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Abstract Information on genetic diversity is fundamental to developing in situ or ex situ conservation strategies. This study assessed the genetic differentiation between plantations and neighboring natural populations of Juglans regia. Genetic structures of three natural population and three neighboring plantations of J. regia in northwest of Iran were assessed using 10 nuclear microsatellite loci (SSR). Natural populations presented higher total number of alleles (119) and observed heterozygosity (Ho= 0.29) than planted stands (101 alleles, Ho= 0.21). The observed alleles of natural stands varied from 2 (WGA61 and WGA9) to 7 (WGA9) and from 2 (WGA321 and WGA276) to 5 (WGA202 and WGA9) in planted stands. One of the planted populations (B) indicated the largest level of genetic diversity. In conclusion, genetic diversity of all investigated plantation and natural stands are similar. This recommends that even plantations might qualify as gene conservation stands.

Wild Pistacia (Pistacia atlantica Desf.) from the Anacardiaceae family is drought and frost tolerant tree species. Due to the dormancy caused by physiological processes and hard and oily coating of the seeds, the reproduction and production of seedlings of this species are facing major obstacles. In this study, the effect of sowing bed, planting date and different pretreatments on wild pistachio seeds were studied in Tabriz's Elgolian nursery. In order to implement the experiment, a factorial design in a randomized complete block design with five replicates and three treatments including planting bed in three levels, planting date in two levels and pre-treatment in four levels were used. During the growing season, the diameter of the collar and seedling height were measured monthly. Also, the daily average germination, seed percentage and seed germination rate were also calculated. At the end of the growing season, biomass of the root and biomass of the stem were measured. Using gibberellic acid as a pretreatment increased seed germination percentage. In addition, the best vegetative traits were the planting bed 1 (1,1,1) and pretreatment 3 (cold, scraping and gibberellic acid) which are recommended for improving the growth and the rate of yield of wild pistachio seedlings in Elgoli nursery in Tabriz.

Loranthus europaeus is one of the major plant parasites threatening the fragile ecosystems of oak forests in western Iran. The mistletoe is a hemi-parasite plant which grows on forest species, especially oaks. Carbon isotope composition (δ13C) has been central to understand the behaviour of mistletoes in the field. This study investigated C and N isotope compositions in leaves of L. europaeus and of its host oaks (Quercus libani, Q. infectoria and Q. brantii) in western Iran. The goal was to assess the degree of heterotrophy, and to estimate the carbon partition between host and mistletoe and possible consequences of this phenomenon for the ecology of these hemi-parasites. Leaf samples from mistletoe and host oaks were collected in the Mirabad forests of Sardasht, Iran. Ten adult trees of each oak species, with the hemiparasite species, were sampled for determination of leaf dry weight and area, concentration in carbon and nitrogen, and contents of stable carbon and nitrogen isotopes. In all three species, we found that the levels of δ13C of the host, were higher than those of the mistletoes. Quercus infectoria, with the highest leaf mass per area and the highest carbon and nitrogen contents on a mass basis, was the oak species with the highest degree of mistletoe heterotrophy, which was negatively related with the host-mistletoe δ13C difference. Our results also showed that host and mistletoe leaf masses per area can be indicators of the heterotrophic degree of the mistletoe and an easy alternative to the determination of δ13C. In conclusion, it seems that the difference in δ13C between host and mistletoe is reduced when the host leaf mass per area, Cmass and Nmass increase. This condition relates to an increased heterotrophic degree of mistletoe.

Heavy metals are of most important environmental pollutants. Industrial activities and using pesticides are mainly causing environment to be polluted by these elements. This study aims to investigate the effect of air pollution on concentration of leaf heavy metals (Fe, Cu, Zn and Mn) of urban green space’s trees and their tolerance in Urmia. For this purpose, leaf samples of Acer negundo and Platanus orientalies individuals were collected in August 2013 and May 2014 from five different regions with different level of air pollution and their heavy metals concentrations were measured. Regarding to increasing of air pollution in the second year comparing to the first year, the accumulation of most elements had been increased by the tree species. In general, P. orientalies was considered as more tolerable species comparing to A. negundo due to higher accumulation even more than permissible defined threshold. Studied species, also, had lower and higher accumulation in the control and polluted places respectively, so it could be possible to use these species to differentiate between the polluted and unpolluted areas.

The increasing amount of air pollutants in large cities has turned into a crucial factor that affects morphological and physiological tree characteristics, particularly on leaf level. In order to study those effects, 5 areas ranging from least to most polluted areas were initially selected in Urmia, the capital of West Azerbaijan province, using fixed and mobile air pollution recording stations of the Environment Office in August 2013. From each three species in each area 5 individuals were randomly selected and the leaves were measured in terms of their length of petiole, length of blade, maximum width of blade and leaf area. The above-mentioned parameters were repeatedly measured in May 2014. The ANOVA, Duncan and paired-t tests were performed analyze the data. The results revealed that the morphological properties of all species are affected by air pollutions (α = 0.05), with the greater effects occurred in August 2013 compared to May 2014.