مجله تحقیقات جنگل های زاگرس
سال سوم شماره 2 (پیاپی 6، پاییز و زمستان 1395)

Mediterranean Cypress (Cupressus sempervirens var. fastigiata) is a native, evergreen species. Due to its various merits, particularly its wide use in parks and urban green spaces, it is of interest in most climatic regions of Iran, including Zagros provinces. Due to the poverty of soil and limitation in water sources, the production of seedlings of this species has become particularly problematic in some of these regions. By using rhizobacteria Pseudomonas fluorescens inoculation in soil, for the first time, the present study aims to determine the resistance and variations of growth characteristics of seedlings under water deficit conditions. The experiment was conducted as a factorial, using a completely randomized design with two treatments (i.e., with rhizobacteria and without rhizobacteria), different watering levels (3, 6, 9 and 12 days) in three replicates. After 5 months, growth characteristics of seedlings were measured. Increasing the watering period (water deficit) caused to significantly decrease the survival, diameter, shoot biomass and total biomass, so that all seedlings were died under 12-day watering level. In watering period of 9 days, survival was reduced to 49.83 percent. There was no significant difference in collar diameter, root length, root volume and root/shoot biomass with water deficit intensity. However, the survival rate, height growth, shoot biomass, root biomass, total biomass and seedling quality index were greater in seedlings inoculated with rhizobacteria, compared with those of non-inoculated seedlings. The seedlings of Mediterranean Cypress inoculated with Pseudomonas fluorescens rhizobacteria are able to tolerate the water deficit stress and increase their growth performance; however, under optimal conditions, the rhizobacteria inoculation has no positive effect on survival rate of the seedlings.

Understanding the spatial pattern of tree species in their social life could have many applications from the standpoint of ecology and applied silviculture for their optimal management. For the purpose of studying the spatial pattern of Quercus brantii and Pistacia atlantica in relation to stand form and topographic factors, we selected the Manesht forested area in northern Ilam. In this research, 75 sample plots (with 2000 m2 area) were chosen, using systematic random sampling method within the study area. The variables in the plots comprised the number of tree species and topographic factors. The dispersion indices of interest included Morisita, Sstandard Morisita, Green, Lioyd and variance to mean ratio. The calculation of quantitative indices, by running the relevant computational formulas, was performed by Ecological Methodology Software. In addition, in terms of accuracy, the efficiency of quantitative indices was studied and compared. Statistical analysis of data was carried out using SPSS Software. The results showed that, for Q. brantii, the values of variance to mean ratio, Morisita and Lioyd indices and for P. atlantica, the values of Morisita, Green and Lioyd were higher in standard and coppice stands than the coppice and standard stands. For both species of Q. brantii and P. atlantica, all of the indices in question increased with increasing elevation, and the highest values of indices were obtained in 2100-2300 m a.s.l. For Q. brantii, the values of all of the indices increased with increasing slope, and the highest value was obtained in the slope class more than 60%. Moreover, for P. atlantica, the highest values of all indices were obtained in the slope class of 30-60%. The spatial pattern in classes of 0-30% and 30-60% was clumped and in more than 60%, it was regular. For Q. brantii, the values of all indices and for P. atlantica, the values of Morisita and Lioyd were the highest in the southern direction. The results of the precision study of the indices showed that for Q. brantii, the indices of Morisita and Standard Morisita and for P. atlantica, indices of Standard Morisita and Green had the highest precision. It was concluded that the value of dispersion indices (especially more accurate indices) varies by environmental factors and thus changes in values could be used in forest dynamic studies and the interpretation of changes in forests

Plant species with wide geographic ranges, exhibit high tolerance to cold stress. Trees in temperate regions must cope with freezing temperatures, especially in late autumn and winter. One of the mechanisms to tolerate cold stress is through decreasing photoperiod and temperature during acclimation. In addition, provenance of a species could be one of the main factors contributing to cold resistance. Therefore, in the present study, the effect of cold stress on physiological responses of Pistacia atlantica seedlings from three provenances was investigated in southern Zagros to select the most cold-resistant provenance.
Material and Seeds of three provenances, namely Margon, Noor Abad and Yasuj, from southern Zagros, were collected and planted in pots. After germination of seeds, induction of acclimation was carried out at two stages for four weeks. This was accomplished through the simulation of temperature and photoperiod of Yasuj region from September to November. Following that, the indexes of photosystem efficiency and chlorophyll content were measured. After each acclimation stage, leaves and stems of seedlings were exposed to three levels of temperature, +4°C (control), -20°C for one hour, and -20 for two hours. Then, relative water content (RWC) and electrolyte leakage (EL) of stems and leaves were measured. This study was conducted as a factorial with three factors of provenance (three levels), cold treatments (three levels) and acclimation (two levels), adopting a completely random design. The results showed that EL increased with decreases in temperature and this increase was the highest in the case of the Noor Abad provenance. In addition, the stem RWC of Yasuj and Margoon provenances decreased in the second cold acclimation stage. Chlorophyll content, photosystem efficiency and electron transport rate were lower in Noor Abad provenance, compared with other two provenances. Moreover, except the electron transport rate, all fluorescence parameters significantly decreased during the cold acclimation. The results showed that measuring EL and fluorescence parameters could be a useful indicator for identifying cold-tolerant provenances. The seedlings of Noor Abad provenance exhibited the least and Margoon provenance showed the highest resistance to cold stress. This could be due to high altitude and cold climate of Margoon provenance

