seyed mohammad hodjati

The relationship between the degree of decay, carbon dynamics, and nutrients of coarse woody debris (CWD) were examined in the experimental forest of Kheirudkenar – Nowshahr as a part of Hyrcanian forests in Northern Iran. CWD (snag and log) with an average middle diameter more than 7.5 cm was recorded in 50 ha. For snag CWD, species type, diameter at the breast height and height, while for log CWD, species type, the average diameter and their length were determined and recorded. In the case of non-circular CWD cross-sections especially in the higher decay stages, diameter was determined by tape. All CWD were categorized in three diameter classes and the degree of their decay (snag and log) was determined. The CWD nutrients examined throughout taking a piece from each CWD and analysing them in the laboratory (60 specimens). The C/N ratio of CWD was obtained separately for diameter classes and degrees of decay. All data were tested for probability of fit to normal distribution. To identify the most influential gradients, principal component analysis (PCA) was applied. The nutrients in the trunk CWD in different diameter classes and degrees of decay showed that in most cases, there is a significant difference between them. The results of the C/N ratio of the total trunk of CWD showed that this ratio decreases by elevating the degree of decay and by upraising the diameter classes of CWD. The degrees of decay of CWD were majority related to N, C/N ratio, C and K respectively. This research demonstrated that the nitrogen and carbon concentrations among the decay classes and species type of CWD should be considered.

This study was conducted to investigate the potential of copper (Cu) absorption and accumulation and the effects of its contamination on the growth and mineral nutrient content of Artemisia absinthium and Silybum marianum under greenhouse conditions. This was done under factorial experiment based on a completely randomized design and Copper sulfate (CuSO4.5H2O) solution was added to the pots with three replicates at 0 (control), 100 and 200 mg/kg and then seeds of two plant species were sown. Plant harvesting was done after two months when growth was completed and then plant growth characteristics and mineral elements (Ca, Mg, K, P, Fe, Zn, Mn, and Cu) were measured for roots and shoots. The results showed that there was no effect of copper sulfate stress on roots and shoots of A. absinthium while shoot biomass and root volume, area and length of S. marianum were significantly reduced. The Cu accumulation in roots of both plant species and in shoots of S. marianum significantly increased by increasing the copper sulfate in soil. The highest level of Cu accumulation was found in shoots and roots of S. marianum with 53.50 and 168.72 mg/kg dry matter, respectively. A transfer factor less than one for both plants indicated their ability to copper accumulation in the roots. Potassium content in the shoot of S. marianum was significantly greater than that in A. absinthium at treatment of 200 mg/kg. There was no effect of copper sulfate stress on the micronutrients content of A. absinthium while it caused a significant decrease in Mn and Zn in shoot and root of S. marianum, respectively, and a significant increase in Fe in the shoot of S. marianum.

Mining activities lead to the degradation of rangeland ecosystem structures and functions. Coal mining in rangelands generates substantial quantities of waste dumps, which serve as the primary environmental pollutants in the area and its surrounding ecosystems. Vegetation restoration in these mining areas can help reduce soil pollution and contribute to the overall landscape restoration. The aim of this study was to assess the physical and chemical properties of abandoned coal wastes in the rangelands of Kiasar, Mazandaran province, Iran. This information can be utilized to promote vegetation restoration on coal mine wastes by identifying the factors that limit plant growth and establishment on such substrates.

This study was conducted at the Kiasar coal mine in Sari, Mazandaran province, Iran. The mine site was established in 1983. The area is located at an elevation of 1030 m above sea level, with an average rainfall of 520 mm and a mean temperature of 13.2°C. A total of 10 coal waste dumps were abandoned in the area over the last three decades. Six age classes were identified based on the time since abandonment of these waste dumps in the surrounding area of the mine site. The identification process involved the assistance of experienced engineers and local workers. The age classes were categorized as follows: 4-6, 8-12, 15-18, 19-21, 22-24, and 25-27 years since abandonment. The control site consisted of natural rangelands around the mine, which are currently used for livestock grazing. Waste and soil samples were collected using a random-systematic method from a depth of 0-20 cm. The samples were then placed in plastic bags for subsequent chemical analysis. The soil samples were air-dried at room temperature, and various parameters, including texture, moisture, pH, EC, OC, CaCO3, N, P, K, Cu, Fe, Cd, Ni, and Pb, were measured in the laboratory. Data were analyzed using one-way ANOVA, and means were compared using Duncan multiple tests.

