فهرست مطالب حمید جلیلوند

Nitrate (NO-3) is an important compound in plant nutrition. However, the leaching of large amounts of it can reduce soil fertility and endanger environmental health and quality of life.

This study was conducted to investigate the effect of rice husk biochar and different types of pure and mixed fertilizers on nitrate leaching from the soil of one-year-old potted saplings of Acer cappadocicum Gled (with an average collar diameter of 17.3 mm and a height of 19.72 cm). This research was conducted in Lajim nursery, north of Iran, using 19 treatments with three replications in a completely randomized design. The treatments included rice husk at 0.5% and 1% by volume, biochar of rice husk at 0.5%, 1%, and 2% by volume, cow manure at 0.75% and 1.25% by volume, and chemical fertilizer at two levels: 1) triple superphosphate 25, ammonium sulfate 18.75, and potassium sulfate 18.75 mg per kilogram of soil and 2) triple superphosphate 50, ammonium sulfate 37.5, and potassium sulfate 37.5 mg per kilogram of soil. The soil treatment of the planting bed (control) and the combination of treatments were also included. To collect drainage water for measuring the amount of nitrate leaching, potted seedlings were irrigated 20% more than the normal irrigation amount, and samples were taken in five stages (from April to September, once before adding ammonium nitrate fertilizer and four times after its addition). In the laboratory, nitrate concentration was measured by the spectrophotometric method. Statistical analysis was performed using R software, and a comparison of means was performed using Duncan's test.

According to the results, in the first stage of sampling, the highest concentration of nitrate in drainage water was observed in the chemical fertilizer level 2. In the second and fourth stages, it was observed in the combination of chemical fertilizer level 1 and 0.75% cow manure by volume, and in the third stage, it was observed in the treatment with 0.75% cow manure by volume. The highest pH value of the drainage water in the first stage of sampling was observed in the combination of chemical fertilizer level 1 and 0.5% biochar. In the second and third sampling stages, the control showed the highest pH value. In the fifth stage, the result was the same as the first stage. Also, the combination of chemical fertilizer level 1 and 0.75 percent cow manure caused an increase of 204, and 0.5% biochar caused a total decrease of 39.4 mg/liter of nitrate leaching.

The results of this research showed that the application of biochar causes a decrease in electrical conductivity and nitrate concentration and an increase in the pH of drainage water. Therefore, considering the beneficial effect of biochar in reducing nitrate leaching and soil salinity, which will definitely bring positive environmental effects, it is recommended to use rice husk biochar to produce seedlings in forest nurseries.

Soil is the largest source of carbon in the biosphere and more than half of its carbon is stored in forest ecosystems. Considering the importance of the soil carbon, the purpose of this research is to investigate how different species of broadleaf and coniferous species affect forest carbon storage in soil, considering their different ability to store and use soil nutrients in the forest Kolet.

In this research, first, three stands of Acer velutinum Boiss, Alnus subcordata C.A.M, and Cupressus sempervirens var horizontalis, as well as one natural forest stand were selected in the study area. Ten samples of 400 square meters (20Î20 meters) were selected in each cluster. Also, soil samples were collected from the four corners and the center of each plot from a depth of 0-15 cm; Then the soils were mixed and a combined sample was separated for the laboratory analyses (40 samples in total), which was used to study the physical and chemical characteristics of the soil (bulk density, soil texture, soil reaction, electrical conductivity, organic carbon, total nitrogen, phosphorus and absorbable potassium). SAS statistical software was used for soil data analysis related variables, and the Vegan R software package was used for principal component analysis (PCA) to identify the most significant factor and differentiate between the studied populations.

Based on the obtained results, soil reaction rate, absorbable potassium, relative humidity, organic carbon, clay and soil carbon storage had significant differences among the four stands (P < 0.01). Alnus subcordata and Acer velutinum showed the highest amount of carbon storage compared to Cupressus sempervirens and natural forest stand. The difference observed in the amount of soil organic carbon in the studied stands depended on the different capabilities of tree species in restoring the soil ecosystem. The planting of broadleaf species resulted in more carbon storage in the short term than coniferous species, because broadleaf tree species increase litter production and nutrient return, making them more effective in restoring degraded forest soils. This is due to faster leaf decomposition, higher nitrogen content and lower C/N ratio, while the presence of resinous and phenolic substances in coniferous leaves negatively affects the decomposition of their litter.

In summary, this research showed that reforestation with broadleaf species in various areas of the region significantly impacted the soil carbon stock and carbon storage potential based on the type of tree species. Particularly, broadleaf species such as Alnus subcordata and Acer velutinum played a crucial role in increasing the amount of carbon stored in the soil of the studied region.

It is important to research in the field of germplasm protection of native and medicinal tree species in northern Iran forests, especially blood hawthorn with many medicinal properties. Sexual reproduction of hawthorn is possible with apomixis due to the thick shell and two types of physical and physiological dormancy, and its asexual reproduction by rooting cuttings faces many problems. Bloody hawthorn (Crataegus atrosanguinea from the Rosaceae family) is considered one of the valuable species of the forests of the north and west of the country, which is very important due to its fruitfulness, very strong wood, and numerous medicinal properties. The medicinal properties of hawthorn have been proven in the treatment of blood pressure, arteriosclerosis, heart congestion, heart muscle weakness, and coronary insufficiency. Hawthorn contains many secondary metabolites such as flavonoids proanthocyanidin and glycosides. Optimizing the in vitro cultivation conditions of blood hawthorn as one of the natural species of Iran can be a suitable solution for its propagation. The present research was carried out to control pollution, control browning, and induce the callus of blood hawthorn (C. atrosanguinea) in vitro. Controlling the contamination of explants, seeds, and plant tissues is of great importance for the success of plant tissue culture. Since the enrichment of natural plant explants is a priority for tissue culture, this is usually associated with many problems with browning, especially for woody plants that have a thick and woody stem. Determining the type and concentration of the growth regulator of a variable factor is necessary for the growth of plants under in vitro conditions. After applying the growth regulator to the culture medium, the plant will show different reactions, but one of the appropriate ways to choose the correct path of plant regeneration is to determine the wet and dry weights of the callus, which is widely measured as a standard of callus growth. The callus growth curve can be obtained using the wet and dry weights of the callus. The results of past research indicate a wide range of changes in the type and concentration of growth regulators on callus formation and regeneration of different species of the hawthorn genus. A specific type and concentration of growth regulators should be applied according to the type of plant species.

