuracy with values of 1.33 m and 0.87 m, respectively. https://www.ijf-isaforestry.ir/article_212576.html Understanding forest structure, biodiversity, and local disturbance patterns is critical for effective community forest management, yet such integrated assessments remain limited. This study evaluates forest structure, plant biodiversity, and the spatial distribution of local disturbances in three community forests (Banelpokhari, Okhardhara, and Suntalidada) located in Godawari Municipality, Nepal. Using a systematic random sampling design, 90 circular plots were established to measure trees (500 m²), poles (100 m²), saplings (25 m²), and seedlings (10 m²). Biodiversity indices (Shannon–Wiener, evenness, richness, Importance Value Index) were computed, and Sentinel-2A imagery (2017 and 2022) was analyzed using NDVI to assess land cover changes. Results show that Pinus roxburghii was the dominant species across all forests, with the highest IVI (281.25) in Okhardhara CF. Suntalidada CF exhibited the greatest Shannon–Wiener diversity (H' = 3.52), evenness (0.96), and species richness (25). Forest structure revealed the highest stem density in the 0–10 cm diameter and 0–5 m height classes, and the lowest in >40 cm and >20.1 m classes. Key disturbances included road development, encroachment, soil erosion, and illegal logging. From 2017 to 2022, dense forest cover decreased by 9% (Banelpokhari), 19% (Okhardhara), and 11% (Suntalidada), with concurrent increases in sparse vegetation and infrastructure. These findings underscore the need for targeted conservation interventions, adaptive management, and collaborative approaches to mitigate anthropogenic pressures and sustain biodiversity in community-managed forests. https://www.ijf-isaforestry.ir/article_231273.html The importance of the Hyrcanian forests, along with the growing wave of environmental concerns about their protection, as well as certain political orientations, led to the Iran’s Sixth Development Plan law banning any timber utilization of forest trees. This ban, which became known as the Forest Breathing Plan, has been viewed by many forest experts as a disregard for the multiple functions of forests, a weakening of Principle 45 of the Constitution, destruction of national wealth and Anfal, layoffs of workers, forest rangers, and chainsaw technicians, leaving them in the abyss of inaction and unemployment, and sometimes creating or strengthening a sense of revenge against the forests and the Natural Resources and Watershed Organization, manifesting in aiding, accessary or stewardship in the crime of timber smuggling. In contrast, the main arguments of those in favor of the Breathing Plan focused on banning forest harvesting, citing the need to protect the Hyrcanian forests as a biosphere reserve, avoiding encroachment on forests by relying on supplying the required wood through imports and tree plantations, allocating budget for forest protection by Parliament, and similar matters. Either way the cessation of wood harvesting from forest trees has led to a shortage of wood production, increased demand from the wood industry, and rising prices. As a result of local poverty and the greed of some smugglers, the forests have become vulnerable to timber smuggling. This situation undermines the establishment of environmental justice between those who commit smuggling for subsistence purposes compared to professional smugglers. The present study attempts to examine the perspectives of forest guards of the Rostam-Abad Natural Resources Unit in dealing with timber smuggling, using open and semi-structured focus group interview techniques. The interview was recorded and transcribed in Word software and analyzed with NVivo software. From the perspective of the Forest Security Unit, the most important reason for resorting to smuggling is the high profits from selling smuggled timber. Also, the lack of organizational transportation vehicles and the lack of legal protection against smugglers are among the most important challenges for the guards. In their opinion, spreading a culture of respect to environment, seeking help from local people, making a sense of belonging to the forest in forest dwellers, and being aware of the heavy fines for timber smuggling are the most important social and cultural solutions to combat this crime. Additionally, the main policy to combat timber smuggling is stated to be inter-sectoral cooperation between organizations. According to interviewees, the performance of the Natural Resources Organization in combating timber smuggling is considered successful and acceptable, especially after the increase in the number of security companies since 2018. Finally, the research concludes that revising the implementation of the Breathing Plan and the cessation of forest timber utilization, amending laws related to tree felling and formulation of new and positive policies to combat timber smuggling, are among the most important solutions in the southern forests of Guilan province. https://www.ijf-isaforestry.ir/article_243803.html The cost of maintaining forest roads is an important factor in forest management and is related to pavement deterioration and the identification of factors affecting the pavement. The aim of this study was to evaluate the deterioration of forest road pavements over a four-year period in watershed 25 of Shenroud in Guilan Province. For this purpose, 213 sample plots were selected