حامد یوسف زاده

Caucasian apple (Malus orientalis Uglitzk) is one of the forest-garden species of Iran that is distributed in Hyrcanian and Zagros vegetation areas in Iran. In this study, the diversity and genetic structure of Caucasian apples were investigated using 26 microsatellite markers. The results showed that the observed heterozygosity was between 0.46 - 0.83 and the allelic richness was between 1.54 - 1.84. In more than 80% of habitats, heterozygosity was expected to be within the expected range. Our founding suggest that between Iranian population wild apples have not experienced a genetic bottleneck in the recent result.The range of inoculation coefficient for Caucasian apples in Hyrcanian forest was between -0.84 and 0.81 and for Zagros forest was between -0.2 and 0.81. The mean gene flow is 0.24 and 0.69 for Hyrcanian forest and Zagros forest, respectively. Based on Hardy-Weinberg equilibrium only populations from Lorestan province and Dorak region from Golestan province were deviated. The study of the results of genetic structure also indicates the formation of three completely different structures for Caucasian apple populations in Iran. based on the analysis of principal components analysis, Hyrcanian and Zagros regions showed a completely different structure from each other.

Oriental beech (Fagus orientalis L.) is one of the most important industrial species in Hyrcanian forests which exploited via forestry projects with various methods, including a single selection method since the last half-century. Genetic diversity in forest trees is critical for their adaptation to the new environmental conditions. This study was aimed to study the effect of single selection method on genetic diversity of oriental beech in the forests of the east of Mazandaran province, Iran by comparing two management method in protected and exploited plots using single selection method in Haftkhal Forestry Plan. Paired sampling was performed from the leaves of 60 mature trees in the control and exploited plots. Ten microsatellite primers were used to assess the genetic diversity. The results showed that a total of all 10 microsatellites loci produced polymorphism bands. The amount of heterozygosity was 0.52 and 0.49 in the control and exploited stands, respectively. The frequency of specific alleles in mother trees were 3.75 and 3.19 in the control and exploited stands, respectively. Based on the single selection method, beech trees were not significantly different in the control and the exploited plots in terms of the total number of alleles, specific alleles, allelic richness and heterozygosity. However, the observed heterozygosity was 41 and 45% lower than the expected heterozygosity in the control and exploited stands, respectively. Therefore, based on the genetic parameters extracted from 10 microsatellite primers; it was concluded that the single selection exploited method did not have a negative effect on the genetic diversity of mother beech masses in the studied forests.

The destruction of Hyrcanian forests has led to the fragmentation of the Caspian poplar (Populus caspica Bornm.) habitat and the destruction of a large part of its genetic resources. This species is distributed in the southern regions of the Caspian Sea, although it has been reported in the list of endangered trees. To select various trees and conserve their gene pools via the collection, their diverse habitats throughout the southern Caspian strip from Astara to Golestan forest were studied, and subsequently, 20 habitats were identified. DNA extraction from the leaves of 359 trees belonging to these habitats was then extracted. After homogeneity removal, genetic parameters were estimated for 314 trees using 14 microsatellite markers. These primers showed 80 alleles in 314 trees of P. caspica. Expected heterozygosity values in each locus ranged from 0.085 to 0.765, while the observed heterozygosity ranged from 0.069 to 0.689. The highest and lowest amount of allelic richness with values of 3.03 and 2.17 were estimated in Loveh and Tonekabon, respectively. The inbreeding coefficient was a possible factor in the Hardy-Weinberg equilibrium deviation. Only 0.8% of trees in a population were immigrants. In general, gene flow was asymmetric and its severity was low. Mantel test showed that there was no significant correlation between genetic distance and geographical distance. However, altitude was a serious barrier to gene flow across the eastern and western slopes of the Caspian poplar distribution. Finally, to preserve its genetic resources, based on the results of molecular, some stocks of this species were clonaly propagated and planted in a relevant collection.