Young and healthy stems of blood hawthorn were collected from Larijan in Amol, Mazandaran province, Iran, with geographical coordinates of 38' 58° N and 10' 52° E, at the beginning of the growing season. The collected stems were immediately transferred to the plant tissue culture laboratory of the Faculty of Natural Resources at Sari University of Agriculture and Natural Resources, Iran. Disinfection of natural hawthorn stems is very necessary due to surface and tissue contamination. For this purpose, explants of 0.5-1 cm size were cut from the stems. The infection control treatments included HgCl2, H2O2, NaClO, and AgNO3, and five treatments were designed to control the browning of explants. Browning control treatments included control, running water, ascorbic acid, polyvinyl chloride, and activated charcoal. In general, the culture medium consisted of substances including mineral salts (micro- and macroelements) as providers of maximum growth, amino acids and vitamins as nitrogen sources, sugar as a source of carbon and energy, growth regulators as growth and morphogenesis stimulants, agar as the solidifier of the cultivation medium, and water, which includes 90% of the cultivation medium. In this research, the culture medium was MS, which was first created by Driver and Koniaki (1984) and prepared according to Dufussard (1976). In this study, the pH of the culture medium was set to 5.8. For callus induction, IBA, NAA, 2,4-D, BAP, TDZ, and Kin treatments at three concentration levels of 0.1, 1, and 6 mg/L and a combination of NAA (6 mg-1) + BAP (1 mg-1), and IBA (6 mg l-1) + BAP (1 mg-1) were used in the MS culture medium. Stem explants were placed horizontally on the culture medium. Among different callus treatments, callus percentage, degree of callus, callus fresh and dry weights, and cross-sectional area of callus were measured to investigate callus induction. The best treatment was obtained by calculating the mentioned characteristics and that treatment was used for planting. It was transplanted approximately every 20 days and a total of 5-6 times. After callus cultivation in the reproduction medium, the explants were placed in a culture chamber and adaptation racks under 16 hours of light and 8 hours of dark treatment at 25 ± 2 °C with a humidity of 70%.

HgCl2 (0.5%, 16 minutes) with an average of 100% health was the most appropriate pollution control treatment. The control treatment with 98% health was observed as the most appropriate browning control treatment. Moreover, the type, concentration, and interaction effect of the type and concentration of the growth regulator significantly affected the callus induction characteristics of blood hawthorn (P < 0.01). The highest fresh and dry weights of callus, percentage and degree of callus formation, and cross-sectional area of callus were observed among auxin and cytokinin treatments, respectively, for 6 mg/L of NAA and 1 mg/L of BAP treatments. The highest levels of the studied callus induction characteristics were observed in the culture medium containing the combination of auxin and cytokinin (6 mg-1 of IBA+1 mg-1 of BAP).

In general, the results showed a 90% chance of controlling the browning of the explants of natural blood hawthorn branches in a normal state and without applying any treatment. It is recommended to use 0.5% mercuric chloride for 16 minutes to disinfect the explants. The combination of growth regulators in the culture medium was evaluated as very suitable for the callus induction of bloody hawthorn. The results of this research can provide laboratory instructions for the regeneration and mass reproduction of blood hawthorn.

Plant leaves react to environmental changes with high adaptability. This study investigated the morphological characteristics of Persian oak (Quercus brantii) and wild pistachio (Pistacia atlantica) leaves from 15 forest sites in Ilam province at an elevation range of 1000 m (from 1111 to 2048 m a.s.l.). At each site and for each tree species, five healthy individuals and five healthy and mature leaves were collected from the outside and middle of the crown. The leaf area index, petiole length, main vein length, leaf circumference, blade length, blade width, and the number of leaf margin dentations were measured. The data were analyzed based on the nested research design, and the means of the studied traits were compared using the LSD test. In the Persian oak trees, the results showed that the petiole length (1.72 cm), leaf circumference (20.23 cm), leaf length (8.17 cm), leaf width (4.43 cm), and leaf area (28.16 cm2) at higher elevations had higher averages than at lower elevations. However, the number of leaf left and right dentations were 12.26 and 12.47, respectively, indicating higher average weight at lower altitudes. In pistachio, all measured characteristics like petiole length (0.46 cm), leaf circumference (13.98 cm), leaf length (5.53 cm) and leaf width (3.29 cm), and leaf area (12.31 cm2) at higher elevations had higher averages than the lower elevations as 0.24 cm, 12.26 cm, 5.18 cm, 3.0 cm, and 10.85 cm2. The significant intra-population changes strengthen the idea of intra-population morphological diversity for oak species at the regional level and even in Zagros to some extent. Among the studied features, those that are less sensitive to environmental changes can be used as distinguishing features for species separation.

