Table 4. Sampled caves, troglobionts (Obs.), single-cave endemics (End.), and estimated species richness by ecoregion in Tennessee.
| Overall | Terrestrial Troglobionts | Stygobionts | ||||||||||||
| Ecoregion | Caves | Obs. | End. | Chao | JK1 | BS | Obs. | Chao | JK1 | BS | Obs. | Chao | JK1 | BS |
| Southeastern Plains | 4 | 3 | 0 | 5±4 | 5±1 | 4±1 | 1 | 1±0 | 2±1 | 1±0 | 2 | 3±1 | 3±1 | 2±0 |
| Interior Plateau | 278 | 116 | 19 | 179±27 | 158±8 | 134±5 | 98 | 155±26 | 135±8 | 114±4 | 18 | 24±8 | 23±2 | 20±1 |
| Western Highland Rim | 29 | 29 | 3 | 41±9 | 42±5 | 35±3 | 22 | 34±10 | 33±4 | 27±2 | 7 | 8±2 | 9±1 | 8±1 |
| Western Pennyroyal Karst Plain | 24 | 15 | 0 | 15±1 | 17±1 | 17±2 | 11 | 11±1 | 13±1 | 13±2 | 4 | 8±0 | 4±0 | 8±0 |
| Inner Nashville Basin | 29 | 16 | 0 | 25±10 | 22±4 | 18±2 | 10 | 23±17 | 15±3 | 12±2 | 6 | 7±1 | 7±1 | 7±1 |
| Outer Nashville Basin | 85 | 53 | 11 | 78±14 | 74±6 | 62±3 | 43 | 61±12 | 60±5 | 51±3 | 10 | 18±12 | 14±2 | 12±1 |
| Eastern Highland Rim | 111 | 66 | 5 | 118±31 | 91±7 | 76±4 | 52 | 82±19 | 71±6 | 60±4 | 14 | 14±0 | 20±3 | 16±1 |
| Southwestern Appalachians | 289 | 102 | 15 | 134±15 | 133±8 | 116±5 | 79 | 107±15 | 105±7 | 91±4 | 23 | 27±5 | 28±2 | 25±1 |
| Cumberland Plateau | 6 | 17 | 0 | 59±39 | 28±9 | 22±5 | 16 | 52±33 | 26±8 | 20±4 | 1 | 1±0 | 2±1 | 1±0 |
| Plateau Escarpment | 260 | 98 | 13 | 126±13 | 129±8 | 112±5 | 75 | 97±12 | 100±7 | 86±4 | 23 | 29±5 | 29±2 | 26±2 |
| Sequatchie Valley | 23 | 29 | 2 | 43±10 | 41±7 | 35±4 | 20 | 33±11 | 30±5 | 24±2 | 9 | 11±3 | 12±3 | 10±2 |
| Central Appalachians | 2 | 4 | 1 | 4±0 | 6±2 | 5±1 | 3 | 3±0 | 5±1 | 4±1 | 1 | 1±0 | 2±1 | 1±0 |
| Ridge and Valley | 75 | 50 | 10 | 120±40 | 79±7 | 62±3 | 37 | 103±44 | 60±6 | 46±3 | 13 | 22±10 | 19±2 | 15±1 |
| Blue Ridge Mountains | 13 | 9 | 2 | 14±7 | 12±2 | 10±1 | 5 | 6±1 | 6±1 | 5±1 | 4 | 4±0 | 6±1 | 5±1 |
| Total | 661 | 196 | 47 | 286±30 | 262±10 | 225±5 | 158 | 239±30 | 215±9 | 183±5 | 38 | 48±8 | 48±3 | 42±2 |
The six Level III ecoregions that contain caves are highlighted in bold. Also shown are Level IV ecoregions (subregions or Level III ecoregions) of the Interior Plateau and Southwestern Appalachians. Observed troglobiont species richness do not sum because some species are present in more than one ecoregion. We also estimated extrapolated species richness from sampled caves using three non-parametric incidence-based estimators, including Chao2 (Chao), first-order jack-knife (JK1), and bootstrap richness estimator (BS). Four troglobionts (including one single-cave endemic) are not included here because their records could not be reliably georeferenced.