yahya kooch

Destruction of vegetation and land use change can have significant effects on the variability of soil characteristics. Based on this, the present research was conducted to study the change of land covers on the characteristics of the soil surface layer in Kohpar Nowshahr, Mazandaran province. For this purpose, different soil characteristics in land cover (Carpinus orientalis Miller.), Crataegus (Crataegus microphylla C. Koch.) and barberry (Berberis integerrima Bunge.), Rangeland with the dominance of Agropyrom longyaristatum species, Rangeland with The dominance of Cousinia commutate species, has been studied in Kohper research station. Therefore, three plots of one hectare (100 m x 100 m) were selected in each of the studied habitats. In each of the plots, 4 samples were taken from the surface layer of the soil (surface 30 cm x 30 cm, 10 cm depth) and a total of 12 soil samples from each of the studied habitats were taken to the laboratory for analysis. The results indicated the significant effects of different land uses on most physical, chemical and biological characteristics of soil; So that the highest values of the characteristics of soil stability, clay content, pH, nitrogen, phosphorus, calcium, potassium, magnesium, fine-root and corse-root biomass, fulvic and humic acids and earthworms, acarina, nematodes, protozoa, fungi and bacterial populations and microbial characteristics were observed in the soil of Carpinus, Crataegus and barberry vegetation.The results of this research confirm that land cover Carpinus, Crataegus and barberry vegetation can lead to the maintenance of soil quality indicators in the semi-arid mountainous regions of the north of the country.

It is essential to investigate the depth, strength, and main mechanisms of edge effects and recreational activities to preserve species diversity in forest ecosystems. This study aimed to evaluate edge effects and recreation on woody and herb species composition, richness, and diversity in Hyrcanian broad-leaved forests.

Two treatments (control and recreational regions) were determined in the Noor forest park, Mazandaran Province, to achieve research objectives. Five transects from the edge to the forest interior were established in each region. Measurements of herb and tree layers were collected at -5 (out of the forest stand), 0 (forest edge), 25, 50, 100, 150, 200, and 300 m along each transect. In total, 45 sample points were assigned to each treatment. To collect data on tree and shrub canopy cover, two rectangular sample plots of 200 m2 (20 × 10 m) were laid out perpendicular to the transect on the left and right sides at each point. The count, diameter at breast height (> 5 cm), height, and canopy cover percentage were the variables measured in the identified tree and shrub species. For sampling herbaceous species, 10 one-m2 (1×1 m) subplots, with five subplots on each of the right and left sides spaced one m apart, were determined at each sampling point. The type and abundance of herbaceous species were recorded. Using a light sensor device (model Lycor 250), the amount of light entering the forest floor at a height of > 1 m above the ground surface was recorded at each sampling point. The species richness and diversity of tree and herbaceous strata in the sample plots were evaluated using the total number of species present in each sample plot, the rarefaction method, Shannon-Wiener species evenness, and species diversity indices. The SHE method was used to determine the contribution of species richness and evenness to the measurement of species diversity. After calculating species diversity indices, GLM analysis and the Tukey test were used to compare means between treatments. The magnitude of edge influence (MEI) and DEI for all were calculated for species diversity indices and environmental variables. DEI for each variable was calculated using the randomization test of edge influence (RTEI). Data were analyzed with R software version 4.3.1.

The light near the edge was more than the interior in the study areas, and the edge positively affected the amount of light. Based on the results of the Rarefaction method and overlap of confidence intervals of the curves related to the study areas, no species richness differentiation was observed between the control and recreational areas. However, the non-overlap of the tree diagrams reveals the highest and the lowest tree species richness in the recreational and control areas, respectively. DEI values of light were -5, 0, 10, and 50 m in the control forest and -5 and 0 in the recreational area. The number of trees per hectare in distances from 10 to 150 m and the volume and basal area per hectare at a distance of 10 m were higher in the control area than in the recreational area. In general, a positive effect of the edge was observed on the species diversity indices of herb and tree layers. The results for the comparison of species diversity indices between the control and recreational areas  showed that species richness and diversity of the herb layer were higher in the distances of 10-300 m of recreational areas than in the control area. In the tree layer, higher species richness was recorded in edges of 10-200 m of the control area than in the recreational area. For the evenness index, DEI values were 10 and 0 m in recreational and control areas, respectively. Moreover, DEI values of herb species richness and diversity were 0 and -5 m in control forests.

Based on the results, the forest edge is considered an essential part of the forest landscape structure that significantly affects the structure, functions, and species diversity. Regarding the tourism and recreation industry as one of the largest industries in the world and its increasing importance, it is necessary to understand and improve the knowledge about its effects and the severity of its impact (due to the construction of roads) on different variables for better management and biodiversity conservation.

The role of different plant covers (i.e. Artemisia aucheri Boiss, Cousinia commutate Bunge and Agropyron longiaristatum Boiss) in topsoil properties and Nitrogen transformation is less known under semi-arid mountains. The main objective of this research was to study the effect of land covers on topsoil properties and nitrogen transformation. The study was carried out for investigating the soil properties of Grazing Exclusion (GE), Grazed Rangeland (GR) and Rainfed Agriculture (RA) in Kojur, Mazandaran province, Iran. Thirty-six 1 m2 plots were set at three treatments to sample the dominant plant species. Soil samples were then taken from the central part of each plot sample in an area of 20×20 cm and depth of 20 cm. Our findings demonstrated that the carbon (C) content of plant materials did not differ for studied land covers whereas GR and RA had higher N content (1.48 and 1.41%, respectively) and lower C/N ratio (13.33 and 14.45%, respectively). In the GE, N concentration of soil (with 0.34%) was 1.5 times more than that in GR and RA (0.20 and 0.21%, respectively). Soil nitrification and N mineralization rates were significantly higher in the GE (0.33 and 0.28 mg kg−1d−1 respectively) as compared to the RA (0.15 and 0.08 mg kg−1d−1 respectively) and GR (0.01 and 0.04 mg kg−1d−1 respectively). There were no significant differences among land covers for bulk density, available K, microbial respiration, and ammonification rates. According to the results, grazing exclusion with presence of grass species increases the organic C contents, total N, and eventually, N mineralization which totally leads to improved soil quality in these regions.

