Table 2. Species Accumulation Index, SAI, for sites prioritized in order of rarity-weighted richness (RWR) compared to sites prioritized by Zonation, for the 11 datasets described in Table 1.
| Target (% of sites) | Plants, Sequoia-Kings NP | Plants, Shenandoah NP | Plants, Chiapas | Plants, Sierra Nevada, Spain | Trees & shrubs, Spain | Birds, Arizona | Plants, UK | Birds, Spain | Birds, Florida | Plants, Zimbabwe | Birds, Western Europe |
|---|---|---|---|---|---|---|---|---|---|---|---|
| 5% | 1.36 | 1.72 | 2.79 | 1.25 | 1.00 | 0.89 | 0.90 | 1.00 | 0.85 | 1.00 | 1.00 |
| 10% | 1.51 | 1.78 | 1.51 | 0.93 | 1.00 | 0.95 | 0.96 | 1.00 | 0.96 | 1.00 | 1.00 |
| 15% | 1.38 | 1.47 | 1.01 | 0.94 | 1.00 | 0.97 | 0.99 | 1.00 | 1.00 | 1.00 | 1.05 |
| 20% | 1.05 | 1.24 | 0.82 | 1.00 | 1.00 | 0.98 | 1.00 | 1.00 | 1.00 | 1.00 | 1.07 |
| 25% | 0.96 | 1.11 | 0.84 | 1.02 | 1.00 | 1.00 | 1.01 | 1.00 | 1.00 | 1.00 | 1.08 |
| 30% | 0.84 | 0.97 | 0.92 | 1.02 | 1.00 | 1.00 | 1.02 | 1.00 | 1.00 | 1.00 | 1.10 |
| 35% | 0.86 | 0.80 | 0.95 | 1.02 | 1.00 | 1.00 | 1.02 | 1.00 | 1.00 | 1.00 | 1.11 |
| 40% | 0.92 | 0.82 | 0.96 | 1.02 | 1.00 | 1.00 | 1.02 | 1.00 | 1.00 | 1.00 | 1.14 |
| 45% | 0.95 | 0.89 | 1.04 | 1.03 | 1.00 | 1.00 | 1.03 | 1.00 | 1.00 | 1.00 | 1.16 |
| 50% | 0.98 | 0.93 | 1.05 | 1.03 | 1.00 | 1.00 | 1.03 | 1.00 | 1.00 | 1.00 | 1.19 |
| 55% | 0.98 | 0.96 | 1.09 | 1.04 | 1.00 | 1.00 | 1.04 | 1.00 | 1.00 | 1.00 | 1.23 |
| 60% | 0.99 | 1.00 | 1.10 | 1.04 | 1.00 | 1.00 | 1.05 | 1.00 | 1.00 | 1.00 | 1.28 |
| Mean 1 | 1.06 | 1.14 | 1.17 | 1.03 | 1.00 | 0.98 | 1.01 | 1.00 | 0.98 | 1.00 | 1.12 |
SAI describes how well RWR improves on random selection of sites relative to how well Zonation improves on random selection of sites, where the goal is to represent each species at least once. An SAI of 0.95 indicates that RWR is 95% as effective as Zonation in improving on random selection of sites, whereas an SAI of 1.05 indicates that RWR is 105% as effective as Zonation.
1 Grand mean is 1.04.