The analysis of variance indicated that all measured parameters of soil and coal, except nitrogen and potassium, exhibited statistically significant differences among the coal wastes and the nearby rangelands. The coal wastes had lower percentages of silt, clay, moisture, and lime compared to those in the surrounding rangelands. However, these properties did not show significant differences among the various abandoned coal wastes. Most of the abandoned wastes were characterized as neutral or alkaline, with an electrical conductivity (EC) less than 1.5 dS/m. An exception was found in the waste that was abandoned 22-24 years ago, which exhibited acidic pH

In conclusion, our study revealed that moisture availability is a crucial limiting factor for plant growth on coal wastes. This limitation can be attributed to the sandy and sandy-loamy texture, unstable slope of coal dumps, and high porosity of the substrate. Moreover, coal waste undergoing erosion and leaching exhibited high electrical conductivity (EC) and low pH levels. The levels of organic matter and available phosphorus were found to be insufficient for supporting optimal plant growth. However, the concentrations of heavy metals remained within the normal range, even after a significant period since the abandonment of coal wastes. We recommend the implementation of remediation treatments in similar restoration projects to enhance plant growth and establishment.

Mining activities causes substantial damage to the environment worldwide. Abandoned mine wastes from mining activities limit the growth of plants due to unfavorable conditions and the concentration of a wide range of heavy metals. Identifying plant species growing on mine waste and assessing their seed germinations are important for vegetation restoration on mining areas. This study aimed at assessing the germination characteristics of Artemisia absinthium, Lepidium draba, and Silybum marianum naturally growing on coal mine wastes in Mazandaran province under different concentrations of copper (Cu), lead (Pb), and cadmium (Cd).

Seeds were collected from plants growing in coal wastes during 2 years. Completely randomized design was conducted with three replicates. Treatments were CuSO4 and Pb(NO3)2 at 0 (control), 50, 100, 200, and 300 mg/L, and Cd(NO3)2 at 0 (control), 5, 10, 20, and 30 mg/L. In each replicate 20 seeds were placed in a Petri dish containing a layer of filter paper. Then treatments were applied and Petri dishes were taken to a germinator under controlled temperature, moisture, and light. Germinated seeds were counted daily and then germination percentage, germination rate, allometric coefficient, seed vigor index, phytotoxicity percentage and seed tolerance index were calculated.

The results showed that increasing the concentration of lead, copper, and cadmium significantly affected the seed germination of studied plants. S. marianum had better germination percentage and rate in lead, and copper while germination of A. absinthium, L. draba, was better in cadmium, and copper, respectively. The greatest reduction in germination percentage was found for A. absinthium in 20, and 30 mg/L Cd. As the concentration of metals increased, significant reduction in germination percentage and rate for A. absinthium started in lower concentrations than the other species. Root and shoot length of all species significantly reduced even in low concentration of metals and S. marianum had greater root and shoot length under all treatments. Reduction in seed vigor index was greater under Cu than that in Pb and Cd. High tolerance index was found for L. draba in response to cadmium and for S. marianum under the stress of lead and copper. In all treatments increase in metal concentration significantly increased phytotoxicity index. Under Cu and Pb S. marianum showed least phytotoxicity index while the lowest phytotoxicity index was found for L. draba under Cd stress. Copper and cadmium in high concentration were more toxic for A. absinthium than that for the other two species. Under similar concentrations of copper and lead, all species showed reduced germination in copper stress. Cadmium in lower concentrations were tolerable for plants but generally it had the greatest inhibitory especially on A. absinthium.

Overall the responses were different regarding to the plant species, metal and concentrations. All three species were able to germinate at high concentrations of heavy metals. The presence of these species in coal wastes and their ability to germinate in high concentrations of heavy metals makes it possible to use these plants in future restoration and phytoremediation programs.