through systematic random sampling and measured. In each sample plot, the pavement deterioration index was measured based on seven indicators: deteriorated cross-section, deteriorated drainage, dust production, corrugation, potholes, ruts, and soil mass loss. Friedman test, analysis of variance, and Duncan’s test were used to analyze the data. The results showed that over time, deterioration caused by cross-section, roadside drainage, dust production, corrugation, and soil mass loss increased, and there was a statistically significant difference between the beginning and the end of the study period. The mean depth (from 4.57 to 4.77 cm), area (from 4.44 to 4.50 cm²), and number of potholes (from 1.23 to 2.20), as well as the mean depth (from 1.95 to 2.00 cm), area (from 1.22 to 1.24 cm²), and number of ruts (from 0.43 to 0.45), showed an increasing trend. The statistical results showed that there was a significant difference between the number of potholes in different years, while there was no significant difference among pothole area and depth or rut area, depth, and number across the different study periods. The results of Duncan’s mean comparison test also showed that there was a significant difference between the average number of potholes created at the end of the study period (2023) and at the beginning of the period (2020). In general, the results of this study show the importance of carrying out continuous maintenance operations and the need to use evaluation indicators in planning forest road pavement maintenance. https://www.ijf-isaforestry.ir/article_231425.html Accurate forest biomass estimation, productivity, yield regulation, and carbon stock rely on precise volume prediction at both the individual tree and stand levels. This study, titled “Comparison of Standing and After-Felled Volume of Timber in Teak Plantation in the Sagarnath Forest Development Project, Nepal,” was conducted in the Sagarnath Forest Development Project (SFDP) in Sarlahi District. The primary objective of this research was to calculate the disparity in timber volume before and after harvesting in a teak forest. The 2D felling site provided 150 sample trees for data collection. Before felling, the diameter at breast height (DBH) of standing trees was measured using a diameter tape, tree height was measured with a range finder, and tree quality class was determined based on community forest inventory guidelines. After felling, the total length of the log, girth at the mid-length of the log, and the length and diameter of hollowness and the depth of the buttress were measured using a measuring tape. To compute timber volume before felling, the formula defined in the Community Forest Resource Inventory Guideline, 2061 was utilized, while the quarter-girth formula was employed to calculate timber volume after felling. The findings indicated an overestimation of 696.80 cubic feet of timber before harvesting. A 95% confidence interval F-test demonstrated a significant difference in timber volume before and after felling. There was a loss of 14.58 cu. ft of timber volume due to hollowness in the tree, and 83.10 cu. ft of timber was lost due to buttresses. Likewise, a difference in volume was observed based on quality class due to inaccurate classification. https://www.ijf-isaforestry.ir/article_243806.html The Arasbaran forest is one of the genetic hotspots of the biosphere due to its high species diversity, and the white oak species plays a special role in the composition and diversity of the biological elements of Arasbaran forests. In this regard, it is necessary and important to evaluate the genetic diversity of the identified seed production area of white oak. In this research, the genetic diversity within and between seven different white oak populations, including 49 different trees, was investigated using the SCoT molecular marker. A total of 129 alleles were observed for these markers, and 100% of the produced alleles were polymorphic. The number of alleles varied from 16 to 29, with marker SCoT41 having the highest number at 29 alleles and marker SCoT7 having the lowest number at 16 alleles. Analysis of molecular variance (AMOVA) showed that 90% of the observed genetic diversity was distributed within populations, while 10% occurred among populations, suggesting that genetic variability within populations was more significant than that among populations. Based on the UPGMA dendrogram, individuals were partitioned into six distinct clades, and according to the UPGMA and PCA patterns, geographical proximity has not played an important role in the formation of the genetic structure of these populations. This research has provided initial insight into the genetic diversity within and between different populations of the Arasbaran white oak species. As a result, it is suggested that, by studying other markers, useful information for conservation and management measures for this valuable species can be obtained. https://www.ijf-isaforestry.ir/article_243808.html Wildfires present a major threat to the ecologically valuable forests of the Zawita District in northern Iraq, where anthropogenic activities (human-caused) and limited firefighting capability create additional threats. While there is an actual fire station (F1) in the district, its coverage is limited. Thus, this study sought to test whether the addition of a new fire station (F2) in the center of the district would improve suppression