Development stages and dynamic of two oriental beech (Fagus orientalis) communities at natural forests of Kheiroudkenar-Noshahr

Considering the morphological characteries of trees and the structure of stands, different development stages could be recognized in natural untouched forests. The development stages as well as the dynamic of the stands are basic references for application and development of nature based silvicultural  interventions. The aim of this research was to study the structure, qualitative and quantitative chareateristics of the main development stages (initial, optimal and decay) in two different plant communities of oriental beech forests, in the Caspian region. For this purpose two communities of Rusco-Fagetum and Carpineto-Fagetum in the experimental forest of Tehran University (Kheyroudkenar-Noshahr) were selected. In each community three sample plots, each one ha, were established and tree spieces, diameter and height of all trees were assessed. Moreover, one transect (10*100) was selected in each sample plot and the structure (vertical and horizontal profile) of the stand was studied. Results showed that all three stages could be recognized in the pure beech community, while the optimal stage has not been occured yet in the mixed beech–hornbeam community. Distribution of stem number, basal area and volume in different diameter and height classes of all development stages are given in this paper

Investigation on site demand of Almond (Amygdalus scoparia Spach.) in Zagros Forests (Case study: Karebassite of Chaharmahal and Bakhtiari province)

Amygdalus scoparia is one of the most important shrubs of Zagros forests. This species could be used as a pioneer element to rehabilitate destroyed forests, therefore having knowledge of ecological characteristics of Amygdalus scoparia can help forest managers for a proper application of this species. This research was conducted in Karebas region from Chaharmahal and Bakhtiari province. Firstly, all of the region were surveyed and the sites of Almond were determined in 1:25000 topographic map. Then land unit map were obtained by overlaying altitude, aspect and slope maps. In each work unit, one or two plots (1000m2) were established, overall 58 plots were allocated and site demands, physical and chemical properties of soil and tree quantitative and qualitative characteristics were studied in each plot. Results showed that one of the most important affecting factors in distribution of Almond is geographical aspect, hence this species is appeared in southern aspects. Also altitude is another factor for the presence of Almond; the highest presence of Almond is observed between 1800-1900 m.a.s.l. The highest amount of regeneration of Almond was appeared on southern aspect, 1800-1900 m.a.s.l. and 40-50 % slope. This species is often distributed on alkaline soils with loamy and clay-loamy texture

Vegetation analysis based on plant associations and soil properties in natural forests

In natural ecosystems, site classification can be used as a model to determine the quality of forest ecosystems based on ecological factors. Therefore, vegetation analysis based on plant communities and soil properties was performed in Kheyroudkenar forest – Nowshahr. Based on Braun - Blanquet method and using ANAPHYTO software vegetation data were analyesed, and associations recognized. Morevere, ecological groups and differential species were determined based on phytosociological data using TWINSPAN. Afterwards, depending on one sample selected in each landform class, the area with differential species were recognized for soil study. Results showed thattwo communities constitute the major part of the study area, Rusco-Fagetum and Carpineto–Fagetum. Soil variables that played the most important role for expantion of Rusco-Fagetum associaton were depth, silt, P and pH, while in Carpineto–Fagetum important were clay, sand, Sp, N and C

The role of coppice oak stand in carbon storage and ‍CO2 uptake (Case study: Khalkhal, Iran)

Regarding to the importance of forest in carbon sequestration, this study attempted to investigate the carbon storage potential and CO2 uptake in a coppice oak stand. An area of 278 ha of Khalkhal forest located in Ardebil province, north of Iran was selected as the study area. After combining slope, aspect and hypsometric maps, 63 land units (polygons) as well as their area were determined. Then 60 sample trees were selected in such a way that all environmental and typological conditions were taken into account. After determining the fresh weight of different parts of trees in the field, their dry weight and biomass was determined after drying in the kiln. The humus was collected and weighted from an area of 400 cm2under canopy of each tree. To determine the organic carbon content of the biomass, ash content was deduced from dry biomass. To determine the amount of stored carbon in soil, samples were collected from 0-10 and 10-30 cm soil depths. The amount of annual sequestrated carbon in biomass and soil was estimated as 1.51 and 0.1 tons per hectare, respectively. The annual carbon dioxide uptake was 5.94 tons per ha

Evaluation of competition indices to assess the effect of management interventions on oriental beech (Fagus orientalis Lipsky) forest of Lavij- Noor region, Mazandaran province

Tree to tree variation in growth results from compositional complexity, stand structure and competition. Therefore, it is essential to know how trees respond to competitive interactions. This study aims to evaluate of competition indices in order to assessment of management interventions effects in pure beech (Fagus orientalis Lipsky) stands (with 36 hectares) in Lavij- Noor region of Mazandaran province. For this purpose, the positions of all 58 marked trees were recorded as cored trees. Competition plots centered on the cored tree with radius of 3.5 × the cored tree crowns were established. The following attributes were measured for each tree (≥ 7.5 cm diameter at breast height (DBH)) within the plots: X and Y coordinates (m), total height, DBH, crown diameter at the base of the living crown in different directions and crown length. In order to quantify the competition level by each of the cored trees, 4 different distance-independent indices including Gerrard, Bella, Hegyi and Braathe were used. The results showed that the studied stands were middle-aged, the major interventions were in the middle DBH classes, and there was no significant change in the amount of competition indices following the interventions. Accordingly, the management interventions (marking) were not targeted and the process of individual tree competition changes was not measured. Therefore, the process of competition changes is necessary to be considered in stand management due to the high importance of the competition factor and its relation to the stand parameters

