FOREST RESEARCH AND DEVELOPMENT
Year:2016 | Volume:4 | Issue:4 |Papers Count:8

Trees are one of the most important constituents of urban green spaces. Considering the high daily traffic of people in sidewalks and vehicles in streets of cities, any defect in trees can lead to life-threatening (personal injury or death) and economic losses. For this purpose, qualitative and quantitative properties and rate of risk possibility of oriental plane (Platanus orientalis L.) trees of Shahid Beheshti St., Urmia were evaluated using transect method with random start point (sampling intensity of 20%). Quantitative factors including diameter at breast height, total height, and qualitative factors including dead woods and branches, cracks, inappropriate branching, structural weakness (defect), wound, root problems and contact with power lines. In total 190 trees were sampled which ranked as follow: 70 trees (36.8%) as very low risk, 102 (53.7%) as low risk and 18 (9.5%) as moderate risk. Finally applying some amending operations such as crown pruning and cutting of dead branches for moderate risk trees are suggested.

Using plant species to adsorb pollutants is one of the common methods of environmental cleanup. Zinc Industrial Park within five kilometers south of Zanjan city is a source of environmental contamination. In this paper, some woody species absorbing heavy metals including copper, zinc, cadmium, and lead, and the extent of the contamination were investigated. In the control area, within Zinc Industrial Park boundaries, and the radii of 0-1, 1-3, and 3-5 kilometers from Zinc Industrial Park leaf samples of six woody species including black locust, ash, white poplar, black poplar, rose, and willow were collected. Heavy metals concentrations were measured and statistical analysis was carried out under the assumption of split-plot design based on completely randomized block design. The results showed that high contamination levels of zinc, cadmium and lead are detectable in a radius of five kilometers from Zinc Industrial Park. Copper contamination level was below the critical level. But the amount of lead pollution within the Zinc Industrial Park is threatening. The best species for phytoremediation of Cadmium and Zinc is white poplar.

This study aimed to investigate the association between the three types of Oak named Quercus brantii Lindl., Quercus libani Oliv. and Quercus infectoria Oliv. with physiographic factors altitude, slope and aspect in the northern Zagros forest (case study: Sardasht forest, Rabat) and area of approximately 25000 hectares, and ranges in altitude from 1000 to 2200 meters above sea level. Transect sampling method with a fixed length of 50 meters were counted. Calculation of community between Oak species in the region and in different physiographic classes per species was done by calculating the Phi coefficient. As well as to determine the correlation between the species Chi-square test and Kendall’s correlation coefficient were used. Results of Phi coefficient between species indicated negative association between Quercus brantii Lindl. with Quercus libani Oliv. and Quercus infectoriaOliv. in all altitude, aspect and slope classes while Quercus libani Oliv. and Quercus infectoria Oliv. in most classes of altitude, aspect and slope there was a positive association. In the entire region, as well as physiographic classes there was negative association between Quercus brantii Lindl. With Quercus libani Oliv. and Quercus infectoria Oliv. and positive association betweenQuercus libani Oliv. and Quercus infectoria Oliv. Also, according to the results of the chi-square and Kendall's correlation coefficient between Quercus brantii Lindl. with Quercus libani Oliv. and negative correlation was found indicating a negative association between these species in physiographic classes and in the region.

This research aimed to investigate the effects of forest management on the presence and abundance of macrofungi. Through a full inventory of all fungus-affected trees and removing the fungi from the trees in the sites under investigation, three of them having a long history of different forest management in the Kheyroud Forest were selected, i.e. one in Patom with three periods of tree marking, another in Namkhaneh with two and the other in Gorazbon with no tree marking. The results showed that the majority of the fungi could be found at the fifth level of tree categorization regarding their health, i.e. at the level of fallen dead wood (log, stump, branches and twigs). Ganoderma lucidum at 14 percent showed maximum abundance, whereas Cookeina at 0.008 the lowest. With regard to the area of the site under investigation, in hectare, the percentage of the fungi in Gorazbon, Namkhaneh and Patom were 1.22, 1.18, and 0.54%, respectively. It could finally be concluded that the percentage of the wood macrofungi in intact forests was more than managed ones.

Large demand of wood and restrictions on the efficiency forest’s wood production caused attention to fast growing trees poplars. Poplar genus trees because of dioecious, have insemination ability and hybridization that wood production of them are more than their parents that known as heterosis phenomena. The most properties of this hybrids are fast grow, smooth and cylindrical trunk for having a flexibility ecological and significant resistance against pests and diseases. In order to select superior varieties of hybrid poplar, four consecutive years of collection poplar clones that are growing on the bank of Sefidroud river have growing strong form that have longitudinal and diametrical growth than the others, cuttings were prepared. They planted in the nursery that already had been prepared for this purpose. Also, from female clone (P.d.69.55) in ripping seeds were collected and they were regenerated and planted in chassis greenhouse and then transferred to fields and planted. Analyze of data were done by analysis of variance for variables and variables mean comparison were done in SAS software by LSD test. The results of this research identified 13 hybrids clones of poplar with two base cutting (preparation of Sefidroud river bank) and seed (the seeds that collected and planted from deltoides clone). Selected clones in comparison with control clone (P.d.69.55) that had superior characteristics, were distinguished. Hybrid clones with superior diameter growth were: P.x.87.1.S, P.x.89.3.C, P.x.88.4.C, P.x.88.5.Cand superior height growth P.x.88.1.S, P.x.89.3.C.

Forest roads play an important role in management, conservation, and forest restoration in mountainous area. In order to find out the influencing factors in the road design, Delphi method was applied. At the first stage, the most influencing factors are determined based on experts choices then at the second stage, those variants has been weighted. In the study, both technical and environmental factors including gradient, distance from fault or landslide, current roads, bedrock, soil texture, harvesting and extraction equipment, distance from river and springs, aspect, elevation from sea level, genetic reservation value, conserved area, animal inhabitant, bio diversity, forest stock, landscape, forest type, access to village, forest settlement, and cattle yards has been investigated. The criteria finally are ranked based on forest road expert idea obtained from questionnaire based on ELECTRE III method using paired comparison analysis. According to the results, factor gradient with 0.17 values ranked at the first place and factor cattle yard with 0.004 values placed at the end.

Fine woody debris (FWD) is a characteristic feature of forest ecosystems. The quantification of FWD amount in forest stands is necessary in forest management. Stem exclusion is one of the most important phases in stand development. This research was carried out in a relatively undisturbed stands in No. 319 compartment, Gorazbon district of Kheyroud Forest in the Hyrcanian forests of northern Iran to investigate the quantitative and qualitative characteristics of FWD in stem exclusion phase. Three one hectare study sites were selected in the phase and all coarse woody debris (>10 cm diameter) properties were recorded. In every sites five quadrates laid out to measure the fine woody debris. Length, diameter, shape and decay class of all woody debris with diameter smaller than 10 cm were recorded. Results showed that beech was the most frequent (54%) constituent in the stand dead wood pool. Hornbeam and other accompanying species encompass 42 and 4 percent of dead wood frequency, respectively. Moreover, the majority of the measured FWD was in 1-5 cm and 5-10 cm diameter classes with 62.5% and 37.5% respectively. The mean and accumulative of dead volume in the study sites was 15.3 and 45.9 m3 ha-1 respectively. In this phase no FWD in the advance decaying class was recorded.