مجله پژوهش و توسعه جنگل
سال ششم شماره 2 (تابستان 1399)

In the present study, firstly, the effective factors of Golestan national park forests fire have been identified. Then, by using these factors, forest fire development modeling is performed based on cellular automata. Multiple linear regression and genetic algorithm are used to determine the effective factors on Golestan national park forests fire. In order to investigate the effect of spatial resolution of the maps are used on the results of modeling, effective factors have been generated in different spatial resolution and these data are used as the input of the proposed algorithm. Also, the neighboring filters 3×3, 5×5, and 7×7 are used to investigate the effect of the neighboring filter in the forest fire development process. Cellular automata is used for modeling Golestan national park forests fire development, and the artificial bee colony is proposed to calibrate it. The results of this study show that using the proposed algorithm with 3×3 neighboring filter is more accurate than the other neighboring filters. In the best case, the Kappa index, the overall accuracy, and the relative operating characteristic are 0.924, 0.960, and 0.494, respectively that these results are for spatial resolution of 30 meters on November 17, 2010.

This study aimed to investigate the effect of Rhus coriaria and Amygdalus scoparia plantation on some chemical properties of understory soil in rangelands of Kakhk region in Khorasan Razavi province. For this purpose, two regions including has been improved area and has not been improved area (control area) were determined. Treatments including understory soil of Rhus coriaria area, Amygdalus scoparia area and control area. Soil sampling by Random systematic method was performed at depths of 0-20 cm in understory soil from each area. The number of samples consisted of: 20 samples from restoration area and 10 samples from control area (30 samples). The soil chemical properties including EC, pH, nitrogen, organic matter, carbon, potassium, calcium, sodium, magnesium, sulfate, bicarbonate and chlorine were measured. In order to study the effect of Rhus coriaria and Amygdalus scoparia plantation on some chemical properties and determine the most effective soil factors, one-way Analysis of Variance (ANOVA) and Principal Components Analysis (PCA) were used respectively. The results of ANOVA showed that, the effect of plantation of Rhus coriaria and Amygdalus scoparia on all soil chemical properties (except pH) were significant (p≤0.01). The results of PCA showed that carbon-to-nitrogen ratio (C/Nratio), potassium and calcium, respectively, had the most effect on the vegetation cover of Rhus coriaria habitat. According to these results, the soil chemical properties from understory of Rhus coriaria (except chlorine and magnesium) were higher than understory of Amygdalus scoparia.

This research was carried out in an unmanaged (934) and a managed (923) comportments of the Shafaroud region of northern old- growth beech forests of Iran. Gap characteristics such as gap area, gap fraction, gap frequency per hectare, DBH of gapmakers, frequency of gapmakers per gap and decay class of gapmakers were measured. Results showed that gap fraction of managed and unmanaged gaps were 13.5% and 9.06%, respectively. There were significant differences in frequency distributions of gap areas, DBH and gapmaker per gap between two study sites. Spatial pattern of gaps was random for both areas in 25m radius and beyond this distance aggregate pattern was determined. Based on this research, decrease of number of gap per hectare and increase of dead wood frequency and volume should be implemented in the next management practices.

The current research was performed to evaluate and to map the fire risk occurrence in the forests and rangelands of Sirachal in Alborz province using fuzzy analytic hierarchy process. The used criteria included four main criteria (physiographic, biologic, climatic and human-made) and their sub-criteria. The maps of all these factors were provided using digital elevation model, satellite images, ground sampling and available data. Also, the map of past fires during past decade was prepared by existence data and GPS sampling. Then, the weight of the effective criteria in fire occurrence was calculated using fuzzy analytic hierarchy process. The fire risk potential map was prepared using the weighted combination of the effective criteria maps. Finally, the fire risk potential map was validated using the past fires and its accuracy was evaluated in identifying the fire high-risk areas. The results showed that among the main criteria, human-made criterion had the most impact (weight) on the fire occurrence risk in the area. Also, the sub-criteria slope and distance from river, type and density of vegetation and distance from the road had the highest importance (weight) in the fire occurrence risk based on fuzzy analytic hierarchy process. According to the results of the fire risk potential map, 58.55 percent of the study area has the high-risk potential for fire.

