mohammad matinizadeh

Cupressus sempervirens var. horizontalis species, as one of the valuable tree species in the Hyrcanian forests of northern Iran, plays a significant role in maintaining biodiversity and the ecological balance of forest ecosystems. Therefore, investigating soil characteristics in the cypress reserve is essential due to its role in preserving biodiversity and soil quality. Since land use change and land degradation impact soil properties, and given the importance of this issue, the aim of the present project was to examine the biological, physical, and chemical variables of soil in the Ramian cypress stand and adjacent agricultural land. This study was conducted in two one-hectare plots: one in agricultural land and one in the cypress stand. The methodology included recording general information and excavating soil profiles to study soil horizons. Soil samples were collected at a depth of 0–15 cm beneath the tree canopy, and physical, chemical, and biological properties of the soil were measured. Analysis of the biological data using independent t-tests revealed significant differences in basal respiration and nitrification rates between the two soil types. Specifically, basal respiration and nitrification were higher in the cypress stand (4.33 mg CO₂·g⁻¹ dm·24 h⁻¹ and 1.714 μg N·g⁻¹ dm·5 h⁻¹), respectively than in the agricultural soil (2.99 mg CO₂·g⁻¹ dm·24 h⁻¹ and 0.454 μg N·g⁻¹ dm·5 h⁻¹, respectively). However, there were no significant differences in microbial biomass and substrate-induced respiration between the two soils. Surface soil samples indicated that the agricultural soil had higher pH (7.96), phosphorus (23.42 mg/kg), potassium (275.2 mg/kg), silt (57.6%), and clay (29%) compared to the cypress stand soil (pH 6.58, phosphorus 10.54 mg/kg, potassium 163.8 mg/kg, silt 41.2%, and clay 4.8%). Conversely, the cypress stand soil exhibited higher electrical conductivity (1.36 dS/m), zinc (1.57 mg/kg), and sand content (54%) compared to the agricultural soil (0.41 dS/m, 1.07 mg/kg, and 13%, respectively). Both soils were classified as Inceptisols. Land use had differential effects on the physical and chemical properties of the soil, mediated by the dominant species, which produce diverse litter and root exudates, thereby regulating the size and activity of soil microbial communities as well as the organic and mineral elements of the soil.

Oak decline is a critical issue in Zagros forest ecosystems. Disruptions in nutrient and water uptake, exacerbated by environmental stress, weaken trees, leading to deterioration. Soil physico-chemical characteristics significantly influence forest habitat performance. Given the spread of dieback trees in Kurdistan province, this study aimed to investigate changes in deep soil parameters associated with control stands (healthy trees) and dieback trees in the coppice stands of Marivan county, northwest Kurdistan province.

The study was conducted in dieback (Garan) and control (Dolah Naw) forest stands in Marivan county. Within each stand, ten trees (five healthy and five dieback) were selected across north and south aspects (totaling 30 trees: 10 in the control, 20 in the dieback habitat) and numbered in 2018. Soil samples were collected on the northern side of the crown, one meter from the tree trunk at a depth of 20-40 cm (first week of August). Laboratory analyses determined moisture percentage, pH, electrical conductivity, available phosphorus, potassium, nitrogen percentage, organic carbon percentage, lime percentage, calcium, and magnesium. Principal Component Analysis (PCA) using PC-ORD 5 software was employed to assess the effect of deterioration on soil physico-chemical characteristics.

Statistically significant differences were observed among the ten physical and chemical parameters across the six treatments. The highest average values for electrical conductivity (599 decisiemens/cm), moisture (13.1%), lime (13.8%), available phosphorus (13 mg/kg), and potassium (1317 mg/kg) were found in soil near trees on the northern slope of control stands. Conversely, the highest levels of organic carbon (3.75%), nitrogen (0.32%), and calcium (44.2 milliequivalents/100g) were observed in soils beneath healthy trees on the southern slope of control stands. Generally, control stands (both northern and southern aspects) exhibited higher values for most soil physico-chemical parameters, except pH and magnesium. Dieback trees showed nutrient and macronutrient deficiencies, with lower element concentrations in the soil under their crowns. PCA revealed that electrical conductivity and moisture had the highest positive loading (0.42) on the first component, while organic carbon and nitrogen loaded at 0.41. Calcium, lime, and pH loaded on the second component with positive values of 0.55, 0.53, and 0.49, respectively. PCA also indicated better soil moisture in healthy trees on the northern slope.

Soil physico-chemical parameters and macroelement concentrations were generally higher near trees in control stands compared to dieback-affected stands. For optimal management of dieback trees in the research area, soil enrichment and strengthening, enhanced protection measures (livestock grazing and traditional exploitation control), increased forest restoration and development in dry areas (particularly southern slopes), and sanitary cuts (branches and stems with red cracking and deterioration) are recommended.

Hazelnut (Corylus avellana L.) is considered one of the most prominent species of Ardabil Fandoghlou forest in. This species is ecologically and economically important and is one of the most valuable medicinal plants in traditional medicine and pharmaceutical industries. Unfortunately, in recent years, conversion of use, livestock grazing, fire and cutting of trees have been effective factors in the destruction of this valuable forest. Considering the ecological and economic importance of the hazelnut species, it is very important to restore the habitats of this species through seedlings. On the other hand, the success of planting depends a lot on the establishment and survival of planted seedlings (Spehbadi, 2019), which chemical fertilizers are used most of the time. The use of these fertilizers has had adverse effects on the soil ecosystem, and in addition to destroying beneficial soil microorganisms and the poor growth of seedlings, it has resulted in several adverse effects on the environment and human health. The use of growth-promoting microorganisms is considered one of the biological methods to increase the yield of plants and reduce the consumption of chemical fertilizers. Trichoderma spp. have been known as plant growth promoter besides its primary function as pathogen inhibitor. This research was conducted with the aim of the effect of T. harzianum on of physiological properties of hazelnut seedlings in field conditions.

At the beginning of May 2016, in Ardabil Hazelnut Nursery, the soil around the roots of potted hazelnut seedlings, produced from the three sources of Fandoglou (Ardabil Hazelnut Forest), Makesh (Guilan) and Makidi (Arasbaran) with T. harzianum were inoculated. Then, in November 2017, the one-year-old hazelnut seedlings were transferred to the area adjacent to the nursery located in lands of the forest edge with an area of 4050 m2. Then they were planted in factorial arrangement in a randomized complete block design (with the two factors mentioned above including three seed sources and T. harzianum inoculation and no inoculation or control in three replications). The number of seedlings in each replication was 25 (450 seedlings in total), which were planted a distance of 3 × 3 m in rain-fed conditions. The characteristics of leaf area, specific leaf area and physiological properties including leaf area, specific leaf area, photosynthesis rate, stomatal conductance, transpiration rate, water use efficiency (WUE) and chlorophyll content were measured. For this purpose, in each treatment, three seedlings were randomly selected and measurements were taken on the fourth and fifth healthy and fully grown mature leaves from the tip of the plant using a photosynthesis meter on a sunny day (mid-September) and it was done in the open air under natural conditions of temperature, light and relative air humidity between 9:30 and 11:30 while the constant leaf temperature was between 20 and 25 o C.

