Iranian journal of Forest
Year:2020 | Volume:11 | Issue:4 |Papers Count:14

Forest marginal villagers often use natural resources. The type and amount of these utilities varies according to the environmental conditions, facilities and culture of the people. Regarding the importance of natural assets to the livelihoods of the villagers in the Zagros forests, it was necessary to study and compare the types of assets of the villagers living in these forest areas. To do so, a multistage research using a library (documentary) and field study (questionnaire) was conducted in the city of Chardavol, Ilam province. In order to determine and prioritize the indicators and sub-indicators determining the livelihoods, the model of the network analysis process was developed and analyzed according to experts. In the next step, in order to weight the villages under study, questionnaires were prepared according to the super matrix of the pair model, the weight of each village was determined by the villagers based on the results. The financial (0. 310), physical (0. 280), human (0. 167), natural (0. 122), institutional (0. 090) and social (0. 031) assets were the most important livelihood assets. A questionnaire was also designed to determine the levels of livelihood assets of residents of forestfringe villages and their dependence on forest. With the help of the weight determined by the experts, the level of livelihoods in the studied villages was determined. The results indicated the Tahmasb village was in the first place in terms of livelihoods, followed by the Kolkol Olya and Miule Olya villages. The research has shown that financial assets are the most important assets that contribute to livelihoods and welfare of rural marginal villagers. The analysis of the normal weight of livelihood assets and natural assets showed that the weight of livelihood assets increased with the weight loss of livelihoods. In fact, these results show that in villages with less livelihoods, natural assets play a more important role in their livelihoods.

Knowledge of soil chemical properties is important for understanding its engineering characteristics in road construction. Reflectance spectrometry is a non-destructive, fast and environment friendly method, but unfortunately no research has been conducted to use this tool to estimate the forest soil characteristics in Iran. The present study was conducted to investigate the ability of VNIR spectrometry to estimate some chemical properties including organic matter, CaCO3, pH and EC in the forest soil. For this purpose, 45 soil samples were collected from Namkhaneh series in Kheyroud Forest and those properties were measured by standard methods. The reflectance of sample was measured in dark room using Fieldspec ASD spectroradiometer. PLSR (Partial Least Squares Regression) method was used to predict soil properties in reflectance and first derivative mode. The results of RPD shows that OM has a very good estimate in two modes of reflectance spectra and derivative reflectance spectra (PRD>2) and pH, EC have acceptable estimate (1. 42), but CaCO3 has poor prediction in two modes of reflectance spectra and derivative reflectance spectra (PRD<1. 4). In general, based on the results of this study, spectrometry can be used to predict the above-mentioned properties except CaCO3 as a fast and an acceptable method and this method can simultaneously estimate several soil properties.

In this study, the effect of irrigation with landfill leachate on the chemicals concept of the tree branches of Populous and Fraxinus was investigated. The treatments included different concentrations of landfill leachate (0, 25, 50, 75 and 100%). The results of the interaction effect of kind of species and concentration of landfill leachate on the chemicals concept of tree branches showed that increased concentration of landfill leachate leads to increasing of the micro nutrient amounts except zinc, the amount of macro nutrients and also heavy metal of plumbum. On the other hand, the amount of iron, zinc and calcium in shoot of Populous was significantly higher than that of Fraxinus trees which was resulted from being fasting growth and high level of absorbance of populous as compared to Fraxinus. According to the results of soil analysis, it can be said that increased concentration of landfill leachate resulted in the significant increasing of the amount of phosphorus, zinc, nitrogen, ferrus and manganese in the soil. Overall, the results confirmed that utilization of landfill leachate for irrigation of trees leads to increased amount of some nutrients in the soil and shoot trees but there have been no sign of toxicity in trees until concentration of 75% of landfill leachate. So, it can be concluded that landfill leachate has potential to be used as liquid fertilizer and its heavy metal concept is tolerable for populous and fraxinus trees. With proper management it can be utilized as fertilizer for reinforcement of soil and some of tree species.