efficiency. Using GIS-based network analysis software (ArcGIS 10.8), we modeled road accessibility and travel time to 33 forest zones based on assumptions regarding asphalt and forest road conditions. Travel times for firefighting trucks were calculated for both F1 and F2 conditions under a critical response time of 15–20 min. We developed a third-degree polynomial regression model and validated the relationship between response time and burnt area, with excellent fit (R² = 0.9999 calibration; R² = 0.9984 validation). Predicting burnt areas for both F1 and F2 scenarios for all forest zones enabled quantifying their relative effectiveness. F1 covered 72% (305 km²) of the study area over the 20-minute time frame, while F2 covered 70% (293 km²). While F1 had one more zone in the critical time frame compared to F2 (27 vs. 26), our regression model shows that F2 produced quicker responses in the key central zones, which led to a net reduction of 288000 m2 of burnt area in the district. The polynomial model demonstrated that brief delays in response time had an exponential effect on fire damage, emphasizing the need for better and strategically placed stations. The suggested model incorporates both stations (F1 + F2) to achieve the best trade-off in overall geography and improved accessibility from a central location. This recommendation corresponds to increased capacity for wildfire suppression, less loss of forests, and serves as a precedent for disaster planning in similar ecologically sensitive, resource-poor areas. https://www.ijf-isaforestry.ir/article_243810.html Zagros forests play a significant role in carbon sequestration; however, the contribution of rare species such as Anagyris foetida L. (Ghareh Ghaj)—with unique traits such as thick leaves and summer dormancy—has been less studied. This research developed, for the first time, species-specific allometric models for this endangered tree to provide a non-destructive estimation of leaf carbon storage and LAI1. The study was conducted in the pure habitat of the species within the Sardasir Chaleh basin (Gilan-e-Gharb). Using systematic line sampling, 30 healthy trees were selected, and biometric parameters (height, crown diameter, and crown area) were measured. Leaf samples were collected from three crown sections and analyzed in the laboratory to determine dry biomass (gravimetric method), organic carbon percentage (combustion in a furnace), and leaf area (leaf area meter). LAI and SLA2 were calculated and scaled up to the forest stand level using the "Mean Tree" method and a density of 253 trees per hectare. Allometric relationships were analyzed using linear, logarithmic, and power regression models. Results showed that mean LCS3, CO₂ uptake, and leaf dry biomass per hectare were 468.13 kg of carbon, 1718.03 kg, and 975.27 kg, respectively. The average LAI at the individual-tree and per-hectare levels was 1.6 and 0.302, respectively. Statistical analyses revealed a strong and significant correlation between crown area and both leaf biomass and LCS, with the linear model based on crown area providing the best fit for predicting LCS (R² = 0.719). In contrast, LAI was only significantly correlated with leaf dry biomass. Overall, the results indicate that, despite its prolonged dormancy period, this species contributes considerably to leaf carbon storage in Zagros forests due to its relatively high density and distinct crown architecture. The simple, crown area-based models presented offer a practical and cost-effective tool for carbon monitoring, ecosystem service valuation, and the development of conservation strategies for this endangered species and similar Mediterranean ecosystems, representing a significant step toward sustainable forest management. https://www.ijf-isaforestry.ir/article_243812.html Introduction: Forests cover about 30% of the Earth’s land surface, but in Iraq they are limited, mainly confined to the northern region, totaling around 1.26 million hectares, or 2.9% of the country’s land area. Forests in this region include coniferous and broad-leaved types. Coniferous forests are dominated by pines, which make up approximately 80% of the stand. Calabrian pine (Pinus brutia), native to the Duhok governorate in northern Iraq, covers an area of approximately 50,000 ha in Zawita, Atrush, and Belkaf. This study deals with the regression of crown width on diameter at breast height to be used in the development of a competition index. Crown width is important for forest dynamics, biodiversity, carbon sequestration, and overall ecosystem health. Materials and Methods: Field data were collected from three distinct locations within Duhok Province, Kurdistan, Iraq. In total, 480 trees were sampled from both open-grown and stand-grown trees. A total of 160 trees were selected from each location (80 open-grown trees, which were free from all competition, and 80 stand-grown trees, where there was inter-tree competition regarding resource access). Of these, 50 trees were used for calibration, while 30 trees were used for validation, resulting in a balanced and robust dataset for analysis. Using Statgraphics Centurion 19 software, separate regressions of Crown Width (CW) against Diameter at Breast Height (DBH) were developed for both tree types. Six groups of allometric regression equations were evaluated using criteria that included the coefficient of determination (R²), bias, mean absolute error (MAE), Ohtomo’s