Climate change can be a major threat to the endemic species of the Hyrcanian forests. However, there have been almost no studies in terms of determining consequences of climate change on the distribution patterns of Populus caspica Bornm. In this study, ecological niche theory and MAXENT software as well as P. caspica presence data across the Hyrcanian forests of Iran were used to identify the relationships between species data to the climatic predictor variables under current and future (RCP 8.5) (2070) climate conditions. According to analysis of area under the ROC curve, the high value of AUC index (0.993) indicated the efficiency of the model in determining the potential habitat of P. caspica. Precipitation of driest month, temperature annual range, mean annual temperature, and isothermality were the most important bioclimatic variables in the determination of potential habitat for P. caspica. Moreover, our results demonstrated that the habitat suitability area of this species was 88317.3 km2 under current climate condition and 38.75% area was identified as a "good potential" level for the presence of P. caspica. Whereas under projected future climate (RCP 8.5), suitable areas would be decreased by 48.4% compared to the current condition. The results of this study can be applied in approaches management, conservation planning and reforestation by taking into account the effect of climate change on habitat suitability and species response to its changes and conservation strategies will be compiled for this species.

Rowan is a tree with a very limited distribution in the upper treeline in the Hyrcanian forest. In this study, seven habitats of this tree from east to west of the Hyrcanian forest were identified and seed germination behaviors and diversity in leaf morphological traits were evaluated. Multivariate analysis showed that the studied populations were not differentiated from each other in terms of morphological traits. The results of germination percentage showed that in cold treatment and hot and cold treatment, germination reached about 100% after about 70 weeks. The germination rate in the cold treatment reaches its peak at week 55 and about 90% of the seeds germinate at week 55. In the hot and cold combination treatment, although before week 50 the germination rate reaches its maximum with a cumulative germination percentage of about 40%, but from this week to week 55 the germination rate again slows down and from week 55 to week 60 second drops. It experiences its peak with about 80% germination. The results of the present study showed that the Rowan tree species does not have a high morphological diversity in its habitats in the northern Iran. Due to lack of knowledge on the long-term seed germination of this tree, mountain nurseries have been unsuccessful in producing seedling.

In this study, the diversity of morphological traits of needle in male and female yew (Taxus baccata L.) along the topographic and longitude gradients in the Hyrcanian forests was studied. To this aim, a total of 580 needles from 58 trees were measured in three sites (Amlash, Gazu and Afratakhteh) along the longitudinal gradient of the Hyrcanian forests. A hierarchical or nested analysis of variance was used to assess influencing sex and site on the 6 measured morphological traits of needles. In addition, Duncan's test was used for multiple comparisons of means. Furthermore, principal component analysis (PCA) was used to determine the most important traits and environmental factors in differing sites. Results showed that variation of morphological traits of yew needles is only affected by site factor. However, the influence of sex was not significantly assessed. Results also showed that most morphological traits of yew needles except the form factor were highest in Gazu site that comprised moderate slopes, northern aspects, faced northern humid air and experienced higher growing season due to lower elevation. Generally, morphological traits of yew needles were lowest in Amlash site, which included steep slopes (loss of soil depth) and western aspects (decrease in relative humidity). Yew trees in Afratakhteh site showed intermediate values. Our results imply that sites with cool summers and higher relative air humidity (settling in the humid northern valleys) provide more favorable growth conditions to morphological traits of yew needles compared with sites with higher average annual rainfall across the Hyrcanian forests.

Spring frost injury is a major environmental limit for the productivity of stone fruits such as almond. Thus, it is important to screen and breed spring frost tolerant trees. Among molecular markers, SSR derived from EST sequences are more desirable for breeding programs. In our previous study, we employed a frost treatment for flowers of a frost-tolerant almond genotype at full blooming stage as the important phenological stage to study frost stress. The transcriptomes of the frost-treated and non-frost-treated flowers (after post-thaw period) were analyzed and compared by using next generation sequencing technology. A total of 63218 sequences were generated and analyzed using SSR-Locator. In total, 2680 SSRs were identified and 2601 of sequences contained SSRs. In 11 sequences, there was more than one EST-SSRs. Among the potential EST-SSRs, five types of the motifs were identified; di-nucleotide and tri-nucleotide had the highest frequencies followed by penta-nucleotide, hexa-nucleotide and tetra-nucleotide repeats. Our study revealed that di- and tri-nucleotide motifs are more frequent. TA/TA and GA/TC were the most abundant di-nucleotide motifs while GAA, AAC and ACC were common in tri-nucleotide SSRs. GO annotation showed that the top GO terms associated with SSRs containing tri-nucleotide motif were involved in the regulation of transcription, regulation of cellular biosynthetic processes, regulation of gene expression, regulation of cellular processes, response to stress and response to stimulus. Our study is the first report on SSR development for fully open flowers of a frost-tolerant almond genotype.

