Table 2.
Parameter values, standard errors and associated probability levels of ordinary least‐squares (OLS, a, b, c) and spatial autoregressive (SR, d, e, f) best‐fit models for total, stygobiotic and cold stenotherm species richness, and log‐transformed environmental variables
OLS models | |||||||||||
---|---|---|---|---|---|---|---|---|---|---|---|
Total species richness | Stygobiotic species | Cold stenotherm species | |||||||||
Variable | Coefficient | Standard error | p(t) | Variable | Coefficient | Standard error | p(t) | Variable | Coefficient | Standard error | p(t) |
a | b | c | |||||||||
Constant | 52.085 | 7.177 | <.001 | Constant | 1.394 | 0.589 | 0.042 | Constant | 1.237 | 0.251 | <0.001 |
Area | 2.315 | 0.644 | 0.001 | Area | 2.500 | 0.346 | <0.001 | Area | 0.880 | 0.265 | 0.003 |
Elevation | −15.431 | 2.277 | <.001 | Discharge | 0.408 | 0.146 | 0.010 |
Autoregressive models | |||||||||||
---|---|---|---|---|---|---|---|---|---|---|---|
Total species richness | Stygobiotic species | Cold stenotherm species | |||||||||
Variable | Coefficient | Standard error | p(t) | Variable | Coefficient | Standard error | p(t) | Variable | Coefficient | Standard error | p(t) |
d | e | f | |||||||||
Constant | 51.602 | 14.363 | 0.001 | Constant | 1.697 | 1.845 | .382 | Constant | 1.299 | 0.884 | .155 |
Area | 1.444 | 0.835 | 0.096 | Area | 2.858 | 0.789 | .006 | Area | 0.451 | 0.388 | .260 |
Elevation | −14.736 | 4.853 | 0.005 | Discharge | 0.337 | 0.292 | .260 |
OLS regression statistics: a) n = 30, R 2 = .859; F = 82.282, p < .001, AICc = 144.128; b) n = 12, R 2 = .839; F = 52.242, p < .001, AICc = 48.844; c) n = 27, R 2 = .762; F = 38.368, p < .001, AICc = 74.552. SR regression statistics: d) n = 30, R 2 (pseudo) = .836 (AICc = 152.630), R 2 (predictors + space) = .621 (AICc = 177.751); rho = .987, F = 68.707, p < .001; e) n = 12, R 2 (pseudo) = .822 (AICc = 55.824), R 2 (predictors + space) = .958 (AICc = 38.501); rho = .916, F = 46.217, p < .001; f) n = 27, R 2 (pseudo) = .668 (AICc = 87.548), R 2 (predictors + space) = .551 (AICc = 95.696); rho = .983, F = 24.173, p < .001.