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.

Knowing the qualitative and quantitative characteristics of plantation is principal of forest management. Laleh Natural Park in DEZFOUL, with a total area of 9.31 hectares, is located 11 km far from Dezful. The 23-year old stands in the studied park were Eucalyptus and Prosopis. In order to study the number of trees, according to the small levels of the studied stands (pure Eucalyptus 1.9 hectare and mixed with Prosopis 1.7 hectare), the full calipering inventory method was selected and the certain characteristics such as diameter at the breast height and height of all trees. According to the results, the average number of trees in the pure Eucalyptus stand is equal to 110.5 trees per hectare, the average diameter at breast height of stand is 25.22 cm and the average total height is 12.10 m. Also, the average number of species in the mixed Eucalyptus and Prosopis stand is 70.6 trees per hectare, the average diameter at breast height is 27.32 cm and the average total height is 9.57 m. In order to study the effect of Eucalyptus and Prosopis on the soil of the area, 50 soil samples were taken at 2 depth of 0-10 and 10-20 cm from pure and mixed stands and some soil characteristics including texture, moisture and acidity were studies. Soil texture of both stands in this study was loam. There was no significant difference between the two populations in terms of total relative humidity. In terms of acidity, there was a significant difference between two soil depths of 0-10 and 10-20 cm soil in the pure stand which was higher at depth of 10-20 cm.

The ecological importance of deadwoods has led to an ever-increasing collection of related information to be taken into account in management plans. Considering the key role of deadwoods in forest ecosystem, the present study investigated some of the most important characteristics of deadwoods, including number, volume and spatial distribution pattern in a natural forest with beech dominance. For this purpose, two managed and unmanaged regions were selected from Gorazbon district of Kheyrudkenar forest in the vicinity of Noshahr as the study area and full calipering inventory of deadwoods was done. Moreover, species, diameter and height of standing deadwoods and in the case of fallen deadwoods, characteristics such as species, median diameter and their length were recorded and measured. In order to study the spatial pattern of the deadwood, the position of each deadwood was obtained by azimuth distance method using a laser distance finder and subsequently analyzed by univariate O-rings statistic functions. The results showed that the frequency of deadwoods were in the managed area more than of the unmanaged area, whereas the volume of deadwoods in unmanaged area was more. The highest number and volume of deadwoods were in low-diameter class of the managed area and in large and very large class of the unmanaged area respectively. The O-ring statistic showed that the spatial pattern of whole deadwoods in the managed and unmanaged area was completely random. Thus it can be stated that disturbances in studied area were in small scale. The amount of deadwood especially in managed area is not enough and its increasing is one of the requirements that with regarding to disturbance and structure pattern should be considered.

The beech (Fagus orientalis Lipsky) stands in the Hyrcanian region of Iran occur on a wide range of soils in a relief row with valley and ridge structures called Catena. This affects soil features and plant species distribution due to its topographic shape and different slope positions. The aim of this study was to compare changes in soil characteristics across V-shaped Catena in the two harvested and non-harvested beech stands in the Asalem region, Guilan Province. We selected three Catena landforms in each non-harvested and harvested stand. In each stand, a 400-m2 plot along each Catena and slope position was designed, in which soil samples were taken from the center and four corners as well as from 10-0 cm, 20-10 cm and 30-20 cm depths. The samples were mixed to obtain a single soil sample for each depth and slope position. Soil samples were transferred to the laboratory to study physical and chemical properties. Based on our results, the variability of soil features was significantly influenced by different depths and forest management plans, whereas they were poorly affected by the different positions of the Catena. The highest amounts of pH and Ec were measured in the harvested stand, while the highest phosphorus and potassium contents were measured in the non-harvested stand and toe slope position, respectively. Absorbable potassium was the only parameter that had a significant difference in management, slope position, and depth of soil interactions. Generally, foot and toe slope positions contained more nutritious soils, which can be attributed to the leaching and erosion of soil from higher to lower slopes.