FOREST RESEARCH AND DEVELOPMENT
Year:2017 | Volume:3 | Issue:2 |Papers Count:7

The aim of this study was to evaluate the effect of soil compaction on functional equilibrium and biomass allocation, root growth and morphological characteristics of Cypress seedlings. As a result, seeds with the highest morphological features were collected and planted in plastic pots in loam or clay loams soils with constant moisture regime. They were studied in six levels soil compaction tension. The morphological parameters of the seedlings, plant growth and seedling architecture were calculated. In all cases, the mean of Cypress seedlings morphological response were significantly decreased when compaction level increasing. The relation of morphological response and increase soil penetration resistance were negative quadratic. Also, the relation between soil penetration resistance and seedling growth parameters were negative quadratic which is high at the beginning and then its value was decreased. The best regression equation distributed between ratio of root length and root weight (0.0126), stem length and stem weight (0.0841), length of lateral root and length of main root (0.1716), weight of lateral root and dry weight of root (0.2676), rate of root biomass (0.0576), weight of root and weight of shoots (0.0466), rate of leaves biomass (0.2426) and rate of stem biomass (0.0541) were obtained quadratic. The results showed that soil compaction tension affect the functional equilibrium and morphological characteristics of seedlings, seedling growth and Cypress architecture.

The aim of this study is to determine the recreation value of Arghavan Forest Reserve in the county of Ilam using contingent valuation method. To determine the influencing factors on the probability of willingness to pay (WTP) of visitors, Logit model was applied using maximum likelihood estimation. Required information were collected via questionnaires and interviews with 245 visitors from the area in 2014. The results showed that 90% of respondents are willing to pay for recreational use of the forest area. Education, income and age variables have a significant positive effect and the variables of offered price, household size and numbers of visits from the region have a significant negative effect on the probability of willingness to pay. The mean of willingness to pay for recreational use of the area was estimated 10202 Rial/person. The annual recreational value of Arghavan Forest Reserve was also estimated 15054352398.33 Rials for total area and 88555014.10 Rials per hectare. The results of the study show that the people are aware of the importance of forest resources and there is a significant willingness to pay to improve and to develop the resources for recreational and protection uses. The results can provide conditions for policy-makers and responsible people in natural resources of Ilam province to conserve and protect more these forest resources.

This study aimed to evaluate the effects of Acer Velutinum, Fraxinus excelsior, Quercus castaneifolia, Pinus brutia plantation stands and oak–hornbeam natural stand on soil (physical, chemical and biological) properties in Darabkla forest (parcel 39), North of Iran. To measure the soil physical and chemical properties, 10 points were randomly selected and soil samples were taken at the depth of 0-10 cm using the core method. The buried bag method was used to measure the net nitrogen mineralization rate, which 5 points were randomly selected and soil samples were taken at the depth of 0-5 cm. Finally, the soil moisture content, bulk density, pH, EC, organic carbon, total nitrogen, available potassium and phosphorus, ammonium and nitrate were measured in the laboratory and indices of net nitrogen mineralization, ammonification and nitrification were calculated. The mean comparison results of soil physical, chemical and biological properties showed significant differences between different stands. So that, the highest value of soil pH, potassium and phosphorus were observed in maple plantation stand and the lowest value of soil moisture content, pH and EC were observed in pine plantation stand. In addition, the net nitrogen mineralization was higher in the broadleaves stands than pine stand.

In this study, network analysis process was used for appointing importance of effective criteria and indices on locating and suitable site selection for forest park development. For this purpose, quantitative criteria was determined, and qualitative ones weighted using paired comparison. Regarding to the most important criteria or indicator of choosing the location of forest park, six regions were identified as options for decision making model. Finally, for selecting suitable site, qualitative and quantitative factors were combined using analytical network process (ANP) and the weight of options were identified. The results of important criteria weighing process for selecting suitable forest park location showed that amongst 7 selected main criteria, water resources criterion with the weight of 0.42 is the most important and climate, landscape and plant-animal criteria were placed in next priorities respectively. In case of sub-criteria of climate, Average of rainfall with weight of 0.5 had the highest weight. Distance of water resources sub-criteria with weight of 0.48 was the most important one for water criteria. The variety of forest covering with the weight of 0.52 was the most important sub-criteria of plant-animal criterion. The most important sub-criteria related to socio-cultural criterion was security by weight of 0.56. The results of options prioritization showed that the “Nizh-Darreh" region with weight of 0.3 should be considered as the best place for forest park.

The main purpose of this study was to collect information about production, collection, consumption and processing of medlar (Mespilus germanica) at Rudsar county, Guilan province. Data were collected within 30 samples, each one hectare, by randomly systematic sampling method. We measured tree characteristics such as large and small crown diameter (LCD and SCD), diameter at breast height (DBH), and fruit weight. Other data about collection, consumption, processing and household income was gathered by semi-structured questionnaire by surveying of 120 households. The correlation analysis showed that LCD (0.494) and DBH (0.487) had a significant correlation with fruit weight in 99% confidence interval. The average fruit weight was 13.6 kg per tree. Considering average trees/ha and mean fruit weight/tree, 190 kg fruit per hectare was expected to be collected annually. Total annual household collection was 3739 kg. The highest quantity of consumption belonged to Siyahkal Chal with 200 kg. The lowest quantity belonged to Lusara with 35 kg. Annual household income from fruit harvesting varied from 1259 to 50000 thousand Rials

The aim of this study is to investigate the effect of fire on stand structure (qualitative and quantitative factors of trees) and regeneration of oak coppice forests, Kuhdasht city, Lorestan province. The study area with an area of 90 hectares is located at 5 km in north of Kuhdasht city. This area has been burned by a surface fire on 6 July 2005. In this study, A total of 60 square plots with an area of 400 m2 were taken in linear transect with 100 m interval. Two types of sample plots were used. Tree cover was measured in main plot. Herbaceous (%) and regeneration were measured in micro plots with an area 4m2. The unpaired t test results showed that the fire caused a significant reduction in canopy cover percent, individuals/ha and an increase in herbaceous cover percent, diameter at breast height, basal area per hectare and regeneration of oak trees in fire area. In general, it can be concluded that the fire caused making an even aged stand and had a negative and positive impact on quality-density and oak regeneration respectively.

The aim of this study was to survey of quantitative situation of Juniperus stands for identifying affecting factors on growth and optimal establishment of this species. For this purpose, an area with 200 ha in Tarom, Zanjan province was selected. Random-systematic sampling was performed with 40 plots, each 1000 meter square area. In sample plots, collar diameter, the diameter of a half-crown, height, canopy, density and regeneration were measured. In each sample, a soil sample was taken to investigate soil characteristics. Analysis of variance results showed that there were significant deference in number/ha, height, canopy percent and regeneration between slope classes, in number trees/ha between aspect classes, in number trees/ha and canopy percent between  elevation classes in 95% probability level. The correlation test results showed that between EC with number/ha was positive correlation. Soil acid saturation had positive correlation with the number/ha and regeneration. Nitrogen percent of the soil had positive correlation with the number/ha, percent of canopy cover and regeneration. Soil organic carbon percent had positive correlation with the number/ha, the diameter of the half crown and percent of canopy cover. P and K had positive correlation with diameter of half-crown. The percentage of sand had negative correlation with regeneration.