Parrotia persica, a native species of the Hyrcanian forests, is distributed from the west to the east of the forests of northern Iran. This study investigated the genetic diversity of Parrotia persica using molecular information from populations collected from three habitats in Gilan, four habitats in Mazandaran, and three habitats in Golestan. Using the Amplified Fragment Length Polymorphism (AFLP) marker, 826 bands were obtained, with more than 90% of the bands being polymorphic. The mean content of polymorphic information (PIC) and marker index (MI) were calculated to be 0.24 and 22.4, respectively. Cluster analysis based on the Jaccard similarity coefficient and Unweighted Pair Group Method with Arithmetic Mean (UPGMA) algorithm revealed a wide variety in the collected samples. Based on the Jaccard similarity coefficient, the range of genetic similarity varied from 0.26 to 0.44. The results of the molecular analysis of variance (AMOVA) showed that 21% of the total genetic diversity in Parrotia persica populations was due to genetic diversity between the populations of the three provinces of Golestan, Mazandaran, and Guilan. Genetic diversity within the populations of the habitats accounted for 79%. It can be concluded that there is no difference between the populations based on the diversity of molecular information, but there is diversity within the populations. The diversity among the evangelical populations seems to be more influenced by the environment than genetically. However, for a more accurate conclusion, it is suggested that different ecotones of the population be examined with molecular markers.

Different fertilizers such as green, animal, chemical, biological and biochar are used in different nurseries to improve germination and growth. The purpose of this research is to investigate the effect of soil conditioners on the germination rate and percentage of Fraxinus excelsior seeds in forest nurseries. This experiment was carried out in Nursery Lajim, located in Sarjangalbani Kaslian, General Department of Natural Resources and Watershed of Swadkoh city. In this research, 20 soil conditioning treatments include rice husk to amount of 0.5% and 1% of soil volume, rice husk biochar to amount of 0.5%, 1% and 2% of soil volume, 150 and 300 grams of cow manure, minimum and maximum chemical fertilizer (minimum chemical fertilizer for super triple phosphate 0.6 grams, for ammonium sulfate 0.45 grams and potassium sulfate 0.45 grams and chemical fertilizer for triple superphosphate 1.2 grams, for ammonium sulfate 0.9 grams and potassium sulfate 0.9 grams) and the control treatment was considered with three repetitions. The seeds selected for the experiment were cultivated in the appropriate soil depth, by observing the first young seed on the 10th of April, counting of seeds has started. The quality of seed germination was leaf emergence. For statistical analysis, after checking the normality of the data and the homogeneity of variances using the Shapiro Wilk and Loon tests at the 95% probability level, one-way analysis of variance was used. If the data were significant, comparisons were made using Duncan's test. The results showed that the effect of soil conditioners on the speed and percentage of seed germination has a significant effect. The highest germination rate and percentage were observed in the treatments of 1.25% cow manure and 1% rice husk, 1% maximum chemical fertilizer and rice husk, 2% rice husk biochar and 1% rice husk biochar, and in general, the use of these materials had the greatest effect on seed Fraxinus excelsior. it is suggested to use organic materials such as rice husk and cow dung to increase the germination of Fraxinus excelsior seeds in forest nurseries.

With sufficient knowledge regarding the presence of fungi and the significance of biodiversity, the forest's management objectives can achieve their sustainability goals. Therefore, in order to properly manage the forest, it is necessary to establish indicators that provide adequate information on biodiversity and monitor changes resulting from management activities. This study aims to identify various macroscopic fungi and investigate their biodiversity in their habitat, i.e., deadwood.

Fifteen specimens of deadwood fungi were randomly selected in Darabkola forest. All macroscopic fungi were numbered and collected, then transferred to the mycology laboratory for identification. The biodiversity of the fungi was calculated using Shannon-Wiener diversity index, Simpson diversity index, richness index, and uniformity index with PAST software

The obtained results revealed that there were 37 species of macroscopic fungi belonging to 27 genera and 16 families. Trametes versicolor, Daldinia concentrica, Trichaptum biforme, and Fomes fomentarius were the most abundant, while Hericium coralloides, Ganoderma resinaceum, Ganoderma adspersum, and Trametes trogii were the least abundant species. Additionally, the families Polyporaceae, Xylariaceae, Ganodermataceae, Pleurotaceae, and Schizophyllaceae were the most abundant, whereas Pezizaceae and Hericiaceae were the least abundant. Most fungi were present in the final stages of decomposition. The results indicated that the mean diversity index for Shannon-Wiener species diversity was 3.24, Simpson species diversity index was 0.95, Margalef's richness index was 6.11, Menhinick's index was 1.95, and uniformity was 0.69. The analysis of the Shannon-Wiener diversity index showed that Trichaptum biforme and Trametes versicolor had a higher diversity value with a score of 1.46.

The results of this study indicate that for the management of fallen deadwood habitats with the aim of increasing the biodiversity of fungi, it is recommended to preserve these fallen deadwood areas within the forest. This preservation would contribute to the revitalization and completion of the ecosystem cycle.

Iron wood (Parrotia caspica (D.C) C.A. Mayer) is one of the endemic tree species of Iran that is widely distributed in Hyrcanian forests from west to east. Due to the fact that climatic factors in the northern forests are variable, the relationship between the ecological conditions of the habitat and the leaf stomata of Iron wood tree species was investigated in this study. For this purpose, leaves of 10 populations were collected from three provinces of Guilan, Mazandaran and Golestan and the morphological characteristics of their surface, density, length and width of the stomata were investigated. Also, habitat characteristics of diameter equal to tree trunk, altitude of habitat, temperature and rainfall were used for climate modeling. The results showed that with a 99% probability there was a significant difference between the stomata characteristics of Iron wood trees in different habitats (P<0.001). The trend of stomata density changes from west to east of northern forests was decreased, but stomata area increased from west to east. The predicted model showed that altitude and temperature had a significant effect on stomatal density (P<0.001). Temperature and rainfall had a significant effect on the stomata area (P<0.001) but the effect of altitude and diameter at breast height on the stomata area was not significant. In general, it can be said that the characteristics of the stomata are closely related to the climate conditions prevailing in the habitat.

