Abstract: A series of parameters including χ² test, interspecific association coefficient (AC), Person’s correlation coefficient (r), variance ratio (VR), and total number of species pairs which do not exist synchronously in a given quadrat size (Na) were used to study the interspecific associations and their elationships with quadrat sizes of the dominant tree species inQuercus wutaiensis communities in Ziwu Mountain of Loess Plateau. Based on the 2×2 contingency table and species abundance data, the effects of different quadrat size on these parameters were examined. The χ²test and AC nalyses showed that significant interspecific associations only appeared at the quadrat sizes of 25 m² and 50 m². Person’s correlation analysis displayed that there were significant interspecific associations at the quadrat sizes from 25 to 200 m², and the r value changed steadily at the quadrat sizes from 25 to 100 m². However, VR didn’t disclose the overall associations of multi-species at different quadrat sizes. The fluctuation of Na was the smallest when the quadrat size was 100-200 m² and the number of quadrats was 40-80. In order to reveal the relationships between species pairs more exactly, the quadrat size should be 100 m², and the number of quadrats should be 45. Under such conditions, the interspecific associations of the tree species inQ. wutaiensis communities in Ziwu Mountain of Loess Plateau could be measured objectively.

Key words: Golf course, Grub, Temporal niche, Spatial niche, Athletic areas