After four years, all measured properties were significantly affected by fungal inoculation. Inoculated seedlings from all three origins displayed higher values for all investigated traits compared to controls. The highest of leaf area (22.4 cm2), specific leaf area (119.2 cm2 g-1), photosynthesis rate (18.45 µmol Co2 m2 s-1), stomatal conductance (0.198 mmol m2 s-1), transpiration rate (mmol H20 m2 s-1), water consumption efficiency (7.69 µmol Co2 mol H2o -1) and chlorophyll content increased by (26.49 %) were obtained from Seedlings of Fandoglou origin inoculated with T. harzianum in compared to the control (non- inoculated seedlings). The lowest of leaf area (12.4 cm2), specific leaf area (85.5 cm2 g-1), photosynthesis rate (8.01 µmol Co2 m2 s-1), stomatal conductance (0.101 mmol m2 s-1), water consumption efficiency (2.41 µmol Co2 mol H2o -1) and chlorophyll content increased by (14.15 %) were observed from Seedlings (non- inoculated) of control with origin of Makidi.

The present study showed that the hazelnut seedlings of the origin of Fandoghlou under the influence of T. harzianum inoculation were superior in terms of the studied traits in comparison to the two origins of Makseh and Makidi. Therefore, for the production of healthy and strong hazelnut seedlings in the nursery, the origin of the Fandoghlou can be used. An important point in inoculation of seedlings with T. harzianum fungus was the increase in the water use efficiency (WUE) of of hazelnut seedlings with the origin of Fandoghlou up 150% compared to the control seedlings. So, it can be concluded that by increasing the rate of photosynthesis rate and reducing transpiration rate, inoculated seedlings increase the efficiency of water use and can have more vegetatative growth and suitable physiological traits in reforestation or create of hazelnut gardens in the prone lands of Fandoghlou forest. Keywords: Arasbaran, Corylus avellana, Stomatal conductance, Specific leaf area.

Soil, as one of the elements of the ecosystem, plays a major role in changing and diversifying forest species, and on the other hand, the type of vegetation also plays a significant role in changing and transforming the physical, chemical and biological characteristics of soils. In addition to these, soil microbial communities play a very important role in the decomposition and stabilization of organic matter in the soil, as well as in the mineralization of its nutrients, and due to their great diversity, they provide very important services in the soil. Therefore, their correct and accurate evaluation based on efficient and reliable indicators can provide useful information. In this research, the indices of basic microbial respiration, stimulated microbial respiration, nitrification potential, microbial biomass carbon and metabolic fraction were evaluated under the influence of stem. In order to obtain the soil quality indicators, the biological characteristics of the soil were investigated. Soil sampling was taken for each selected trunk tree from a depth of 0-15 cm under the tree crown (in the distance between the trunk and the end edge of the crown) in the east direction of the tree. 15 soil samples were randomly taken from the depth of 0 to 15 cm in each sample plot for this existing and dominant tree species (one to three species) and all three soil samples in each sample plot were well mixed and made into one composite sample for each sample plot. Species were transformed (five soil samples for each species). Also, 15 soil samples were randomly taken from the depth of 0 to 15 cm inside each sample plot, outside the crown and in the place outside the cover, and all three soil samples were mixed well and made into one composite sample for the sample plot. transformed (5 soil samples for each sample plot). In this research, two treatments were used, one under the canopy and the other outside the canopy with pasture cover. A total of 30 soil samples were collected, 15 samples under the canopy and 15 outside the canopy with pasture vegetation, in each treatment three samples were combined and converted into one sample. In fact, for each treatment, 5 samples were sent to the laboratory, and the coordinates of each sample were recorded in order to prepare a sampling map. Immediately after sampling, a part of the soil samples was kept in plastic bags and the other part was kept in cold conditions (4°C) and transferred to the laboratory for further analysis.Send feedback. The results showed that the effect of treatment on basic respiration, clay percentage, silt percentage and sand percentage was not significant. The effect of treatment on stimulated respiration, microbial biomass carbon and nitrification potential was significant at 1% probability level and metabolic fraction at 5% probability level. Also, the average value of stimulated respiration, nitrification potential and metabolic deficit in the soil sample under the baneh tree was higher than outside the tree. Most of the biological characteristics in the soil were affected by the stem and showed significant changes compared to the control, which will indicate the effect of the application on the life rings in the soil. In general, the results indicated that most of the biological characteristics in the soil were affected by the log and showed significant changes compared to the control, which would indicate the effect of the application on the life cycles in the soil. The trend of changes in stimulated respiration and the potential of nitrification and metabolic deficit under the canopy was not consistent with the trend of changes in microbial biomass carbon. Due to the increase in the characteristics of stimulated respiration and the potential of nitrification and metabolic fraction under the crown of the corm cover in the region, these indices can be useful for evaluating the soil quality of the region. While the reduction of microbial biomass carbon under the canopy compared to the control soil (outside the tree canopy), could be due to the change in the type of substrate or the difference in the diversity of the microbial population in the soil under the canopy or outside it. The results of this research show that in evaluating soil quality, improving soil fertility and managing plant nutrition, the role of soil biological characteristics cannot be ignored. On the other hand, having the biological parameters of the soil, as a knowledge-based approach with accessibility and flexibility, more information can be provided to experts and users for decision-making to improve soil fertility and manage root tree nutrition.

This study was conducted in the Zagros forests to investigate and monitor the status of elements in the soil and their absorption in areas with and without oak decline. Two plots, each with 100 trees, were randomly established in the south direction in the areas of "Sama Castle" and "White Mud," representing the decline and control (without decline) sites. In the oak decline plot, five healthy and five declining trees were selected, while only five healthy trees were chosen in the control plot. Selection of healthy and declining trees in the first year was done selectively and with proper distribution throughout the sample. In the following years, soil and leaf samples were collected from the selected trees. Soil samples were collected under the tree crowns at two depths (0-30 cm and 30-60 cm). Additionally, 20 leaves per tree were sampled in late July and early August. The results showed that the amount of phosphorus in the leaves of trees in the both decline and control sites was significantly different at a 99% confidence level. As the intensity of drought increased, the amount of phosphorus in the leaves also increased. Soil moisture was estimated at 5.74% in the decline site and 7.14% in the control site, with this difference being statistically significant. The amount of calcium in the soil of the control area was approximately 1.5 times greater than in the area experiencing decline. The results of this research, focusing on soil characteristics related to oak decline, can provide important data for the oak decline information system in the Zagros forests of Iran.