Considering the current state of the Zagros forests and the necessity of using information related to quantitative characteristics in the management of these forests, it is essential to prepare more accurate information so that the control of this area can be done more accurately. One of the ways to obtain statistical information is linear sampling (transect.( In this regard, the present study aims to compare the efficiency of the length of transects with the inventory method and to investigate the performance of this method in forests with different densities.
To carry out the present research, taking into account the area and topography of the region, a square survey grid with dimensions of 100 x 100 meters was used in the customary forests of Olad -Ghobad located in Lorestan province. Then 30 one-hectare plots were implemented in the area and fully surveyed. In the next step, transect sampling was performed in two modes using tree position simulation in GIS. In the first step, transects with lengths of 25, 50, 75, 100, and 125 meters were harvested inside each one-hectare plot. Then, the quantitative characteristics of the trees that were placed along the desired tracts, such as two diameters perpendicular to each other, were measured. In the second stage, the forest area was divided into three classes low density, medium, and dense, and again transects with the studied lengths were created again. Quantitative characteristics of trees were measured on transects in each class. The results of characteristics comparing the number of trees per hectare and canopy cover showed no significant difference between different transect lengths with a full inventory. The results of estimating the E%2×T index in the study area showed that for both characteristics of the number of trees per hectare and canopy cover, a 25-meter transect with values of (19038.82) and (958338.9) have the highest precision, respectively. The results showed that the value of this index has the highest accuracy for medium numbers in hectare with 75 m transect length, and low canopy covers with transect length of 50 m.

Gathering accurate information for statistics requires high cost and precision. The time factor is also one of the important issues that should be seriously considered in statistics. Therefore, the use of sampling methods and satellite images will be a good alternative for this purpose. In the present study, the aim of the effect of different cluster sampling schemes in estimating the quantitative characteristics of the traditional forests of Olad Ghobad in Koohdasht township, Lorestan province using Sentinel 2 sensor images. To estimate the studied characteristics, 150 clusters in the form of six designs (triangular, square, star 1, linear, L-shaped, star 2) were implemented in the region. Then, in each subplot, the characteristics of the number and area of the tree canopy were measured. Afterimage preprocessing and appropriate image processing (principal component analysis, texture analysis, and different spectral ratios to create important plant indices), the corresponding digital values of the ground sample plots are extracted from the spectral bands and used as independent variables. Modeling was performed using nonparametric methods of random forest, support vector machine, and nearest neighbor. The results showed that the average density per hectare was 51 and the canopy area was 32.94%. The diagram of the mean squares of the error of the training and test data against the number of trees for the characteristic number per hectare and canopy showed that the optimal number of trees was obtained at approximately 75 and 350 points. The results of validation according to the percentage of squared mean squared error showed that for both density and canopy surface characteristics of random forest algorithm with linear and double star sampling designs with the squared percentage of mean squared error respectively (46.00%) and (10.44%) and Bias (-0.02%, 2.82%) along with cluster sampling designs linear and double star, respectively, had better performance in modeling. In general, the results showed that the use of different cluster sampling schemes, nonparametric modeling methods, and Sentinel2 sensor images can better performance estimate the quantitative characteristics of Zagros forests.

The consequences of global climate change that Iran and other countries are now facing are the pressures and stresses that have been placed on terrestrial ecosystems, especially forests. This is a serious threat to the extinction of many species. Evaluation of plant functional traits changes along height from sea level gradient is very useful in order to understand the adaptation of communities and their response to the environment in climate change. The purpose of this study was to understand the trend of changes in leaf morphological traits and also to investigate the segregation of populations of three important broadleaf species of Hyrcanian forests in the altitude gradient.

For this purpose, five populations at altitudes of 300, 600, 1200, 900 and 1500 m above sea level in the forests of Neka region were selected according to the natural distribution of the studied species. Leaf sampling was performed in four directions and in the middle of tree canopies and seven leaf morphological traits were measured and calculated. Data were processed using analysis of variance, Duncan multiple comparisons and diagnostic analysis.

The results of analysis of variance showed that all leaf traits of all three species have significant differences between different classes of altitude. The trend of changes in the traits of the three species in the altitude gradient was different. Diagnostic analysis of traits in altitude classes performed grouping of the individuals with high accuracy for all three species. The results of this study showed that among the leaf morphological traits of all three species of oak, hornbeam and beech in response to altitude, the traits of leaf area, perimeter, length and width are considered as the best traits.

In general, considering the trend of changes in leaf morphological traits of species in the altitude gradient based on the nature of the species in the study area and good detection of phenotypic differences of populations by Diagnostic analysis concludes that the forces of natural selection in order to adapt and develop the populations of these three species in the altitude gradient of this region, have a good effect on leaf characteristics and have caused the separation of populations. Also, the leaf area trait was introduced as the most effective applied trait and the difference in height of 300 meters was proposed as hypothetical boundaries of the separation of altitude provenance of all three species. Therefore, with the help of the findings of this study, the stability of separate populations of all three species against some consequences of climate change can be evaluated and also in choosing the optimal forest management method to protect the genetic resources of species and improving risk prevention management can be used.

