Iranian Journal of Forest and Poplar Research
Year:2017 | Volume:25 | Issue:1 (67) |Papers Count:23

The crisis of water shortage and the impact of El Nino in the past few years, are the most important issues that should be considered. The aim of this study was to introduce optimal models for monitoring water reserves in the trees with respect to water cycle in Glandrood mixed-beech forests, Noor. Therefore, after sampling of disks for 2- 5 meters of trunk length of 174 individuals, wood samples with fixed dimensions were ovendried. After weighing each tree trunk in the field and difference between the wet mass and dry biomass considering the ratio of drought index, the whole water reserves were measured. To develop the models for predicting response variable, simple, multiple linear and nonlinear regression analysis were used. The results showed that simple and linear models had no considerable accuracy to predict the response variable. In contrast, power function, exponential and curve-models predicted the response variable with the high accuracy. Power function was the best model and that was developed to predict the water reserve value with the highest accuracy. Using this equation provides possibility for predicting the loss of water resource related to water cycle after cutting out the tress from the studied forests.

Air pollution is one the threatening factors affecting human and plants health in the cities. Since human continuance is closely related with the plants’ survival, different effects of pollution on plants can affect green areas and vegetation management and preservation in urban zones. Therefore, this study was carried out to define the effects of urban pollutant gases (SO2, NO2 and O3) on quantitative characteristics of round-leaf ash (Fraxinus rotundifolia Mill.) in Tehran. The study was carried out in seven municipal districts of Tehran, which were selected to include the wide spectrum of climatic conditions and contrasted levels of air pollution within the city. Quantitative characteristics including leaf area, specific leaf area, wet and dry weight, leaf toughness and thickness and water content percentage were studied by means of correlation analysis and t- test. The correlation results showed that increasing air pollution results in decreasing dry and wet weights and leaf area. Amongst the seven studied districts, the analysis revealed that Azadi and Sorkhehesar areas were associated with significant differences in pollution and non-significant differences in soil and climate. Our study indicated that all of the characteristics are significantly different in two areas. Furthermore, the quantities of all parameters except leaf thickness significantly decreased in more polluted areas.

The purpose of this research was to investigate the role of hillshade values, in comparison with terrain aspect, in the canopy changes and evaluation of ecological capability in vegetation domain of Zagros forests. In conducting the research, digital elevation model (DEM) was prepared and soil map was extracted from that. Due to the direct relationship of forest canopy with the site ecological capability, the raster map of hillshade was multiplied by forest canopy; and canopy area was calculated at different values of the hillshade map. Also, the map of the main slop aspects extracted by the DEM map and that was multiplied to the map of forest canopy. Then canopy area was calculated for different aspect; and that was presented as a histogram. Thereupon, the histogram and quadratic model equation of relationship between forest canopy percent and hillshade regime was prepared, in the entire study area. The histogram and the model, show that reducing the intensity of sunlight (Rising Shadow), strong influence on the increase in canopy. Also, the quadratic regression model (R2=0.58) and linear regression model (R2=0.56) of the correlation, with 17 repetitions, obtained in the form of a square block network. Because of the easiness and the low cost of hillshade mapping, and also, its superiority over the terrain aspect map; we recommend that hillshade maps be used as one of the key factors for of land ecological capability, in the Zagros forest and other arid and semi-arid forests.

This study was carried out to estimate the branch and leaves (crown) biomass of Lebanon oak (Quercus libani Oliv.) and gall oak (Q. infectoria Oliv.) trees at single and stands level in different ages after Galazani (pollarding). We selected three oak stands which have been pollarded one, two and three years ago and an undisturbed (untouched) stand as a control. In order to estimate the amount of biomass produced from tree crown partial harvesting method and allometric equations were used. We selected 36 Lebanon and 36 gall oak trees in the various diameter classes with an average and almost uniform crowns. In the middle of tree crowns, four branches were cut from four cardinal directions randomly, and then fresh weight of leaves and twigs were measured in each branch to estimate crown biomass. Power regression model was performed as the best predictor model and relative bias and RMSE % were calculated at branch level. The results showed that there is no significant difference between measured and estimated biomass in branch level. Also, partial harvest method is unbiased procedure in biomass estimation. According to the results, amount of crown biomass at tree and stand level, in the untouched stands (9.21 tons ha-1) were more than the crown biomass in one, two and three years after pollarding (1.26, 2.32 and 3.16 tons ha-1 respectively). These results can be used to do a better management and monitoring of oak forests which affected by pollarded.