This study investigates the response of some soil bio-physicochemical properties under different grazing intensities management in a 17-year-old arid rangeland ecosystem of Iran.

The grazing intensity gradient was as follows: (1) without herbivore grazing over a whole year (NG), (2) grazing by sheep and goats done communally from November to May (RG), and (3) continuous and heavy grazing over a whole year (HG). The soil samples were collected from the upper 20 cm in November and May. 

The significantly higher bulk density values (P<0.05) were measured with increasing grazing intensities, i.e., 1.65, 1.82, and 1.96 g.cm-3 in NG, RG, and HG, respectively. The management system affected significantly (P<0.05) organic carbon (OC), total nitrogen (TN), available phosphorus (P), exchangeable potassium (K), as well as enzyme activity of acid- and alkaline phosphatase (ACP, ALP) and urease. Similarly, the time of sampling affected significantly (P<0.05) OC, P, C, ACP, ALP, and urease activity in the soil. The soil OC ranged from 0.46 to 2.78 %, K ranged from 51.81 to 92.06 ppm, TN and P showed significantly (P<0.05) higher HG and RG values than NG. The soil pH ranged from 7.89 to 8.32, and EC (electric conductivity) ranged from 0.47 to 0.93 dS.m-1, which was significantly affected neither by the grazing management system nor by sampling time. The TN showed a high positive correlation with ALP (r = 0.89), urease (r = 0.72), and dehydrogenase (r = 0.76). The OC, P, ACP, and ALP responded more sensitively to grazing management systems.

The presence of animals in our study site positively affected soil fertility. However, similar studies are required to complete our knowledge under different climatic conditions, vegetation-grazer types, and grazing duration.

Poplars are important tree species in poplar plantations and agroforestry programs due to their fast growth, high biomass production, and ecological adaptation. On the other hand, arbuscular mycorrhizal fungi can have a good symbiosis with different poplar species. With this symbiosis, growth parameters, biomass production, absorption of water and nutrients, as well as the resistance of poplars to environmental stress, will be increased. Understanding the relationship between mycorrhizas and poplars and how mycorrhizas affect the growth and nutrition of such species may contribute to producing stronger and healthier plants and more sustainable practices in the future.

 In this study, first of all, the root mycorrhizal colonization percentage of some poplar species (available in the poplar research collection of Alborz Research Center) with arbuscular mycorrhizal fungi was investigated. Then, considering the high percentage of mycorrhizal symbiosis of Populus nigra “62/154” trees and the importance of this clone as a high-yielding poplar clone, widely used in poplar plantations in different parts of the country, symbiotic fungi with this clone were identified through the morphological properties of spores in the rhizosphere soil, and then the identified mycorrhizal fungi were used to produce mycorrhizal plants. Then, poplar cuttings were collected from the Alborz Research Center and planted in pots filled with clay-loam soil. The pots were kept outdoors during the experiment. At the time of planting, mycorrhizal inoculum was applied around each cutting. After that, under an experimental layout consisting of a completely randomized design, some morphophysiological (growth parameters, biomass production, and physiological parameters of leaves) and biochemical (macro and micro nutrients of root, stem, and leaf) responses of one-year-old mycorrhizal and non-mycorrhizal poplar plants were investigated.

 The results showed that the percentage of root mycorrhizal colonization of different poplar species was different. The highest percentage of root mycorrhizal colonization was observed in P. nigra “62/154” and P. euphratica, and the lowest percentage in P. deltoides “69/55”. In the soil samples collected from the rhizosphere of P. nigra “62/154”, five species of arbuscular mycorrhizal fungi, including Claroideoglomus luteum, Diversispora tortuosa, Glomus aggregatum, Septoglomus constrictum, and Scutellospora heterogama, were identified. The results demonstrated that mycorrhizal treatment had a significant positive effect (P < 0.01) on growth parameters (diameter and stem length), biomass production (root and shoot dry weight and total dry weight), relative water content of leaves, and nutrient concentrations (nitrogen, phosphorus, potassium, calcium, iron, zinc, and copper) of some plant tissues. Likewise, the content of proline and soluble sugars and the activity of antioxidant enzymes in leaves of mycorrhizal plants increased compared to non-mycorrhizal plants.

 The high symbiosis percentage of different poplar species with arbuscular mycorrhizal fungi in natural conditions and the positive effect of mycorrhizal symbiosis on one-year-old poplar plants show that, considering the importance of the role of soil microbial communities in plant nutrition, growth, and protection against environmental stresses, investigating the biological interactions between soil microorganisms and poplars, especially in the early stages of growth, can be used to produce healthy and strong plants for poplar plantations.

Flood spreading is one of the most important soil protection and improvement measures, which both prevent flood waste and help fight desertification. This research aimed to investigate the effect of flood spreading and plant type on the activity of some physicochemical and biological properties of the soil in pasture fields with and without flood spreading in the Garbayegan, Fasa in 2019-2020. Soil sampling was carried out in spring and autumn to a depth of 20 cm in three repetitions around the rhizosphere of plants and modified according to the materials and methods section. The averages were compared with Duncan's test at the level of 1.5% and using R software. The results showed that the amount of usable phosphorus and potassium in the flood spreading conditions and the control area was without significant difference, but the amount of carbon and nitrogen in all the studied species in the flood spreading area was significantly different. It was more significant than the witness was. However, the amount of respiration in the flood spreading area was the highest, while the respiration and microbial biomass in the control area showed the highest amount. However, the amount of basal heat and microbial biomass in flood spreading areas showed a lower amount, which can be the result of the low amount of organic matter in the soil as a result of excessive livestock grazing in these areas. Finally, it is recommended to implement flood-spreading projects in arid and semi-arid areas to increase the productivity of soil characteristics.