Many of the human environmental problems arise from maladaptive behaviors and unstable patterns of life. The reason for the disappearance of forests is not beyond this discussion. One-sided management methods of natural resources and unfamiliar with the needs and traditional way of life of villagers and families living in the forest areas of northern Iran, unfavorable economic and social situation of villagers and low and unsustainable development in rural areas are effective factors in destroying Hyrcanian forests. One of the nature-friendly management methods that that has become popular in the world in the last two decades is "Ecovillage".The purpose of this study is to localize rural ecosystem criteria and indicators in developed countries and prioritize these indicators in rural ecosystems along the Darabkola forest with the aim of preventing the destruction and improper use of Natural areas, including forests and pastures.

In this study, the Delphi method was used to identify and localize the criteria and indicators of ecological, economic and socio-cultural evaluation. Entropy Shanon and TOPSIS techniques were also used to determine the weight and prioritization of these criteria and indicators.

The results showed that ecological criteria with 0.460 had the highest and socio-cultural and economic criteria with 0.375 and 0.165, respectively, had lower weights.

In general, the results of this study showed that attention to ecological category indicators has a higher priority than social and economic indicators. As a result, it is more important to pay attention to these indicators for decision making and management.

The aim of this study was to investigate the effects of rice husk, rice husk biochar, cow manure and chemical fertilizers on the morphological and physiological characteristics of coliseum maple (Acer cappadocicum Gled.) and ash (Fraxinus excelsior L.) seedlings. A total of 60 pots were considered for nine modifying treatments and nursery soil with three replications in a completely randomized design in Lajim nursery located in Savadkuh county, north of Iran. Results showed that different treatments had significant effects on some morphological characteristics of ash. The highest diameter, height, stem length of this species were observed in 150 g of cow manure treatment and the highest dry leaf weight was observed in 300 g of cow manure treatment. Different treatments had significant effects on the height of first stage, leaf area, volume, cross section and length of roots, leaf dry weight and stem volume of coliseum maple seedlings. The highest height in first stage of this species was observed in the control and the highest root volume was observed in the treatments of 300 and 150 g of cow manure and 2% of rice husk treatments. The highest root cross section, root length, leaf dry weight and stem volume of coliseum maple seedlings were observed in 300 g of cow manure treatment and the highest mean leaf area was observed in 150 g of cow manure treatment. In addition, no significant difference was observed in chlorophyll content and photosynthesis of different treatments. In general, the obtained results show that the use of cow manure compared to chemical fertilizers and biochar has a better function in increasing the growth of Fraxinus excelsior and Acer cappadocicum seedlings during a period of plant growth in the nursery.

 Biodiversity is one of the most important indicators of the sustainability of forest ecosystems, which is affected by stand mixture. Vegetation composition and diversity data are the most important basic information for recognizing the natural capacity and targeting for the principled management of forest habitats. On the other hand, the correct understanding of the regeneration status in the forest is the most important The components in predicting the future of the forest are in terms of structure and composition of tree elements. The aim of this study was to compare the diversity of herbaceous cover and regeneration in pure beech, pure hornbeam and mixed stands in Darbakola educational and research forest of Sari.

 For this purpose, the inventory was performed by randomized systematic method with grid dimensions of 75 × 100 meters and in each stand, 25 sample plots with an area of 400 square meters were implemented and the diameter and height characteristics of the trees were collected. To study biodiversity, names of herbaceous species and the type and number of regenerations were collected in 2×2 meter micro sample plots in four quarters and the center of the sample plots in two stages (May and September). Diversity indices of Shannon and Simpson richness indices of Margalf and Manhenick and evenness Owens and Burger Parker diversity indices were used to study the biodiversity of regenerations and grass cover. One-way analysis of variance was used to compare quantitative characteristics of biomass and biodiversity between habitats and to compare the means by SNK test in SAS software environment and to draw graphs using Excel-2010 software. Past software was used to study biodiversity.

 The results of the present study showed a higher density of beech regeneration in all three studied stands. The highest total number of regeneration was observed in mixed habitat (4040). The highest indices of diversity, richness and regeneration evenness were observed in pure hornbeam and the lowest in pure beech. Regarding herbaceous cover, no significant difference was observed between diversity indices among different stands, while the average of these indices was higher at the beginning of the growing season than at the end of the growing season. Therefore, stand mixture has more tangible effects on regeneration diversity than herbaceous cover, and herbaceous cover diversity is more affected by the during the growing season than type of stand mixture.

 Based on the results of the present study, the future composition of the studied populations will be affected by the dominant species of beech. Also, due to the species diversity in the mixed habitat, the highest total number of regeneration and forest density will be related to this stand. Regarding the grass cover, the higher average of diversity indices at the beginning of the growing season than at the end of the growth season, indicates that the environmental conditions are better in terms of temperature and soil moisture in this season. Therefore, mixing has more noticeable effects on regenerative diversity than grass cover and the difference in grass cover diversity is more affected by the time period of the growing season.

Protection and conservation of forests require access to information and awareness of structural features such as number per hectare and canopy cover of trees. This study aimed to select the optimal cluster sampling design in estimating the quantitative characteristics of the forest according to the three measures including accuracy, precision, and time required for the sampling. For this purpose, 30 hectares of watershed Olad Ghobad forests in the west of Lorestan province were selected. The Cartesian coordinates of all the trees in them were determined. In Matlab2014 software environment, the position of all trees was simulated. Then different cluster sampling designs (triangular, square, star 1, linear, L-shaped, star 2) were  defined in the research  by taking into account the number of samples (30, 60, and 90) and three distances (10, 20, and 30 meters). These processes repeated 10,000 times. The results showed that there was no significant difference between the estimated mean of different designs of cluster sampling methods of the study area. Based on the number of samples and the distance studied, it was found that sampling error for linear design has the highest accuracy compared to other designs. The results of estimating the E%2× T index for the characteristic number of trees per hectare and canopy cover showed the lowest values for the square (770.99) and linear (2347) designs, respectively. The results of accuracy estimation for both mentioned characteristics of Star 2 Design showed the lowest values (18.83) and (-5.54), respectively. The results of accuracy estimation for both mentioned characteristics of Star 2 Design showed the lowest values (18.83) and (-5.54), respectively.

