Table 1.
Empirical details of two data matrices and null model results for temporal change analysis. See text for definitions of variables.
| source | Grossman et al. (1982) | KBS (1995) |
|---|---|---|
| taxon | stream fishes | grassland insects |
| study site | central Illinois stream reach | successional grassland plot |
| sampling method | seining | sticky traps |
| observed number of species | 55 | 9 |
| estimated number of undetected species (Chao 1984) | 16 | 0 |
| sampling interval | ∼ annual | annual |
| timespan | September 1963–September 1974 | 1989–2002 |
| number of sampling dates (T) | 15 | 14 |
| average count per sample (minimum, maximum) | 914 (87, 5344) | 401 (71, 1152) |
| average count per species (minimum, maximum) | 266 (1, 4304) | 624 (2, 2793) |
| total count (N) | 14 142 | 5614 |
| observed temporal change index (TC) | 0.256 | 156.90 |
| average of 1000 simulated values of TC (95% confidence interval) | 0.095 (0.082, 0.111) | 39.16 (31.81, 47.22) |
| P(observed TC| null model) | <0.001 | <0.001 |