Taxus baccata is an indigenous and valuable species in the Hyrcanian Forests. According to recent studies, the presence of this species in the distribution areas is declining; therefore, preserving and restoring this valuable species is of great importance. One of the most strategies for conservation and rehabilitation of valuable species is identification of its potential distribution and prioritization of areas with potential presence of this species using species distribution models. This study aims to prioritize the suitable habitats for preservation and restoration of yew in the Hyrcanian forest. In this study, the Boosted Regression Tree (BRT) algorithm was used to model the distribution of yew species in relation to climatic, edaphic, and topographic variables and to identify the most important variables affecting the distribution of yew. The results showed that the model constructed with climate variables in terms of such model evaluation criteria as true skills statistics (TSS=0. 83) and area under the receiver operating characteristic curve (AUC =0. 97) has better performance as compared to the edaphic and topographic models. Also, among the climate variables, mean temperature of driest quarter and precipitation of warmest quarter has the most effect on the distribution of yew species. Soil organic carbon, sand percent, cation exchange capacity, altitude, and slope percent were also the other important factors affecting the distribution of yew species. Finally, by combining the suitability maps of climatic, topographic, and edaphic models, a map of the conservation and restoration prioritization of yew species was prepared, which is very valuable in planning for restoration of this species in the Hyrcanian Forests.

Wild Pistacia (Pistacia atlantica Desf. ) from the Anacardiaceae family is drought and frost tolerant tree species. Due to the dormancy caused by physiological processes and hard and oily coating of the seeds, the reproduction and production of seedlings of this species are facing major obstacles. In this study, the effect of sowing bed, planting date and different pretreatments on wild pistachio seeds were studied in Tabriz's Elgolian nursery. In order to implement the experiment, a factorial design in a randomized complete block design with five replicates and three treatments including planting bed in three levels, planting date in two levels and pre-treatment in four levels were used. During the growing season, the diameter of the collar and seedling height were measured monthly. Also, the daily average germination, seed percentage and seed germination rate were also calculated. At the end of the growing season, biomass of the root and biomass of the stem were measured. Using gibberellic acid as a pretreatment increased seed germination percentage. In addition, the best vegetative traits were the planting bed 1 (1, 1, 1) and pretreatment 3 (cold, scraping and gibberellic acid) which are recommended for improving the growth and the rate of yield of wild pistachio seedlings in Elgoli nursery in Tabriz.

In this study, morphology and pollen grain diversity of eight maple species including Acer negundo, A. palmatum, A. monsspesulanum, A. velutinum, A. cappadocicum, A. campestre, A. tanoide L, A. hyrcanum and a cultivar of A. negundo (A. negundo variegatum) were studied to examine their roles in this genus and to find the diagnostic attributes. The results showed that pollen grains of this genus are tricolpate and are of medium size, often heteropolar with no radial symmetry, and are classified in plicate class. Studying the quantitative traits by using one-way analysis of variance and cluster analysis showed a high inter-specific variations among the traits. In the principal component analysis, the distance of two pollen lengths from each another, the length of the equatorial diameter of the pollen grain, the window environment, and the window area were determined to separate the existing species. In order to test the accuracy of the analysis, the detection analysis was used, which confirmed up to 80% of the results of grouping of each species is based on the pollen attributes.

Forest decline is an important and complicated phenomenon that happened in most world oak forests. This research aims at the determination of mortality rate, the volume of deadwood, and also the designation of the ecological factor affecting these mentioned parameters in Tange Alamdar, Behbahan. To do so, a 50 hectares oak forest was selected and 30 systematic randomized sample plots (25 Are) were established in this site. Within each sample plot, mortality rate, deadwood volume in different classes (coarse and fine dead wood), slope, elevation, landform, and terrain shape indexes, and aspect were recorded. Pearson’ s correlation coefficient and one-way ANOVA were used for data analysis. The result indicated that standing dead tree, fallen dead tree, and fine woody debris volume were 7. 01, 15. 21, and 0. 039 m3 ha-1, respectively. Persian oak mortality rate in the studied site was 57 percent and the highest rate belonged to the 10-15 cm d. b. h class. The high rate of mortality had no correlation with elevation and aspect. Also, deadwood volume and number in the different studied groups had no significant correlation with physiographical features. A high level of mortality rate in all of the diameter classes might imply that mortality is not the result of aging but some kind of disturbances. One of the possible reasons for low fine woody debris volume could be related to human disturbances. Overall, reforestation should be considered in the studied site to decrease the mortality rate.