To investigate the effect of physiological factors of photosynthetic properties and accumulation of smolites on declined Persian oak trees (Quercus brantii Lindl.), two forest stands were selected in Gachan and Sheshdar from Ilam province, Iran.

The trees were classified into 4 groups in 4 replicates based on the severity of crown dieback (healthy, weak = 5–33%; moderate = 34–66%, and severe > 66%). The physiological activities such as photosynthesis, transpiration, respiration, concentration of carbon dioxide in the stomata, mesophilic conduction, water use efficiency, leaf temperature, soluble sugars and free amino acids were measured from leaves in the middle and outer part of the crown. The random sampling was carried out in the dominant slope of the site. The tree DBH ranged from 30-40 cm. One-way ANOVA and LSD tests were used to compare the different treatments and all statistical calculations were prepared in SAS software.

In severe dieback trees from Gachan, the photosynthesis rate (1.06 μmol CO2 m-2s-1,) was associated with a decrease in mesophilic conduction (0.0021 molm2 s-1), transpiration (3.82 mmol H2O m-2s-1), water use efficiency (0.27 μmol CO2 molH2O-1) and an increase in 9intercellular carbon dioxide concentration (488.15 μmol CO2 mol-2) and leaf temperature (36.05 Cᵒ). The results of correlation test indicated the significant role of stomatal and non-stomatal factors to reduce photosynthesis rate. Furthermore, no increases were detected in soluble sugars (0.009μg gr-1FW) and free amino acids (0.012 μg gr-1FW) as compatible solutions to osmotic regulation. In site Sheshdar, photosynthetic parameters did not show significant differences between different crown dieback severities, while they were associated with increased accumulation of soluble sugars in diebacked oak trees. In addition, no significant correlation was observed between photosynthesis and stomatal factors indicating the ability of this species to keep open stomata under severe drought stress.

In general, our results show the variation in photosynthetic capacities of diebacked oak trees to resist the drought stress and/or to escape it in the two sites.

Reforestation stands can effect on diversity of plant species and soil characteristics of an area. In this study, the effects of 25-year-old reforestation stands with Acer velutinum Bioss., Alnus subcordata C. A. M. and Cupressus sempervirens species on plant biodiversity, understory vegetation and some physico-chemical of soil properties were studied compared with natural forest (Carpinus betulus and Fagus orientalis) in the Kolet forests of Mazandaran province.

In each reforested stands and natural forest, ten plots (2020 meters) were selectively sampled in transects which were 100-m stretches systematically. Then, the list of all herbaceous species and their abundance (cover percentage) was recorded. Also, in each sample plot, a soil sample was taken from the four corners and its center at a depth of 0-15 cm, then these samples were mixed together and a composite sample were taken to study the physic-chemical characteristics of the soil (bulk density, soil texture, acidity, electrical conductivity, organic carbon, total nitrogen, absorbable phosphorus and potassium). The indices of richness (Margalf and Menhenic), evenness (Shannon-Wiener) and diversity (Simpson and Shannon-Wiener) were also studied.

The results showed that reforested stands were significantly different from natural forest (control) in terms of soil reaction rate (P <0.05), potassium, clay and relative soil moisture (P <0.01). Also, the amount of acidity and absorbable potassium reaction in Acer velutinum Bioss mass (6.99, 904.51 mg kg-1) was the highest and lowest in natural mass (6.18, 557.57 mg / kg). It was observed that the highest percentage of clay in natural mass (43.57%) and the lowest percentage in Alnus subcordata mass (39.32%) and the relative moisture in Acer velutinum Bioss mass (40.78%) was the highest and It has the lowest value in Cupressus sempervirens mass (20.12%). But other soil variables did not show significant differences with natural forest. Margalf and Manhenic richness in the four reforestation stands was significantly different (P <0.05). The diversity indices (Simpson, 0.58 and Shannon-Wiener, 1.26) and the richness (Margalf, 2.00 and Mannick, 1.57) were higher in the natural forest than four reforestation stands and the evenness index (Shannon-Wiener, 0.82) showed the highest value in the Cupressus sempervirens stand. Multiple regression of soil variables with the first and second axes of DCA analysis indicates that only potassium has been effective in the separation and differentiation of vegetation in the area and the four studied stands can be distinguished in terms of understory vegetation.

In general, the results of the present study showed that the richness indices of understory vegetation species as well as the characteristics of moisture, soil reaction and adsorbable potassium changed under the influence of reforestation and according to DCA analysis is the most important component in mass segregation. Potassium is an absorbable plant. Also, the study of biodiversity indices showed that the diversity and richness indices were higher due to the fusion of species in the natural massif (Carpinus betulus and Fagus orientalis) compared to the reforested massifs of conifers (Cupressus sempervirens). In other words, the results show a greater protective role of broadleaf stands (Acer velutinum Bioss and Alnus subcordata C.A.M) and natural stands (Carpinus betulus and Fagus orientalis) than needle stands (Cupressus sempervirens) for richness and diversity of understory vegetation species and sustainable maintenance of communities the underside is in the Kolet area.

Species diversity is a combination of two interrelated components of species richness and evenness. The first component is the species richness, which is related to the number of species in the sampling unit; The second component is evenness, which refers to the distribution of species in the site. One of the important problems of these indicators is not determining the contribution of these two components in the diversity index value. An effective method that has been developed for this purpose is called SHE. The aim of the was to investigate the contribution of diversity of understory species in four natural stands, Acer velutinum Boiss, Alnus subcordata C. A. M. and Cupressus sempervirens. var horizontalis afforestation in Colet forest.