The determination of effective parameters on survival, growth and vitality of Haloxylon shrubs is essential for sustainable management of Haloxylon plantations of desert areas. This research aimed to investigate of soil surface height pruning effect on ecological situation of Haloxylon plantations in Hares Abad region of Sabzevar. Six sample plots (20 m × 20 m) were chosen systematic-randomly in two fields (control field and pruned field). In each plot, height, crown diameter, number of secondary branches separated from collar and vitality of Haloxylon shrubs and also number, height and crown diameter of auxiliary regenerated species were measured. The results indicated that annual increment of height and crown diameter and number of secondary branches separated from collar in pruned shrubs were significantly greater than control shrubs. Number of trees in hectare and number of auxiliary regenerated species was also higher in pruned field than control but without significant difference. Furthermore, questionnaires were filled out by regain residents for assessment of environmental impacts of these Haloxylon plantations. The results of this opinion poll showed that Haloxylon plantations have had positive effects for residents of Hares Abad region.

Protection of forest soil is one of key factors in having sustainable productive forests. In this research extent and intensity of soil disturbance due to extraction of logs of felled trees (20.5 m3/ha) were studied in Nav-e Asalem forest in Gilan province. After finishing the skidder logging operations, soil disturbance were studied by point-transect sampling method and visual assessing. Results indicated that about 19 ± 6.2 percent of surface soils were disturbed due to winching of logs that 11.3 percent of them disturbed with shallow intensity and 7.7 percent disturbed with deep intensity. The extent and intensity of soil disturbance were decreased by increasing distance from skid trail. The extent and intensity of soil disturbance were increased by increasing of ground slope. Soil bulk density in the shallow disturbed soils (1.29 g/cm3) and deep disturbed soils (1.44 g/cm3) were increased 2.4 and 14.3 percent, respectively, than control soils. Soil bulk density of disturbed areas were increased by increasing ground slope, so in slopes greater than 50 percent soil bulk density was increased 20.8 percent more than control soils. Including ways to reducing soil disturbance during skidder logging in the study area are reduction in harvest intensity, implementation of felling direction and skidder logging limitation to slopes less than 50 percent.

Natural and anthropogenic disturbances result to loss of biodiversity and ecosystem stability decline. Metrics that aggregate more qualitative information on individual species and overall community composition could be useful to better assess factors such as the conditions of natural areas, their conservation value and the impact of human disturbance. This is the first study that determine conservatism coefficient for vascular plants in Lorestan province. The standard modified multi-scale Whittaker plots were used for vegetation sampling. A panel of botanists and ecologists were asked to assign conservatism coefficient to each native species based on their knowledge and previous experiences about plant species sensitivity to disturbances and fidelity to a specific habitat by using floristic list. Results showed that conservatism coefficient were accepted by botanists and ecologists and can be used in the next researches for identifying forests conservative values. Based on the results of 57.67 % of plants were ranked fell into the first category (1-3), while 32.27 % fell into second category (4-6), approximately 8.46% of plants were ranked into third category (7-8) and finally 1.58 % of plants were ranked in the forth category (9-10). Astragalus leonardiiMaassoumi, A. longirostratus Pau. and Bunium luristanicum Rech. f. have the most values of conservatism coefficient were ranked fell into the forth category. Based on the results and with regard to species conservation status, these species can be introduced as an indicator of intact oak forest. Determining CC in the natural intact regions and comparing it with other regions is useful for evaluation of restoration programs succession.

