Preleminary study for application of O-ring function in determination of small-scale spatial pattern and interaction species (Case study: Bayangan forests, Kermanshah)

Aim of this study was to investigate O- ring application function to study tree species interaction and spatial pattern in the Zagros forest. According to the aim of this study that was testing O-ring function, the size of two-hectare plot (200m×100m) in Bayangan forest was selected; and full callipering method was surveyed. Coordinates of all Manna oak (Quercus brantii lindl.) and Wild pistachio (Pistacia atlantica Desf.) trees, as two dominant species in studied plot, by distance-to-parallel lines method were determined. Finally, stem-mapped trees prepared. We used O-ring bivariate function to investigate interaction between tree species in studied plot, also O-ring univariate function was used to analyze spatial pattern in the different scales. Results showed the ability of O- ring function for determination of mixed spatial and association patterns in different distances. The proof of this spatial variety forms are seed dispersal limitation, inter-specific, high vigor germination of Q. brantii and quility diffrence small scale in plot studied. Moreover, the results showrd that the O-ring functions describe spatial pattern and interaction as well as in the diffrent scales. This method, could be useful as a key to recognize and to decision making for management programs and silviculture interventions