Table 1. Carabid beetle abundance and species richness (mean ± SE) at 500 × 500 m beetle survey sites in six housing categories (see Methods for category definitions). The species included in each group are given in Appendix 2. Different lowercase letters indicate significant pairwise differences between categories for those response variables for which housing category had a significant effect in single-factor analyses of variance (square-root or log transformations were applied to response variables prior to analyses if the assumptions of normality and homoscedasticity were not met).

Forested Exurban Suburban Urban Suburban Neighbor Urban
Neighbor
n 4 4 4 4 3 3
Housing density (mean dwellings/km2 ± SE) 0 31.00 ± 9.30 555.00 ± 101.10 3754.00 ± 491.92 434.68 ± 159.53 1637.32 ± 281.98
All beetles
Abundance 181.75 ± 49.51 151.50 ± 28.01 208.50 ± 56.99 136.25 ± 38.72 238.00 ± 81.22 428.67 ± 114.57
Species richness 18.00 ± 4.26 25.00 ± 2.80 21.50 ± 2.90 18.75 ± 2.72 14.33 ± 4.06 23.00 ± 3.46
Forest beetles
Abundance 117.00 ± 30.82a 73.25 ± 14.42a 6.75 ± 1.93b 3.50 ± 1.32b 54.00 ± 22.81a 97.33 ± 8.65a
Species richness 9.50 ± 0.87a 9.25 ± 0.75a 2.00 ± 0.41b 1.50 ± 0.29b 6.00 ± 1.53a 9.33 ± 0.88a
Open-habitat beetles
Abundance 37.50 ± 32.31a 29.00 ± 10.19ab 131.25 ± 49.49b 71.75 ± 28.29ab 38.33 ± 17.70ab 158.67 ± 77.92ab
Species richness 2.25 ± 0.95a 6.75 ± 2.59ab 11.75 ± 1.70b 11.00 ± 2.27b 2.33 ± 0.88a 3.00 ± 1.00ab
Native beetle abundance 179.25 ± 48.58 121.50 ± 25.50 142.25 ± 50.76 76.75 ± 29.10 114.67 ± 36.98 321.33 ± 70.55
Non-native beetle abundance 2.50 ± 1.04a 30.00 ± 10.82b 66.25 ± 19.14b 59.50 ± 10.02b 123.33 ± 67.40b 107.33 ± 64.54b