unbiased test, and additional proposed metrics. Results: Crown width was regressed on diameter at breast height using different types of functions; among them, linear, nonlinear, and logarithmic models with different forms of dependent variables were used. Upon statistical analysis of the developed models, the linear model of the form, Cw = b₁ + b₂ DBH, was selected as the most appropriate one that fit the study data in both tree types across all locations. As a result, there was no major difference between the regression slopes for open-grown trees and those for trees growing within a stand. In addition, this study presented a new method for calculating the competition index. Conclusion: From the analysis of the samples collected, certain key conclusions can be drawn. First, in all the study sites, the relationships between crown width and diameter at breast height (DBH) did not show any statistically significant differences between open-grown and stand-grown trees. This indicates a relatively low stand density, resulting in minimal competition for resources among stand-grown trees. Second, given the improvement of overall forest structure and productivity, it is advisable that replanting strategies should fill the existing canopy gaps in all sites, since this will make better use of available resources, promote the long-term health of forests, and maintain biodiversity. Lastly, the present study confirmed a strong linear relationship between crown width and DBH for Calabrian pine in Iraq. https://www.ijf-isaforestry.ir/article_218806.html Introduction: Estimating the volume stock of poplar plantations plays an important role in understanding the current status and sustainable management of these resources in order to planning production and improve management decisions for the development of wood farming in Chaharmahal and Bakhtiari province. The stem form factor is one of the most important characteristics for determining the exact volume of trees. The aim of this research is to determine the stem real form factor for white poplar (Populus alba L.) and compare it with the natural and artificial form factors. Material and Methods: To conduct this research, first, the major poplar plantation stands were identified in the province using the field operations. Then, in 10 different stands of poplar plantation with white poplar species, a total of 67 trees were selected using stratified random sampling method based on diameter classes. After selecting the sample trees, their diameter at breast height and total height were measured, and from the height of the stem base of each sample tree, the location of 2 m sections and the diameter at 0.1 of the tree height were determined using a Leica model D810 laser device, and then the diameter of that height was measured using the same device without felling the trees. Then, the real volume of each tree stem was obtained from the sum of the volume of 2 m logs using the Smalian’s formula to be used in calculating various stem form factors. To check for a significant difference between the stem real form factor with the other two form factors (natural and artificial), a paired t-test was used.Results: The results showed that the stem form factors of real, natural and artificial of white poplar in this province were 0.44, 0.47 and 0.39, respectively. Also, the results of the paired t-test showed that there was a significant difference at the 99% confidence level between the form factors of artificial and natural with real. Also, based on the calculated slenderness coefficient, the studied poplar plantations were unstable in all diameter classes. Conclusion: According to the results of this study, it can be concluded that the form factors of natural and artificial cannot be used as a substitute for the real form factor for white poplar species in this province. The findings of this research can provide valuable basic information for use in determining the exact standing and saleable volume of each poplar tree, planning and management decisions in the field of wood farming development and related industries development in Chaharmahal and Bakhtiari province. https://www.ijf-isaforestry.ir/article_224723.html Introduction and Objective: Due to the extensive climate changes and the increase in the frequency of drought stress, the Hyrcanian forests are facing serious threats that challenge the growth and dynamics of native species of these unique ecosystems. Caucasian alder (Alnus subcordata C.A.Mey.), as one of the key species in afforestation and rehabilitation of degraded lands, is particularly affected by these climate changes due to its environmental characteristics and strong need for water resources. Since this species plays an important role in nitrogen fixation and maintaining the stability of Hyrcanian forests, it is necessary to study the effect of drought stress on its presence and distribution, both in terms of biodiversity protection and forestry management. According to the literature review, no research has been done regarding the effect of drought stress on the distribution of alder species, so the purpose of this research was to investigate the effect of drought stress on the distribution of alder species in the entire area of Hyrcanian forests.Material and Methods: This research was carried out in the entire area covered by Hyrcanian forests. For this purpose, the data bank of forest inventory in the north of the