Persian honey locust(Gleditsia caspica Desf.) is an endemic tree in the northern forests of Iran and southeastern Azerbaijan, which has low seed germination because of water impermeability of seed. In this research, effects of hot water at 70 °C and 100 °C (5, 10, 15 and 20 minutes), dry heat at 60 °C, 80 °C and 100°C (15, 30 and 60 minutes) and sulphuric acid treatment at two concentrations of 70% and 98% (at immersions of 5, 20, 40 and 60 minutes) were studied on the characteristics of seed germination of this species. Experiment was carried out based on completely randomized design in three replicates. No germination was observed in the seeds treated with hot water (100 °C), dry heat and control, while the seeds treated with semi-hot water (70 °C), sulphuric acids of 70% (60 minutes) and 98% (20 and 40 minutes) obtained 20, 84 and 100 percent of germination, respectively. In general, hot water, warm water and dry heat are not good treatments for seed germination of Persian honey locust seed. It suggests that for seed dormancy breaking as well as seedling production of Persian honey locust,sulfuric acid 98% (with immersion of 20 or 40 m.) to be used.

Zarde-Kija mushroom(Cantharellus alborufescens) is one of the edible mushrooms belong to the Cantharellaceae family. It is widely distributed in the northern forests of Iran and is desirable for local residents in these areas. Despite the economic importance of this genus, litthe is known about their habitat requirements. This study was conducted to identify the environmental factors affecting the distribution of this mushroom in a plain forest of Noor city (Mazandaran province, northern Iran) with 120 ha area. For this purpose, 20 pair plots (20 m × 20 m) with at least 100 m distance were established (20 plots with Cantharellus and 20 non-Cantarellus plots). To analyze the species-environment relationship (soil characteristics), three groups of plant species were identified by the TWINSPAN method. The results showed this mushroom presents in oak-hornbeam stands with following conditions: clay-loam soils, pH value 5.7-7.2, soil C content 2.2-3.7%, total N 0.16-0.27%, C:N ratio 10.8-18.9, water content 29.4-46.2% and litter thickness 4.8-19 mm. In this regard, soil C content, C/N ratio, amount of sand and clay in plots with Cantharellus was 36, 71, 30 and 18 percent greater than those in plots without Cantharellus. Also, Nitrogen concentration (N), ammonium (NH4+), nitrate (NO3–), litter thickness and amount of silt in non-Cantarellus plots were respectively 30, 20, 19, 48 and 28 percent lesser than those in plots containing Cantharellus. Overall, our findings showed that C content, C:N ratio, sand (%) and clay (%) were the most important factors influencing the presence of C. alborufescens.

The use of wild germplasm and identification of resistant genotypes is an effective strategy to reduce the economic damage caused by the occurrence of fungal diseases in domesticated cultivars. In this study, three populations of wild apples in the west of Hyrcanian forest, Siahbil, Masal and Asalem were selected and the presence of resistance genes of two fire and powdery mildew diseases in trees were considered along an altitudinal gradients. After DNA extraction, screening for the presence of 9 resistance genes (six genes: Vf, Vr, Vr1, Vr2, Vm and Vbj and the three genes: Pl-1, Pl-w and Pl-d associated with Scab and powdery mildew diseases, respectively) was done. The results showed that all of the six genes studied in all three populations (except for the Vf gene in the Siahbil population) were present and the genes. Vr and Vf had the highest and lowest levels of presence in the studied trees, respectively. Also, for powdery mildew, Pl-d gene was observed in all three populations. Pl-w gene was present in some trees of Asalem population, while Pl-1 gene was not found in any of the trees. Our study showed the high prevalence of candidate genes for resistance to scab disease and the rare presence of candidate resistance genes to Powdery mildew in western populations of wild apple in Hyrcanian forest. This indicates a high vulnerability of the populations studied, especially populations located at lower altitudes in facing to an outbreak of powdery mildew in apple habitats.