Evaluation of afforestation success by broad leaf species in Arak city

In order to investigate on situation of broad leaf afforestationin Arak city, a forest plantation around 160 ha, including ash (Fraxinus rotundifolia) and Black locust trees (Robinia pseudoacacia) was selected. For every species three treatments employed: 1- area with suitable and organized management and high social effects, 2- area with moderate irregular management and medium social effects and 3- area with low organized management and low social effects. Line sampling method was used for forest inventory regarding to the stripped shaped of the forest area by 200m intervals between plots. Finally, 148 sample plots with 200m2 surface area were measured. In each sample, qualitative and quantitative characteristics were recorded. T and Tukey tests were applied for quantitative data analysis as well as Kruskal-Wallis and Chi-Square tests for qualitative data. Seven soil profiles were digged for studying of soil condition in the study area. In each profile, two soil samples (depths 0-30 and 30-60 cm) were taken to analyze soil chemical and physical properties. Principal components analysis (PCA) was used to analyze soil characteristics. The results showed that the area with regular management has better condition than other treatments. Evaluation of plantation success indicated that black locust species is more successful  than ash trees considering quantitative characteristics and plantation establishment indices. However, considering qualitative characteristics and aesthetic issues as well as visual vision, ash tree generally has more privileges

Relationship between leaf area index and phisiographical and edaphical condition in a Quercus macranthera stand (Case study: Andebil's forest, Khalkhal)

This study attempted to investigate leaf area index in Quercus macranthera coppice stand. A forest of 278 hectares located at the northeast of Khalkhal was selected as the study region. The leaf area index was determined by direct method and by collecting all the leaves from the 60 coppice sprouts and measuring the mean leaf area and crown cover area of each coppice group. To determine the soil properties and its relation to the leaf area index, samples from the depth of 0 - 10 and 10 - 30 cm was selected. Physical (percent of clay, silt and sand) and chemical (amount of nitrogen, phosphorus, potassium, organic carbon and pH) properties of soil samples were determined in the laboratory. As a result, the leaf area index of oak species was 3.33 and the average dry weight of leaf was estimated to be 1864 kg/ha. No statically significant relations were observed between the phisiographical conditions and crown canopy density to the leaf area index. Considering the characteristics of the stand and soil, the aboveground biomass, diameter at breast height, tree height and the soil nitrogen showed the maximal correlation with the leaf area index

Determination of optimum number of ecological groups in vegetation classification (Case study: Kheiroudkenar Forests)

This study was carried out in Carpino-Fagetum orientalis, Rusco-Fagetum orientalis, Fagetum orientalis and Alno-Fagetum orientalis forest communities of Namkhaneh, Gorazbon and Chelir districts of Kheiroudkenar forests. The aim of the research was determination of the optimum number of ecological groups in the study area using indicator species analysis. Selective stratification sampling method was used to locate samples. One plot was laid out on each aspect and on each community. Totally, 120 samples were selected in the Fagus orientalis communities in the study area. The plot size was 400m2 considering to minimal area method. At each sample, floristic list in separate strata (trees, shrubs and herbs) were recorded using Braun-Blanquet scales. Cluster analysis was used for classification of samples. In this method, Sorenson distance measure was applied to calculate the distance matrix and flexible beta method as a cluster linkage measure. Indicator species analysis accompanied with Monte Carlo test was used to choose the optimum number of the clusters. Results showed that if four clusters were selected in the vegetation classification of Fagus orientalis communities in the study area based on cluster analysis, the number of indicator species, which had significant indicator values, would be maximum. Therefore, four groups could be introduced as the optimum number of ecological groups of Fagus orientalis communities in the study area

Investigation on Cryptococcus fagi (L.) population in relation to silvicultural characteristics of oriental beech forests (case study: Safaroud, Ramsar)

Cryptococcus fagi, the vector of Nectria sp., is one of the most important pests in beech forests which can cause beech bark disease. Because of its dispersion in the most beech forests of the northern Iran it should be taken under consideration. In this study, after forest survey, the infected area in watercatchment 30, district 5 of Safarod/Ramsar region were distinguished and 123 infected individual trees have been demarcated. Some characteristics such as d.b.h, height, infection intensity, structure and forest type have been determined. Results showed that, the most infected trees were categorized in small timber, but the highest infection intensity was observed in large timber trees. Also the pest high abundance can be seen in the small timber with regular structure. On the other hand, the stands with less stem density have been appropriated for most infection. The pure beech stands were more infected compare to mix stands. The pest abundance rate was higher in north and north-west directions. According to the results, although the disease symptoms are being observed, but no sever disease is recognized yet. As a matter of fact, it can be concluded that the pests are in their primary attack stage which could be controlled easily in this stage

Comparison of lead content absorption in different parts of Eldar pine (Pinus eldarica Medw.) in Tehran city

Evaluation of toxic metal concentration in soil and plants are the most important subject according to the health of ecosystem. This study was carried out to investigate on the lead content absorption in different parts (leaf, root and branch) of Eldar pine (Pinus eldarica Medw.) trees in Tehran city. For this aim in polluted sites (Azadi, Bahman and Bazar) and controlled site (Aghdasiyeh), in defferent seasons (January, March, July and September) and in different distance of air pollution measurment station (0, 500m and 1000m), 432 samples from leaves, branches and top root were collected and lead content density in each samples determined by atomic absorption instrument model Varian 220. Result indicated that lead content absorption in root of pine was higher than aerial parts (leaf and branch). Lead absorption in parts of tree in Azadi site was higher than other sites and the lowest content of lead was measured in Aghdasiyeh site. However, the highest lead content in parts of trees was observed in September and the lowest in March. The results also showed that by increasing of distance from air pollution measurment station, lead content absorption in parts of trees decreased