The rangeland ecosystems of arid and semi-arid regions play the most important role in the distribution and density of vegetation in these areas due to the specific environmental conditions governing the soil, which is the bridge between living and non-living parts of ecosystems. Soil enzymes play important biochemical roles in the decomposition of organic matter at all stages in the soil system. These enzymes play an important role in the stability of the soil structure, the decomposition and formation of organic matter, the cycle of elements and the activity of soil microorganisms. Environmental stresses, such as drought, have negative impact on plant growth and soil microorganism's activity. Therefore, evaluating the effect of flood spreading on soil quality indicators can be a useful step in improving knowledge in this field. Therefore, this research was conducted during 2018 and 2019 to investigate the effect of flood spreading, plant types and characteristics on biological soil in the Kowsar floodplains located in Gareh-Bygone, Fasa.

Sampling of the soil around the roots of Artemisia sieberi Besser, Dendrostellera lessertii (Wikstr) Van Tiegh. and Heliantemum lippii (L) Pers, in two situations: with flood spreading and without flood spreading (control area) in spring and autumn from a depth of 0-20 cm and in three repetitions. After ensuring the normality and homogeneity of the variance of the data by the Shapiro–Wilk and Levene tests, the data were analyzed using the two-way variance method and mean comparison were made using Duncan's test at the 1% and 5% level and using the R software.

The results of soil fertility characteristics showed that there was no significant difference in the amount of phosphorus and potassium in the three pasture species studied under flood spreading and the control areas. However, the amount of carbon and nitrogen in all studied species was significantly higher in the flood spreading area (containing 0.3% organic matter) than the control area (with 0.15% organic matter). In addition, the results of this research indicated that the highest activity of acid phosphatase enzyme was observed in the rhizosphere of D. lessertii species and in the spring season, and on the contrary the lowest activity was observed in the rhizosphere of H. lippii species under the flood spreading condition. Alkaline phosphatase activity in all species was significantly higher in spring than in autumn season. The highest activity of this enzyme was observed for A. sieberi in the spring season with an average of 186 (µg p-nitrophenol g-1 soil h-1) in the flood spreading area and the lowest level was observed for H. lippii in the control area with an average of 57 (µg p-nitrophenol g-1 soil h-1) in the autumn season. In general, the level of phosphatase enzyme activity for the A. sieberi species in the spring season was approximately 89% higher in the flood spreading area than in the control area. The dehydrogenase enzyme activity was higher in spring than in autumn. Also, the highest activity of this enzyme was observed in the spring season for the D. lessertii  species with an average of 8.5 (µg TPFg-1 soil 24 h-1 ) in the control area, and the lowest level was observed in the autumn season for the A. sieberi species in the flood spreading area with an average amount of triphenol formazan was 1 (µg TPFg-1 soil 24 h-1 ) .In other words, the amount of dehydrogenase enzyme activity in the spring season was approximately 66% higher than that in the fall season in both areas (control and flood spreading). The results of this research showed that the activity of urease enzyme under flood spreading conditions in both seasons (autumn and spring), with an average of 270 and 300 (µg N/g.dm.2h) is more than the control area with an average of 173 and 250 (µg N/g.dm.2h). Also, the soil quality indices in all three studied species in the two (control and flood spreading) areas have a significant difference, so that the flood spreading operation has upgraded the value of these indices for the H. lippii species and the A. sieberi, while which has reduced the soil quality index of D. lessertii.

The results of this research showed that the flood spreading system is a desirable method for improving soil organic carbon, and its efficiency increases with the plant planting. The increase in moisture and the amount of organic matter in the flood spreading area can be a reason for increasing the activity of enzymes in the flood spreading area, so that in both autumn and spring, the activity of soil enzymes is more in the region. Considering the important role of organic matter in improving biological indicators and soil quality and health, the restoration of floodplains with native species can play an important role in providing these conditions. In addition, it is recommended that these tests be repeated with more samples and in different areas and the nitrogen, carbon, sulfur and phosphorus cycles and its relationship with the activity of other soil enzymes related to this cycle should be investigated.

The Zagros forests vegetation area with an area of more than 5 million hectares and providing more than 40% of the country's water are ecologically very important and the forest covers 256000 hectares of Kurdistan province (8.8% of the province) and in recent years, Oak decline and decay have increase in these forests. Oak decline in the Zagros forests has started in the last two decades and has caused serious damage to the forests of this vegetation area and study of the effective and aggravating factors of Oak decline provides valuable information to natural resource managers. The factors of slope aspect and physical and chemical soil parameters can has an effect on the aggravation oak decline in this forest. The aim of this study was to investigate and compare the physical and chemical soil parameters in around healthy and dieback trees under the influence of slope and dieback in Marivan forests (in Kurdistan province).

Deteriorated (Garan) and control (Dolah Naw) stands were selected in the northern and southern slopes aspect. In the Garan habitat (Oak decline) on the northern slope, five healthy trees and five dieback trees were selected (10 trees in total), on the other hand, in this habitat on the southern slope, 10 more trees were selected (five healthy trees and five trees with dieback). In Dolah Naw habitat (control habitat), five healthy trees were selected in each aspect (in total, 10 trees in the control habitat). In total, 30 healthy and dieback trees were selected and numbered (20 healthy trees in the control and dieback trees and 10 trees in the dieback stands). Then, in the vicinity of the trunk of each tree (in the shaded part of the crown), a soil sample was taken at a depth of 0-20 cm (Horizon A) and the samples were transported to the laboratory in plastic bags. Physical and chemical characteristics (moisture percentage, acidity, soil electrical conductivity, absorbable phosphorus, absorbable potassium, nitrogen percentage, organic carbon percentage, lime, calcium and magnesium percentage) were measured for each soil sample. The two-way analysis of variance test was used to compare the effect of each factor and the interaction effect of the investigated factors on the physical and chemical parameters of the soil and data analysis was done in SPSS 20 software.

The one-way analysis of variance test showed that there was a significant difference between the parameters of pH, electrical conductivity, percentage of organic carbon, potassium, nitrogen, moisture, lime, magnesium and calcium among the soil samples of healthy and dieback trees in the northern and southern slopes. The results of the analysis of variance test confirmed the interaction effect of kind of stands × slope aspect for electrical conductivity and calcium and for slope aspect × tree health in the parameter was lime percentage. Other findings showed that the highest average parameters of electrical conductivity, available phosphorus, potassium, organic carbon, nitrogen, and moisture were respectively 2.654 (d s m-1), 1.10 (mg/kg), and 869.5 (mg/kg). ), 4.03%, 0.35% and 12.4% were observed in the soil adjacent to the control trees in the northern slope and for magnesium, calcium and CaCO3 parameters of healthy trees in the southern slope with the values ​​of 21 (meq/100), 42.2 (meq/100) and 13.60% was significantly more than other treatments. On the other hand, in the soil sample adjacent to the trees located in the stands affected by dieback, the average physical-chemical parameters were lower than the control stand (Doleh Naw) and this shows the importance of the physical-chemical parameters of the soil in reducing or increasing the resistance of trees to tree dieback. The findings of the research showed that the highest average macro elements (available phosphorus, potassium and nitrogen) in the soil adjacent to healthy trees in the northern slope and for calcium and magnesium, the highest amount of these elements were observed and confirmed in the soil adjacent to the trees in the southern slope and in the total amount Macro elements were more in the soil of the trees of control (north and south domain); Therefore, the physical and chemical characteristics of the soil (especially macro elements) have an effect on the resistance of oak trees to dieback and other environmental stresses, and the lack of macro elements causes the trees to be weak against the phenomenon of oak dieback.