Apple (Malus orientalis) has been distributed throughout the Hyrcanian forest from lowland regions to steep and mountainous areas. For evaluation of genetic diversity, leaf materials were collected from 60 individuals of 6 populations. DNA was extracted and studied by six SSR primers: (GD142), (GD12), (GD147), (GD96), (GD100) and (GD162). The results showed that 45 alleles with 0.39 heterozygosity were detected for six primers. The mean of heterozygosity was 0.39 and the lowest (0) and highest amount (1) were observed for (GD100) in “Afratakhte”, “kodir”, “Sourdar”, “Yoush bala”, “Yoush paein” population and for GD162 in “kodir”, “asalem”, “yoush miani” and “yoush paein” populations, respectively. The maximum Nei genetic distance was belonged to “asalem” and “sourdar” populations and the minimum was related to “Yoush bala” and “asalem”. The result of AMOVA indicated that the intra and inter population diversity were 97% and 3%, respectively that indicated significant diversity within population of this species. Because of different habitat conditions and long geographical distance among populations, The low genetic differentiation and similar heterozygosity within populations show high gene flow among populations of Malus orientalis in north of Iran.

This research was carried out with the aim of dormancy breakage and seed germination improvement in mature and immature seeds of T. rubra subsp. caucasica form angulata. The seeds were collected from middle altitude (500 a.s.l.) forests of Chamestan, north of Iran. Mature and immature seeds with pericarp were treated as 1) cold stratification (without pretreatment), 2) imbibed with NaOH (30%)+cold stratification. Also, mature and immature seeds without pericarp were treated as 1) imbibed with gibberelic acid (500 mg/l)+cold stratification, 2) imbibed with kinetin acid (1 mg/l)+cold stratification. The examination was performed as completely randomized design with three replications. The highest amount of seed germination belonged to mature seeds without pericarp-imbibed with pretreatments of acid (giberelic or kinetin) and also immature seeds with pericarp-without pretreatment. The highest germination speed allocated to immature seeds with pericarp-without pretreatment, and the maximum mean germination time to mature seeds without pericarp-imbibed with giberelic acid. The results of this research showed that for optimizing seed germination of this species with above mentioned provenance, the best conditions for seed germination is, immature seeds with pericarp, subjected to cold stratification (without any pretreatment).

New wintering populations of Whooper Swan have been recently reported from west Asia, a lack of information about the population and its origin. The understanding the genetic structure and connectivity are crucial for determining strategies of management for its conservation programs. The samples were collected from two populations in northern Iran, Finland, Sweden, and Iceland, where with large breeding populations and Poland, where it has started nesting recently. Total genomic DNA was isolated from fresh blood or feather samples and six microsatellites markers were chosen based on their level of polymorphism. The results indicated that the maximum and minimum of Allele richness were observed for Iranian (5.6) and Polish (3.44) populations respectively. The analysis of molecular variance revealed that 77 % and 23% of the total diversity belong to within and between populations, respectively. The 114 Whooper Swans from six populations were categorized into four gene pools. Structure analysis suggested that the Scandinavian populations (Finland, Sweden, and Iceland) were differentiated from the Poland population and from both the old and new Iranian populations. Generally, both populations from Iran have comprised maximum variety in terms of having different gene pool and it is likely that the new population of Iran (Feredonkenar), is composed of individuals that migrated from an old Iranian population (Guilan) to this area as well as some individuals from Scandinavian.