In recent years, increasing of greenhouse gases results in global warming and climate changes. Carbon sequestration is a result of carbon capturing in different parts of ecosystems, particularly in soil. The purpose of the present study is evaluation of carbon sequestration potential in wheat field, citrus garden and grassland in urban district of Behshahr.

The soil samples were collected from ten different points for each land use. They were randomly taken from a depth of 30 cm using systematic random sampling. Texture, apparent specific density, acidity, humidity, organic carbon and nitrogen of the soil were measured in laboratoty. The analysis of variance of soil properties indicates significant difference in studied land uses regarding to carbon sequestration.

The results showed that the average carbon sequestration in wheat field, citrus garden and grassland were 36% (Ton/Ha), 54% (Ton/Ha), 51%(Ton/Ha) , respectively. Totally, citrus garden had the highest carbon sequestration among studied land uses. Grassland and wheat field were ranked in second and third places, respectively. Via Pearson product-moment correlation, it was revealed that among all analyzed parameters, nitrogen had the most effect on soil carbon sequestration.

The results of the present study show how land use effects on soil carbon sequestration, hence considering these results is necessary for Lands Management in North of Iran.

Classification of forest sites is one of the most basic tasks for optimal forest management, which has practical and long-term concepts, such as regulating the structure of forests, increasing forest productivity, selecting fast-growing species suitable for afforestation, afforestation. The most productive methods are increasing the yield of wood to facilitate the relationship between supply and demand, revitalizing forests, increasing access to forest resources, and also fulfilling the ecological function of forests. In recent years, the use of different factors to classify habitats has become more and more widespread. This research aims to investigate the changes of the most important soil characteristics in beech habitats in Nav-e-Islam region.

This study was carried out in the series 3 Nav Asalem and in parcels 318, 320, 336 and 350. The desired parcels are located at two heights of 1100 and 1700. Parcel 320 was considered as a control parcel. In order to investigate and determine the types of trees in the surveyed parcels, 84 square samples with dimensions of 20 x 20 meters were taken randomly with a statistical grid of 200 x 150 meters. In each sample plot, in addition to recording the characteristics of slope, aspect and height above sea level, the variables of species type, height and diameter at the breast height of all tree species were taken. Then, the tree types of the target samples were determined using two-way analysis of indicator species (TWINSPAN). To determine the location of the soil profiles, a map of the shape of the land was prepared and considering the variety of habitat features and the area of the shape of the land, 35 sample plots were determined in homogeneous units, and the profiles were dug in these units and soil samples were taken. The soils were collected from horizons A and B. After digging each profile in the desired types, the vertical section of each profile was divided into different parts based on distinguishing features such as color, texture or soil structure. The preliminary analysis of soil profiles was done in nature and then soil samples were taken from each of the separated horizons A and B and transferred to the laboratory. Then, in a dry laboratory environment, after pounding, it was passed through a 2 mm sieve and the most important characteristics of the soil were investigated. To investigate the relationship between soil characteristics and tree types, conventional comparative analysis (CCA), one-way analysis of variance (ANOVA) and Duncan's test were used.

Based on the results of the TWINSPAN analysis, the area is divided into five types of trees, including pure Fagus (F), mixed Fagus –Acer velutinum (FA), mixed Carpinus-Fagus followed Alnus (CF), mixed Fagus-Carpinus (FR1) and mixed Fagus-Acer cappadocium (FR2) was classified. Based on the ranking results, clay percentage, carbon deposition and height above sea level in A horizon have a significant correlation with the positive direction of the first region, and organic carbon, accessible phosphorus and exchangeable potassium and carbon deposition have a correlation with the negative direction of the second region. It showed significant. In B horizon, the percentage of sand and height above sea level showed a significant correlation with the positive direction of the first axis and the percentage of clay, carbon, accessible phosphorus, exchangeable potassium and carbon deposition with the negative direction of the second factor. All five tree types were affected by altitude and clay percentage in A horizon. But (F), (FR2) and (FR1) were affected by clay percentage in B horizon and carbon deposition in both horizons and potassium in A horizon. (FR1), (FR2) and (FA) were influenced by the percentage of sand in both horizons and accessible phosphorus and exchangeable potassium in both horizons. The results of analysis of variance of physical and chemical properties of soil in tree types showed that there is a significant difference between bulk density, percentage of clay, percentage of sand, base saturation, acidity, organic carbon, accessible phosphorus, exchangeable potassium and so on. There is carbon sequestration among the tree types, no significant difference was observed between the characteristics of silt percentage and porosity percentage among the tree types. Also, the results showed that there is a significant difference between the percentage of organic carbon, exchangeable phosphorus and available potassium in two soil horizons, while there is a significant difference between the differences related to appearance, percentage of clay, percentage of silt, percentage of sand, percentage There is no saturation, porosity percentage, acidity and carbon deposition in two soil horizons.

The variety of topographical conditions in the forests of northern Iran and in the studied area is the cause of many changes in plant types and soil characteristics. According to the results of this research, in the types where the beech species is more dominant, the soil conditions are not very suitable, and the mixed types of beech are settled in the habitats with more slope and lower altitude, and the shallowness of the soil and Lack of nutrients is one of the main conditions of the soils of these habitats. The presence of different types in the forest is the result of the interaction of many factors, and it has been shown in this research that soil is one of the most important environmental conditions, and its significant relationship with tree types has been confirmed. Therefore, soil can be used as a suitable indicator to distinguish forest types.

Soil, as habitat substrate, helps to regulate important ecosystem processes, including nutrient absorption, organic matter decomposition. Water availability and the well-being of humanity are directly linked to soil functions. On the other hand, vegetation with different species and ages have significant effects on the status of the surface soil layer through the creation of diverse environmental conditions and the production of different organic substances. However, few studies have been conducted in relation to the effect of the age of afforestation and the type of vegetation on the soil status. Considering that a practical, complete and effective assessment of soil condition should be the result of simultaneous measurement of physical, chemical and biological indicators, hereupon, the present study aimed to investigate the effect of 20-year old poplar stand, 20-year old maple stand, 10-year old poplar stand, 10-year old maple stand and rangeland cover, in plot 3 of Delak-Khil series of wood and paper forests in Mazandaran province, on the organic layer properties and physical, chemical and biological (including microbial activities, enzyme activity, earthworm population and biomass, the number of soil nematodes and root biomass) properties of the surface soil layer.  

