TABLE 1.

Summary of E. coli spatial patterns and large-scale sources of genotype variationa

Population or point patternPatch size (m)Interpatch distance (m)Spatial gradientbLandscape gradientbEdaphic gradientbTemporal gradientb
B1A5 to 1020 to 300.178*0.223** (ES)0.187** (PMO)0.163*
B1B<5c20 to 300.295***NSNS0.094*
B2<5c20 to 300.141**NSNS0.384***
D<5c40 to 450.117**0.261*** (S)0.231*** (PO)0.086**
E<5c30 to 350.152*0.149* (E)NS0.110*
ET1<5c65 to 70NSNSNS0.146*
Soil isolates<5cNSNS0.065*** (S)0.149*** (O)0.095***
Fecal deposition3 to 919 to 30NANANANA
  • a Summary of spatial autocorrelation patterns and trends in genetic structure on the scale of the entire field site. ND, not determined; NS, not significant.

  • b Partial Mantel's R values are reported with P values of <0.05 (*), <0.01 (**), and <0.001 (***). Variables included in the edaphic and landscape matrices are listed in parentheses. P, pH; M, %M; O, %OM; E, elevation; S, slope.

  • c Significant positive autocorrelation was not observed into the 10-m distance lag, preventing estimation of the smallest patch size.