Lilium ledebourii (Baker) Boiss, with white aromatic flowers is a native rare species and the only National monument of Iran. This plant has medicinal, ornamental value and high economic potential as a new flower that is extremely endangered and as its wild populations are currently at risk of rapid eradication because of irregular grazing, pest and poaching. Tuse, the aim os this study was determining the nutritional value of L. ledebourii in vegetative, flowering and seeding phenological stages, samples were randomly collected including three replication and five plants from the aerial shoots of lily in Kelardasht and Asalem. And Nutritional Value indices including crude protein (CP), Acid detergent fiber (ADF), dry matter digestibility (DMD), metabolic energy (ME) were analyzed. The results of this study showed that the phonological stages have a significant effect on the nutritional value of Lily, and the nutritional value of vegetative stage is higher than of the other stages in both habitats. As Crude protein, dry matter digestibility and metabolic energy content decreased from early growth to the end of growth  and ADF increased significantly with the growth progress. Also the highest nutritional values were obtained from Kelardasht. It seems that nutritional value are affected by ecological factors changes such as the soil, direction, slope and altitude.

Pterocarya fraxinifolia is an ancient tree in north of Iran that have been recently reported two small stand of this species in west of Iran, Lorestan and Ilam province. In this study, population diversity and genetic differentiation of west populations and their vulnerability were assessed using ISSR markers. Eight to ten trees were selected from two west population as well as four populations of north of Iran, DNA extracted from leaf and genetic diversity was evaluated. AMOVA result indicated that the value of intra and inter population diversity is 88% and 12%, respectively. Shannon index is 0.157 and mean of heterozygosity is variable 0.064 to 0.119. Based on neighbor joining algorithm, the under study populations were split to two main groups that the west populations (Ilam and Lorestan) as well as Savadkouh were comprised the main group 1. Also, PCoA analysis showed clearly differentiation of Lorestan population from other under study populations.

One of the problems of propagation of lindens (Tilia spp.) is low seed germination. In this research, different treatments for stimulating the germination in immature seeds of Tilia rubra subsp. caucasica form angulata collected from middle altitude (500 m a.s.l.) and high altitude (1500 m a.s.l.) of Chamestan forests (northern Iran) were examined. In both altitudinal seed sources, immature seeds with pericarp were subjected to 1) cold stratification, and 2) imbibed with NaOH (30%)+cold stratification. Also, immature seeds without pericarp were examined as 1) imbibed with GA3 (500 mg/l)+cold stratification, and 2) kinetin acid (1 mg/l)+cold stratification. The most germination percentage (87%) allocated to non-pericarp seeds of higher altitude, treated respectively, with 1) GA3+cold stratification, and 2) kinetin acid+cold stratification. The most germination speed (6 seeds/week) belonged to seeds of with pericarp collected from middle altitude, treated respectively with 1) cold stratification, and 2) imbibed with GA3+cold stratification. The lowest mean germination time (20 days) allocated to seeds with pericarp of middle altitude (only cold stratified). Generally, even though, non-pericarp immature seeds of higher altitude, imbibed with GA3 (and kinetin acid)+cold stratification had favorable germination percentage, the immature seeds with pericarp of lower altitude (only cold stratified) represented satisfaction germination percentage along the shorter period. However, in future investigations, effect of treatments on seed vigor index and growth of Tilia seedling in order to employ the proper method for seed propagation and seedling production of this species in nursery are advised

Lilium ledebourii (Baker) Boiss, is the only national and natural heritage of Iran, which grows in mountainous regions of Hyrcanian forests with limited distribution that many ecological, ornamental and medicinal aspects of this plant has not been studied yet.
Material & Ethanolic extract was prepared by maceration method. Then, total phenol and total flavonoids of ethanolic extracts were respectively performed by the Folin- Ciocalteu and AlCl3 method. Antioxidant activity was measured by scavenging free radicals of DPPH. Statistical analysis of the data was performed by ANOVA (Analysis of Variance) and Duncan Test to compare the means.
The total phenols of Lily shoots was between 59/6 ± 65/43 and 21/9 ± 14/66 and its antioxidant activity was between 51 to 90 percent at four habitats, The highest and lowest amount of total phenols and antioxidant activity of Lily shoots obtained from Kelardasht (maximum altitude) and Rostam Abad (minimum altitude). The total flavonoid were reported between 91/7 ± 41/33 mg GAE g-1 and 21/1 ± 72/43 mg QUE g-1. The highest and lowest content of Total flavonoid were respectively observed in Asalem and Namin.
The results showed that the antioxidant capacity of Lily is relatively high compared to other medicinal plants, also antioxidant activity of the Lily extract is variable in different sites and significantly affected by habitat altitude.

