FOREST RESEARCH AND DEVELOPMENT
Year:2015 | Volume:1 | Issue:1 |Papers Count:7

Knowledge on forest stands is crucial for forest ecosystem management. This study aims at investigating some quantitative and qualitative characteristics of Arasbaran Forest Protected Area in different slope gradient classes. For this purpose, circular plots of 400 square meters at 50-meter elevation intervals were established along three to five altitudinal transects, 100 meters apart from each other, from the lowermost altitude (1,100 m a.s.l.) to the uppermost (1,725 m a.s.l.) forest limit. In each sample plot, the physiographic conditions, including slope gradient, altitude and geographic coordinates were determined. Woody plant taxa were identified at species level and the diameter of all trees (above 7.5 cm diameter at breast height), the height of the thickest tree and the closest tree to the center of each plot, the origin, the health status, the number of stems, and the tree leaning were measured. The frequency of regeneration of each species taller than 1.30 m in three diameter classes (0-2.5, 2.5-5 and 5-7.5 cm dbh) and shorter than 1.3 m in three height classes (0-10, 10-50 and 50-130 cm) were examined within 100 m2 (10 x 10 meter) sample plots inside the main plots as well. Our results showed that common hornbeam (Carpinus betulus) oak species (Quercus petraea and Q. macranthera), and field maple (Acer campestre) played the most important role in terms of abundance (i.e. 93.3%) in forest composition in the area. The average number of stems, basal area, number per hectare of regeneration, and percentage of seed-origin regenerations were highest at medium slope gradient class (36-50%).

Understanding the distribution of plant spatial pattern is useful for explaining the ecosystems stability, designing proper management plans, and preservative and reforestation operations. Considering the importance of the northern Zagros forests in terms of socio - economic, protection and reforestation, and given that most research which has been done on the spatial patterns in the Western forests of the country focused on the even-aged coppice forests, the woody species spatial pattern in Havare-Khol forests of Baneh city, governed by a combination of both even-age (on the tree) and uneven-aged forests (on the ground), was studied. In this research, using the randomized-systematic method and 200×300 m inventory network, sixty sampling points were measured by the nearest individual, T-square and compound methods. Data analyses were accomplished by the distance methods of Johnson and Zimmer, Eberhart, Hopkins, Hinez and C index, using of Ecological Methodology software. Results showed the clumped pattern for Johnson and Zimmer, Eberhart and Hinez, the clumped pattern towards the random patterns for C index, and the uniform pattern for Hopkins indices. The clumped tree spatial pattern in Havare-Khol forest was totally determined. The results generally illustrated that based on some indices, taking distance the tree spatial pattern in Havare-Khol forest from natural condition was mainly related to the major jobs of forest dwellers, animal husbandry, and their activities (pruning and cattle grazing etc).

Tortrix viridana L. is the most important pest of oak trees in Iran. The larvae of the pest impose high economic damages because of feeding on the leaves and buds of oak trees and leaving heavy destructions on the invaded trees. To determine the biological characteristics and also the rate of the infestation with this pest, random sampling was performed from 30 trees of Quercusinfectoria, Q. libani and Q. brantii and four branches from 4 cardinal sides, each of 50 cm length were cut off as units for the enumeration of green oak moth larvae (or pupa) and after counting the larvae, were transferred to the laboratory. Larvae of the last instars are separated based on their host oak species and were reared till their entrance to pupa stage. The weigh of 4 day old female pupae was measured with a digital balance. Results showed neonate larvae of T. viridana in Mirabad and Pardanan enter oak buds after being hatched in 25th Februray and 10th March, respectively. Larvae enter 2'd instar after eating the internal contents of oak buds, then the third and 4th instar larvae consume whole buds and even oak leaves and after development to the 5th larval instar and roll the leaves and enter pupal stage in Mirabad and Pardanan regions. The occurrence of the peak of adult insects in Mirabad and Pardanan was recorded in 20th May and 7th June, respectively. Adult activities take two months. The pupa which is formed on Q. infectoria was the heaviest. Attacked trees from early May onwards revitalization and create a new leaf. New leaves, pale green and are smaller than normal leaves. Unfortunately, in this situation local people to imagine of wizened of damaged trees, they proceeded to cut them.

