مجله پژوهش و توسعه جنگل
سال پنجم شماره 1 (بهار 1398)

In this research, with the aim of investigating the capability of the sector sampling method in juniper forests and comparing it with the fixed area plot (FAP) method, a 12.5 hectare district was first taken continuously and point map of the trees was prepared. Seven parts were identified based on land physiography (crest and valley). For the sector sampling method, four sectors of 45 degrees were determined systematically and density was calculated. A network of circular plots in a 50×50 m grid was also specified and the density for each district was calculated. As actual density was determined in the whole forest, the accuracy and precision of estimates were calculated and compared. Estimates of the density were compared together using paired-samples t-tests and with actual data using one-sample t-test. The results showed that there was no significant difference between methods and with actual values. The sampling error was lower in FAP method, but sector sampling was obviously superior in accuracy. The root mean square error (NRMSE) of the estimates in FAP method was more than the sector sampling method, but the variance of the error values in the different parts of the region was less than the sector method, which indicates a more consistent sampling method.

In this study proliferation potential of four thousand year old cypress (Cupressus sempervirens L. var. horizontalis (Mill) Gord) using auxins and cytokinins plant growth regulators in in vitro condition was investigated. This study was performed as a factorial experiment and completely randomized design with six replications and each replication were contained three explants. Auxiliary bud explants in two different experiments were cultured in WPM culture medium consisted of cytokinins plant growth regulators (kin, BA, TDZ and 2ip) in five levels (0, 0.1, 0.5, 1 and 2 mg/l) and combination of 0.1 mg/l kin, BA, TDZ and 2ip with 0.01 mg/l IBA. Results showed that the maximum shoot numbers per treatment (2.66) was obtained in WPM culture medium contained 0.01 mg/l IBA + 0.1 mg/l BA and the highest length of shoots (1.85 cm) was obtained in media contained 0.1 mg/l cytokinins and without IBA. For root induction different culture media consisted of WPM, SH and LS contained four concentrations of IBA and NAA (0, 2, 2.5 and 3 mg/l) and also four concentrations (0, 0.5, 1 and 2 mg/l) of Kin was used and only in WPM culture medium contained 2 mg/l kin root was obtained.

Plant functional traits reflect their responsiveness and adaptability to environmental changes. Leaf traits influence the adaptation of plants to environmental changes and determine the community structure and function of ecosystem. The objective of the present study was to determine the oriental beech leaf traitschanges regarding to elevation gradients. Thus, three populations of this species were selected at 700 m a.s.l, 1200 m a.s.l and 1700 m a.s.l in Masal forests in Guilan province, respectively. In each altitude, in August, 20 tree stands were selected randomly. Then, from each tree stand, number of leaves were collected from southern and northern parts of the crown of healthy and mature trees. Then, some morphological characteristics (leaf length, leaf width, petiole length, leaf index, petiole index, leaf area distance to the widest leaf area) and morphophysiological characteristics (leaf area, specific leaf area, dry weight, specific dry weight and relative water content) were measured. The results indicate changes in the traits of beech leaves with increasing altitude. This process was shown decreasing in some of traits (leaf length, leaf index, and specific dry weight) and in others increasing (petiole length, petiole index, BW, leaf area, Specific leaf area, and relative water content). The results showed that some morphological and morphophysiological characteristics measured in different populations have a significant difference in the level of 0.05%. The results show that with increasing elevation, the leave traits of Fagus orientalis were changed.

This study was conducted to study the environmental literacy of students in Urmia University. In this study, the sample size was determined using the Krejcy-Morgan table. From the 7810 students of Faculty of Natural Resources, Engineering, Agriculture and Economics, 466 students of them responded to the questionnaire by random sampling. The questionnaire used in this research is a researcher-made questionnaire, which includes questions in two sections: general environmental questions and regional environmental questions and is set in quintuple Spectrum Pattern. The validity of the questionnaire was confirmed by the experts and the Cronbach's alpha coefficient was used to assess the reliability of the questionnaires. To compare the level of environmental knowledge of college students, one-way analysis of variance and Duncan's comparison test were used. Spearman correlation test was used to determine the relationship between the level of environmental knowledge and parameters such as age, number of family members, father's education, mother's education and monthly income level of the family. There was no significant difference between the studied faculties (5% = α) regarding to level of general knowledge. However, in the case of regional environmental knowledge, the level of this knowledge is the highest in students of the Faculty of Natural Resources and the least amount was in the students of the Faculty of Science and Engineering.