Vegetation in riparian areas, including trees with various hydrological and mechanical effects has an essential role in soil reinforcement. This is accomplished by increasing soil shear strength and inhibiting the higher layer of soil into the lower layers and reducing erosion by roots. The aim of this study was to evaluate the tensile strength changes of Salix purpurea L. trees in different trunk distances and soil depths. Therefore, five trees were randomly selected for root system sampling, which was done by using the soil core technique. Sampling was taken in three different depths, tree horizontal distances and in four directions of the trees. Finally, 97 successful tensile tests were performed on root samples. The relations between tensile force- diameter and tensile strength-diameter were analyzed and compered. The results showed the average of tensile strength of 57.91, 46.96 and 46.27 Mpa for depths 0-10, 10-20 and 20-30 cm, respectively. Furthermore, the average of tensile strength was 29.18, 76.81 and 28.78 Mpa for 0.5, 0.75 and 1 m distances, respectively. Root diameter and tensile force fallowed positive power and exponential trends. However, the association between root diameter and tensile strength followed a negative power trend. Results of Wald test showed no significant difference between tensile strength of three soil depths and three horizontal distances, though root diameter as a covariate parameter with a significant effect on tensile strength.

This study was conducted to investigate the devastating impact of Mistletoe (Viscum album L.) on asymmetry index and leaf characteristics of Ironwood (Parrotia persicaDC.) in Tamishan Forest, Noor, Iran. For this purpose, 20 Ironwood trees were selected inside and outside of the forest. The results showed that the highest and lowest values of leaf area and specific leaf area were observed in healthy and infected trees, respectively, both inside and outside of the forest. Stomatal characteristics of diameter, area and density also varied depending on location of trees and branch types (healthy or infected). Analysis of variance (ANOVA) indicated that the effect of left or right sides of leaves (sides) and trees were significant, while the interaction between side×trees was not significant. The difference between left and right sides of leaves were also significantly affected by location of trees and branches types. Generally, this study showed that the presence of mistletoe influenced the asymmetry index and have been caused to changes in the morphology of the infected trees. Finally, due to nutrition importance of Viscum album for animal to prevent from death of host trees, mechanical removing of Viscum album from host trees with high density is recommended.

Vegetation enhances the soil resistance against instability and erosion through increasing the soil cohesion. The main effect of vegetation in stability improvement is soil reinforcement by roots. The amount of reinforcement depends on distribution and strength of roots. The aim of this study was to assess the quantity of these two parameters of Persian oak roots and also comparing the tensile strength and reinforcement effect of roots in winter and summer seasons. Damage survey method was used to assess the distribution of roots. The diameters of all roots in trenches were measured by a digital caliper. Some root specimens were randomly selected from five tree samples and their tensile strengths were measured using a standard Instron. The range of root diameter and corresponding force and tensile strength were 0.1-5.5 mm, 1.3-411.3 N and 0.93-1217.39 MPa, respectively. Maximum and minimum root densities were in 0-10 and 50 cm soil horizons. The maximum reinforcement effect was belong to winter and 0-10 cm horizon. Minimum and maximum reinforcement effects for winter season were 0.0001 and 3.37 and 0.0004 and 2.87 MPa for summer.