Corticolous mosses are one of the most important components of biodiversity in forest ecosystems but unfortunately there is no sufficient information about their role in forest ecology because these are not known as prominent components of the forest ecosystems. In the current research, we identified mosses species which were distributed on bark of Caucasian Walnut. Also we surveyed the correlation of biodiversity index with some bark physic-chemical characterizations. Fifteen individual trees were selected in Noor forest park-Mazandran and the data was collected in a sampling quadrat with 30×40 cm dimension on their bark. The bark samples were collected from the north and south aspects and transferred to laboratory for measuring of pH, electrical conductivity and water holding capacity. After taxonomic study, 11 moss species were identified that Palamacladium euchlora were found on more than 93% of all individuals. Among all of 11 species, Hypnaceae family with three species had the most numbers. There was no significant difference in pH between north and south aspect, although water holding capacity was higher and electrical conductivity was lower in north aspect in comparison with south aspect. Biodiversity indexes such as species diversity, species richness and evenness didn’t have significant correlation with bark physic-chemical characterizations. It seems that bark morphological and physical traits provided a suitable condition for the corticolous mosses. The correlation of bark thickness and track size with biodiversity index can be considered in the future researches.

Gall forming is one of the various damage forms of insects and mites on plants. This study carried out in collecting and identification of willow pests and their natural enemy’s fauna in West Azerbaijan province in a research project during 2010-2014. The fauna of willow gall makers were evaluated at 15 day intervals starting in May to October. In order to sampling, 4 branches of each tree were studied in four geographical directions. All statistical procedures were performed using the SPSS 19 software. Susceptibility and resistance of willow species to two important gall pests were determined in Saatloo station. A total of 10 species of gall inducing pests on willow trees were collected. The results showed that Salix excelsa S. G. Gmel and Salix triandra Linnaeus were susceptible species to Pontania vesicator Bremi-Wolf and Rabdophaga heterobia Loew., respectively. The highest similarity indexes (Sorensen and Jacard) of gall inducing factors of willow trees were recorded between Salmas and Darre Khan (Urmia - Ghasemloo).

Wood and woodfuel are the dominant energy sources for cooking and heating for over two billion people, mainly rural households in the developing countries. In order to conserving forests, it is necessary to substitution of fossil fuel with wood fuel. Therefore, the main purpose of this research is studying the impacts of conservation program in changing the type of fuel used in Arasbaran forests. Data were collected using a semi-structured questionnaire administered to 60-samples households, followed by field observations in 7 villages. Results showed that just three households from sixty households did not use wood fuel. The average of wood fuel used per family in spring and summer was 2522 Kg. The average of wood fuel used per family in autumn and winter was 6968 Kg. Fuelwood consumption annual value was 620765 Rials per household in 2010. Fuelwood consumption annual value was 167477 Rials per capita in 2010. Fuelwood collection had negative effects on household economy because of high labor costs. Most of households used oak (Quercus macranthera) and birch (Carpinus betulus) as wood fuel. Based on our results, it is concluded that the conservation program had a positive significant impacts on changing the type of fuel in Arasbaran forests.

Urban forests are an indicator for establishing cities and they have important aesthetic values due to environmental effects as well as providing green spaces. Trees have the most important effect on the weather of cities among green spaces and the larger the area of the forested land, the more positive outcomes would be obtained. The present study was done to compare ground survey method with Ikonos images in Google Earth Meta data for estimating various quantitative characteristics of urban forests in some parts of Sari, Iran. Using the ground survey method, we employed systematic random sampling design to estimate trees canopy cover on Jomhouri Eslami Street in Sari. The canopy of each tree was measured in two perpendicular directions and the diameter at breast height was also measured for each tree. The results of t-test showed that estimates resulting from the two methods were not significantly different (df=118, t=1.39). The results of regression analysis indicated that using Ikonos images (R2= 0.97) was suitable for estimating canopy area on the street. Based on our results, it can be concluded that considering the high accuracy and quick interpretation of satellite images, Ikonos images can be reliable alternatives for ground survey method in measuring tree canopies in cities with similar forest structure.