فصلنامه تحقیقات جنگل و صنوبر ایران
سال بیست و هفتم شماره 3 (پیاپی 77، پاییز 1398)

Today, tree species classification and mapping play an important role in decision making for sustainable forest management. The high spatial resolution of the UAV images makes them an effective tool for identifying tree species. The aim of this study was to evaluate the capability of unmanned aerial vehicle (UAV) imagery to detect Brant`s oak (Quercus brantii Lindl.) and gall oak (Q. infectoria Oliv.) species in the Kakasharaf area in the Lorestan Province, Iran. For this purpose, three stands were selected with areas of 3.6, 4.9 and 5.4 ha. The images were taken in May 2017 by a Phantom 4 UAV. Mosaic images were prepared using 10, 12 and 15 ground control points, respectively. Specifically, differentiation between two species was based on the classification of images by artificial neural network and spectral information. The reference data was prepared to evaluate the classification results by field survey, and classification was conducted by using 70% of the samples as training samples and the remaining 30% as test samples. Results showed that better performance achieved by neural network classification in all three stands with kappa coefficients of 0.77, 0.76 and 0.82 and overall accuracy of 84.03, 83.42 and 87.37 percent compared with the spectral classification method, which returned kappa coefficients of 0.7, 0.64 and 0.63 and overall accuracies 78.81, 73.4 and 72.19 percent, respectively. Conclusively, UAV data revealed to have a good ability to distinguish between Q. brantii and Q. infectoria in the study area, which suggests that those data can be used for discriminating between different tree species in similar forest areas.

With its unique properties, zeolite is important as a soil amendment in increasing the stability, health and soil productivity, and thus improves soil properties and plant nutritional and vegetative status. In this research, a potted method was used with chestnut-leaved oak (Quercus castaneifolia C. A. Mey.) seedlings. Zeolite was used at levels of 0 (control), 5, 10 and 15 wt%. To measure nitrate leaching, urea treatment was used as a nitrogen source of 0.5% by weight. Growth parameters of seedlings including height, basal diameter, biomass of root, stem, leaf and total were measured at the end of the period. The nutritional characteristics of leaf (nitrogen, phosphorus, potassium), soil characteristics (nitrogen, phosphorus, potassium, carbon, pH, electrical conductivity, relative humidity) and aggregate stability indices including mean weight diameter (MWD), geometric mean diameter (GMD), fractal dimension (D), water aggregate stability (WSA), degree of aggregate (DOA) and station of aggregate (SOA) were measured at the end of the period. Results showed that the use of zeolite significantly increased the height, collar diameter and total biomass of plant and improvement of soil and leaf nutrients, as well as soil aggregate stability indexes. The findings of this study confirm that adding 5% zeolite have desirable effects on preventing nitrate leaching and increasing soil aggregate stability and oak seedling growth.

In this study, the Qalajeh protected area in the Kermanshah Province (Iran) was investigated for its plant associations. Based on the map of the region, areas of natural and semi-natural habitats were initially separated from inhabited, farms and disturbed areas, in which 98 releves were stablished. Vegetation data were collected using the Braun-Blanquet method and soil samples were collected to analyze soil characteristics. The vegetation analysis was carried out by the Braun Blanquet tabular synthesis using the JUICE software, while classification of releves was carried out using TWINSPAN. Results showed that  19 associations including Aveno barbatae-Trifolietum scabri, Aegilopetum triuncialis-umbellulatae, Sanguisorbetum minoris, Astragalo flexilipedis-Acanthophylletum caespitosi, Trifolio echinati-Anemonetum coronariae, Scirpoidetum holoschoeni, Daphno mucronatae-Quercetum brantii, Pistacio eurycarpae-Quercetum brantii, Pruno orientalis-Quercetum brantii, Fico caricae-Quercetum brantii, Pistacio khinjuk-Quercetum brantii, Crataego ponticae-Quercetum brantii, Festuco ovinae-Astragaletum veri, Pruno microcarpae-Quercetum brantii, Ferulago carduchori-Quercetum brantii, Pyro oxyprii-Quercetum brantii, Aceri cinerascentis-Quercetum brantii, Juncetum inflexi and Typhetum grossheimii in the area. Furthermore, their distribution was found to be mainly due to climatic factors of temperature and precipitation, which are resulted from difference in elevation levels, aspect and soil factors including texture, lime, available potassium (K), available phosphorus (P), organic carbon and electrical conductivity.

