LAUSR

Abstract Spatial aggregation of individual plant species is their common response to biotic and abiotic conditions within heterogeneous environments. While conspecifics are clustered in favorable parts of the environment, they compete for scarce resources in these aggregations. Competitive interactions among conspecifics may negatively influence on their growth rate and other ecological processes. Therefore, the spatial distribution patterns of old-growth wild pistachio (Pistacia atlantica) stands were investigated to explore the effects of intraspecific interactions of this dioecious species on the stand spatial structure in the south of Zagros woodlands (Iran). The study was conducted within a 35-ha study plot in a wild pistachio nature reserve and all trees with dbh ≥ 2.5 cm were stem-mapped and measured. Uni- and bivariate pair- and mark correlation functions were applied to describe the interactions of male and female individuals at two life stages (i.e., sapling with dbh