مجله پژوهش و توسعه جنگل
سال دوم شماره 3 (پاییز 1395)

In this study the distribution and infection percentage of infected trees to Loranthus europaeus in various height above sea level classes areas were investigated. For this purpose 65 circular sample plots with an area of 500 m2 were taken in Mirabad forests of Sardasht. Quantitative characteristics like DBH, tree height, crown height and diameter were measured in each plot. Results showed that the highest percentage of infected trees in all three Oak species (Quercus brantii, Q. libani and Q. infectoria) were on the highest elevation class (1751-1800 m) and the lowest percentage of infected trees were on lowest elevation classes (1450-1550 m). Percentage of infected trees in highest elevation class was about 4 to 3 times more than percentage of infected trees in lowest elevation classes. Mean number of L. europaeus per tree in Quercus brantii and Q. infectoria in highest elevation class was almost 2 times more than lowest classes (elevation range from 1551 to 1600 m) and for Q. libani it was 3 to 5 times more than lowest classes (1450 -1550 m). Eventually, for effective fighting with this pest, it is better to start from upper altitude.

Study Spatial Pattern and biodiversity in plant communities the basic requirements to solve a lot of issues in ecology and forest management. West Oak Forests were formed of the structural composition in two type's high forest and coppice. Understanding the structure combination of each part separately and in comparison together is necessary for the correct management. In this study, the landscape structure of the Karzan forests, Ilam Province were investigated using modeling quantitative analyses. The results of implementing of metrics such as number, density, canopy cover and statistical metrics canopy area of (mean, weighted mean, median, range, and coefficient of variation) in two types of high forest and coppice showed greater amounts in coppice type. In this framework, the distance between trees statistical metrics (mean, weighted mean, median, range, and coefficient of variation) as well as indicators of richness, Shannon, and Simpson were greater in high forest type than coppice. According to the dispersion index (R), the distribution range of high forest type was pile and coppice type was random–uniform. This model predicts structure transformation from high forest to coppice type in future properly. This Subject shows the necessity and importance of taking proper management policies to prevent such a structure transformation in future.

This study was carried out in three regions including the undisturbed, moderately disturbed, and highly disturbed of Yaghub-abad, Shoy, and Sadbar in Oak forests of Baneh County in order to investigate the effect of human made destruction on flora and plant species diversity. Three forest patches with similar physiographic conditions of each treatment were selected and three 1000 m2 plots (transect method and the 100m distance interval) were taken in each patch to record the floristic information. At the plot center, in a 400 m2 plot, type and abundance of tree and shrub species type were estimated. Also abundance of understory species in 5 micro plots with 1.5×1.5 m dimensions were recorded in this sample. . Species richness, Simpson and Shannon diversity and Shannon evenness indices were calculated to each sample. The results showed that there were 195 plant species which 47, 25, 15 species were exclusively observed in less disturbed, moderate disturbed and severe disturbed respectively. The results revealed that Asteraceae family is dominant in the area and in terms of Raunkiaer life forms, hemicryptophytes are dominant and considering chorotypes, vegetative region of Iran and Turan (Iranian-Turan) was mainly observable. This study also showed that the highest species richness and species diversity of Shannon-wiener belongs to the less disturbed region and the lowest ones calculated for sever disturbed region.

This study aimed to evaluate the results of applying Local maximum filtering, Template matching and Watershed segmentation algorithms on aerial image of UltraCam-D to delineate and detect automatically the single tree crowns of Persian Oak (Quercus brantii Lind) in comparison with the results of visual interpretation techniques and the filed measurement method of crown covers. After preprocessing of image, in a terrain with an area of 10 ha inside Yasooj forest park, 100 trees of Persian oak were selected randomly. The crown area of the selected trees was determined and calculated using visual interpretation and was accepted as the control data. Using the field inventory, the areas of the tree crowns were measured and the numbers of sprouts in each coppice form were counted. Using the field inventory, the areas of crowns of trees were measured and the numbers of sprouts in each coppice form were counted and recorded. Moreover, to delineate and recognize the crown of trees automatically, using programming, the Local maximum filtering, Template matching and Watershed segmentation algorithms, were applied on the mentioned image. The results showed that the accuracy of Watershed segmentation algorithm is better than the method of field measurement and it was 2.41 percent of the control method. Total accuracy and kappa coefficient obtained by error matrix algorithms for each algorithms of Local maximum filtering, Watershed segmentation and Template matching showed that Template matching algorithm was more accurate to detection crowns, or in other words, to detect single base or coppice trees than other algorithms used in this study.

This study aimed to analyze spatial patterns and associations of the studied trees in the developmental stages for achieving required information to prevent undermining stability of Nour Forest Park, to implement close-to-nature silvicultural prescription and to simulate distributions of aforementioned species in non-protective situations. Product of volume and specific wood density were used for estimating biomass of Caspian poplar trees in the forest. Mathematical parameters were used instead of absolute variables of wood density for estimating bole mass and crown mass of each tree. After distinguishing the developmental stage in the studied forest, three plots with one hectare area of 100 × 100 m dimension were outlined and the trees were coordinated by using measurement or trigonometric relations. Spatial analysis resulted from univariate O-ring application showed that the distribution was aggregated in the initial and optimal stages in the specified distances. In the decay stage, as well as being aggregated and random distribution, regular pattern of Caspian poplar trees was observed in the distance of 36 and 40 meter. Furthermore, the results of bivariate O-ring indicated that there was an intra-species positive attraction between medium class of biomass (medium size) and small class of biomass (small size) in a similar distance (8 m) in both initial and decay stages. As such, the intra-species attraction in the optimal stage was in attraction format in definite distances, and associations in the other distances were independent. The results showed that the association of aboveground biomass between large size and small size of trees in the developmental stages, implying that the density of small size trees is not under effects of intra-species competition resulting from the large sizes of trees in the developmental stages.

Oak decline is an expression used for describing the death and drying up of Oak trees. The current study aimed to evaluate the relationship between different geographical directions, locatios and the factors leading to Quercus brantii decline in Shurab forest, Accordingly, in the study area (150 h), a sampling network with the dimensions of 200*200 meters was designed on a regular-random basis and trees were measured by 1500_square_meter circular plots (radius is 21.85 m). In each plot, information such as the position of the plot, tree species, diameter at breast height, type of pollution, pollution severity, and tree’s vigor were recorded. The results indicated that there is a significant relationship at the 0.05 level between type of pollution, severity and vigor of trees and the geographical location and direction of the plots. The highest percentage of healthy trees and those polluted less than 25% were located in Ridge. In all locations and aspects the Frequency of insects was registered more than the other pests and diseases (Oak Charcoal Disease).This study showed that aspect and location play an important role in the severity of the pollution and Oak decline trees, Pests and diseases cause tree mortality and significant changes in the structure of the forest depending on stand conditions.

Exploitation and use of new technologies for improving of deleterious effects of drought stress are of great importance. An experiment was operated on Pinus nigra in order to investigate the effects of silicon (SiO2) (SNPs) nanoparticles on declining the deleterious effects of water stress. Nanoparticles spraying with 0, 10, 30, 60 and 100 ppm were applied every week for five months on the leaves of seedlings irrigated based on field capacity in the intervals of 4, 6 and 8 days. Applying SiO2 NPs increased height growth, water potential, relative water content and decreased electrolyte leakage. The increased SiO2 improved aboveground biomass and root length of seedlings as affected by drought stress. In general, it can be deduced that in this study the use of silicon nanoparticles, especially concentrations of 60 and 100 mgr/l, induces growth and physiological activities of Pinus nigra seedlings under drought stress.