Table 3. Similarity (Morisita-Horn index) of species composition for bees sampled at the E. S. George Reserve from June through August during different time periods over a 40-yr study.

Sampling perioda
No. species (no. specimens)
Sampling period
1970
1980
Early 1970

1950

70 (297)

0.54

0.27

0.44
1970
86 (647)
-
0.69
0.90
1980
82 (553)
-
-
0.66
Early 1970s
138 (2729)
-
-
-

a1950 = 1957, 1958, 1959; 1970 = 1975, 1978, 1979; 1980 = 1984, 1986, 1989. We included early 1970s (1972, 1973), during which very intensive sampling was carried out, to illustrate the effect of different sampling effort on similarity measures.