The present study aims to investigate the potential of biodegradation of cadmium, nickel, lead and zinc metals by Plane, Ash and Pine wood species in Hamedan parks. After composed sampling of the unwashed leaves and soil in the 11 parks, the samples were dried, acidified, and finally, the concentration of metals were measured by atomic absorption spectrometry. The results of concentration of lead and nickel metals were higher than those in the earth's crust and the concentration of cadmium and nickel metals more than the global mean concentration of metals in urban soils. On the other hand, the highest concentrations of cadmium, lead and zinc were found in Plane leaf and nickel element in Ash leaf. In general, the concentration of metals from unwashed leaves were more than washed ones. In this regard, there was a positive and significant correlation between the amounts of metals in the soil at the site of tree growth with their concentration in leaves. According to the results of bioconcentration factors, it can be said that the Plane species is more suitable for biodegradation of heavy metal contamination, especially cadmium. Finally, due to the results, it is necessary to pay attention to the establishment of cumulative species in urban gardens.

This study investigates floristic quality of central Zagros forest in relation to environmental disturbances using conservatism coefficient. Tree layer of the most important forest types in central Zagros was surveyed using 24 plots (500 m2 area) and herb layer was measure by 72 plots (4 m2 area). Then the list of collected flora send to an expert group of botanist and ecologist to assign conservatism coefficient to them based on the amount of each species sensitivity to disturbances and fidelity to the ecological site condition. Based on the results only a few species take high rank score which means the most collected plant species were sensitive to the disturbances and have low fidelity to the site. In fact more than half of the collected species belong to the lowest class of conservatism coefficient (1-3), which pyrus glabra forest type involves the most plant species of this class.

Juniper (JuniperusfoetidissimaWilld.) is classified as a Least Concern (LC) species of the International Union for Conservation of Nature (IUCN), but its distribution has decreased as a flagship and longevous species in East Azarbaijan province during last decades, and hence it is important to protect its habitats. In this research, the habitat suitability of Juniper in Arasbaran biosphere reserve, as the only habitat of this species in Iran, was considered. For the habitat suitability modeling of this species, Ecological Niche Factor Analysis (ENFA) method and ENFA software were used. Results showed that this species has narrow ecological niche and is sensitive to habitat changes. Information layers determined as affecting variables on this species include slope, aspect, elevation, land form, Geology and climate. Results showed that 27.17% of Arasbaran biosphere reserve were suitable for Juniper. The suitable habitats were recognized to be in areas with elevation range of 330 to 1500 meters above sea level, 10 to 60 percent of slope, hillsides, mediterranean and semi-arid climates. The results of this research is suitable for sustainable management of forest ecosystems, reclamation and land protection.

This study is about stoma and Secretory duct in Ash leaves along an altitudinal gradient (500–700–900 m) in Shafaroud zone. First, 10 trees 30-50 cm D.B.H were selected and 3 leaves of each tree and 90 leaves were collected then leaves of Ash discolor and coloration stage and Some images (×10 and ×40) were prepared of them by light microscopy. The stoma and Secretory duct characteristics including area, length and width and density have been measured on the surface by Digimizer software. Kolmogorov-Smirnov and Levene test for testing normality and Homogeneity of Variances, one way ANOVA for analyzing data, Dunnetts T3 for comparing mean were used at (p=0.05). The results showed that length, width and area of stoma and resin duct have significant differences among the altitudinal zones. The area and width of stomata have decreased with an increasing altitude. The area, length and width of the Secretory duct in 900 m is more than other zones. The area of stomata decreased and the density of stomata increased with increasing elevation the cause of this variation is adapt to the environmental change.

