Chemical and physical characteristics of oak forest soils in different climates in Ilam Province

Among the soil forming factors, climate is one of the most important factors that determines the soil physical and chemical properties. This research aims at studying the effect of different climates in Ilam Province on soil chemical and physical characteristics of Iranian oak forest (Quercus brantii Lindl.) including high and coppice growth types. Soil samples were randomly taken at 0-20 cm depth under each growth types. According to the results, the climate significantly affected all soil chemical and physical characteristics (p < 0.01) which indicates the importance of climate effect in three study areas of Ilam province. While, except for soil’s K (p < 0.01), growth type had no significant effect on soil properties which indicates that climate effectiveness is more important than growth type on soil properties. The highest and lowest pH was found in Syrvan with 7.4, and in Ilam and Eyvan with 7.1, respectively. Ilam region with 556 mm rainfall had the most amount of OC=31% compared to Eyvan and Syrvan regions. Simple correlation for two growth types showed steady trends between variables and most soil variables had strong and significant correlation (α=0.01). Generally, climate had more influence than growth type on soil properties which indicates the importance of climate on soil forming processes. Based on growth type characteristics, Ilam has the best conditions for oak tree growth in terms of soil and climate.