نشریه بوم شناسی جنگل های ایران
پیاپی 4 (پاییز و زمستان 1393)

The aim of this study was to investigate some of the most important ecological features of the Hackberry trees in Guilan forests. Data was collected using 25 and 20 plots (Rezvanshahr and Tanean sites, respectively) based on the presence and absence of Hackberry. The inventory was selective sampling method. A circular sample plot with an area of ​​1000 m2 was used. Some geographical and ecological characteristics of each sample plot and some quantitative factors of the Hackberry trees were recorded. Soil samples were collected from the center of all plots at the depth of 0-30 cm. The results revealed that the average diameter and height of Hackberry trees in the south aspect of Tanean was more than Rezvanshahr site, and significant differences were observed between two sites. But there was no significant difference in other aspects. Highest percentage presence of Hackberry trees was on slope ranges from 31% to 50%. In addition, the results showed that the values of nitrogen, organic carbon and organic matter were positively correlated with Hackberry, and Cation Exchange Capacity (CEC) and P were negatively correlated with them.

In this study, the abundance and biomass of soil macrofauna were investigated in natural forests of tamarisk and Euphrates poplar in riparian forests of Maroon River in Khuzestan province. Soil macrofauna were collected using 175 sampling plots 50 meter distance from each other on 21 parallel lines with 100 meters distance from each other and perpendicular to the river. Soil macrofauna sampling were taken using hand-sorting procedure in the 50 × 50 cm plots from of 0-10 cm depth. Number of trees, percent of total crown cover, percent of Euphrates poplar and Tamarisk crown cover, height of tree crown cover, total height, Diameter at breast height and Crown diameter of nearest Euphrates poplar and Tamarisk to macrofauna plot, distance of nearest Euphrates poplar to macrofauna plot, distance of nearest tree to macrofauna plot and distance of plot to the tree with the highest diameter in the plot. Results showed that earthworm abundance and biomass have significant correlation with number, percent of crown cover, crown height, total height, diameter and crown diameter of nearest Euphrates poplar tree. Arthropod abundance had significant correlation with number, percent of crown cover, crown height, total height, diameter and crown diameter of nearest tamarisk tree. Therefore it could be concluded that tamarisk and Euphrates poplar were respectively correlated with arthropod and earthworm. The CCA predicted 11.9 percent of total changes of macrofauna. As the three factors of number, crown cover and diameter of nearest Euphrates poplar had the most significant influence on the soil macrofauna distribution in this area, it could be approved that Euphrates poplar have more influence on soil macrofauna distribution.

Trees have been affected by environmental changes, including climatic conditions. Thus, the study on anatomical and morphological characteristics of tree rings provides the possibility of climate study. The present investigation aimed to study the effect at climatic factors such as temperature (maximum, medium and minimum), precipitation on the growth rings of Pinus brutia. 30 Pinus brutia trees have been selected and were cut for this purpose. The discs were taken from each tree stump height. After sample preparation, the width of the growth rings were measured using Corel Draw graphics soft ware, with an accuracy of 0.001 mm. Mean age of trees 33 years (1977 to 2009) were recorded. A value ​​for the growth of the software ARSTAN standard and growth index was created. The correlation results indicated a positive and significant effect of climatic factors, growth index, minimum temperatures in June, the average temperature in February and maximum temperature in February and September maximum temperature on Pinus brutia rings. October precipitation has direct and significant effects on growth.

In the high forests which managing with close-to-nature silvicultural method, the future of forests depends on the stable establishment of saplings planted in the gaps; hence, the current study was done by selection sampling method with the aim of qualitative and quantitative investigation of natural regeneration based on the gap area in two different beech (Fagus orientalis Lipsky) forests: pure beech forest and beech with other species, in three areas of 1.5- 3, 3-5 and 5-10 R, totally amounting to 60 gaps for two different beech types (30 gaps per forest type) in Sourdar Anarestan forest management plan, Mazandaran province, North of Iran. Number of saplings in different gaps was significantly different at 0.01for both forest types. The number of saplings in small and medium area gaps was greater, whereas that of the larger ones was lower. Concerning the mean area of gap with beech forest types, there was significant difference at 0.01.The area of gaps created in the mixed beech stand was more than that in the pure beech forest and according to Duncan's test; maximum gap area was east aspect and then north eastern and west aspects. Also, results showed that as the gap area increased, the number of saplings and their quality decreased for each type. Therefore, maximum the best gap area of 3 to 5 R can be suggested to ensure the future of the planted saplings.

Protection aspects are important in Zagros Forest because degradation and soil erosion is an important problem in this area. Consequently, the responsible organizations use needle-leaf species for forest restoration. The object of this study was investigation effect of exotics needle-leaves plantation on soil quality and compare with natural soil forest in Garan research station in Marivan. In order to study soil conditions, 10 soil samples were collected from 0-20 cm depth of each plantation stand (P. nigra Arnold, P. eldarica Medw. and C. arizonica Greene) and the natural stand of Q. brantii Lindl. as control. In total, 40 samples were collected. The results showed that nutrients of soil decreased significantly under needle-leaved species than control treatment. The amount of pH, C, N, P and K were decreased 0.5-3, 4-20, 26-36, 47-55 and 10-22 percent respectively under needle-leaved compared with natural stand as control.

The selection of tree species is one of the most important steps to achieve a successful forest plantation projects. In this study we used Analytical Hierarchy Process (AHP) and Technique for order of Preference by Similarity to Ideal Solution (TOPSIS) techniques in order to selecting the suitable species for plantation endeavors using tangible and intangible criteria in southern Zagros forests. The problem is decomposed into 3 levels to better study of the problem. Goal of the problem was adjusted at the first level and accordingly six criteria were located at the second level, including conservation cost, cost of price, growth speed, resistance, adaptation and the conservation of soil and water. Also five alternatives were located at the third level including Quercus persica, Pistacia atlantica, Pyrus commonis, Cupressus arizonica and Thuja orientalis. The results of expert’s judgments showed that the resistance to the environmental condition was the most important criteria and Quercus persica was the most suitable species (priority scores= 0.321) accordingly, while Thuja orientalis introduced as a less important species for this objective (priority scores = 0.104). The results of TOPSIS confirmed these results, too. Totally, the results showed that we should much focus on native species in rehabilitating Zagros forests and Quercus persica may only be a prominent species than the other species for achieving this objective.

Undoubtedly, Khorram-Abad Country has been considered as one of the most beautiful, scenic and pleasant weather areas of Iran because of many natural, cultural, historical, etc attractions. Despite the great potential for ecotourism development in this country, it has not been implemented a good plan for ecotourism development in this area. This study intends to identify the effective criteria and sub-criteria in ecotourism evaluation with respect to the area conditions and suggest the suitable areas for ecotourism development. For this regard Geographic Information System (GIS) and Analytical Hierarchy Process (AHP) have been used. At the first step, effective criteria and sub-criteria in the evaluation process determined and the weight of each criterion and sub-criterion determined using the Delphi technique and expert's knowledge. Then, the required maps were prepared. After that, with the integration of maps and their corresponding weights the capability map for ecotourism was prepared. The results showed that 7.80, 60.75, 46.37 and 5.50 percent of the study area has excellent, good, moderate and poor potential respectively and 2.35 percent of the area is not suitable for ecotourism at all.