In arid and semi-arid ecosystems, isolated trees have an important effect on soil properties and can determine the structure of the soil fauna communities and herbaceous under the tree. The aim of this study was to understanding the effect of Pistachio canopy on the spatial distribution of soil nutrients (OC, N, P, K), as well as Na and Li. Soil samples were taken under and around a Pistachio (Pistacia atlantica Desf.var.Kurdica) tree in the Zagros region of western Iran. The samples were taken every 2 m and then at 50 cm intervals in a regular grid of 20 m × 20 m around the tree, in order to analyze the spatial properties using geostatistics. Total nitrogen content similarly to soil organic carbon (OC) was higher under the tree. Phosphor content also was higher under the tree canopy. Potassium was decreased with distance from the tree base. Sodium had a medium spatial distribution related to tree canopy, while Lithium showed a sparse spatial pattern and its distribution seems to be independent of the tree position. These results support the hypothesis that the presence of a tree, differentially affects the spatial distribution of the various nutrients depending on their chemical characteristics.