In this research, using 40 square plots with an area of 400 square meters, which were selectively sampled in the study area. Then, the list of all herbaceous species with its cover percentage were recorded by Vandermarel criteria. Woody species were counted in each sample plot. The grass and wood cover data were organized in Excel and PAST software for analyzing of richness (number of species, Margalf richness and Menhenick richness), evenness (Shannon-Wiener), diversity (Simpson and Shannon-Wiener). The normality and homogeneity of the data was evaluated using Kolmogorov-Smirnov and Leven test, respectively. SHE analysis was used to determine the contribution of each component of richness and evenness.

The results of comparing the mean of different diversity indices related to herbaceous species showed that the four studied stands (natural, Acer velutinum Boiss, Alnus subcordata C. A. M. and Cupressus sempervirens. var horizontalis) have significant differences in terms of richness (Margalf and Manhenic) (P <0/01). The results of classification of plants in terms of biological form by Raunkiaer method also showed that hemicryptophytes have the highest abundance in the study area. Also the SHE analysis of richness and evenness components for woody regeneration species in the Colet area showed that the evenness of the trend is constant between the four stands and the richness index in the Cupressus sempervirens and natural stands were fluctuating and its trend has an increase shape. In the Alnus subcordata stand, the evenness and richness index had the same contribution in determining the diversity of herbaceous species and woody regeneration in this region. In addition, SHE curve showed that the richness curve (LnS) and the uniformity (Ln E) do not change with each other, and the change in the richness curve is greater than the evenness. This indicates a greater contribution of richness than evenness in contribution of determining the diversity of data related to herbaceous species and woody regeneration. In fact, this showed that with the increase in the number of samples, only rare species were being added to the list of herbaceous and woody species.

In general, the results of the present study showed that the diversity of herbaceous species due to species composition in the natural stand had the highest value in this region. Also, richness and diversity of woody species in natural stand and broadleaves reforestation stands were higher than coniferous reforestation. Therefore, reforestation with broadleaves species has a positive effect on the diversity in the region. Also, the effective factor on the diversity indices in the four stands was the richness component (Ln S), which means that severe changes and fluctuations in plant species and their composition have been observed.

Today, Metropolises require more green space because of air pollution, but water scarcity in aried areas  should lead to irrigation of unconventional sources such as wastewater, which due to the contamination of these sources, tree species with high phytoremediation capability should be used.

In this study, two-year-old seedlings of four species of Judas Tree (Cercis siliquastrum L.), Arborvitaes (Thuja orientalis L.), Persian Lilac (Melia azedarach L.) and White Mulberry (Morus alba L.) were planted in pots and were irrigated with Tehran West Water Treatment Plant effluent which contained manganese and chromium from March to October 2017.

The amount of chromium and manganese in the organs of species irrigated with effluent showed a significant increase compared to ordinary water. All four species irrigated with water treatment plant effluent showed a same growth compared to ordinary water. The highest amount of manganese was in leaf and chromium in root of all four species. The lower than one BCF and more than one TF for manganese in all four species indicated that they were not suitable for phytostabilization of this metal, but all four species (Cercis siliquastrum L.) (1.87), (Morus alba L.) (2.07), (Thuja orientalis L.) (1.96) and (Melia azedarach L.) (1.83) with a more than one TF are suitable for manganese phytoextraction. However, because BCF in them is lower than one, further investigation is needed. White mulberry and Persian lilac with a lower than one BCF and TF for chromium indicated that none of them were suitable for chromium phytostabilization and phytoextraction; But both Judas tree (1.39) and arborvitaes (1.04) with higher than one BCF and lower than one TF for chromium were appropriate to phytostabilization of this metal.

As a result, Judas tree and arborvitaes, which have both the ability to phytostabilization chromium and the ability to phytoextraction manganese, are the best species for the phytoremediation of these two elements in soil irrigated with effluent. Equal growth parameters of all four species after irrigation with this effluent indicated that reuse of Tehran West Water Treatment effluent can be an approach to compensate water scarcity but further studies and monitoring of conditions in order to select the most suitable species for phytoremediation of heavy metals as well as long-term effects of irrigation with effluent, are required.

This study focused on vegetation classification of Darabkola forest in the middle part of Hyrcanian forests in north of Iran. For this purpose, 139 releves were sampled using systematic- selective method in 400 m grid dimensions by the consideration of indicator stands concept. Based on modified TWINSPAN method and Braun-Blanquet phytosociological method, five associations (Parrotio persicae-Carpinetum betuli, Zelkovo carpinifoliae-Quercetum, Solano kieseritzkii-Fagetum orientalis, Aceri velutini-Parrotietum persicae and  Euphorbio amygdaloidae-Fagetum orientale) and four sub-associations (Zelkovo carpinifoliae-Quercetum castaneifoliae subasso a typical subasso Quercetosum, Zelkovo carpinifoliae-Quercetum castaneifoliae subasso Fagetosum orientale, Aceri velutini-Parrotietum persicae subasso Carpinetusum betuli and Aceri velutini-Parrotietum persicae subasso Pteroetosum fraxinifoliae) were distinguished. Demonstration of plant communities along the first two axes of detrended correspondence analysis (DCA) showed that these associations had almost distinct pattern. Also, results of multiple regression of topographic factors with the two first ordination axes of DCA indicated that elevation was the most important topographic factor in distribution of the associations in the Darabkola forests. In addition, the results of this study can lead to the more efficient management and better protection of Darbakla forest.