In this study, the shape, structure and elemental composition of the deposited particles on the leaves of Ulmus Carpinifolia, Platanus Orientalis, and Robinia Pseudacasia in Azadi and Chitgar areas in Tehran was investigated through individual particles analysis with SEM-EDX. The properties of 128 particles were analyzed through SEM-EDX. Thirty-four elements were identified in all the samples. The diameter of particles in Azadi was greater than Chitgar. The average diameter of particles was 7.26 microns. The average diameter of particles was 7.51 microns in Platanus Orientalis, 6.88 microns in Ulmus Carpinifolia, and 4.42 microns in Robinia Pseudacasia, respectively. The diameter of 45% of the particles was smaller than 2.5, 31% of the particles between 2.5 to 10, and 23% of the particles bigger than 10 microns. The distribution of metal particle size in all samples showed that the average diameter of the metal particles was 14.05 microns and the diameter of 14.28% of the particles was below 2.5, 42.85% between 2.5 to 10, and 42.85% was above 10 microns. Various structures of the elements were observed in the areas. Particles morphology showed that the origin of particles production is natural resources and they are man-made. In general, the average diameter of deposited particles on Platanus Orientalis and Ulmus Carpinifolia was more than those on Robinia Pseudacasia. Moreover, the particles diameter distribution showed that in Platanus Orientalis and Ulmus Carpinifolia particles are deposited with different sizes while in Robinia Pseudacasia there is less variation in particles size.

The aims of the study were to estimate the canopy and trunk ecohydrological parameters of a Fagus orientalis natural stand and a Picea abies plantation in Siahkal (Gilan province) during one-year measurements. The results showed that the estimated canopy saturation point, canopy saturation point, canopy storage capacity, free throughfall coefficient, the ratio of mean evaporation rate from canopy to the mean rainfall intensity, trunk storage capacity, stemflow partitioning coefficient, and trunk saturation point were 1.81 mm, 1.63 mm, 0.44 mm, 0.57, 0.16, 0.21 mm, 0.13, and 1.61 mm in a F. orientalis stand, respectively. For the P. abies stand, the corresponding values were 3.19 mm, 1.87 mm. 0.94 mm, 0.34, 0.17, 0.19 mm, 0.07, and 2.74 mm. Based on the amounts of canopy and trunk ecohydrological parameters, it can be stated that rain water entering the forest in a F. orientalis stand is more than that in P. abies stand. Due to the time consuming and costly measurements of throughfall, stemflow, and rainfall interception, especially in Iran where there is no possibility of using automated systems, and also because the measurements have to be performed manually in the field after each rain storm, determination of the canopy and trunk ecohydrological parameters is an effective step for predicting throughfall, stemflow, and rainfall interception for each rain storm.

Riparian forests in terms of plant communities, soil, topography and hydrological features are distinct from their adjacent areas. The aim of this research is to study some structural characteristics of Aras River riparian stand forests in Pars Abad Moghan region. For this purpose, 20 line samples (transect) with variable length perpendicular to the main axis of the Aras River within 200 meters interval, and to study regeneration on each line samples circular plots of 100 square meters at 50-meter intervals were established. In each transect, these characteristics for the trees that trunk or crown of them cut the sample line were measured: species type, trees distance from each other, diameter at breast height or DBH, crown diameter, origin (coppice or seedling), trees health, crown symmetry, tree tendency, buttress root presence and number of sprout. Also, regeneration of woody species were recorded in the relevant classes. Results showed that Populus caspica Bornm played the most important role in terms of abundance (i.e. 70.9%) in forest composition in the area. On the other hand, other species (Salix, Morus and Ficus) with 4.2%, had the lowest percentage of composition. DBH, height and crown percentage of trees have had significant changes in relation to the distance from the river. Also, there was a positive and significant correlation between distance from the river and crown percentage, seedling percentage and number of sprout. This study showed that riparian forests of Aras in Parsabad can be considered as uneven aged and irregular age.

