Table 1. Best-fit models of plant diversity
All sites Urban Desert
Model type Spherical semivariogram GLM GLM
Data transformation Log link Log link Square root
Spatial autocorrelation Absent Absent Present
Predictor variables Land use Family income (8.08)* Elevation (7.59)***
Urban (27.35)*** Median housing age (-6.65)* Distance from urban center (-2.89)*
Agriculture (10.21)* Ever farmed (4.34) Median housing age (2.50)
Elevation (24.88)***
Family income (12.72)**
Ever farmed (6.04)
  • Significant variables are listed in order of importance as judged by the level of significance denoted by asterisks (***, P < 0.0001; **, P < 0.001; *, P < 0.01; no asterisk, P < 0.05). GLM, generalized linear modeling.

  • The appropriate test statistics are shown in parentheses, consisting of χ2 values for all sites and urban models and a T value for the desert model.