For this purpose, some parts of the study area were selected which are continuous with each other and have minimum height difference from the sea level, minimum change in percentage and direction of slope. Then, in order to take samples from the organic and surface layer of the soil, three one-hectare plots with distances of at least 600 meters were selected in each study habitats. From each of the one-hectare plots, 5 leaf litter samples and 5 soil samples (30 cm × 30 cm by 10 cm depth) were taken to the laboratory for analysis . In total, 15 litter samples and 15 soil samples were collected from each of the habitats under study. One part of the soil samples was passed through a 2 mm sieve after air-drying to perform physical and chemical tests, and the second part of the samples was kept at 4 °C for biological tests. One-way analysis of variance tests was used to compare the characteristics of organic layer and soil between the studied habitats. In the following, Duncan's test (P>0.05) was used to compare the average parameters that had significant differences among different habitats.

The results of this research showed that afforested stands with different ages and pasture cover had a significant effect on the characteristics of the organic and surface soil layers. The results indicated the improvement of most of the characteristics of the organic and surface soil layer in the afforested stands, especially the 20-year old afforestation compared to the rangeland cover. The organic matter produced in 20-year old afforestation, especially with poplar species, had a higher quality (high nitrogen and carbon content and low carbon-to-nitrogen ratio) compared to organic matter produced in 10-year old afforestation and pasture cover. Most of the physicochemical characteristics of the soil under 20-year old afforestation were in a better condition than the other studied habitats. Also, according to the results of this research, the highest values of biological characteristics such as microbial activity, enzyme activity, and the population of earthworms and nematodes were observed in the subsoil of 20-year old afforestation especially with poplar species. Based on the results obtained from the principal component analysis, the higher values of nitrogen, phosphorus, calcium, magnesium and potassium content of the organic layer led to the improvement of soil fertility characteristics, microbial activities, enzyme activity, earthworm population, the number of soil nematodes and root biomass, respectively, under poplar and maple plantation for 20 years, meanwhile, 10-year old plantation, especially with maple species, and rangeland with the production of organic materials with high carbon content and carbon to nitrogen ratio, resulted in the reduction of organic matter decomposition (greater thickness of organic layer), and consequently the reduction of the mentioned properties of the surface soil layer. 

According to the findings of this research, it can be concluded that plantation with poplar species, especially after 20 years, had a higher ability to improve the soil condition compared to maple, which can be considered by managers in future afforestation. Also, with the passage of time, the presence of tree covers (poplar and maple) had a higher priority than rangeland cover in improving the fertility status and suitable edaphological conditions of the soil.

Water stress is one of the most important abiotic stresses that harms the growth of plants in arid and semi-arid regions. Plant traits reflect their response and adaptation to environmental changes, which play an essential role in predicting various environmental effects on plants and plant processes. In order to investigate the effect of biochar on the morpho-physiological characteristics of the species (Kochia prostrata L.) in water shortage conditions, a factorial experiment was conducted in the form of a completely randomized design with three replications in greenhouse condition. Drought stress treatments included four levels (25, 50, 75, and 100% of the field capacity), and biochar treatment included four levels (control, 5 g, 15 g, and 30 g). Morphological traits (plant height, root length, aerial biomass weight, and root biomass weight) and physiological traits (photosynthesis, plant water potential, stomatal conductance, and transpiration) of the target species were assayed under drought and biochar treatments. Results showed that the interaction effect of drought stress and biochar on all characteristics except for plant height was significant. Moreover, the main effect of drought stress on all characteristics except for photosynthesis and water potential and also the main effect of biochar on all characteristics except for root length) were significant. The treatment with 30 grams of biochar caused an increase in morphological characteristics (root length, plant height, and plant biomass) by 22%, 36%, and 50%, respectively, compared to the control; this treatment also caused a significant increase in photosynthesis and stomatal conductance by 107% and 32%, respectively compared to control. According to the findings, the biochar treatment of 15 grams resulted in a better performance and can be suitable to increase the efficiency in the species under study. The results obtained from this research can be an essential step toward the practical use of biochar in restoration and improvement of rangelands.

Arbuscular mycorrhizal fungi constitute an important component of soil microflora and coexist with 80% of plant species. The present study was conducted with the aim of Morphology identifying arbuscular mycorrhizal fungi in three habitats (Shanachir, Ilam and Malekshahi) with different climatic conditions and in two aspect slopes, north and south, in the Oak forests of Ilam province.

In order to take soil samples, in each habitat   and both north and south aspect slopes 20 mixed soil samples were taken. A total of 60 samples was taken from all three habitats based on a completely random sampling plan from a depth of 0-20 cm in the spring season. Spore extraction of mycorrhizal fungi was done using the method of sieving and centrifugation with sucrose, and the identification of fungi was done based on the measurement of morphological characteristics and using the identification key and reliable internet sites. The abundance percentage of fungal species was also calculated using the percentage of spores belonging to a fungal species. Venn diagram was used to determine the similarity percentage of fungal species in different habitats and aspect slopes in each habitat.

The results of this study showed that a total of 39 species of arbuscular mycorrhizal fungi belonging to 11 genera were identified in three studied areas and two aspect slopes. 36 fungal species belonging to 11 genera were identified in Ilam habitat, 37 mycorrhizal fungal species belonging to 11 genera Malekshahi and 34 fungal species belonging to 10 genera were identified in Shanachir. The highest percentage of the relative frequency of the fungus genus also belonged to the two genera Acaulospora and Glomus.In all habitats and aspect slopes, the two species Glomus nanolumen and Acaulospora lacunosa had the highest percentage of fungal species abundance. The results of species similarity in different habitats showed that 30 species of mycorrhizal fungi, equivalent to 76.92% of the species, were common among the habitats, and there was one endemic species (Glomus macrocarpum) in Malekshahi city. The results showed that there was a significant difference in the spore density in the study areas (p=0.000), which was higher in Malekshahi and Shenchir than in Ilam. The average spore density was higher in all habitats in the southern aspect slope than in the northern aspect slope. The average density of spores in different areas varied from 111.20 in Ilam to 140.25 in Malekshahi and among different aspect slopes from 105.60 in the north of Ilam to 150.90 in the south of Malekshahi.

