مقالات رزومه دکتر مسلم اکبری نیا

The humus index is a numerical score based on the visual assessment of organic horizons and humus forms identification. This index reflects different characteristics of forests stand and soil. Forest humus is an intermediate between plants and soil, which is affected by various factors, such as topography, climate, vegetation and soil. Nevertheless, by digging the humus profile and determining its index, it is also possible to determine many ecological factors. The aim of this study was to investigate the humus index and its relationship with topographic, soil and forest cover characteristics along an altitudinal gradient in the four-altitude class, including 0, 500, 1000 and 1500 meters above sea level (m a.s.l.), in Vaz forests located in Mazandaran province.

In each altitude class, the characteristics of the trees such as crown canopy, density, diameter and height, as well as topography and soil characteristics such as altitude, slope percentage, soil moisture and temperature were taken in 400 m2 plots, and in each plot, five 30 × 30 cm profiles for identification of humus forms were drilled and then identified and classified based on Humusica classification. In order to evaluate the humus index between different altitude classes was used one-way analysis of variance (ANOVA), as well as to analyze its relationship with the mentioned characteristics, multiple linear regression analysis (MLR) was used.

The results showed that the highest amount of humus index and litter thickness belonged to the altitude class 1500 m a.s.l. and their trend is increasing along the altitudinal gradient. Also, the results of MLR indicate the existence of a linear and significant relationship is between humus index and topographic and soil characteristics with high determination coefficient (R2 = 0.76), especially soil temperature with (P-value = 0.000), while the tree cover characteristics with a low determination coefficient (R2 = 0.31), cannot well be a good predictor for evaluating the humus index. Meanwhile, soil temperature and trees crown canopy are two factors that have shown the highest t-statistics in relation to the humus index, so that the decrease in soil temperature and trees crown canopy has increased the humus index.

In general, it can be concluded that with increasing altitude, the organic part of the forest floor and Humus index increase, and their variability is mostly due to changes in topographic and soil temperature characteristics.

In a study of growth and morphological differences among Populus caspica Bornm., trees within Hyrcanian biogeographical region, 15 stands were selected from which one-year cuttings were cut from three plus-trees in each stand. The cuttings were planted in March 2017 at Chamestan Research Station, and the rooted cuttings were cut from the collar base after one year. Cuttings were separated from the one-year sprouts in the next winter and planted based on Randomized Complete Block Design with three replications. We sampled five leaves of each stand-tree seedling on late June and 17 leaf morphological and growth traits as well as collar diameter and height of the rooted cuttings. Data were analysed by hierarchical cluster analysis, two-way ANOVA and Duncan comparison of means test. Four groups were separated according to cluster analysis, among which rooted cuttings from Golestan province showed the highest morphological diversity. The maximum and minimum collar diameters and height growth were observed in seedlings originated from Rostam-Abad (Guilan province) and Golestan National Park (Golestan province) respectively, yet they were similar in some of their morphological traits like their minimum leaf width at 10% of the total length, maximum leaf width, lobe depth and number of veins, which id presumably due to the location of their mother stands at the border of Hyrcanian and Irano-Turanian regions. Thus, they can be considered as morphological traits of P. caspica in the ecotone regions. However, the two regions had a high value for conservation, especially in Rostam-Abad due to high growth rate as well as prominent morphological differences in comparison with the other genotypes. Therefore, they are suggested for being integrated in tree improvement programs in the future.

Forest management is one of the important issues in protecting and identifying the priorities of forest areas. Therefore, due to the involvement of individuals and legal entities in making managerial decisions, the use of methods with the least damage to the environment and accelerating the process of society requires the use of appropriate methods such as game theory. The power and ability of game theory as a mathematical tool for decision making is due to its methodology in terms of constructing and analyzing the problems and issues that human beings face in strategic choices. Therefore, in the applied experiment of this method, the strategies of global registration conditions of several Hyrcanian forests were studied. A series of questionnaires were used to study the strategy of the games; the tree model was tested for a 12-step question solution with a permutation of 5 sites and 4 IUCN criteria. The results of the analyzes in this section show that only one strategy out of

Hyrcanian forests are one of the most valuable forests in the world, dating from about 25 to 50 million years old. Climate variation, unique plant and animal species accompany with habitat diversity have made these forests one of the most unique ecosystems on Earth and worthy of being listed on the UNESCOchr('39')s World Heritage List. Therefore, the main purpose of this study is to use both Delphi and Ideal Point methods to identify effective criteria and prioritize proposed habitats for inscription on the UNESCOchr('39')s World Heritage List. For this purpose, five habitats from east to west of the Hyrcanian forests including Golestan National Park, Afra Takhteh Yew Forest (Golestan Province), Zarbin Hassanabad Chalus Forest, Kojoor Forest (Mazandaran Province) and Lomer Forest (Gilan Province) were selected. The results of this study showed that Golestan and Afratakhte with 0.8 and 0.5 points have the highest potential for listing on the UNESCOchr('39')s World Heritage List. In contrast, habitat access, animal species dispersal and disasters such as floods and fires have a negative impact on inscription of the sites. According to the results of this study, prioritization of habitats for inscription is very consistent with criterion X؛ and finally criteria such as endemic species and IUCN endangered species can have a significant impact on the selection of a habitat as a proposed habitat for inscription.