In general, in the soil adjacent to the dieback trees, the poverty of nutrients and macro elements and lower values ​​of the studied parameters were observed. In general, in the trees affected by Oak decline, the poverty of nutrients and macro elements was observed, and the lower values ​​of the parameters were observed in the soil adjacent to the trees affected by Oak decline. Based on the results, for the optimal management of dieback stands and trees, increase protection measures (control of livestock grazing through grazing and reduction of traditional exploitations), increase restoration programs and forest development in the stands affected by dieback (increase seeding and enrichment operations). In degraded stands and planting with native species in dieback stands) and implementation of health cuts (withered and dieback branches and stems) were suggested.

Corylus avellana L from the Corylacesae family is one of the pioneer species in the early stages of the hazel forest sequence and plays a very important role in the restoration of degraded forests. Unfortunately, in recent years, conversion of use, livestock grazing, fire and cutting of trees have been effective factors in the destruction of this valuable forest. The low percentage of survival and vegetative growth in the early years of hazelnut seedlings increases the production costs of seed-roasted seedlings in the nursery and also causes delays in afforestation programs. This research was conducted with the aim of the effect of T. harzianum on the establishment and improvement of the growth and nutritional characteristics of hazelnut seedlings in field conditions.

At the beginning of May 2016, in Ardabil's Hazelnut Nursery, the soil around the roots of potted hazelnut seedlings, produced from the three sources of Fandoglou (Ardabil Hazelnut Forest), Makesh (Gilan) and Makidi (Arasbaran) were treated with the fungus T. harzianum were inoculated. Then, in November 2017, the one-year-old hazelnut seedlings were transferred to the agricultural lands on the edge of the Fandoglou forest, and according to the above two factors (fungi, seed origin) in the form of a randomized complete block design with three replications of 25 in the conditions They were cultivated dry and the percentage of survival, growth, collar diameter, height and nutrition of hazelnut seedlings were measured during four years.

The results after four years showed that all the examined characteristics were affected by the mushroom inoculation treatment. The main effect of seedling and mushroom origin on all investigated traits was significant at the five and one percent level. The interaction effect of seedling origin × mushroom inoculation on the characteristics of survival percentage, root biomass at the level of 1% and for growth of collar diameter and height, stem and leaf biomass and nutritional elements of leaves of hazelnut seedlings at the error level of 1 And five percent was significant. So that the inoculated seedlings of all three origins had the highest values in terms of all investigated traits compared to the control seedlings. The highest amount of studied traits was found in the seedlings of the origin of Fenugreek inoculated with the fungus T. harzianum was assigned. So that in these seedlings, the survival rate is 65.8%, the shoot growth is 52.2%, the height growth is 54.6%, and the dry biomass of root, stem and leaf is 48.603, respectively. 46.5 and 37.40% and the concentration of leaf nutrients including nitrogen 27.81, phosphorus 23.23, potassium 34.7% increase compared to the unfertilized seedlings of Fandoglou origin. Although the responses of the seedlings were different in terms of the studied traits. Hazelnut saplings with the origin of Fandoglou and Makesh were superior in terms of the studied traits compared to the origin of Makidi..

For the production of strong hazelnut seedlings for afforestation in susceptible lands, the mentioned two sources can be used. Finally, according to the findings of this research, T. harzanium can be used as a biological fertilizer to increase the percentage of success and improve the vegetative characteristics of hazelnut seedlings

The purpose of this research is to evaluate and compare the effects of two native and non-native species of Prosopis (Prosopis cineraria and P. juliflora) on the physical, chemical, and biological characteristics of soil in Sistan and Baluchistan province in Iran. For sampling, 30 trees from each species were selected, and soil samples were taken from a depth of 0-30 cm both under and outside their canopy. After combining all 5 soil samples for each species, samples were obtained for laboratory analysis. Soil properties such as saturated moisture (SM), pH, electrical conductivity (EC), organic carbon (OC), total nitrogen (TN), phosphorus (P), potassium (K), calcium (Ca), magnesium (Mg), microbial respiration (SMR), substrate-induced respiration (SIR), microbial biomass carbon (MBC), nitrification potential (PN), as well as urease, dehydrogenase, alkaline phosphatase, and acid phosphatase enzyme activity were measured in the laboratory. Based on these measurements, a soil quality index was calculated. The results significantly showed that the highest values of SM, TN, SIR, and dehydrogenase enzyme were found under the canopy of P. cineraria, while the highest values of Mg, P, TN, and acid phosphatase enzymes were observed under the canopy of P. juliflora species. The lowest values of these parameters were observed outside the canopy of both species. The soil quality index indicates that soil quality under the P. cineraria tree is higher than under the P. juliflora tree and outside the crown canopy of both species. The conclusion suggests that native Prosopis tree species improve soil fertility and acidity, with soil quality under their canopy being numerically higher than under non-native Prosopis. Therefore, preserving natural forests of P. cineraria species and afforestation with it are recommended to maintain and improve soil quality in Sistan and Baluchestan province.

Tree species can cause changes in soil characteristics and organic carbon storage due to their tolerance to harsh environmental conditions. Therefore, by knowing the species that have more ability to store carbon, it would be possible to follow the improvement and regeneration of urban forests from the perspective of carbon sequestration index. Haloxylon ammodendron and Tamarix hispida shrubs are among the important halophyte species of the Irano-Turanian vegetation zone. In these areas, it is important the role of these shrubs in storing carbon and increasing plant biodiversity. The current research aims to investigate the soil carbon sequestration and plant biodiversity indicators in the habitats of these two species in Qom province.