Apple (Malus orientalis.) distributed throughout the Hyrcanian forest from lowland regions to steep and mountainous areas. For evaluation genetic diversity, leaf material were collected from 104 individual of were 14 population. DNA was extracted and DNA polymorphism were considered using four primers (GA)8YC, (AC)8YA,(AG)8AT and (AC)8G with ISSR-PCR method. The results showed that for four primers was detected 385 allele with 0.049 heterozygosiyt.The mean heterozygosity was 0.049 and varied from 0.031 in “Afratakhte” population to 0.059 in “kodir” and “Lamzer” populations. The maximum Nei genetic distance was belong to “Siahbill” and “Masal” populations and the minimum was related to “Yoush”, “Afratakhte” and “Dinekooh”. the AMOVA result indicated that the intra and inter population diversity were 94% and 6%, respectively that indicate significant within population diversity of this species.Despite the different habitat conditions and long geographical distance among populations, The low genetic differentiation (excluding Siahbill population) and similar heterozygosity within populations suggest high gene flow among populations of Malus orientalis in north of Iran.

Previous studies have shown that vegetation enhances the soil shear strength and the stability of slopes through soil reinforcing. The amount of reinforcement mainly depends on the density and tensile strength of the root. The objective of this study was to assess the impact of pollarding on tensile strength of Quercus persica roots. For this purpose, five treatment and five control tree samples were randomly selected. Some root specimens for each tree were collected and tensile strength was measured by a standard Instron. 150 successful tensile tests were conducted on roots withdiameter ranging from 0.9 to 5.5 mm, force range of 3-374.5 N and tensile strength range of 1.22-217.80 MPa. The relationship between root diameter and force was following a positive power one but the power relationship between the root diameter and tensile strength was not statistically significant. The results of Wald Chi square test showed there was no significant difference between the tensile strength of treatment and control sample trees, although the root diameter (as covariate) had a significant effect on tensile strength. It can be concluded that no significant differences may relate to short history of pollarding (3 years) in the study area, and therefore it is suggested to assess the stands with longer history of pollarding.

Increasing of degradation process in Chestnut (Castanea Sativa) pure stands as reserved forest in west of Hyrcanian forest led to genetic erosion of the stand. Understanding of ecological demands of plant species is necessary for their management and conservation. So we investigated on leaf morphologic characteristics of chestnut in response to different light regimes.
For this purpose 60 trees of natural stands around of Ebrahim Emamzade (in Shaft city located in Guilan province) were selected. Ten leaves (40 leaves from every tree) randomly were selected from four aspects of trees (north, south, east and west). These leaves were imposed by different light regimes. Some of the parameters such as lamina length, lamina width, distance from leaf base to the leaf maximum width, petiole length, nerves (counted variable), teeth (counted variable), leaf tooth width, leaf tooth length, tooth distance and tooth index were measured and analyzed after calculating the plasticity for each character in four aspects.
Findings: The plasticity values showed that there is no significant differences among four aspects of crown. The results indicated that plasticity of all studied characters is so low while the most value of C.V was belonged to leaf limb width (4.04%).
Discussion and The results of ANOVA showed that all studied parameters had no significant differences between surveyed aspects except distance from leaf corner to the most leaf limb width. Our finding confirmed that morphologic characters of Castanea sativa leaf has low flexibility in response to light conditions. We suggest that study of other ecological demands are necessary for presentation of accurate guidelines to forest managers.

Birch is one of the oldest remaining tree species in the Hyrcanian forest which categorized in plants with limited distribution, rare and critically endangered. Hybridization and polyploidy are two main reasons for uncertainty in taxonomy of the genus Betula in the world. The taxonomic status and genetic affinity of Iranian population of Betula with other species from this genus were investigated. Leaf samples were collected from four Birch populations form North and North west of Iran and after DNA extraction, trnH-psbA region amplified. Comparative sequence analysis of PCR product from five populations in iran with 17 sequences of other species of the genus Betula recorded in NCBI were done. Phylogenetic analysis indicated that birches were in three clades A, B and C which all Iranian samples located in clade A. Sharestanak population formed the subclade Aa, whereas the Siahmarzkouh, Sangedeh, Nohshar and Marmisho comprised subclade Ab. Based on ABGD method, the birches of Iran comprised three separated groups. Sharestanak sample showed the greatest similarity with Betula pendula based on K2P methods. Finally, this study support the belong of Iranian populations to subgenus Betula.