Forests and rangelands are the most important natural resources of a country. In addition, they have a special position in the ecosystem of the earth, and, thus, they play an essential role in soil conservation as well as climate moderation. However, serious and, sometimes irreparable, damage has been ocuured by both natural and man-made factors. One of the areas where degradation of rangelands and forests could clearly be recognized over the past years is the central District of the Dena County. Therefore, the purpose of the current study was to identify and analyze factors affecting the degradation of rangelands and forests in the central District of Dena County. A mixed research method including qualitative and quantitative methods was used in two phases, using interview and questionnaire as instruments. In the first phase of the study, the population comprised the villagers and officers of the Department of Agriculture, Dena County and also the Provincial Department of Natural Resources in Kohgiluyeh and Boyer-Ahmad Province. In the second phase, the population consisted of the academic faculty members of local universities who were native and were familiar with the region. Snowball sampling technique was adopted in both phases of the study. Factors affecting the degradation of rangelands and forests were identified in the first phase of the study. These factors comprised organizational factors (monitoring, supportive and administrative), infrastructural, socio-cultural, legal, economic and natural factors. Following that, in the second phase of the study, the participants were asked to rank the factors identified based on AHP procedure principles. The results showed that lack of grazing management in monitoring factors, less governmental support for natural resources in supportive factors, administrative corruption in administrative factors, road construction in infrastructural factors, poor cultural patterns in socio-cultural factors, lack of appropriate legal actions when faced with illegal possession in legal factors, rural poverty in economic factors, and finally drought in natural factors were the most important factors contributing to the problem of degradation. Finally, out of the recommendations made to prevent the degradation of forests and rangelands, one can mention the employment of native people to improve the management of rangelands and forests in areas of guarding and conservation affairs of natural resources. In addition, for the purpose of constructing roads, building power plants, etc. it is necessary to seek the expert advice of engineers with expertise in road construction, civil engineering and rural development

  Familiarity with the appropriate soil conditions for Pistacia atlantica leads to improve and develop forest vegetation cover in Zagros zone. The main aim of this research was investigate suitable soil characteristics ranges for natural growth of this species in Fars province. Field studies and soil sampling was done based on network sampling (20×20 km grid) in wild pistachio forests of Fars province with crucified pattern. The filed study showed mountain and hilly land are the main land types that pistachio species have placed on them. These land types include the displacement of rock, stone and gravel as high and low soil depth with moderate to severe water erosion. Main physical and chemical properties measurement of soil samples showed that the only limiting growth factor has been the low soil depth. The low effective soil depth and light soil texture are the most important limiting factor on soil moisture storage ability (from rain). This deficiency, transition from drought or very dry periods (resulting from an undesirable distribution of rain) makes it difficult. Statistical analysis methods based on principal component analysis (PCA) and cluster analysis (CA) shows that wide ranges in soil characters, even up to about 40% differentiation in the measured properties do not make restrictions for pistachio Natural growth. Ecologically, Pistacia atlantica is a drought-tolerant plant. Wild pistachio (Pistacia atlantica) is one of the high resistance species in wide range of soil condition (soil characteristics) and this feature (desirable survival) make it favorite for Zagros forest rehabilitation. Land and grazing management (land use planning), along with watershed management practices can conserve and improve soil and environment of wild pistachio habitats of the Zagros forests

The recent movements opposing deforestation are indicative of the fact that in most programs carried out, less attention has been paid to the socio-economic status of the local people. In extensive deforestation, rural communities play a significant role. Therefore, this study examines the role of economic and social factors in the destruction of the forests of the Oulad Ghobad regions. This research was carried out as a field study, using a questionnaire. The population comprised 398 families living on the outskirts of the Saman-e Orfi Forest in the Oulad Ghobad region. Out of this population, 150 families were randomly chosen, using Cochran’s sample size formula. Furthermore, 40 questionnaires were distributed among the officers of Lorestan Natural Resources Office. The validity and reliability of the questionnaire established by a pre-test and Cronbach's alpha were 0.83 for local people and 0.705 for officers, respectively. The findings showed that from the viewpoints of both officers and local people, human factors (such as lack of agricultural lands, conversion of forests into agricultural lands by forest dwellers, poverty and and low income, and high unemployment rate) contribute more to deforestation, compared to natural factors (such as drought and forest fire). As for prioritizing human and natural factors contributing to deforestation, the results showed that according to local people, lack of agricultural lands (mean rank of 7.58), and according to officers, conversion of forests to agricultural lands by foresters (mean rank of 11.25) were the main contributing factors. In addition, the results showed that there was a significant negative relationship between income and the factors contributing to deforestation (P <0.001). In general, the results showed that human factors have a significant effect on the deforestation of the Oulad Ghobad region of Koohdasht and the role of human factors is more conspicuous compared to natural factors.