The natural habitat of Tamarix located in Mesila plain of Qom province and the cultivated habitat of Haloxylon in 1362, located in Hossein-Abad area of Mish-mast in Qom plain with arid climate. Soil sampling was done randomly on one hectare with 30 samples from the eastern direction under the canopy and outside the canopy, by a cylinder at the depth of 0-15 cm in both Haloxylon and Tamarix habitats separately. Sampling was done to calculate the soil organic carbon reserve to obtain the apparent specific mass and organic carbon and some soil physical and chemical factors. To study the vegetation coverage in each habitat, from a plot of 400 m2 with the method of implementing the plot in the form of four plots of 10 x 10 meters in order to better distribute it on the surface of one hectare, and to study the vegetation of the floor from 20 micro-plots of one m2 (five micro-plots in each plot) was used. The values of species diversity in each microplate from each sample plot was calculated using Simpson, Shannon-Wiener indices and species richness using Margalef, Menchick and uniform indices with Pillo and Sheldon indices. Spearman's test was used to calculate the correlation between soil carbon deposition factors and some physical and chemical factors.

The average of all measured factors in the soil was higher for Tamarix. The effect of species and sampling position and the mutual effect of species in sampling position on the amount of acidity factors, percentage of organic carbon, potassium and carbon deposition (organic carbon storage) of the soil had a significant difference at the level of 5%. Furthermore, based on the comparison of the average of the treatments, it was found that the highest amount of soil carbon deposition is in the treatment under canopy of the Tamarix shrub with the amount of 191.13 tons per hectare. The results showed a significant difference in the amount of soil carbon sequestration between two species of Haloxylon and Tamarix, and it is higher in Tamarix soil. Soil characteristics such as carbon deposition, %OC, pH and K under canopy of Tamarix are higher than outside the canopy. The correlation between carbon sequestration characteristics and other factors showed that OC, pH and EC factors can be used as the most important influencing factors to estimate soil carbon sequestration. The indicators of plant biodiversity, including species diversity, species richness and uniformity, were calculated for each micro-plot only in Haloxylon habitat, because the Tamarix habitat was lack of floor cover and reproduction due to severe drought stress. The Menhinik and Margalef indices with the values of 1.39 and 1.68, respectively, have assigned the average species richness of Haloxylon habitat.

Due to the positive effect of Tamarix on the increase of organic matter and soil carbon deposition, which improves the soil structure in the long term, as well as the ability to adapt and resist the dry and fragile weather conditions of Mesileh region. The revival of this valuable species is vital and it is a suitable species for forestry in areas with such characteristics. Likewise, considering the positive effect of Haloxylon species in increasing habitat biodiversity indicators, which in the long term protect the soil structure, the issue of preserving and revitalizing these valuable plants is necessary for Qom province.

Mycorrhizal fungi are one of the useful soil microorganisms, which can increase the growth of the host plant by absorbing and transferring more water and nutrients to the plant due to symbiosis with plant roots. Therefore, in order to investigate the effect of mycorrhizal fungi on the biomass and nutrient absorption of hazelnut seedlings, a factorial experiment was conducted in the form of a randomized complete block design in field conditions. The investigated factors included the three origins of the seedlings (Fandoghlou, Makesh, and Makidi regions) and fungal inoculation in three levels (Rhizophagus irregularis, Myco root inoculum and control) with three replications of 25 at a distance of 3x3 m, in an area of 6075 m2 in the agricultural lands on the edge of Fandoghlou Forest in Ardabil, Iran. After four years, the results showed that the inoculated seedlings of all three origins were superior in terms of all the examined characteristics compared to the control (non-inoculated) seedlings. The highest traits belonged to Fandoghlou seedlings with R. irregularis inoculation. In these seedlings, root colonization, dry mass of root, stem and leaf were, respectively, 51.9%, 54.4%, 45.1%, and 40.7% higher, and N, P, K, Fe, and Zn were, respectively, 38.8%, 45.4%, 62.9%, 35.5%, and 42.6% more compared to the control seedlings. Finally, it can be concluded that planting of hazelnut seedlings inoculated with mycorrhizal fungi (especially R. irregularis) will have higher vegetative growth.

One of the concerns for the executive organizations to introduce an alternative plan of rest of the Hyrcanian forests is to make decision regarding the exit of coarse woody debris (CWD) volume from the Hyrcanian forests. The research was carried out in the permanent plot with 400 m2 based on the protocols of the comprehensive research plan enacted by Agricultural research Education and Extension organization in Iran. Within each plot beneath the CWDs over than height of 1.5 m and dimensions of 7.5 cm, the organic accumulations resulted from the decay trend were sampled. Besides, the soils mineral layer up to 10 cm depth were sampled after removing the organic accumulations, and were transported to the laboratory. The results of PCA (Principal Component Analysis) showed that beneath the CWDs including higher organic accumulations, amount of the organic carbon and the nutrients were lower in the substrate soil mineral layer. Furthermore, the results of Spearman test indicated that amounts of organic carbon and nutrients in the organic and substrate mineral layers were independent of each other (P > 0.05), and amounts of the organic carbon with Nitrogen were significantly correlated (P < 0.01). Also, the results of two-way PERMANOVA test indicated that interactions of form, species and decay of the CWDs in the study sites were not significantly effective on the organic carbon under the CWDs.

Arbuscular mycorrhizal fungi, due to their very beneficial effects in the growth and development of plants through supplying the water needed by plants, especially in drought stress conditions and increasing their tolerance to salt stress and in general, helping the plant to overcome living and non-living tensions, they are the focus of many researchers. This research was conducted during 2020-2022 with the aim of investigating the effect of flood spreading, vegetation type on the abundance and diversity of mycorrhizal fungi in Kowsar Station.

In spring and autumn, in different land covers, including planted Eucalyptus and Acacia forest, planted pasture with Atriplex bushes with 37 years old and natural pasture in two situations with flood spate irrigation and without spate irrigation. Three samples were prepared from roots less than 1 mm of trees and dominant plants (Heliantemum, Dendrostellera, and Artemisia) in the pasture and the rhizosphere soil up to a depth of 20 cm. After separating and staining the roots, their microscopic examination to determine the presence of symbiosis in the root tissue and to determine the extent of root colonization with mycorrhizal fungi and the extent of mycorrhizal symbiosis based on the extent of root contamination with structures of mycorrhiza was done. The soil passed through a 2 mm sieve was used to separate the spores, and the genus and species of mycorrhizal fungi were identified based on the morphology of the spores using identification keys and information available in scientific sources.