The objective of the present research was to study the effect of some physiographical factors (Aspect, slope, elevation) and features of Persian oak (Quercus brantii Var. persica( including height, DBH and crown diameter on fine root biomass in Hashtad- Pahlu forest, Lorestan. For this purpose, fine roots of oak trees were sampled randomly at   soil depths of 0-15 and 15-30cm in north and south positions under canopy of trees, then the amount of biomass and carbon were measured in laboratory. Analysis of variance and independent t test results showed that aspect and altitude had influences on fine root biomass so the highest amount was observed in the west aspect and the altitude of 1670-1870 m a.s.l )p<0.01(. The slope factor had no effect on the root biomass of trees in the site, as well Pearson’s correlation indicated that with increasing height and DBH of trees, biomass and carbon content were decreased )p<0.05(.

To study on competence of nonparametric geostatistical models including Indicator Kriging, Probability Kriging, Indicator Cokriging and Probability CoKriging, in zoning the probability of presence of Persian oak (Quercus brantii Lindl) regeneration in a forest stand to suggest the most suitable model and produce its related map, a forest stand with an area about 200 ha in nearby Yasouj was inventoried. Using a systematic random grid, 150 m by 250 m, general and silvicultural characteristics of the forest stand were inventoried in circular sample plots with an area of 1000 m2. the number of Persian oak regeneration were counted
To study on competence of nonparametric geostatistical models including Indicator Kriging, Probability Kriging, Indicator Cokriging and Probability CoKriging, in zoning the probability of presence of Persian oak (Quercus brantii Lindl) regeneration in a forest stand to suggest the most suitable model and produce its related map, a forest stand with an area about 200 ha in nearby Yasouj was inventoried. Using a systematic random grid, 150 m by 250 m, general and silvicultural characteristics of the forest stand were inventoried in circular sample plots with an area of 1000 m2. the number of Persian oak regeneration were counted in four small-circular plots with a radius of 1.55 m located with a distance of nine meters from the center of the main plots in line with the four main geographic directions. Using Geostatistic Analysis in ArcGIS10.2, the models of circular, spherical, tetraspherical, pentaspherical, exponential, gaussian, rational quadratic, hole effect, k-bessel, J-Bessel and stable were fited on the variogram. The cross validation method was used to evaluate the accuracy of the model. The results showed that the pantaspherical model of probability kriging have the strongest spatial structure (75.63%) and the highest level of credit in aspect of accuracy, ME (-0.0106), ASE (0.4424), RMSE (0.4470) and RMSS (1.0113) and would be suggested as the suitable model. After drawing semivariogram of regenerations and fixing the suggested model on that, they indicated on anisotropy in semivariogram quantity.
four small-circular plots with a radius of 1.55 m located with a distance of nine meters from the center of the main plots in line with the four main geographic directions. Using Geostatistic Analysis in ArcGIS10.2, the models of circular, spherical, tetraspherical, pentaspherical, exponential, gaussian, rational quadratic, hole effect, k-bessel, J-Bessel and stable were fited on the variogram. The cross validation method was used to evaluate the accuracy of the model. The results showed that the pantaspherical model of probability kriging have the strongest spatial structure (75.63%) and the highest level of credit in aspect of accuracy, ME (-0.0106), ASE (0.4424), RMSE (0.4470) and RMSS (1.0113) and would be suggested as the suitable model. After drawing semivariogram of regenerations and fixing the suggested model on that, they indicated on anisotropy in semivariogram quantity. The map of spatial distribution of regeneration could be an applicable guide in plantation projects in Zagros Region.

In order to comparing the regeneration and diversity in natural and created gaps, all of the gaps in two compartments in Asalem forests were identified and divided into three categories: small gaps (2), medium gaps (200-500 m2), and large gaps (>500 m2). Seven plots with an area of 4m2 (2m×2m) were taken in each gap. The number of individuals of tree seedlings and saplings were recorded and coverage percent of herbaceous species were estimated in each plot based on extended Braun - Blanquet cover - abundance scale. In addition to counting the number of species, diversity indices including Simpson (1-D) and Shannon-Wiener (H') and Smith- Wilson’s evenness indices were calculated. The Kolomogrov-Smirnov test was used to study the normality of data and then one-way ANOVA test was performed using SAS software. Totally 38 natural and 30 created gaps were identified. The results revealed that mean of each gap size was 371 m2. There were no significant difference between the size of natural and created gaps but the number and total regeneration were significant differences among natural and created gaps. The least abundance of seedlings were obtained in the small gaps. Also diversity indices had maximum in the created gaps.