country was used. Meteorological data, including annual precipitation and mean annual temperature, were obtained from the POWER project. In order to calculate the drought stress, the medfate software package was used in R software. In this research, environmental variables including elevation, slope, radiation, annual rainfall, mean annual temperature, distance from the valley, topographic location index, topographic curvature, topographic humidity index and drought stress were prepared for each sample plot, and were used for modeling the suitable habitat of Caucasian alder. Caucasian alder distribution in Hyrcanian forest was predicted using three models including random forest (RF), support vector machine (SVM) and generalized linear model (GLM). Modeling algorithms and relative importance of variables were implemented and calculated in the caret package in R software. The cross-validation technique was used to evaluate the performance of the models. Then, the area under the curve (AUC) statistic was used to evaluate the performance of each model.Results: The value of the area AUC for the RF model (0.73) was higher than other models. Elevation and drought stress were respectively the most important factors for predicting the presence of Caucasian alder using the RF model. Also, based on the results of SVM and GLM, annual rainfall was the most important factors in predicting the presence of Caucasian alder. Also, the results of investigating the respond of Caucasian alder to the elevation and radiation using the RF model showed that the probability of Caucasian alder presence increases with the increase of both variables. While the probability of Caucasian the presence of alder decreases with the increase of drought stress. The results of interpolation maps showed that Caucasian alder has a higher probability of presence in the western and central parts of the Hyrcanian forest, while the probability of its presence in the eastern parts of the Hyrcanian forest is very low.Conclusion: The results of the present study showed that drought stress is one of the most important factors limiting the distribution of Caucasian alder in Hyrcanian forests. The decrease in rainfall and increase in temperature due to climate change will increase the drought stress in the region and will directly limit the growth and regeneration of alder. In general, it is suggested to avoid afforestation with Caucasian alder in areas that are vulnerable due to drought stress, and instead use species more resistant to low water conditions in order to preserve the structure and function of forest ecosystems in the best way. https://www.ijf-isaforestry.ir/article_227249.html Quantitative description of forest structure are recognized as one of the most effective tools in modern forest management. As such, obtaining accurate and comprehensive information about the structure of tree species is crucial for the sustainable management of forest ecosystems. This study, conducted as part of a comprehensive monitoring plan for the Zagros forests using place-based monitoring, evaluates the structure of two forest stands: Sarabtaveh on the northern slope and Parikadan on the southern slope in the forests of Boyer-Ahmad County, Kohgiluyeh and Boyer-Ahmad Province. In each stand, a one-hectare square sample plot was randomly established, and quantitative variables related to tree bases were measured. The findings revealed that the dominant tree form in both stands was coppice or branch-derived. The spatial distribution pattern for the dominant species, Persian oak, was clumped in both regions. The mingling index was calculated as 0.23 for Parikadan and 0.14 for Sarabtaveh, indicating higher species diversity in Parikadan compared to Sarabtaveh. However, the mingling index for both regions (study area) was relatively low, which aligns with the fact that Persian oak is the predominant species in the studied areas. The Clark-Evans index was 0.61 for Parikadan and 1.13 for Sarabtaveh. The diameter differentiation index was 0.33 for Parikadan and 0.32 for Sarabtaveh, suggesting no significant difference in the average diameter at breast height (DBH) and highlighting the homogeneity of trees in terms of diameter. Additional measurements and calculations included the uniform angle index, diameter dominance indices, canopy cover, neighborhood distance index, and structural diversity index, among others. The results of these indices provide a valuable foundation for comparing the studied forests with other similar ecosystems and identifying deviations caused by natural processes and human activities. Such comparisons will contribute to the development of effective management models and appropriate forestry methods tailored to the region's forests. https://www.ijf-isaforestry.ir/article_231426.html Since time immemorial plants have been used as a source of food & medicine. At present, the traditional knowledge on medicinal plants and its practices are at the risk of extinction. Therefore, this study aimed to list out medicinal plants used by indigenous people to treat human diseases, explore the ethnobotanical knowledge and its parts used & assess its knowledge level with respect to demographic characteristics. Questionnaire survey (n=68), key informant interviews (KII=8), focus group discussion (FGD=4) & Field visits were adopted for the primary data collection. Cluster sampling technique was applied & entire respondent were