The result of the present study showed that mycorrhizal fungi in different areas and aspect slopes were different in terms of the number of fungal species, distribution and number of spores and the highest spore density was observed in the southern aspect slope and in Malekshahi region.

The canopy of woody species is one of the most important components of rangeland ecosystems. The genus Crataegus spp. is the dominant shrub covers of rangeland habitats in the north of the country. From the habitat point of view, the presence of this plant in rangeland can be seen as an almost pure canopy or mixed with other shrub species. In the current study, the effect of different land covers [i.e. Crataegus melanocarpa M. B., Berberis integerrima Bunge., Ribes Uva – crispa L. and Prunus spinosa L. (CM-BI-RU-PS); Crataegus melanocarpa M. B., Berberis integerrima Bunge and Ribes Uva – crispa L. (CM-BI-RU); Crataegus melanocarpa M. B. and Berberis integerrima Bunge (CM-BI), and pure Crataegus melanocarpa M. B. (CM)] on variability of soil characteristics and microbial respiration dynamic, in the Kinj region of Mazandaran Province, was considered. In each of the land covers, 15 soil samples (0-10 cm depth) were collected and transferred to the laboratory. The amounts of soil organic matter, bulk and particle densities, texture, aggregate stability, coarse and fine root biomass were measured. In order to determine the changes in soil moisture, temperature and microbial respiration, sampling was carried out in the middle months of each season. The highest amount of soil organic matter was observed in CM-BI-RU-PS and CM-BI-RU habitats. Pure CM habitat had the highest value of bulk density, while the lowest value of this characteristic was assigned to CM-BI-RU-PS and CM-BI-RU habitats. CM-BI-RU-PS and CM-BI-RU habitats had the highest soil porosity. The CM-BI-RU-PS shrub cover has the most aggregate stability, and with the decrease in the diversity of shrub species, their stability decreased significantly. The highest amount of sand content was assigned to the pure CM habitat and the highest amount of clay was allocated to the CM-BI-RU-PS shrub cover. The highest coarse root biomass was observed in CM-BI-RU-PS and CM-BI-RU, while the fine root biomass was the highest in CM-BI-RU-PS. The characteristics of soil moisture, temperature and microbial respiration have shown statistically significant differences in different seasons of the year and also pure and mixed Crataegus covers. The highest soil moisture values were observed in the soil of CM-BI-RU-PS and CM-BI-RU habitats and winter season, while the highest soil temperature was assigned to the summer season and pure CM habitat. Soil microbial respiration was also higher in the summer season and CM-BI-RU-PS and CM-BI-RU habitats than other seasons and land covers. According to principal component analysis (PCA), the amount of organic matter, moisture content, and soil porosity in CM-BI-RU-PS and CM-BI-RU habitats have an effective role in soil microbial respiration of this type of land cover compared to other habitats. The results of this research confirm that the presence of species diversity in land cover can lead to the protection of soil quality indicators. In this regard, it is suggested to use other native shrub species in addition to Crataegus for the restoration of degraded rangeland in the study area as well as areas with similar ecological conditions.

Mountainous habitats are sensitive areas with lower plant diversity, and degradation caused by human activities has resulted in vegetation loss or reduction. This study aimed to investigate the impact of different intensities of degradation on soil biological indicators in the Mirkola region of Kojoor district, Mazandaran Province, Iran, focusing on Crataegus and Berberis, which are the dominant shrubs in the mountainous habitats of northern Iran.

Four sites with different percentages of cover (90-100, 70-60, 40-30, and 10-0 percent) were selected as non-degraded and degraded habitats with light, moderate, and heavy degradation intensities. Three one-hectare plots were established in each habitat, and five soil samples were taken from each plot at depths of 0-10, 10-20, and 20-30 cm. In total, 45 soil samples were collected and analyzed for soil biomass, carbon, nitrogen, phosphorus, calcium, magnesium, and enzymatic activity.

The non-degraded habitat had the highest biomass of coarse and fine roots, carbon content, and nitrogen and phosphorus content in roots. The highest calcium values were observed in the fine roots of non-degraded and low degraded habitats, while the non-degraded habitat had the highest calcium values in coarse roots. Magnesium values were lowest in the coarse and fine roots of habitats with heavy degradation. The highest activity of urease enzyme was observed in non-degraded habitats and the upper soil layers, while arylsulfatase and invertase enzyme activities decreased significantly with increasing degradation intensity.

The study findings suggest that vegetation degradation has a significant impact on soil ecological activities. Protection of natural vegetation can have positive effects on soil quality and health, and the study provides valuable information for natural resource managers to evaluate the ecological capacity and nutrient cycles of natural vegetation in mountainous areas of northern Iran.

Afforestation with oak (Quercus brantii Lindl) trees has been done for restoration of degraded areas in Zagros forests, however, few studies have been done on the dynamics of leaf and soil nutrients compared to natural trees (standard and coppice). The aim of this research is to compare the nutritional elements of leaves in natural trees (standard and coppice) and planted forms of persian oak (with an average age of about 30 years).

