Influence of individual Populus euphratica trees on soil macrofauna in river side forest

In forest ecosystems espcially riparian ones، individual trees have important effects on soil macrofauna. This research was conducted to study the effect of Populuseuphratica on soil macrofauna in Karoon River Side Forest near Shooshtar. Soil macrofauna were sampled in November 2012. Soil macrofauna under tree crown (in three crown diameter category) on parallel transects with 100 m distance from the river and eachother was sampled. Soil macrofauna in 50 cm× 50 cm plots upto 10 cm depth were hand sorted and identified to family level. Totally 342 plots were sampled. The results of correlation showed that there were negetive relationship between distance to tree crown center and soil macrofauna and this relationship was higher in the case of trees with lager crown. The results of ANOVA also showed that the crown diameter size did not have significant effect on soil macrofauna except on soil macrofauna evenness with low significant level. The correlation of distance to river with soil macrofauna showed higher abondance، richness and diversity in farther distances to the river while evenness were higher near the river. Totally it should be saied that indvidual P. euphratica wereeffective on soil macrofauna and it also should be considered the distance from riverside had massive influence on crown diamere.