Palynologial analysis of a core from Ganli-Gol wetland reveals the Late-Holocene vegetation dynamics and the role of climate and man on the past environment in northwestern Iran. Our pollen diagram shows substantial changes in vegetation over the period 3000-1600cal.BP. Artemisia and/or Chenopodiaceae must have abundantly contributed in the vegetation composition of the area. Poaceae and Cyperaceae were important wetland vegetation as the high values of their pollen suggest. The low values of arboreal pollen throughout the record indicate the negligible contribution of forest vegetation over the whole period. We used C/A (Chenopodiaceae/Artemisia) pollen ratio, to estimate the past dry/wet periods in the area. During 3000-2850cal.BP, a relatively dry climate and the expansion of steppe vegetation can be inferred from low values of C/A. Increased values ofArtemisia with the occurrence of oak during 2850-2652cal.BP may reflect less drier condition with semi-steppe vegetation. The end of this period is marked by low values of Quercus and Artemisia and high Chenopodiaceae, suggesting the prevalence of a cold and dry condition with steppe-desert vegetation. Increased values ofQuercus combined with high values of Artemisia and Poaceae could be taken as indications for improved climatic condition during 2338-2020cal.BP. The occurrence ofVitis and relatively high values of anthropogenic pollen types, e.g. Plantago lanceolataand Centaurea solstitialis, are evidences for increased agricultural activity in this period. The period 2020-1614cal.BP is marked by low values of Quercus andArtemisia and high Chenopodiaceae pollen suggesting that steppe vegetation and a relatively arid condition prevailed in the area.

In Iran Zagros forests, forest dwellers on forest and forest products overdependence understanding of socio-economic issues in order to prevent and even reduce forest degradation is essential. The aim of this study was to investigate some forest dwellers livelihood dependence on forest resources in the northern part of city functions Kouhdasht is Namjoo watershed. For this purpose, the household data collection questionnaire and interview with the forest residents, Statistical Center of Iran, and the information contained in VA village and County of Kouhdasht were used. The results showed that local people's income is less than their cost. This caused the locals to cover their living costs to cultivate their unauthorized forest understory. This contribution is causing deforestation and degradation. The relationship between income and household expenses using the Pearson test showed that there are no significant correlation between them (R2=0.041; p=0.784). Also, the results have proved that the relationship between the dependent and the income derived from forest are no significant (R2=0.327; p= 0.36).

Regeneration of natural Pistachio forests of Iran distributed in arid and semi-arid regions have been disturbed by human activities and environmental stresses. One of the modern methods of reforestation in disturbed forests is utilization of mycorrhizal seedlings in reforestation projects. In this research mycorrhizal seedlings of common pistachio (Pistacia vera L.) was produced under environmental condition and fungi symbiosis effect on one year seedling growth characteristics were evaluated. At the first step, the most frequent species of arbuscular mycorrhizae were identified Funneliformis mosseae C. Walker & A. Schuessler (=Glomus mosseae T.H. Nicolson & Gerd.) and seeds of host trees were gathered for cultivation. After a growing season, some of the morphological characteristics such as stem length, collar diameter, shoot numbers and number of branches were calculated within 100 seedlings (50 seedlings per treatment) and compared with control. A significant different were observed between studied parameters (p<0.01). Results revealed 60% stem length, 40% collar diameter, 67% bud number and 51% branches numbers increment in compare with control. The producing cost per mycorrhizal seedling was 2.3 times higher than non mycorrhizal seedling. Wasting percentage per seedling was 10% for mycorrhizal seedlings and 30% for non mycorrhizal seedlings. Significant correlation was observed between colonization percentage and morphological factors of pistachios seedling. These results have a sharp message for utilization of mycorrhizal seedlings in rehabilitation project of this species.