In this experiment, one year old Cerasus mahaleb seedlings were inoculated with six treatments of mycorrhizal fungus (Diversispora versiformis, Claroideoglomus etunicatum, Rhizophagus irregularis, Funneliformis mosseae, and a combination of these species) and control, then were planted in five soil treatments (control or No contamination, normal contaminated, contaminated with lead, zinc contaminated and contaminated with lead and zinc) were cultivated. The highest amount of colonization in combination treatment was 51% and lowest in control treatment was 24%. Diagonal growth, Seedling height and leaf area index in inoculation with combination strain were 1.42, 11.9 and 19.01, respectively. The highest fresh and dry weight of shoot in the treatment of strain Recipes were 42.04 and 21.36 grams and the lowest in the control were 22.34 and 11.33 grams, respectively. Combination strains and non-contaminated soil treatment caused maximum growth in Mahleb, in plants grown with mycorrhizal fungi were inoculated, mean of all measured variables was significantly higher than that of control plants. Combined strain treatment had the highest effect on dry matter accumulation.

The aim of this study is to evaluate the effect of slop on root system characteristics of Q. castaneifolia. For this purpose, an experiment was conducted in the nursery of Forestry and Forest Economics department, Natural Resources faculty, University of Tehran with three treatment including flat area, area with 25 percent slope, and area with 45 percent slope with three replicates for each treatment. After preparing seeds, they were grown in pre-prepared plots. Seeds were cultivated after germination, in four periods (96, 124, 152, and 201 days). In each period, seven seedlings were selected randomly from each treatment and extracted carefully from soil. The characteristics of root system like number of roots, root length and root tensile strength were recorded. The results of the ANOVA showed that the slope had a significant effect on the number of the roots and the highest number was related to the flat treatment and the lowest was belonged to the treatment with 45 percent slope. While the maximum total length of the roots related to the 45 percent slope. The results showed that tensile strength decreased with increasing root diameter which the relation was power-law regression. The various growth periods had not a significant effect on tensile strength, however, root diameter as a covariate factor was significant.

The management of Hyrcanian forests is experiencing the first period of logging ban since 2017. The transition from traditional forestry to modern forestry and the suitable management strategies is an indispensable step to prevent the forestry plans from mismanagement. Aiming at strategic planning, this study deals with factors affecting forestry with the aid of value engineering and including experts' viewpoints and study records screened through fuzzy Delphi. The result of the concurrency of the scores of the internal and external factors in the evaluation matrix of SWOT could select the strategies countering weaknesses and threats. The results of the measurement of the attractiveness of defense strategies with selected SWOT factors in the QSPM matrix from experts' viewpoints showed that the impact of external factors on forest management was more than internal factors; hence prioritized strategies were reselected regarding the main stakeholders and the social view of the forest. Based on the weighted average of internal factors, the strategy of the necessity of increasing forest adaptability to climate change was chosen as the first priority, indicating the necessity of science-based management in the Hyrcanian forests.

The present study was carried out to investigate callus induction, vegetative embryogenesis and indirect regeneration of Paulownia shangtong. This experiment was conducted as a factorial experiment in a completely randomized design with five replications. The studied factors were explants and different compositions of the Murashik-Skogh medium. The interaction effect of explant and medium was significant for callus production rate, callus production percentage, callus area and vegetative embryogenesis percentage. The results of the mean comparison showed that the highest regeneration rate of vegetative embryos was obtained with petiole explant and medium of½&A/4 MS + 0.3 mg/l + 2mg/l KIN + 4 mg/l BAP + 0.30 mg/l. To test the root induction of regenerated seedlings a factorial experiment was conducted based on a randomized complete block design with five replications. The factors were different mediums (MS medium and 1/2MS medium) in combination with hormones of IBA, NAA and IAA. The highest percentage of rooting was observed in ½MS supplemented with 1.5 mg / l IBA. The regeneration of vegetative embryos in MS base medium was less than other mediums.