Due to the increasing trend of destructive effects of land use change due to human activities, it is necessary to discover and highlight these changes in order to plan and make managerial decisions. In this study, land use changes in the metropolitan area of ​​Tehran during the years 2000 to 2015 were studied. For this purpose, ETM, OLI satellite image data of four periods of 2000, 2005, 2010 and 2015 were used. Also, 1: 25000 digital maps of the study area and information obtained from the field visit were used to supplement the collected data. After pre-processing the images and correcting them, information was extracted and extracted, and land use maps were extracted for the studied years. The overall accuracy and kappa index indicated the reliability of the output maps used. The results showed that in all periods, the highest level was related to man-made use, the trend of changes in this use from 2000 (61.8%) to 2015 (78.7%) has increased and the area of ​​this use has increased. According to the results, during the three periods under study, land use, barren and other land uses have decreased in area and the rate of this decreasing trend has been more intense in the period of 2000-2005. On the other hand, man-made land use has shown an increasing trend during three periods. This increase is due to population growth and the highest increase in this land use has been observed in the northeastern parts.

Reforestation operations, recovery and acceleration of the regeneration and rehabilitation process of deforested areas are important to reach the pioneering forest. The current research aimed to study the effect of native broad-leaved species, redwood (Sequoi sempervirens) species and natural forest in Sardabrood forest, located in Mazandaran Province. For this purpose, four hectares from each studied forest stands (i.e. natural forest, redwood, maple, maple-alder and alder) were considered. In each of the stands, 16 sample plots (20 m ×20 m area) were taken to study of species diversity, richness and evenness indices in the term of plant biodiversity. Based on our data, the species of Carex sylvatica L. -Oplismenus undulatifolius (Ard.) P. Beauv- Pteris cretica L.- Viola alba L. - Microstegium vimenium (Trin.)- Ruscus hyrcanus Woron.- Rubus persicus Bioss. were found in all of studied stands. The highest diversity of forest floor belonged to the natural forest, so that the highest values of Simpson (0.94) and Shannon-Wiener (3.17), Camargo (0.49) and Smith-Wilson (0.24) were found in the natural forest. The greater amounts of Margalef (7.34) and Menhinic (4.78) were allocated to the redwood plantation. In the present study, monoculture plantation has led to the reduction of biodiversity. It is recommended to managing the degraded ecosystems. While maintaining the long-term quality and sustainability of forested areas, the maintenance of natural stands is prioritized and the reforestation with non-native needle-leaved species should be considered as next priority.

Fraxinus excelsior L. is a forest species with versatile biological and medicinal activities that its extracts are used as a model for making new compounds in the treatment of various human diseases. In this study, in order to investigate how the biochemical characteristics of this forest species are affected by environmental conditions, four habitats of Perchink, Amreh, Alandan and Qarnsara with an altitude of 200 to 1400 meters, were selected in Tajan and Siahroud watersheds located in Mazandaran province. In each habitat, skin samples were taken from 3 trees (repeated) in summer. Ethanol extracts were obtained by maceration and were analyzed by GC/MS and the physical and chemical properties of the soil samples were measured. The most important compounds of extracts were included:  benzeneethanol (30.33-51.35%), d-allose (6.20-31.72%), scopoletin (14.65-26.83%), tyrosol acetate (5.37-9.06%), carvacrol (0-4.93%), homovanillyl alcohol (3.84- 6.53%) which increased with increasing altitude. Also, there was negative relationship between the identified compounds and soil nutrients. Among them, only polyphenol tyrosol acetate behaved differently from the other compounds in a way that showed a negative relationship with the altitude factor and a positive correlation with the amount of carbon and absorbable phosphorus in the soil. Also, the chemical composition of d-allose was not observed in Perchink habitat. These results were showed that the chemical properties of this tree skin are affected by habitat conditions, which caused increases the species' resistance to pathogens. As a result, considering that the amount of active ingredients in this species was higher at higher altitudes and the presence of these compounds increases the resistance to pathogens, it seems planting this species is more productive at higher altitudes to achieve multiple goals in afforestation.

The qualitative characteristics of forest soils can change under the influence of complex climatic interactions, soil type, management type, and tree species type. The aim of this study was to investigate the variability of soil quality characteristics in two forest plantations of Quercus castaneifolia C. A. Mey and Pinus radiate D. Don in Wood and PaperForests of Mazandaran Province. In both stands, 36 samples were randomly selected for determination of soil physical characteristics, in one season (autumn), and chemical and biological characteristics, in four seasons (autumn, winter, spring and summer). Physical characteristics (clay, silt, sand, moisture, bulk density and lime), chemical characteristics (pH, EC, nitrogen, phosphorus, potassium, carbon to nitrogenratio) and soil biology (soil respiration, microbial biomass carbon, fine root biomass, metabolic rate, and urease enzyme activity) were measured. The results of this study showed that the concentration of nitrogen, phosphorus and enzyme urease activity in oak stands was significantly higher than pine stand (p < /span><0.01), but potassium concentrations were significantly (p < /span><0.01) higher in the pine stand. In all seasons, the rate of soil respiration in the pine stand was higher than in the oak, but this difference was only significant in summer (p <0.05). Characteristics such as carbon to nitrogen ratio, soil carbon, microbial biomass carbon, fine root biomass, and metabolic coefficient were significantly higher in pine stand than in oak in all seasons (p <0.01). The results of this study showed that, in the nitrogen cycle, the oak stand, but in relation to the carbon cycle and global warming, the pine stand had more effects on the soil characteristics. Overall, the practical results of this study suggest that, to improve soil conditions in the degraded forestlands in northern parts of Iran, plantation of oak species is preferred.