The aim of present research was to investigate the effects of Growth Promoting Rhizobacteria on growth (height, collar diameter, dry weight of root and shoot, total dry biomass and quality index of seedling) and nutrient absorption (N, P, K, Fe and Zn) in leaf of common hazelnut (Corylus avellana L.) For this purpose, effects of three bacteria including Pseudomonas putida, Bacillus subtilis and Enterobacter cloacae, alone and together, for 7 months on filbert seedling in pots containing of autoclaved soil under nursery conditions were evaluated. The results showed that the greatest height (26.88 cm), collar diameter (7.17 mm), leaf area index (23.87 cm2/g) and N concentration (2.81%) were observed for seedlings inoculated with all bacterial. The biggest root dry weight, root volume, seedling quality index and P concentration were observed in seedlings inoculated with P. putida (alone). The highest Fe and Zn were obtained in seedlings inoculated with B. subtilis and P. putida, respectively. Generally, according to beneficial effects of Growth Promoting Rhizobacteria on absorption of nutrient elements and morphologic growth, P. putida, B. subtilis and E. cloacae are recommended for seedling inoculation, respectively. In fact, inoculation of root with Growth Promoting Rhizobacteria (root engineering) can be an appropriate approach to produce healthy and strong seedlings in nursery and increasing success of plantation in disturbed and degraded habitats.

This study was conducted in order to Morpho-physiological assessment of salt stress on Euphrates poplar (Populus euphratica Oliv.) seedlings in the greenhouse. Annual stems of Euphrates poplar were collected from Masoumieh desert rangelands (Qom) and were planted in pots containing homogenous mixture of sand, gravel and farm soil. Salinity stress was applied using different levels of NaCl in four levels of 50, 100, 200 and 400 mM and control, with two times a week and for two months with irrigation water. The results showed that salinity stress of 400 mM NaCl causes full dehydration of Euphrates poplar seedlings and this amount of salt tolerance was out of plant tolerance. Also salinity of 50 mM NaCl on the viability and survival traits and characteristics, including growth and vitality, height, diameter, biomass of leaves, stems and roots showed no significant difference with control treatments. Higher salinity levels in some of the characteristics and attributes of viability, vitality and the height and diameter of seedlings in different treatments showed significant difference. Also the amount of accumulation of some elements such as chloride, magnesium, calcium, sodium, potassium and phosphorus, had significant differences (p<0.01 and p<0.05) with control treatment. Overall, our results represent that Populus euphratica is a moderate halophyte which could be suggested to reclamation of saline lands with high water table.

One of the serious problems across the world is heavy metal pollution in water bodies that caused by Lead (Pb). This study was designed to find out the effect of Pb toxicity on physiological and biochemical changes in three Eucalyptus species (Eucalyptus camaldulensis Dehnh., E. microtheca F. Muell and E. occidentalis Endl.). Seeds were grown in marble chips and irrigated with nutrient solution. The seedling (42 days old) were exposed to Pb (NO3)2 treatments (Pb: 50, 100, 200 mM) for ten months. After this period, leaf, stem and root tissues were harvested. Lead content were determined by ICP-OES and some physiological and morphological characters were determined. The order of Pb accumulation in three species were E. occidentalis>E. camaldulensis>E. microtheca. The concentrations of lead in root tissue were higher than leaf and stem tissue and stem concentration was lower than the concentration of leaf (root Cu>leaf Cu>stem Cu). Tissue concentration increased as Pb increased in three species. The content of prolin, soluble sugar raised by increasing metal concentrations, but the content of pigments, relative water content and specific leaf area decreased. These results suggest that eucalypts have efficient mechanism to tolerate Pb toxicity, as evidenced by accumulating of osmoprotectants. Comparison of three Eucalyptus species revealed that E. occidentalis had the highest concentrations of Pb in the leaves and stems. Accumulation of Pb in the E. occidentalis leaves was 2.38 and 1.82 times more than E. microtheca and E.camaldulensis respectively. Although the least amount of stress tolerance index (0.76) was observed in E. occidentalis. In general, the results showed that Eucalypts could be considered as a tolerant species for hyperaccumulation of lead and phytoremediation of contaminated soil by lead.