interviewed using semi-structured set of questionnaires. Chi square test for independence was used to find out significant differences. Altogether 99 medicinal plant species belonging to 60 families & 88 genera were documented for the treatment of various ailments. Highest number of plant species belonged to family Poaceae with 5 number of plants respectively followed by families Asteraceae and Zingiberaceae with 4 plant species each. From this research, it was found that herb (56%) as most dominant form followed by trees (16%), climber (12%), shrub (9%), grass (6%), stoloniferous (1%), fruit (17%) as most utilized part of the medicinal plants followed by root, leaf, whole part. Corm is the least used plant part by 1%. Allium sativum was found to be a species with high use value (UV=1.3) followed by Rubus ellipticus whose UV was found to be 1.23. Our findings reveal significant differences (p < 0.001) in the number of plants described across gender and age groups, while no significant variation (p > 0.05) was observed among different ethnic groups. These results highlight the critical need for programs focused on documenting and cultivating medicinal plants. Actively involving local communities as both participants and educators is essential to the effective conservation and sustainable use of these resources, ensuring the preservation and transmission of invaluable indigenous knowledge to future generations. https://www.ijf-isaforestry.ir/article_240658.html Introduction: Setting the wheels of sustainable development in environmental areas, including mangrove forests, in motion requires social-based management. The aim of this study is to investigate the drivers affecting the participation of local communities in the mangrove social forestry project.Materials and Methods: The scope of this study is the three villages of Soheili, Tabl, and Haftrangou on Qeshm Island. The statistical population includes fishing, tourism, and dock workers, of whom 211 people were randomly selected as a sample. The questionnaire was the measurement tool of this study. The questions were a five-point Likert scale from very low (1) to very high (5). The validity of the questionnaire was confirmed by using university professors and a technical expert from the Hormozgan General Directorate of Natural Resources. Cronbach's alpha values were calculated to estimate the reliability of the questionnaire for "willingness to participate", "economic factors", "social", "environmental", "environmental knowledge" and "perceived environmental value" as 0.92, 0.90, 0.86, 0.92, 0.85 and 0.89, respectively. SPSS version 25 software was used to analyze the research data. Mean and standard deviation were used in the descriptive statistics section. Stepwise regression was used to examine the determinants of willingness to participate in the mangrove social forestry project. Then, a causal path analysis model was used to explore the direct and indirect effects of independent variables on the dependent variable. Results: Participants reported a mean score of willingness to participate related to the mangrove social forestry project of 3.18 (standard deviation = 1.067). Also, the results showed that the economic factor was the strongest predictor of the community's willingness to participate in the mangrove community forestry project (β = 0.444, p < 0.000). Perceived environmental value was the second factor for predicting the willingness to participate (β = 0.388, p < 0.000) and social factors were the third predictor for the dependent variable (β = 0.381, p < 0.000). According to the causal model of the research, the highest direct effect on the willingness to participate was related to the "economic" index, and the highest indirect effect and the highest total effect were related to the "perceived environmental value" index.Discussion: Among the variables studied, the economic index was the strongest predictor of participation and had the highest direct effect on the willingness to participate in the mangrove community forestry project. Due to the expectations of local communities regarding the economic impact of these projects on their livelihoods and in order for the mangrove social forestry project to be effective, the economic dimension of the project should be given more attention by planners and decision-makers. Therefore, with coherent planning and continuous monitoring of the implementation of the mangrove social forestry project, it is possible to provide a platform for improving the economic situation and, as a result, a desire for greater participation of local communities.Conclusion: According to the results of the research, mangrove social forestry, with its emphasis on sociality, takes on its true meaning when local people actively take steps towards sustainable development. Achieving sustainable development is possible by moving through the economic channel and focusing on the economy of the projects. https://www.ijf-isaforestry.ir/article_241784.html Introduction: To preserve and restore natural habitats, before any work, sufficient information should be available on the effects of constituent plant species on environmental factors and their habitat needs. Identifying the constituent elements of the forest, is the most principled way to optimally manage its, because nutrients and soil microorganisms activities, especially in arid and semi-arid ecosystems, accumulate under the canopy, and these