Journal of Forest and Wood Products
Year:2018 | Volume:71 | Issue:2|Papers Count:8

Salinity is an important abiotic stress affecting the seedling growth in saline soils. In this research, Populus caspica Bornm. potted seedlings were examined under control environment in five salinity levels (0, 5, 100, 150, and 200 mM NaCl) as RCBD with three replicates for 45 days. The results showed salinity significantly reduced the survival rate, stem growth, collar diameter growth, leaf number, root length, total biomass, net photosynthesis, photosystem II photochemical, leaf water potential and enhanced free proline content. In 100 mM salinity, 74 percent of seedlings survived while they increased the stem growth by 40 mm. In 50 mM salinity, even though collar diameter growth and stem growth decreased a little (0. 6 mm and 0. 8 cm, respectively) but survival rate was still 100 percent. In general, the tolerance threshold for salinity of P. caspica seedlings, from viewpoint of survival, can be estimated to be 50 mM. This implies that in coastal areas and/or deforested lowland sites of northern Iran where the soil salinity is < 50 mM, plantation of P. caspica can be employed. Further studies in longer periods will raise the strength and accuracy of this statement.

Different parts of forest roads and uphill are usually the main sources of surface runoff, sediment, water resources pollution in forest streams and soil loss. Today, soil erosion and its consequences is a global matter of concern. This study was conducted in Kohmiyan forest near-Azadshahr in order to assess the effect of forest road uphill gradient in controlling the runoff production and soil loss by a rainfall simulator. Treatments include four levels of gradients (>20%, 20-40%, 40-60% and 60-80%). Other parameters such as soil moisture content, resistance to penetration, vegetation cover and precipitation were considered constant. Then, the amount of runoff and soil loss in each level were collected at an intensity of 80 mm/h with 15 min duration and sampled at three minute intervals. The results indicated that the average amount of total runoff in level 1 (gradient >20) to level 4 (60-80%) were 5. 97, 10. 14, 14. 27 and 18. 60, respectively. Sediment concentration were 4. 15, 5. 87, 7. 84 and 10. 68 g/l-1; runoff coefficient were 12. 01, 20. 25, 28. 51 and 37. 20 percent and total soil loss were 21. 65, 54. 67, 108. 13 and 191. 51 gr, respectively for each one square meter. The results of ANOVA showed there is significant difference between the amount of runoff and soil loss due to road gradient. The results of Duncan test also indicated that with increasing uphill gradient, the amount of runoff and sediment increased significantly.

The use of statistical experimental models is common practical methods among forest resource managers. Regression analysis is also a statistical method that can be used to estimate the volume. This method has limitations and requires assumptions such as normality, homogeneity of variance and non-linear relationship. The use of new techniques such as artificial neural networks can deal with these limitations. This study aims at comparing the performance of Artificial Neural Networks (ANN) and regression analysis to estimate the total volume of logs. For this purpose, 367 trees out of marked trees in research and educational forest of kheyroud were selected and DBH, diameter at stump height, stump height, total tree height, species, tree situation, minimum median diameter and topographic factors such as aspect and elevation were measured with high accuracy. Multilayer perceptron (MLP) and multivariate regression were developed to estimate the total volume of logging trees. The results indicated that the Neural Network was more accurate about 40% in estimating the total volume of logging trees than the regression method. Comparing evaluation criteria showed RMSE value 1. 411 for ANN modeling and 3. 49 for regression analysis. The difference between estimated and actual total volume was 6. 5% to regression analysis and 1. 7% to Neural Network. According to the results, the amount of difference was less for ANN model than regression model.

Sumac (Rhus coriaria L. ) is a multi-purpose indicator species in Arasbaran region, especially in Horand County and a remarkable amount of its fruits is traditionally exploited every year. This research was focused on the quantitative evaluation of production and the economic importance of sumac in the household's economy of Aghboraz Village of Horand County. The data were collected in two parts, including the quantitative evaluation of fruit production via random-systematic sampling strategy and socio-economic analysis about harvesting, selling and processing of sumac via semi-open questionnaire. Based on the results, the average number of sumac stem per hectares was 3928 and its average yield was estimated 428. 16 kg per ha. Sum and average of harvested sumac by rural household was 8455 kg and 422. 75 kg, respectively. The average annual harvest value of households was 46500 thousand Rials. The average annual household income from raw and processed sumac was estimated 7740 and 46480 thousand Rials, respectively. The average share of household income from the sumac harvesting was 44% of total household income varied from 0. 9% to 100% among different households. The average added value created by processing was 332500 Rials. According to the results, it can be concluded that sumac species can be effective in improving the economic situation of the villagers.