Juniperus excelsa is a light demanding and long-lived tree species of the Cupressaceae family. This species has been shown good tolerant to harsh conditions such as cold and drought situations. This research aims to assess the effect of different concentrations of auxin and cytokinin on callus induction of J. excelsa as factorial based on completely randomized block design and to study the effect of salicylic acid on phenol, flavonoid and inhibition of DPPH radicals of calli. The explants were selected from sound trees with no diseases and pests. Woody plant medium (WPM) was selected with same laboratory conditions (experimental place, temperature, explant age, hormone type). The experimental treatments were auxin with 5 levels (0, 1 mg/l NAA, 2 mg/l NAA, 1 mg/l 2, 4-D, and 2 mg/l 2, 4-D), and cytokinin with 3 levels (0, 0. 25 mg/l Kin, 0. 5 mg/l kin). The results showed the explants gradually swelled after 3 weeks, and completely induced callus after 6 weeks. The interaction of auxin and cytokinin hormones showed that the highest amount of callus induction (80%) was obtained in the interaction of 0. 25 mg/l Kin and 1 mg/l NAA. The highest fresh weight of callus was in the interaction of 0. 25 mg/l and 1 mg/l NAA as 1. 1 gr. Besides, the dry weight of callus was recorded in the interaction of 0. 25 mg/l Kin and 1 mg/l NAA. Kin combined with NAA caused the formation of compressed and yellow callus, and Kin combined with 4, 2-D, created a friable and green callus. On the other hand, we found that the total phenol content in 100 µ M SA (31. 8 mg gallic acid/ grDW) was higher than other treatments. There was no significant difference between control and 50 µ M SA. The highest (9. 3 mg quercetin / grDW) and lowest (2. 05 mg quercetin / grDW) flavonoid contents were found in 100 µ M SA and control, respectively. In addition, the maximum inhibition of DPPH was recorded in 100 µ M SA (35. 06%), while the minimum was observed in control (25. 3%).

The present study aimed to assess the effect of canopy combination of beech trees and mixed species (beech-hornbeam-maple, beech-hornbeam, beech-maple and pure beech) on microbial indices and soil nutrient stocks characteristics in Mazandaran Province, north of Iran. Leaf litter sampling was done by using litter traps and soil samples (30 × 30 × 30 cm) were taken in each of the stands with five replicaties under the canopy of beech trees. Characteristics of litter (organic carbon, total nitrogen, carbon to nitrogen ratio, phosphorus, potassium, calcium and magnesium) were measured. The physical, chemical, biochemical and microbial properties of soil (bulk density, Sand, silt, clay, pH, EC, organic carbon, total nitrogen, carbon to nitrogen ratio, sequestration of organic carbon, total nitrogen, phosphorus, potassium, calcium and magnesium, ammonium, nitrate, microbial respiration, metabolic and microbial quotient) were also investigated. The results showed that beech-hornbeammaple stand had the highest pH, nitrogen sequestration, phosphorus, potassium, magnesium, microbial biomass of carbon and nitrogen, and microbial respiration. Also, the highest amount of soil carbon, carbon to nitrogen ratio, carbon sequestration, metabolic and microbial quotients were allocated to pur beech stands. In addition, the highest ammonium and nitrate levels were also observed in beech-maple and beech-hornbeam stands. According to the present study, beech-hornbeam-maple stand improved the litter quality, nutrient storage and microbial indicators of the soil, followed by beechhornbeam, beech-maple and pure beech stands. The practical results of this research indicate the positive effects of tree species diversity on improvement of soil qualitaty and health.

Tourism in natural areas can affect the biodiversity, density and structure of stands and plants health. The present research aims at studying the effects of tourism on vegetation structure and species diversity in Noor Forest Park, Mazandaran province. To do so, the study area was divided into three main zones: without pressure, moderate, and high tourism pressures. Then, sampling was done with 20 sample plots of 20 × 20 m sample with random-systematic distribution in each zone (60 plots in total). Within each sample plot, trees, shrubs, herbs and regenerations were counted and quantitative and qualitative characteristics of all woody species were measured. The species richness, evenness and diversity indices were then calculated and the calculated indices and forest structural features were compared amongst the mentioned zones. Based on the results, diversity of forest floor flora in high tourism pressure zone was higher than other zones and there was no significant difference in woody species diversity among three zones, nevertheless a considerable reduction was seen in density of both woody and floor species. The lowest regeneration abundance was observed in high tourism pressure zone and the most, in medium tourism pressure zone. In zone without tourism pressure, average height and canopy of trees were more compared with the high tourism pressure zone. Also, most snags, the highest ratio of broken trees to total trees and the highest number of diseased and damaged trees were observed in high tourism pressure zone. In this zone, Alnus glutinosa, Populus caspica and Parrotia persica had the lowest vitality.