effects are also related to the size and extent of the canopy and cause changes in the various soil characteristics. So far, no research has been conducted on the various soil characteristics under and outside the canopy of the native and valuable species of Ziziphus spina-christi (L.) Desf. and Ziziphus nummularia (Burm.f.) Wight & Arn., as well as determining their soil quality index in these habitats. The purpose of the present study is to investigate the effect of their canopy cover on various soil properties so that, by better understanding and being aware of their impact on the soil and the causes of changes in their habitat, a general perspective can be provided to managers in the fields of natural resources.Materials and Methods: 15 soil samples were randomly collected from the surface soil under the canopy and outside the canopy (control) of natural masses Z. spina-christi in Dashti and Z. nummularia in Dashtestan in Bushehr province in an eastward direction from a depth of 0 to 15 cm. To obtain a composite soil sample from under and outside the canopy of Z. spina-christi and Z. nummularia trees, soil samples taken from under and outside the canopy of all three trees (randomly) were thoroughly mixed together and converted into a composite sample, resulting in five composite soil samples from under the canopy and five composite soil samples from outside the canopy of Z. spina-christi and Z. nummularia trees. Using standard methods, the physical, chemical and biological properties of the soil were measured in the collected samples. Then, the normality of the some variables was confirmed by the Shapiro-Wilk test and the positions under and outside the canopy of the normal data of the two species, Z. spina-christi and Z. nummularia, were compared with the Independent T-test and the non-normal data with the non-parametric Mann-Whitney U test. Soil quality index was obtained based on three steps: determining the minimum data, giving a score to each of the data used, and merging and averaging the scores, and was analyzed as above.Results: Under the canopy of the Z. spina-christi, Mn and Zn respectively, 202.8±9.3 and 49.2±1.46 (mg/kg), basal microbial 2.08±0.09 (mg CO2.gˉ¹ dm.24 hˉ¹) and Substrate-induced respiration 59.02±6.35 (mg CO2.100 gˉ¹ dm.hˉ¹), under the canopy of the Z. nummularia, saturated moisture 41.2±0.71 (%), Oc, 26.2±0.12 (%), N, 0.22±0.012 (%), and microbial biomass carbon 2.98±0.36 (mg biomass-C.100 gˉ¹dm), outside the canopy of Z. nummularia, Na, 4670±59.54 (mg/kg), were significantly more. Under the canopy of both species, pH, 7.38±0.04 and 7.64±0.06, P, 959.6±21.24 and 783±8.3 (mg/kg), nitrification potential 376.87±17.64 and 633.23±59.93 (µg N.gˉ¹dm.5hˉ¹), and SQI 8.74±0.04 and 8.8±0.15, respectively, were significantly more.Conclusion: The exchange of nutrients, biological activities and soil quality index were higher under the canopy of Z. spina-christi and Z. nummularia trees. Therefore, the type of tree species and canopy cover can have different effects on different soil properties, and improve the their properties, it is necessary to maintain the vegetation cover of the area and, if necessary, restore it with native species. With continuous soil monitoring, at different time intervals, it is predicted that in the future it will be possible to more accurately assess the changes in the soil of their habitats and collect valuable information. https://www.ijf-isaforestry.ir/article_243931.html Introduction: The forests of western Iran are among the natural ecosystems whose regeneration has been severely disrupted by anthropogenic and natural factors. Among these, livestock browsing is one of the most significant drivers of vegetation degradation and morphological alterations in plant species. This biotic stress can impair plant competitive ability by damaging photosynthetic organs, reducing growth, and altering leaf structure. This study was conducted to investigate the effects of livestock grazing on the anatomical traits of leaf stomata and trichomes in Prunus argentea (Lam.) Rehder, a shrub species native to the region. Given the limited experimental and laboratory-based studies on the micro-morphological responses of this species to environmental stressors, the present study aims to elucidate how browsing induces changes in leaf microstructure, thereby triggering distinct adaptive responses that may reflect divergent survival strategies under browsing pressure. Furthermore, the study identifies which leaf traits exhibit the highest degree of plasticity in response to the stress. The findings may contribute to improved forest management and conservation of valuable tree species that are also important forage resources.Materials and Methods: In each of two study sites near Ilam City (Darreh-ye Arghavan and Choghasabz), three individual Prunus argentea shrubs exposed to continuous livestock browsing were randomly selected (six shrubs in total). For each selected shrub, leaf samples were collected from both lower branches (accessible to browsing animals) and upper branches (out of reach of browsers). Sampling was conducted along the dominant slope direction at each site. Overall, six samples per site (three shrubs × two vertical canopy positions) were collected. From each shrub, 10 leaves were randomly collected from lower (browsed-accessible) and 10 from upper (non- browsed) branches. To enhance observation of stomata and trichomes, photosynthetic