SUZUKI(1952)reported the ratio of variation (r) on the distribution of a plant community by using the following equation : [numerical formula], where d is distance (meter)between two quadrats, x_a and x_b are measuring value of species at each plot. In of d is constant, the ratio of variation between two quadrats can be compared with each other by that equation. Mean while, we observed the rise and fall of the dominance of each species in a grassland community. If the quadrats are arranged on a line such order as 1,2,3,...n ; with a constant distance between each, the total of the pairing groups is equal to[numerical formula]. For example, if 5 quadrats (z_1,z_2,z_3,z_4,z_5)are arranged on a line with a constant distance between each, the pairs of quadrats can be expressed as follow : (z_1,z_2)(z_1,z_3)(z_1,z_4)(z_1,z_5)(z_2,z_3)(z_2,z_4)(z_2,z_5)(z_3,z_4)(z_3,z_5)(z_4,z_5) Next, both the ratios of variation where the distance is variable (r) and the distance is the median of total length (r') are computed. If the arithmetic means of r' and r'are R and R'respectively, the difference between : R and R'is regarded as the difference of variation ratio(D)by the author. We can find whether a grassland is homogeneous or not by the value of D.
抄録全体を表示