Table 2. Changes in the density of leafy spurge (shoots/m²) during 1951–1957 according to the intial density (Selleck et al. 1962).

Initial density Year Mean density
1951 1952 1953 1954 1955 1956 1957
1–35 shoots/m² in 1951 19.1 38.0 56.9 69.4 109.3 121.2 144.2 79.7
36–99 shoots/m² in 1951 61.5 84.5 102.0 112.0 162.9 179.9 199.4 128.9
≥ 100 shoots/m² in 1951 122.5 125.5 141.3 156.7 202.8 241.6 207.7 171.1

Note: The study site was divided into quadrats that were classified according to the intial density, and the density was determined annually for each density class.