According to the objectives of the research, in the city of Ilam, where afforestation with persian oak species was carried out in the vicinity of its natural form, sampling were done from leaves and the soil (at a depth of 0-20 cm) in the two seasons of spring (April) and summer (September) to compare the changes in carbon, nitrogen, phosphorus, potassium, calcium and magnesium and some physical and chemical characteristics of the soil. Two-way analysis of variance (GLM) used to compare the soil and leaf properties among different regions. Principal component analysis (PCA) and Pearson's correlation test were used in order to investigate the relationships between leaf and soil nutrients and their changes in different forms.

results of GLM showed that nitrogen and phosphorus of leaves were affected by different forms of oak species and season, and their amount is higher in spring than in summer. So that the amount of nitrogen in the leaves of standard (20.2% to 1.68%) and planted trees (1.78% to 1.25%) was higher in spring compared to summer. The amount of calcium in the leaves in summer was between 1.5 and 2 times higher than in spring (planted oak; 303.66 ppm to 170.33 ppm, coppice; 282.33 ppm to 149.33 ppm, standard tress, 285.66 to 233 mg/kg. Leaf potassium was influenced by different oak forms and seasons. So that it was more in spring than in summer and in standard (201.16 mg/kg) and planted trees (161.47 mg/kg) it was 1 to 1.5 times than that of coppice trees (128.30 mg/kg). Principal component analysis and Pearson correlation showed that in two seasons, different forms of oak can be separated from each other.

Therefore, it can be said that the planted Persian oak trees are similar to the standard form in terms of nitrogen, potassium, and phosphorus elements and were more than coppice trees. In addition, in planted, unlike natural forms, the amount of leaf elements were higher in summer than in spring.

despite occupying a relatively small space, the border forests have the potential to accumulate more and faster carbon, are centers of biodiversity and provide many valuable ecosystem services. Riverine forests also affect plant biodiversity patterns, soil characteristics, and habitat quality. Despite having high environmental and conservation values, the riverine forests have been paid less attention as forest covers, and most of the studies related to the distribution pattern of species and characteristics of the animal community It was their soil. The aim of this research was to investigated the effect of different types of land use on the physical, chemical and carbon deposition characteristics of the soil along the Karkhe River. In this research, the effect of natural forest uses, forestry, agriculture and barren lands on the banks of the Karkheh River on some physical and chemical characteristics and soil carbon deposition was done. Thus, by random method, 30 points were selected in each field and soil samples were taken from a depth of 0-20 cm in the center of each plot. The characteristics of moisture percentage, texture, specific gravity, pH, electrical conductivity, organic carbon, total nitrogen, absorbable potassium and phosphorus, and calcium carbonate were calculated in the measuring laboratory and the amount of carbon deposition. Data were analyzed using one-way analysis of variance (ANOVA) and SNK mean comparison test. All statistical analyzes were performed using SAS 9 software. The results showed that agricultural use with 18.45% clay, natural forest and agricultural use with 46.29 and 43.92% silt, respectively, and forestry and barren land use with 60.47 and 56.86% sand, respectively. They showed a significant difference. Apparent specific mass increased during forest use change. The highest value of electrical conductivity with 3.17 decisiemens/meter was observed in barren lands, which had an increase of 71.35% compared to the natural forest. In agricultural use, absorbable potassium reached the lowest level with a decrease of 62.04% compared to the natural forest. According to the results, the change of use has a significant and decreasing effect on the amount of carbon sequestration, so that the natural forest has the highest amount of carbon sequestration with 63.37 tons per hectare, and the lowest carbon storage related to agricultural use with 41.53 tons. It was per hectare. In general, the forests along the river have more quality and soil carbon deposition, and the change of land use causes damage to these habitats. Investigating carbon sequestration in coastal ecosystems may help determine baseline conditions and can be used to strengthen restoration plans or address the impact of climate change on carbon stocks in these areas.

Soils are one of the largest carbon stores in the biosphere with the highest carbon storage potential to mitigate the effects of climate change. The aim of this study was to investigate different land uses on carbon storage and other physical, chemical and biological characteristics of soil in Shahriar. For this purpose, rangelands including 26-year-old, 16-year-old and 11-year-old Atriplex and 18-year-old Haloxylon, and agricultural lands including rainfed and irrigated cultivation, as well as control lands were selected.

 Soil samples from the depths of 0-10, 10-20 and 20-40 cm were randomly and systematically collected and analyzed. After drying, the soil samples were first passed through a 2 mm sieve and then the percentage of stones and pebbles was determined. Next, soil texture (percentage of soil constituents) by hydrometric method, acidity of saturated soil extract by pH meter, electrical conductivity in saturated extract by EC meter, soil lime by calcimetric method, nitrogen by Kjeldahl method, phosphorus by spectrophotometric method, sodium and potassium were measured by film photometric method, soil organic carbon content was measured by Walkly-Black method, and apparent specific gravity was measured by the clod method. Microbial respiration of soil samples was measured through a closed bottle, carbon and nitrogen of microbial biomass by fumigation-extraction method and metabolic contribution by dividing the released carbon dioxide (mg of carbon per gram of soil per hour) by the microbial biomass of soil carbon (gram of carbon) per gram of soil) was calculated. The microbial contribution was obtained by dividing the two parameters of soil microbial carbon (mg carbon/g soil) by soil organic carbon (g carbon/g soil). One-way analysis of variance (ANOVA) was used to compare soil data among different land uses. . Duncan's test was used to test the difference at the one percent level (p<0.01). All statistical analyzes were performed using the statistical software package SPSS, 19.       

The results showed that the physical, chemical and biological characteristics of the soil were significantly different (p < 0.01) between different land uses, so that the highest amount of carbon storage was related to irrigation treatment of 1.38% and the lowest rate was related to the control treatment of 0.14%. Also, the lowest bulk density is related to irrigated treatment of 1.36 gr/cm3 and the highest amount of basal respiration is related to 18-year-old Haloxylon treatment of 0.73 mg CO2 g−1 day−1. and Also the highest amount of microbial biomass carbon related to irrigated treatment of 124.55 mg g-1 soil. In general, agricultural lands have more potential for carbon storage than other land uses studied in this area. Finally, it should be said that different land uses have a significant effect on the physical, chemical and biological properties of the soil, and play a significant role in the long-term carbon storage in the soil.                                             

This research showed that success in restoring desert areas by using these species depends on knowing the relationship between soil and vegetation. The physical, chemical and biological properties of the soil affect the carbon exchanges between air and soil. The type of vegetation and land use are factors affecting soil properties. This research shows that the most appropriate ways to store carbon in the soil are preventing desertification and deforestation, also preserve and restore vegetation cover.

