Abstract: The objective of this study is to investigate the spatial structure of Rhizophora stylosa prop roots in different community types in terms of 3 parameters of the uniform angle index, neighborhood comparison and nearest neighbor by setting the location of R.stylosa prop roots. The results showed that the average uniform angle indices of R.stylosa pure forest, R.stylosa+Avicennia marina and R.stylosa+Bruguiera gymnoihiza savigny mixed forests were 0.772, 0.692 and 0.636, respectively, which were larger than the values of 0.475-0.517 when they are arranged evenly which showed the aggregated distribution pattern. The diameter neighborhood comparison and height neighborhood comparison of R.stylosa prop roots were all around 0.5. By analyzing R.stylosa prop roots and their close prop roots, the main brace roots and minor brace roots were distributed uniformly according to the diameter neighborhood comparison. There was a good uniform in evaluating the growth potential of R.stylosa prop roots and their close prop roots in terms of the diameter neighborhood comparison and height neighborhood comparison. R.stylosa prop roots in 3 community types had the nearest neighbors of 2.83, 1.00 and 2.24 cm, and the average neighbors of 10.54, 9.07 and 8.63 cm, respectively. The determination of the spatial relationship between R.stylosa prop roots and their close prop roots has positive effects on the efficient protection of R.stylosa.

Key words: Rhizophora stylosa, prop roots, uniform angle index, neighborhood comparison, nearest neighbor