Wild almond (Amygdalus scoparia Spach.) is a drought resistant species with a wide spatial distribution that is extensively used in arid and semi-arid afforestation plans of Iran. Increasing the success of rehabilitation of deforested areas and classification of germplasms entail employing seed resources with good germination rate. To investigate the effect of drought stress on seed germination traits of wild almond populations in Fars province, a factorial experiment was conducted in a completely randomized statistical design. Almond populations were tested on 7 levels (Marvdasht, Pasargard, Arsanjan, Fasa, Kavar, Darab and Khonj), and osmotic stress of polyethylene glycol was studied in 4 levels (0, -0.05, -0.1 and -0.5 MPa). Results of analysis of variance (ANOVA) showed that the main effects of water stress, population and their interactions were significant on all indicators of germination at p ≤ 0.01. In addition, a diverse sensitivity of populations was observed to levels of drought stress. Increasing the water potential in the germination media had an adverse effect on most seed germination traits. At the highest drought stress levels, the average germination time in populations located in northern Fars was more than those in the southern populations. The population of Khonj showed the highest germination percentage, coefficient of velocity of germination, germination index, and germination rate index and germination value compared to the other studied populations. Using the seeds of this population is therefore recommended if approved in field trials.

Considering the important practical properties of musk willow (Salix aegyptiaca L.) as a multipurpose species, this research was carried out in order to evaluate its growth and survival percentage with 10 musk willow populations (from Kurdistan and West Azerbaijan provinces in Iran) in agricultural and natural resource research station of the Gerizah – Sanandaj (Kurdistan-Iran). The analysis was conducted in three replications based on the randomized complete blocks design (RCBD) during 2013-2018. The results showed significant difference (p ≤ 0.01) among musk willow populations for studied traits. The total mean of tree collar diameter (D0), tree height (TH) and crown diameter (CD) and the mean of CD/TH ratio of 7 years old plants were 6.5, 379.5, 418.6 cm, and 1.1, respectively. In addition, the mean of trees vitality degree was 3.7 (1-5) and the mean of survival percentage was ca. 77%. With exception of the tree height, all studied traits of Kurdistan group of populations were higher than those of West Azerbaijan group. However, their differences were significant (p ≤ 0.01) only for crown diameter, vitality degree and survival percentage. Therefore, the musk willow populations of the Kurdistan 6, Kurdistan 4 and Kurdistan 3 could be introduced as higher growth and adaptable with survival percentages of more than 80% for establishment of musk willow cultivation and its related industries in the Sanandaj (Kurdistan Province) and similar ecological conditions of Iran.

This research aimed to analyze the cited references for articles published from 2005 to 2011 in the Iranian Journal of Forest and Poplar Research. In this research, 319 articles with 6160 references were collected and analyzed. Data were prepared using a complete list from the archive of the journal in the given (mentioned) years, subject categorizing and counting them for each volume and registering them in the data bank. Analysis of variance and Duncan test were performed in order to compare the mean values of citations in each article and in different years. Results showed that the mean number of articles per volume was 11 with an average of 220 references for each volume and a mean of 19 references for each article. Among the subjects, afforestation (forest plantation) had the top rank followed by forest ecology and silviculture. Duncan test showed a significant difference between the number of references for each article among the studied years; the years of 2010 and 2011 showed the highest mean number of references for each article. Fifty-seven percent of the references were from the English literature. Among the Persian language literature, the rate of citation to books was higher than other sources, while citation to articles was higher among the English literature. In addition, 84% of the published articles in 2017 were written by more than two authors.