Sustainable management of a forest management unit requires adapting to international and national criteria and indices at the local level. In this study, criteria and indices of sustainability were determined and prioritized in Lirabi watershed of Ardal in Chaharmahal and Bakhtiari province. According to the local condition, 6 criteria and 30 indices from the initial 10 criteria and 48 indices were selected. The results of weighting criteria showed that economic and social, conservation and protection functions are of greatest weight amongst the others. Amongst the indices, the following were determined to be of greatest importance: livestock management and its contribution to reduce damages, strengthening of protective forces, economic development and participatory afforestation, increasing the non-wood forest products, involving and equal rights of local communities in the benefits of forest, training the locals for alternative jobs and developing mechanisms for resolving conflicts between people and the Department of Natural Resources. The results of this study can be used as a guide to develop local criteria and indices.

This study was carried out to evaluate the application of the 15d method and monitoring the alteration within the improvement area in district one from Loveh forest management plan after 28 years. A systematic sampling have been designed in a network of 150×200m with circle plots of each 0.1 ha for forest stand inventory and circle micro plots of each 0.01 ha for regeneration inventory. Based on available data from the previous inventory in the forests management plan and the current data that is collected from our inventory, some parameters including basal area, volume, forest composition and distribution in diameter classes were compared between 1982 and 2010 using analysis of t-test and chi-square test. The result showed that under this method, distribution in diameter classes in both 1982 and 2010 years have significance differences with normal distribution. The differences of basal area for Cappadocian maple (Acer cappadocicum), field maple (Acer campestre), elm (Ulmus glabra) and hornbeam (Carpinus betulus) were statistically significant. Volume of chestnut-leaved oak (Quercus castaneifolia), Cappadocian maple, elm, hornbeam and total volume per ha were also significantly different. Comparing of stem number and height of the stand showed that the density and height of the studied stand have increased after application of this method. Study of regeneration showed that the interventions cause the stand composition altering to hornbeam-oak. Our result indicates that the application of the method 15d has affected the mixture, species diversity and the structure of the stand. Therefore, in order to improve the structure and favoring of oak and noble species, we suggest thinning operations for 20 to 30 years with a positive selection from above.

Skidding logs from stump to depot areas is the most important part of ground-based logging operations, which often leads to an increase in soil bulk density and decrease in soil porosity. In this study, woody slash and sawdust treatments with a weight of 10 kg m-2 were used to decrease soil compaction on skid trails during the trips of rubber-tired skidder To f E655 in compartment of 29 in Bahramnia forestry plan in Gorgan, Golestan province. Soil samples were collected by steel cylinder from 0-10 and 10-20 cm soil depths after 2th, 6th, 10th and 16th skidder trips on treated and control plots. Bulk density, porosity percentage and moisture content were measured in laboratory. Results showed the soil bulk density of 1.05, 1.12, 1.18 and 1.2 g cm-3 at the depth of 0-10 cm in bare soil after two, six, ten and sixteen trips. On trails treated by sawdust protective layer, the soil bulk densities were 0.98, 1.02, 1.07 and 1.09 g cm-3. These values for slash treatment were 0.64, 0.98, 1.05 and 1.07 g cm-3, respectively. The soil bulk densities after two, six, ten and sixteen trips were 1.31, 1.38, 1.43 and 1.45 g cm-3 at the depth of 10-20 cm in bare soil. By using sawdust these values decreased to 1.22, 1.26, 1.31 and 1.32 g cm-3, whereas the use of slash resulted in 1.18, 1.21, 1.28 and 1.31 g cm-3, respectively. The results indicated better performance of slash treatment in reducing soil compaction compared to sawdust treatment. Moreover, soil porosity at the both depths of treated plots by woody slash was more than that of other treatments and was near to forest soil porosity. Furthermore, sawdust treatments could more retain the soil moisture compared to slash treatment. Using coverage material in skid trails was concluded to reduce of destructive effects of skidder transport.