Nowadays the effective role of organic matter has been proven in improving soil productivity. Regarding to sensitivity of sustainable organic matter component to different land use practices in addition to the organic matter, investigation of changes in its compound is important. Determining the evaluation of organic matter and amount of carbon stabilization in soil system, and their quality and quantity will be varied according to the type of land use.

Due to extensive land use in the north of Iran, present study focused on effect of these uses on the content of organic matter and its humic components. In this regard a study was carried out in five land use including: beech forest, Fraxinus plantation, black pine plantation, degraded forest and agriculture in Tajan watershed. Eight points were selected in each site and soil samples were taken at a 25 × 25 area to a depth of 15 cm.

Highest of organic matter (4.68 %), fulvic acid (668.750 mg/100 gr soil) and humic acid (976.620 mg/100 gr soil) were observed in agriculture land cover. Some soil physical, chemical and biological features were also measured. Whole of studied soil characters were significantly different among land covers, except silt content.

Though as for the results, highest contribution of organic compounds were observed in agriculture land, according to the PCA analysis, soil nutrition condition and microbial activity were more appropriate in forest stands. More quality of debris along the favorable environmental condition and presence of microbial activity can be attributed to a reduction in rate of accumulation of remains following the process of organic matter decomposition and mineralization in forest stands. The findings of this study suggest that protecting of natural forest is very important. In addition, in degraded areas of northern Iran, planting of Fraxinus excelsior species can be considered due to improvement of soil quality and health.

This study aimed to investigate the effect of different intensities (i.e., light, moderate, and heavy) of habitat degradation on soil biological characteristics as the main indicators of soil health in the Khanikan forest of Nowshahr. For this purpose, from each of the different intensities of degradation, 12 samples of topsoil (0-10 cm depth) were transferred to the laboratory. Also, in order to measure the stratification ratio of organic matter, soil samples were taken from a depth of 10-20 cm in addition to 0-10 cm depth. In order to investigate the presence or absence of statistically significant differences between the studied characteristics in different intensities of habitat degradation, a one-way analysis of variance (ANOVA) test in a completely randomized design was employed. In addition, principal component analysis was used to study multiple relationships. According to the results, the highest values ​​of coarse and fine root biomass, number and biomass of epigeics and anecics, number and biomass of total earthworms and the populations of Acarina, collembola, nematodes, protozoa, bacteria and fungi, nitrogen and phosphorus microbial biomass and enzyme (i.e. urease, acid phosphatase, arylsulfatase, and invertase) activities were found in forest cover with light degradation intensity. The number and biomass of endogeics did not show a statistically significant difference in the studied ecosystems, while forest stands with light and moderate degradation intensities had the highest values ​​of basal soil respiration, substrate-induced respiration, and carbon microbial biomass. Principal component analysis results indicate that fertility indices (C/N ratio and available P, available Ca and Mg, available K) and clay content had the greatest effect

The humus index is a numerical score based on the visual assessment of organic horizons and humus forms identification. This index reflects different characteristics of forests stand and soil. Forest humus is an intermediate between plants and soil, which is affected by various factors, such as topography, climate, vegetation and soil. Nevertheless, by digging the humus profile and determining its index, it is also possible to determine many ecological factors. The aim of this study was to investigate the humus index and its relationship with topographic, soil and forest cover characteristics along an altitudinal gradient in the four-altitude class, including 0, 500, 1000 and 1500 meters above sea level (m a.s.l.), in Vaz forests located in Mazandaran province.

In each altitude class, the characteristics of the trees such as crown canopy, density, diameter and height, as well as topography and soil characteristics such as altitude, slope percentage, soil moisture and temperature were taken in 400 m2 plots, and in each plot, five 30 × 30 cm profiles for identification of humus forms were drilled and then identified and classified based on Humusica classification. In order to evaluate the humus index between different altitude classes was used one-way analysis of variance (ANOVA), as well as to analyze its relationship with the mentioned characteristics, multiple linear regression analysis (MLR) was used.

The results showed that the highest amount of humus index and litter thickness belonged to the altitude class 1500 m a.s.l. and their trend is increasing along the altitudinal gradient. Also, the results of MLR indicate the existence of a linear and significant relationship is between humus index and topographic and soil characteristics with high determination coefficient (R2 = 0.76), especially soil temperature with (P-value = 0.000), while the tree cover characteristics with a low determination coefficient (R2 = 0.31), cannot well be a good predictor for evaluating the humus index. Meanwhile, soil temperature and trees crown canopy are two factors that have shown the highest t-statistics in relation to the humus index, so that the decrease in soil temperature and trees crown canopy has increased the humus index.

In general, it can be concluded that with increasing altitude, the organic part of the forest floor and Humus index increase, and their variability is mostly due to changes in topographic and soil temperature characteristics.

Two habitats of rangelands that are dominated by Stachys byzantina and Rhamnus pallasii and a forest area is dominated by oak (Quercus castaneifolia( were selected. In the plots, 36 litter and soil (0-20cm depth) samples were collected and conveyed to laboratory for measuring of the amounts of C, N, Ca, Mg, K and P elements in the litter and calculation of theirs storage in soil. The results showed that the amount of organic C and N of the litter (84.52 and 2.97%) were highest in rangelands of Rh. pallasii. Whereas the greater amounts of Ca and Mg (0.77 and 294.4%) found in forest litter, and also the higher values of K and P (0.31 and 149.0%) were observed in St. byzantina rangelands. The storages of organic C, N, Ca and Mg (1042088, 29298.3, 188396.88 and 7589.258 kg/ha, respectively) were increased in forest soils, but the St. byzantina rangeland cover improved the accumulation of P and K (18920.28 and 300.97 kg ha-1). In general, the findings of this research showed that the relationship between different plant species and the amount of accumulation of soil elements is not constant, And the positive effect of oak species on soil nutrient storage could be due to the quantity and quality of litter produced by this species compared to other species studied in this study.