Abarkooh cypress (Cupressus sempervirens L. var. horizontalis (Mill) Gord) is one of the oldest cypresses in the world. Tissue culture is a method for saving and propagation of endangered and rare plants such as this cypress. This study aims at investigating the effects of different cytokinins and auxin plant growths regulators and coconut milk on micropropagation of plant. Experiments were performed as completely randomized design with six replicates. After sterilization for proliferation, explants were cultured in WPM medium culture by different treatments consisted of 1. Plant growth regulators (Kin, BA, TDZ and 2ip) at concentrations of (0, 0. 1, 0. 5, 1 and 2 mg/l) 2. Interaction effect of 0. 1 mg/l cytokinins (Kin, BA, TDZ and 2ip) with IBA (0 and 0. 01 mg/l) and 3. Coconut milk (0 and 50 ml) + 0. 05 mg/l IBA. According to the results the number of shoots in culture media contained 1 mg/l BA and 0. 1 and 1 mg/l 2ip increased. Addition of 0. 01 mg/l IBA on culture media contained kin, TDZ and BA increased the number of shoots, but decreased the shoot length. Using coconut milk significantly increased the number of shoots and decreased their length. For root induction different media cultures of WPM, SH and LS with different hormonal treatments was used and only in WPM medium culture contained 2 mg/l kin root was obtained.

Analyzing the spatial patterns of individuals and the interaction between them are essential for understanding the spatial and temporal dynamics of plant populations. This research was conducted to study the spatial patterns and interaction of three oak species (Quercus brantii Lindl., Q. infectoria Oliv. and Q. libani Oliv. ) in Baneh forests of northern Zagros region of Iran. Data collection was done using six one-hectare square sample plots which randomly selected and fully mapped. Spatial patterns and spatial association of different oak species were then analyzed using O-ring univariate and bivariate statistics, respectively. Results showed that the general spatial patterns of the trees in total and at larger scales were random, while at small scales was clumped at least up to 15 m. Spatial association analyses revealed that there was no significant inter-specific competition among the three oak species, where the spatial association was positive (attraction) at small scales (up to 5 m) or independence at larger scales. It is concluded that clustered-random pattern is due to high forest origin of the most studied stands, homogeneity of the habitat, and lack of interspecific competition among the three oak species in the study area. Whereas there is no significant interspecific competition among the three oak species, every intervention in order to enrichment and restoration of these stands should be based on keeping clustered-random spatial pattern and making individual species mixture.

In the recent years, rising oil prices, limiting these resources, and also environmental concerns raised by the increased consumption of plastic materials in the food packaging industry, increased global public concern. Recently, experts in the food packaging industry have sought to find suitable biodegradable substitutes for synthetic polymers. The nanocomposite of poly (butylene succinate) (PBS) and different content of cellulose nanofibers (CNF) including 5, 10 and 20 wt. % were prepared by solvent casting method and physical, mechanical and photodegradation properties of obtained cellulose nanocomposites were characterized. The photodegradation of materials was assessed by weight loss and FTIR spectroscopy. The tensile strength and elastic modulus of PBS films were improved by the addition of the cellulose nanofibers (CNF) compared to the neat polymer. The nanocomposite with 10 wt. % CNF had the highest tensile strength and lowest modulus of elasticity and the elongation at break. By adding the CNF, water vapor permeability decreased from 9. 05×10-5 g/m. h. Pa for pure PBS film to 6. 96×10-5 g/m. h. Pa for PBS film containing 10 wt. % cellulose nanofibers. In addition, the water uptake and contact angle properties were enhanced by the adding of cellulose nanofibers. The biodegradation results showed that the addition of CNF increased the percentage of the samples weight loss. Therefore, due to the results obtained, it can be concluded that the composites obtained in this study have the potential to be replaced with synthetic polymers.

The main cause of the wood degradation in domestic and artistic applications is deformation due to the moisture changes and also the bio-damages. Wood protection in these sectors requires much attention due to their contact with humans, so toxic chemicals may not be used. The beeswax is a natural substance and has no toxicity for humans. The main purpose of this study was to use the different concentrations of the beeswax (0, 4, 6 and 10 wt%) dissolved in the hot ethanol, as well as its combination with boric acid (6 wt% beeswax + 2 wt% boric acid) to impregnate poplar wood for enhancing the dimensional stability and the fungal resistance. The result showed that the uptake of the beeswax, even in low weight gain, had significant effect on the water absorption and volumetric swelling of wood, especially in short periods of water contact. As the immersion time in water increased, the volumetric swelling of the treated samples increased and finally that was as much as controls. By increasing the concentration of the beeswax, its effect on the resistance of wood against fungal decay was revealed. In general, the efficacy of the beeswax on the fungal activity was limited. The best result was obtained with the combination of the beeswax and boric acid, which even after leaching and no decrease was observed on the protective efficacy against fungal decay. The use of this protective formula for industrial applications is not economical, but it can be used for domestic (kitchen utensils) and artistic (sculptures) uses.