Persian honey locust(Gleditsia caspica Desf.) is an endemic tree in the northern forests of Iran and southeastern Azerbaijan, which has low seed germination because of water impermeability of seed. In this research, effects of hot water at 70 °C and 100 °C (5, 10, 15 and 20 minutes), dry heat at 60 °C, 80 °C and 100°C (15, 30 and 60 minutes) and sulphuric acid treatment at two concentrations of 70% and 98% (at immersions of 5, 20, 40 and 60 minutes) were studied on the characteristics of seed germination of this species. Experiment was carried out based on completely randomized design in three replicates. No germination was observed in the seeds treated with hot water (100 °C), dry heat and control, while the seeds treated with semi-hot water (70 °C), sulphuric acids of 70% (60 minutes) and 98% (20 and 40 minutes) obtained 20, 84 and 100 percent of germination, respectively. In general, hot water, warm water and dry heat are not good treatments for seed germination of Persian honey locust seed. It suggests that for seed dormancy breaking as well as seedling production of Persian honey locust,sulfuric acid 98% (with immersion of 20 or 40 m.) to be used.

Increasing concentration of atmospheric CO2 is one of the most important reasons for climate changes and global warming. one of the most appropriate solutions offered to solve this problem is its reduction by carbon sequestration in soil by plants. Concentration of atmospheric CO2 will increase to the range of 415 to 421 ppm in 21st century. Only with optimistic assumptions and low growth rates, increase of carbon-dioxide-induced temperature will be held below 2°C over the next century. Conservation, flexible energy choices and control options could lessen the potential effects of carbon dioxide otherwise it will cause global warming crisis. Besides the economic and social disadvantages, it will lead natural ecosystems to loss their stability. Thus, effort to reduce greenhouse gas concentrations through suitable management is important and ultimately will lead to sustainable development. Methods such as filtering to reduce the concentration of carbon dioxide in the atmosphere will be high costly. So at the macro levels it will not operational. The world needs to reduce the concentration of Co2 can be satisfied by less expensive methods such as the carbon sequestration by plants.

The effect of arbuscular mycorrhizae fungi (AMF) on morphological and physiological characteristics of Pistacia khinjuk under drought stress were studied in Ilam, Iran. First, the mycorrhizae fungi associated with Pistacia khinjuk trees were isolated and identified and then their effects on morphological and physiological characteristics of Pistacia khinjuk under greenhouse condition were assayed. It was found that survival of seedling was not affected by mycorrhizae and irrigation, but other physiological and morphological characteristics were affected, separately. Therefore, mycorrhizae as well as irrigation increased root collar diameter, seedling height, terminal growth, leaf number, refresh weight of shoot and root, root volume, leaf area, photosynthesis and transpiration. In contrast to irrigation, AMF didn’t effect on root length, root dry weight, leaf surface temperature, stomatal conductance and photosynthesis. So, we can propose that in dry and sub dry region, for best success in afforestation, seedling is better to be associated with AMF.

The aim of this study was finding the Autecology of sumac species (Rhus coriaria) in Khorasan province (Binalood Mountains). Sampling of soil and plant vegetation carried out in two sites (Darroud and Bojan with 5 and 6 hectare surface area respectively). Climate of these sites was semi arid. Samples gained from 33 plots with systematic random method by using of 50 * 50 meter net. The factors of tree measurements including tree height، crown height، crown percentage، tree density and seedling density measured in all plots. ANOVA test showed: 1- Among aspects the factors of seedling density، crown percentage and crown height had significant differences،2- the effect of slope was significant on tree density and crown percentage،3- The increase of stone percent decreased crown percentages، tree density and crown height. 4- Increase of gravel percent deduced tree height، crown percentage and tree density. In general، due to little requirements of this species to water and nutrient and due to distribution of this species in soils with medium nutrient levels and even week soils and to widespread distribution of sumac species in Iran، utilization of sumac for development of green space in arid and semi-arid areas can be ordered.

The aim of this study was ecological survey and site classification of Arghavan valley, north of Ilam, Iran. For this study, vegetation (tree, bush, shrub and herbaceous species), soil and physiographic factors were investigated in 57 plots. Multivariate analysis recognized four sites. Amygdalus scoparia group had positive correlation with elevation and had low species diversity. Cerasus microcarpa group had positive correlation with organic matter and negative correlation with elevation. This group had high diversity and richness. Ficus carica group was in rocky site, while Quercus brantii was in compacted soil with high clay ratio. Results showed that elevation from sea level, stone proportion of soil, soil texture and organic matter were the most important factors influencing vegetation.

In 2000, fourty seed trees which were located at Sanghdeh Forest of Caspian Region with altitude ranged between 1700 to 2300 m-above sea level, were selected. 200 seeds were collected from each tree, subsequently. The seeds were sown in 2000 and in 2001 repeatedly, in plastic bage containg forest soil and kept in a forest nursery located at the same forest at 1550 m. above sea level altitude. Seed germination and seedling survival was measured in 2000 and 2001. According to T-Test data analysis, there were significant differences between seed germinatin and seedling survival of the treatments in both years. Total seed germination (TSG) in 2000 was 9.22% more than TSG in 2001. Seed germination was correlated significantly and negatively with the seed trees age and diameter. Seed trees with moderate age and at diameter class of 30 cm, performed the highest percentage of seed germination in 2000 (without seed storage). There was minimum reduction in seed germination for seeds collected from trees at moderate diameter class and stored for one year.