The results showed that the spore density of mycorrhizal fungi in both sampling seasons was higher in areas with flood spreading than areas without flood spreading. The highest spore density in the field of flood spreading in the autumn season is related to H. lippii with the number of spores 50.20 per gram of soil and the lowest with the number of spores 18.80 per gram of soil related to this species in the field without flood spreading in spring. So that the difference between the two was statistically significant with Duncan's test at the 5% level. Also, in all land uses, spore density was higher in autumn than in spring. The highest percentage of root colonization or the percentage of symbiosis was related to Acacia with 61.81% in the field without flood spreading in spring season and the lowest value was related to Eucalyptus with 12.26% in the field without flood spreading in autumn season. In this research, 21 species belonging to 9 genera Acaulospora, Claroideoglomus, Diversispora, Entrophospora, Funneliformis, Glomus, Rhizophagus, Scutellospora and Septoglomus were identified in with and without flood spreading areas. Septoglomus constrictum was the most abundant with 100.0% frequency. Glomus heterosporum and Rhizophagus aggregatum were in the second category with a frequency of 50.0% and Funneliformis mosseae, Glomus ambisporum, Glomus intraradices and Rhizophagus fasciculatus were in the third category with a frequency of 33.3%.

Considering the fact that the identification of mycorrhizal fungi in the rhizosphere of tree plants and pasture bushes in dry areas and their use can be a fundamental step to reduce the negative impact of various stresses, including drought stress, it is suggested the active and effective species of these fungi may be identified and propagated and used as inoculum (biofertilizer) to restore rangelands in these areas.

Biochemical activities of soil have been proposed as one of the most well-known indicators of soil quality and health, which are considered in evaluating the effect of afforested species on soil characteristics. This research was conducted with the aim of investigating the long-term effect of flood spreading operation and type of vegetation on the activity of acid and alkaline phosphatase, urease and dehydrogenase enzymes and soil microbial activity, including basal respiration and stimulated respiration, in 2019.

Sampling the soil around the roots of Acacia salicina Lindl., Eucalyptus camaldulensis Dehnh., Atriplex lentiformis (Torr.) Wats. (0-20 cm depth) was carried out with 6 treatments in three replications. Statistical analyzes were performed using SPSS software as a factorial test in the form of a randomized complete block design and the means were compared with Tukey test at P<0.05.

The results showed that the interaction between flood spreading and vegetation type on the activity of acid phosphatase, alkaline phosphatase, urease, dehydrogenase, stimulated respiration and organic carbon was significant at P<0.01. The activity of acid phosphatase and alkaline phosphatase enzymes in the soil under cover of Acacia and Eucalyptus plantations was higher than the activity of these enzymes in the soil under cover of Atriplex, especially in the situation with flood spreading. The activity of urease enzyme showed the highest value in the soil under the Atriplex with flood spreading and the lowest value in the soil under the Atriplex without flood spreading, and this difference is statistically significant with Tukey's level test at P<0.05. The activity of dehydrogenase enzyme showed the highest value in the soil under the Atriplex with flood spreading and the lowest value in the soil under the Atriplex without flood spreading, and this difference is statistically significant with Tukey's test at P<0.05. Dehydrogenase activity in the soil of Atriplex with flood spreading compared to the activity of this enzyme in the soil of Acacia with flood spreading and also the activity of dehydrogenase in the soil of Acacia and Eucalyptus in the situation with flood spreading, statistically with the test Tukey did not show a difference at P<0.05. In the conditions of flood spreading, the basic respiration rate in the understory soil of Acacia, Eucalyptus and Atriplex was higher than the basic respiration in the soil under the cover of these plants without flood spreading, although the difference in the basic respiration in the two situations with flood spreading and without flooding were not statistically significant at P<0.05. The amount of stimulated respiration in the soil of Atriplex with flood spreading was higher compared to the amount of stimulated respiration in the soil of Eucalyptus with flood spreading, but it was not statistically different from the amount of stimulated respiration in the soil of Acacia with flood spreading and Acacia without flood spreading. The highest and lowest amount of stimulated respiration was observed in the soil under the cover of Acacia and Eucalyptus, respectively, in the condition without flood spreading, and these differences were statistically significant at P<0.05.

Conclusion and Recommendations:

The results of this study showed that the activity of soil enzymes can potentially predict the amount of nutrient deficiency. In addition, afforestation in arid areas, improves soil quality indices. Considering the important role of organic matter in improving the biological properties, quality and health of the soil, in order to increase the amount of organic matter in the soil, rehabilitating flooded rangelands with native and compatible trees and bushes, managing grazing and increasing non-grazing periods are recommended.

The purpose of this study is to clarify the necessity of considering buffer area and its role in natural or man-made ecosystems, with specific functions. Evaluating the direct and indirect destructive consequences of human manipulations, such as high-rise construction in buffer areas and its effects on the central core of this type of ecosystem is very essential. The National Botanical Garden of Iran has other functions such as preserving Iran's important and endemic species and is a source of their reproduction. In addition, as one of the respiratory lungs of Tehran, it plays a key role in air conditioning and educational programs. Based on this, the signs of urban development on different parts of the environment of this garden including water, soil, air, vegetation and wildlife have been investigated in this article. Based on the available information and the results of field survay, the long-term effects of this type of development on the NBGI have had an irreversible effect on the hydrological changes of the underground water resources, and in the future, the survival and sustainability of the NBGI will be affected due to the lack of underground water supply. In addition, reducing the wind and preventing the necessary ventilation and the formation of thermal islands will cause an outbreak of pests and important diseases on plants. Also, the limitation of soil permeability and the damage to aesthetic values of the garden are other negative consequences of this excessive development, which will threaten the sustainable life of the NBGI.

To investigate the inoculation effect of Pseudomonas fluorescens and native mycorrhizal fungus on growth, morphological characteristics and essential oil percentage of Thymus kotschyanus Boiss. & Hohen., an experiment was conducted in a Randomized Complete Block Design with 5 treatments and 3 replications in Research Institute of Forests and Rangelands. Understudied treatments were included as Pseudomonas fluorescens, P. fluorescens and Rhizophagus clarus, P. fluorescens and Funneliformis badium, P. fluorescens and Acaulospora laevis, and control. According to the results, all treatments had a positive effect on thyme growth and P. fluorescens treat had the most essential oil percent. The results showed that all treatments had a significant effect on root volume, with the highest one in the treatment of F. badium and P. fluorescens (36.25 ml). The highest mean weight of dry and fresh root and dry plant belonged to A. laevis and P. fluorescens (p≤ 0.05) (, 13 g, 6.9 g and 32.25 g). This result confirms the synergistic relationship between P. fluorescens and A. laevis. The most amount of colonization was observed in R. clarus and P. fluorescens (94.9%). The results indicated that the synergistic intraction between P. fluorescens and native mycorrhizal fungus has different effects on morphological traits of this medicinal plant and these findings can be used to enhance the growth and yield of T. kotschyanus for organic production.