Black Hawthorn and Barberry species cover, predominantly, coverings the rangeland habitats of the northern parts of Iran. The effect of the composition of the canopy (pure and mixed) of these species on soil functional characteristics has not been considered so far. In the present study, five types of canopy composition of Black Hawthorn and Barberry (i.e. pure Black Hawthorn, pure Barberry, Black Hawthorn and Barberry with almost equal canopy cover, Black Hawthorn dominated-stand and Barberry dominated-stand) is considered in the Peydeh Region, western Mazandaran. We studied the effect of these five types on soil biochemical activities and microbial stoichiometry. After identifying the desired canopy composition from the studied species, three sample plots, one-hectare each, were selected from each composition. Inside the plots, five soil samples were taken from the depths of 0-10, 10-20 and 20-30 cm. A total of 45 soil samples were transferred to the laboratory. A part of soil samples was air-dried and passed through a 2-mm sieve for the determination of soil physical and chemical properties. Other parts of soil samples were stored at 4 °C in plastic boxes for the determination of microbial tests. Based on principal component analysis, more clay accumulation, increased organic matter stratification ratio (first to second depth), soil pH, organic carbon and nitrogen lead to increased biochemical activities (nitrogen mineralization, ammonium, nitrate) and microbial stoichiometry (microbial biomass of carbon to carbon, microbial biomass of nitrogen to nitrogen and microbial biomass of phosphorous to phosphorous) of the soil in mixed canopy composition of Black Hawthorn and Barberry (especially with almost equal canopy cover). While pure Black Hawthorn and Barberry types with higher values ​​of organic matter stratification ratio (second to third depth), sand and silt contents had the lowest soil biochemical activities and microbial stoichiometry. According to the results of this study, it can be concluded that the mixture Black Hawthorn and Barberry with almost equal canopy cover can provide better conditions and higher yields for soil performance in rangeland habitats, which can be considered by managers to rehabilitate rangeland lands.

The aim of this study was to investigate the effect of land use age on dynamic of different forms of soil organic carbon in Chahar Dangeh region of Kiasar, Mazandaran province. In this area, the studied habitats include pastures conversion to agricultural lands (barley) and orchards (apples and walnuts) in three different ages (more than 30 years, more than 20 years and less than 10 years) in Era, Erost and Vavsar villages. In each land use, soil sampling was performed systematic- randomly from 0-15 and 15-30 cm depths. In total, ten soil samples from land uses were transferred to the laboratory for analysis of soil organic carbon, particulate organic carbon, microbial biomass carbon, labile organic carbon. The variance analysis results indicated that the higher values of soil organic carbon, particulate organic carbon, microbial biomass carbon, labile organic carbon found in orchard use during 30 years old, which was located at a depth of 0-15 cm. Due to the conversion of rangeland to orchard use (age more than 30 years), soil organic carbon, particulate organic carbon, microbial biomass carbon, labile organic carbon increased in 86.18%, 68.42%, 61.13% and 66.94% respectively. Also, the highest amount of EC was found in orchard use older than 30 years. But pH in barley land use older than 30 years at a depth of 15-30 cm had the highest value. In general, the results of this study indicated that the effects of the studied factors on different forms of soil organic carbon depend on the time. Therefore, soil organic carbon management strategies should be adjusted according to the time period.

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.

In recent years, with an alarming degradation rate of Caspian forests, afforestation can be considered as a suitable solution to restore the degraded areas. Different species especially Oak (Quercus castaneifolia C. A. M) and Alder (Alnus subcordata C. A. M) were planted in vast areas. Elements quantitative relations (stoichiometry) has an important roll in organic matter decomposition by changing these elements availablity in soil and is a main index to better undrestanding of microbial and OM conditions in soil as well. The aim of this study was to determine the effect of tree species in deferent ages on quantitative relations in these afforestations. This research was carried out in 15-, 20-, and 25-years old stands of Mazandaran wood and paper company afforestations and 30 soil and litter samples were collected from 10 cm depth of soils in each stand using systematic random method. Based on the results, the highest amount of quantitative relations of soil C/N (18.33), C/N microbial biomass (15.88), carbon to particle organic nitrogen ratio (10.36) and carbon to dissolved organic nitrogen ratio (3.00) were seen in older oak afforestations which had significant differences with alder afforestations. Also, oak stands in higher ages amend quantitative relations of soil carbon and nitrogen in future years of the afforestations, these findings provide a scientific theory for use in the evaluation of soil nutrients in afforested areas.

Forest stands have an important role in the ecosystem function, quantity and quality of produced organic matter, nutrients and finally soil biological characteristics. In pure and mixed stands, effects of deciduous tree species on soil processes have been received less attention. Therefore, this study aimed to investigate the variability of some soil biological characteristics in beech and hornbeam forest stands with a certain composition ratio, which has not been reported so far.

In this study, 5 combinations of forest stands (1. pure beech, 2. pure hornbeam, 3. beech and hornbeam, 4. beech-hornbeam, 5. hornbeam-beech) were considered by 5 sample plots replications in each stand in 3 parts (east, center and west) of Hyrcanian region (total of samples were 75). Sampling as a selected sample plots are considered circle form (1000 m2) in the center of each stands, with same conditions for aspect (northeast), slope (30-60%), altitude (average 1200 m) and the stands with middle-aged trees (diameter 40-60 cm) to each sample (for establishment the same conditions). Sampling of organic layers and mineral soil from 25 × 25 area and 0-10 cm depth was performed in the center of each sample plot and four main directions. Statistical analyzes were performed using ANOVA analysis of variance and Duncan multiple comparisons in SPSS 20 software, also using principal component analysis or PCA by PC-Ord V. 5. 0 software.

The results showed that the organic layer carbon in pure beech (49.73%) and organic layer nitrogen in pure hornbeam (2.57%) stands had significant difference and had the highest measured value. Soil organic carbon (5.17%) and C/N (28.17%) had significant difference in pure beech and showed the highest measured amount, while soil pH (7.10) and N (0.50%) had significant difference and showed the highest values in pure hornbeam stands. Fine root biomass (93.36 g m-2), density and biomass of total earthworm ecological groups (respectively 2.47 n m-2 and 32.08 mg m-2) and microbial respiration (0.53 mg CO2 g-1 day-1) were significantly different in pure hornbeam stands and showed the highest values compared to other studied stands. In this study, the analysis of all the characteristics studied on the first and second axes of PCA analysis justifies 47.62 and 14.22 percent of variance, respectively, which shows the highest soil biological activity in pure hornbeam and dominant hornbeam stands compared to pure beech and dominant beech.

