تغییرات تنفس میکروبی خاک در رابطه با دما و رطوبت خاک در جهتها و فواصل مختلف از تنة گونههای مختلف بلوط)مطالعة موردی: جنگلهای آرمرده بانه(

1-Introduction Carbon dioxide emissions caused by human activities, industrial activities and other sources are increasing day by day. The increase of this gas as an important greenhouse gas can cause fundamental changes in global temperature and climate change. Soil respiration is one of the main natural ways of releasing carbon dioxide into the atmosphere in terrestrial ecosystems, and by studying it, one can gain a lot of knowledge about the global carbon cycle. Tree species can influence soil microbial respiration by affecting biogeochemical processes through the amount of litterfall. On the other hand, the different directions of the trees, due to the changes in the radiation angle, which affects the amount of moisture and temperature, probably cause different responses of soil microbial respiration. 2-Methodology In this research, spatial changes of soil microbial respiration by integrating geographical aspects (north, west, east, south) and five different distances (0.5, 1, 1.5, 2 and 2.5 meters) from the tree trunk for the study of soil microbial respiration in three different oak species (Quercus infectoria Oliv., Quercus brantii Lindl. and Quercus libani Oliv.) were carried out in Baneh, Armardeh forests. Three oak trees were selected in the types with the dominant percentage of the desired species (almost identical in terms of height, diameter at breast and canopy). Soil microbial respiration was recorded using Anderson method and moisture in the laboratory and the temperature of the soil were also recorded at the same time sampling at the sample site (soil samples were taken from a depth of 0-10 cm). One-way analysis of variance and Tukey's test were used to check the significance of the difference in the measured characteristics between different oak species. 3-Results: The results showed that there was no significant difference in the parameters of microbial respiration and moisture between the different aspects of each of the different oak species. The results of soil temperature also showed a significant difference in Quercus brantii species between different aspects, and no significant difference was observed in Quercus infectoria and Quercus libani species. On the other hand, there were significant differences between different distances from the trunk. Also, the results of comparing the average soil microbial respiration between different species were not significant, but the results of comparing the average between different oak species at different distances showed differences between the three species. The main environmental factors in this study included soil temperature and soil moisture, which were significantly affected by spatial heterogeneity. The average soil temperature related to Quercus brantii species had a significant difference in different aspects, which could be due to the difference in the intensity of lighting during the day and the aspects of the sunlight and the change of shade over time. There was a difference in soil temperature at different distances in all three species, and this could be due to the low canopy density of the Zagros forests. 4-Discussion & Conclusions Single trees affect the substrates on which they grow and may leave their traces on the soil through the influence of the canopy and roots. The "single-tree influence" concept envisions the soil landscape as a mosaic of small patches that are spatially and genetically linked to individual trees. There are two aspects to this concept: first, within the circle of influence of each tree, soil properties vary predictably in relation to distance from the trunk and crown edge, and second, at any location relative to the trunk and crown, the degree of feature development varies as well. Soil properties are different among tree species. In other words, the organic matter produced by any tree species is different and the related grass cover contains different proportions of nutrients, lignin and secondary metabolites, which determine the quality of organic matter and the rate of decomposition. This study also showed that the spatial heterogeneity in soil temperature and moisture content may be intrinsic mechanisms that drive differences in soil microbial respiration. These findings can deepen our understanding of changes in microbial respiration and soil respiration and clarify the ecological role of different species for us. [ABSTRACT FROM AUTHOR]