pigments were removed from the abaxial leaf surface. Following staining and preparation of microscopic sections, 11 anatomical traits related to stomata, trichomes, and vein density were measured using a digital camera equipped with image analysis software. All measurements were repeated to ensure high repetition and accuracy.Results: The results indicated that livestock browsing significantly altered most leaf anatomical traits. Specifically, the mean length and width of stomata, stomatal pore length, stomatal density, and stomatal pore index were significantly reduced under browsing pressure. In contrast, trichome dimensions, including length, width, and density, showed a significant increase in browsing conditions. Principal component analysis (PCA) revealed that traits such as stomatal density and stomatal pore index contributed most to the separation of non- browsed samples, whereas vein density and trichome width were more influential in distinguishing browsed samples. Furthermore, leaf trichome traits exhibited higher phenotypic plasticity compared to stomatal traits in Prunus argentea.Conclusion: Overall, livestock browsing exerted significant effects on all anatomical traits of stomata and leaf trichomes, leading to notable changes in both the size and density of these structures. The high plasticity observed in trichome-related traits suggests a strong adaptive capacity of Prunus argentea in response to browsing-induced stress and altered environmental conditions. Therefore, anatomical modifications in leaves likely impact plant performance and physiological efficiency, potentially reducing overall productivity. These findings highlight the importance of considering plant structural plasticity in ecological restoration and sustainable forest management, particularly for species that are both ecologically and economically valuable. https://www.ijf-isaforestry.ir/article_243994.html Introduction: Variation in species composition and tree distribution leads to highly complex characteristics in forest ecosystems, arising from interactions among smaller‐scale spatial structures. Forest stand structure encompasses three major aspects: spatial pattern diversity, species diversity, and tree size diversity. The present study aimed to determine the minimum plot size required to assess structural characteristics of Juniperus excelsa M. Bieb. stands and to evaluate the structural diversity of these stands in the Aminabad forest reserve of Firuzkuh, located within the Irano–Turanian phytogeographical region. Materials and Methods: Three 3-ha sample plots (three stands) were randomly chosen., each consisting of six nested square subplots with areas of 0.5, 0.75, 1, 1.5, 2, and 3 ha. For all trees and shrubs within each subplot, species identity, spatial coordinates, height, and crown variables (maximum crown diameter and its perpendicular diameter) were measured. Tree spatial coordinates were recorded using a multi-frequency GPS. Stand structure was quantified using the uniform angle index, nearest-neighbor distance, mingling index, tree size differentiation, and size dominance indices. To determine the most appropriate plot size, species–area curves and statistical comparisons of variables across different plot sizes (analysis of variance and Kruskal–Wallis test) were applied. Results: A total of 13 tree and shrub species were recorded in the study area. Analysis of species number variation with increasing plot size showed that species richness increased up to 1.5 ha, after which the curve reached a plateau and species number remained constant; however, with further increase to 3 ha, species richness increased again. The first increase represented the species within the target plant association, whereas the second increase resulted from inclusion of areas outside the association boundary. Mean crown diameter of Juniperus trees did not differ significantly among plot sizes. Mean tree height also showed no significant difference among plots ranging from 1 to 3 ha, although in the first station significant differences were observed compared with smaller plots. No significant differences were detected in shrub size attributes among different plot sizes; however, results indicated that plots smaller than 1 ha may not include a sufficient number of shrub individuals for reliable analysis. The uniform angle index indicated a random pattern tending toward clustered in the first and second stations and a random pattern in the third station, with no significant differences in spatial distribution patterns of trees and shrubs across plot sizes. In none of the stations did mingling, size diversity, or composite structural diversity indices show significant differences when plot size increased from 1 to 3 ha; however, significant differences were observed in smaller plots, particularly in the first and third stations. Conclusion: Based on the results, a plot size of 1 ha was identified as appropriate for structural studies of Juniperus forests in Alborz. In stands with higher density (e.g., the second stand), satisfactory results can also be obtained using 0.75-ha plots, whereas in lower-density stands (e.g., the first stand), plots of up to 1.5 ha may be required. To record tree and shrub species within a Juniperus association, an area of approximately 1.5 ha is necessary, while larger areas (up to 3 ha) are required to capture the complete tree and shrub flora of Juniperus habitats.