In general, the results of this study indicated that the composition of hornbeam tree species in beech stands caused significant differences in the improvement of soil biological indicators, so it was verified for mixing regulation and afforestation on the presence of hornbeam species in pure beech stands. The findings of this study can be used to prioritize the selection of stands consisting of beech and hornbeam tree species to regulate mixture in breeding operations and rehabilitate degraded areas in the north of Iran. Therefore, it is suggested that during marking operations, management planning and afforestation in the habitats of these two species, maintaining their mixture should be a priority.

Management practices such as land use change is one of the main components of global change that affects the process, structure and function of ecosystems by changing microbial communities (due to their role in the decomposition of organic matter and food mineralization(.Changes in soil biological characteristics due to land use change and management practices may lead to significant changes in soil organic carbon dynamics, soil microbial respiration and affect nutrient cycle and plant growth. Therefore, to better understand human management on carbon cycle, it seems necessary to understand the correlation between soil microbial properties during land use change.

The aim of this study was to investigate the temporal dynamics of soil microbial characteristics during land use change in rangelands around Kiasar Chahardangeh city of Mazandaran. For this purpose, in this basin, the studied habitats were including Erost village with pastures turned into agricultural lands (barley) and orchards (apples and walnuts) with an age of more than 30 years, with a control pasture, Vavsar village with pastures turned into lands. Agriculture (barley) and orchard (apple and walnut) with an age of more than 20 years and also rangelands converted to garden use (apple and walnut) less than 10 years, with a control rangeland and Ara village with rangelands converted into agricultural land (Barley) less than 10 years old with a pasture. Soil sampling in each land use was done systematically randomly from two depths of 0-15 and 15-30 cm.In total, nine soil samples from landuses were transferred to the laboratory for analysis of soil physico-chemical characteristics including texture, bulk density, moisture content, organic carbon, total nitrogen, pH and microbial characteristics including Basal respiration, Substrate induced respiration, Microbial biomass carbon, Microbial biomass nitrogen and Microbial biomass phosphorus, qCO2, microbial ratio and carbon capability index.

The results showed that the highest amount of physicochemical characteristics (except sand and silt percentage and bulk density, pH and C/N) and soil microbial characteristics (qCO2, microbial ratio and carbon capability index and MBC/MBN) at both depths and mean depths belonged to orchard land uses older than 20 and 30 years. Principal Component Analysis (PCA) indicates that over time, higher values of microbial activity and soil fertility in the orchard uses are older than 20 and 30 years with a completely different location on the axis. In general, the results of this study showed that the variability of organic carbon, total nitrogen, acidity and soil moisture content in the long run caused an increase in microbial respiration rate (Basal respiration and Substrate induced respiration), While the qCO2 in the orchard less than 10 years old and control rangeland for lands older than 20 years, also the microbial ratio in the control rangeland for lands less than ten years old had the highest value, while the carbon capability index showed no significant difference between users of different ages.

In general, the results of this study showed that soil characteristics in orchard uses with older ages were in a better condition. Also, variability in soil physicochemical properties changed the microbial characteristics of the soil over time. Therefore, it is suggested that long-term studies and management strategies to reduce uncertainty and estimate the rate of organic carbon pool of ecosystems, which are not unrelated to soil microbial characteristics, are considered necessary during land use change.

Degradation of forest habitats and change of land cover can have significant effects on the variability of soil quality indicators. In the present study, different soil characteristics in forest habitat (almost intact) dominated by Zelkova carpinifolia, rangeland cover dominated by Festuca ovina and single trees of Zelkova carpinifolia and Ulmus minor, rangeland cover dominated by Dactylis glomerata and Thymus transcaspicus and rangeland cover dominated by Stachys byzantina in Zanus region of Kojoor district of Mazandaran province were examined. For this purpose, 36 soil samples (including 12 samples at spring, summer and autumn) were taken from each land cover from a depth of 0-10 cm and transferred to the laboratory. The results indicating the variability of most of the studied soil characteristics in different seasons of the year under different land covers. Based on the principal component analysis (PCA), higher amounts of clay, macro and micro aggregate, pH, total nitrogen, nitrogen in macro and micro aggregate have lead to increasing soil biochemical and microbial activities (i.e. ammonium, nitrate, carbon microbial ratio and nitrogen mineralization) under Zelkova and Festuca covers. While Stachys and Dactylis cover with higher amounts of sand, carbon in macro and micro-aggregate had the lowest soil biochemical and microbial activities. According to the results of this study, it can be claimed that the presence of tree cover (i.e. Zelkova carpinifolia and Ulmus minor) in habitats can provide better conditions for soil functions, which can be considered by managers to rehabilitate degraded lands.

The aim of this study was to evaluate the vegetation cover of alder and broadleaved coniferous forests of alder, maple and oak and compare it with natural forest in Ramsar Ridge. 96 sample plots of 400 square meters were collected by regular random sampling.The bio-spectrum of plants was determined based on the vegetative forms of Rankier and the geographical distribution of species based on the Zohary method. The results showed that 30 plant species belong to 23 families, most of which belonged to Fabaceae and Poaceae, Rosaceae. In terms of biological form, hemicryptophytes and cryptophytes were dominant with 68.73% of vegetative forms. The study of geographical distribution of plants in the region showed that the plant elements of Europe-Siberia constitute the most of the plant elements in the study area. Evaluation of plant biodiversity in forest stands showed that Simpson and Shannon Wiener diversity indices and Ghanaian Margalph index were not statistically significant and Kamenergo and Smith Wilson richness indices and homogeneity indices were not significantly different. Showed. Biodiversity of woody species regeneration in Simpson species diversity indices was highest in Alnus subcordata C.A. Mey and lowest in Cupressus Semprvienes L.Var. horizontails.