One of the main reasons for the failure of planting projects with hazelnut is climate change and subsequent drought stress in the early years of growth. The aim of this study was to rehabilitate and develop degraded hazelnut forest stands in rainfed conditions in Ardabil hazelnut forest. For this purpose, in early May 2016 in Ardabil hazelnut nursery, new hazelnut potted seedlings produced from three seed sources including Fandoglou (Ardabil Fandoglou forest), Makeh (Aghvalar Gilan forest) and Makidi (Arasbaran forest) were inoculated with fungi Rhizophagus irregularis as well as Mycoroot (containing arbuscular mycorrhizal fungus Glomus mosseae, G. etunicatum and Rhizophagus irregularis). Then, in April 2017, uniform annual hazelnut seedlings were transferred to the lands to Fandoglou forest (area 6075 m2) and were tested in factorial arrangement in a randomized complete block design with three replications of 25 in dryland conditions. The results after four years showed that mycorrhizal seedlings, produced from seeds of all three origins, had larger sizes in most of the studied traits than control seedlings. The highest root colonization of seedlings (51.9%), as well as the largest sizes of most of the measured variables belonged to seedlings of Fandoglou origin inoculated with R. irregularis. Survival, collar diameter growth, height growth, photosynthesis rate, stomatal conductance, water consumption efficiency, and chlorophyll content, respectively, increased by 52.7%, 82.1%, 58.9%, 102%, 152.2%, 272.9%, and 63.6% compared with the control (non-mycorrhizal seedlings of Fandoglou origin). Considering the satisfactory symbiosis of hazelnut seedlings with mycorrhizal fungi, for the production of hazelnut seedlings in Fandoglou forest nursery and its planting in degraded areas of this region, seedlings produced from the origin of Fandoglou seeds coexisted with the R. irregularis is preferred to seedlings with the origin of Makeh and Makidi inoculated with Myco root.

In arid and semi-arid ecosystems, the relationship between tree species and habitat is fragile due to environmental stresses. Native species of Prosopis cineraria and non-native Prosopis juliflora are among the species that in addition to water-soil-plant relationships, affect the life of other animal and plant species in these areas. In these areas, the role of native trees in carbon storage and change in soil properties is important. Soil plays an important role in the carbon cycle and is an important source of carbon storage and tree species can make changes in soil properties and organic carbon storage due to tolerating hard environmental conditions such as high temperatures and radiation. Soil biological properties are a good indicator for measuring soil quality and by examining them, appropriate information about respiration, nutrient cycle, microbial biomass and mineral nitrogen mineralization capacity is obtained. (Prosopis cineraria (L.) Druce) is one of the most important native species in the Sahara-Sindhi area, which has a good ability to establishment and adapt and improves soil properties. The non-native species of (Prosopis juliflora (SW) DC) is widely planted with fast growth and prevention of fine dust as a fodder tree. Trees in these areas can have a range of different effects on the soil under their canopy in various ways and have a vital effect on the richness of soil microorganisms. Due to the importance of both species in this habitat, a comparison of changes in soil biological properties and organic carbon storage under and outside the canopy of Prosopis cineraria and Prosopis juliflora bases was performed in Assaluyeh in Bushehr province.

To measure basic and induce respiration, microbial biomass carbon and nitrification potential, 24 soil samples were collected from 0-30 cm depth randomly from under and outside the canopy of both species. To calculate organic carbon storage of soil with the cylinder in a 1×1 m2 plot, sampling was done from a depth of 0-10 cm of soil to obtain the bulk density and organic carbon. Also for measuring organic carbon storage in litter and grass cover in the same sample plot, litter and grass cover were collected and their weight was recorded. Finally, 120 samples were taken in two location under and outside the canopy of both species.

The results of analysis of fragmented plots showed that the effect of species as the main factor on basic (p<0.05) and induce (p<0.01) respiration was significant and it was in Prosopis cineraria 2.73 and 22.47 mg Co2 in day and hour and in Prosopis juliflora 0.9 and 15.57 mg Co2 in day and hour, respectively was higher in Prosopis cineraria than Prosopis juliflora and had no significant effect on microbial biomass carbon and nitrification potential. The effect of sampling location was significant for all variables studied and under the canopy was greater than outside the canopy.

Due to the positive effect of Prosopis cineraria species on basic and induce soil respiration, preservation and revitalization of this valuable native species is very vital and negative effect of non-native species of Prosopis juliflora on basic and induce soil respiration can reduce microbial activity and upset the balance of the nutrient cycle, especially carbon. Therefore, it is recommended to use native species for improvement and quality of soil in natural forests, afforestation and restoration of ecosystems and the entry of non-native species avoid into the natural forest. Also Prosopis juliflora species is better to be cultivated because high resistance in de- desertification areas and for quicksand stabilization.

This study was done to investigate the effect of slope aspect and crown dieback intensity on the nutrient status of leaves of Persian oak trees influenced by dieback and site soil in the forests of Ilam province. For this purpose, the Forest area of Melah-Siah was considered and two one-hectare areas on the northern and southern aspects with almost the same altitude levels were selected. In each selected area, 10 trees were sampled in two intensities of healthy and dieback affected. Leaf samples were collected from the four main sides of tree crown and the middle part of the crown and from their terminal branches. Furthermore, from the south side of the selected trees, soil samples were prepared from two depths. Collected samples were transferred to the laboratory for analysis of OC, N, P, K, Ca and Mg.  The results showed that the slope-aspect and crown dieback intensities have significant effects on the amount of phosphorus, calcium and magnesium in Persian oak tree leaves. So that, the amount of leaf phosphorus in the northern site was higher than the southern site. Leaf calcium and magnesium concentrations were higher in the north site than the south site and in dieback-affected trees than the healthy trees. Also, the amount of soil organic carbon was significantly affected by slope aspect. The OC content in depth of 0-20 cm, in the northern site was less than the southern site. The amount of pH, CaCO3 and soil moisture in the depth of 0-20 cm and soil moisture in the depth of 20-50 cm were also changed under the slope aspect. It was concluded that leaf nutrients had more changes than soil elements under the influence of considered factors and the amount of these changes was more attributed to the slope-aspect. The studied Persian oak trees with different crown dieback degrees had a similar situation in terms of soil macro elements, but had different conditions in terms of leaf macro elements. Considering the differences between their habitats in terms of soil moisture and pH, it can be said that the dieback severity of tree crowns is related to physiological mechanisms in trees for absorbing water and nutrients.