The northern mountains of Tehran are amongst the most valuable natural ecosystems in Iran, which have been destroyed in recent decades due to improper use of land and land-use changes. Therefore, studies on the land-use changes via spatial occurrence probability maps are necessary to deal with this phenomenon. In the present study land use/land cover of 2000 and 2017 were mapped using Landsat satellite images by supervised classification method and maximum likelihood algorithm for the Kan watershed in the Tehran Province. In order to determine the most important factors affecting land-use change as well as zoning the probability of changes, digital data of biophysical (nine variables) and human (four variables) factors were analyzed in the GIS. Finally, the map of probability of land-use changes was produced by applying logistic regression. Validation of the model was performed using relative operating characteristic, which indicated the high ability of the model to describe the changes and determine the areas prone to changes. The results showed that about 60% of the Kan watershed is classified as highly prone to land-use changes. In those areas, variables such as elevation, aspect, slope, soil depth, average growing season precipitation, and average growing season temperature were identified as the most important factors affecting the land-use changes. Conclusively, the results of this research indicated significant land use/cover changes in the studied area during the recent years, as well as a high occurrence probability of future land-use changes.

One of the most important consequences of climate change is the anticipated reduction of rainfall in the future. This study aimed to investigate the dynamics of organic carbon and microbial biomass carbon in the simulated condition of the rainfall reduction in the beech-hornbeam managed stands, followed by its comparison with unmanaged stand. Following site selection of district one of Dr. Bahramnia Forest Management Plan (Shastkalate experimental Forest), 24 sub-samples in each stand were considered as the control treatments as well as treatments of 25, 50 and 75 percent decrease in precipitation. A comparison of the temporal variation of these two important soil characteristics indicated that the soil microbial carbon was more variable to changing environmental conditions. In addition to the significant temporal variations of soil microbial biomass carbon, annual changes in the gaps and below-canopy were also different. The results showed that the effects of 50 and 75 percent of precipitation reduction on soil organic and microbial carbon were significantly different from both 25% and control treatments that showed similar conditions. Changes in these markers in the current condition and the decrease shown by simulated rainfall revealed no significant difference and were similar in the control and managed stands with the selection system. Therefore, and provided the decrease of precipitation in future climatic conditions, forestry plans and harvesting operations with selection systems in mixed beech stands would not lead to significant changes in the amount and temporal pattern of soil organic carbon and microbial biomass carbon. Therefore, it is recommended to apply the selection system for the management of the eastern beech forests of Iran.

Although livestock grazing is known as a historic disturbance in forest ecosystems, but we still need more understanding about how it can affect soil properties. The purpose of this study was to investigate the effect of grazing intensity and type of livestock on the physical and chemical properties of soil in the Armardeh forests, Baneh County in the Kurdistan Province. Therefore, five areas were selected with different grazing intensity and livestock types. In total, 68 soil samples from 0-10 cm depth were taken and the most important physical and chemical soil factors including N, P, K, SOM, soil texture, and compaction were measured. Redundancy Analysis (RDA) method and CANOCO software were used to analyze the data. The results revealed that environmental variables are able to interpret 58.9% of the total variation. Four variables including stocking rate in grazing season, (Maraz goat+Mo goat+ sheep and cow), Mo goat+sheep, and finally Q. libani-Q. infectoria forest-type were selected as the most important variables in forward selection of RDA and responsible for 42.1% of total variation. Soil properties showed the most similarity between control and second treatment (Maraz goat with low-density grazing) and with generally lower soil compaction and higher SOM, N, K and P. On the contrary, the fifth treatment had the highest soil compaction and the lowest soil nutrient level. In conclusion, Maraz goat associated with low-intensity grazing rate caused lower effects on physical and chemical properties of soil in the study area and it can be recommended to local herder as a better adapted livestock to the Zagros oak forests.

Urban forests play a key role in CO2 reduction and consequently in controlling climate change. Therefore, quantifying carbon storage is essential to understand the role of urban forests in reducing atmospheric pollution. This study quantified carbon storage in the Abidar urban forest of the Sanandaj in the Kurdistan Province. To achieve the aim, trees, leaf litter, grass biomass, and soil were sampled and analyzed. Results showed the carbon storage of 147.72 t/ha in the Abidar forest; with trees above-ground biomass, trees below-ground biomass, leaf litter and grass, and soil storing 40.29, 8.66, 1.055, and 97.72 t/ha of carbon, respectively. The results also confirmed different carbon storage levels in various species, with Robinia pseudoacacia storing more carbon in above and below biomass than Cupressus arizonica, Chamaecyparis sp., and Fraxinus rotundifolia. The results of the study could be beneficial for urban forestry, green areas management, and urban planning to foster clean air and manage greenhouse gas emissions in urban landscapes.