Table 1

Ecogeographical variables (grouped into four factors) considered for modeling Ixodes ricinus abundance and I. ricinus-borne pathogen prevalencea

FactorVariable codeVariable descriptionMean (SE)Range
Spatial locationLoLongitude (m)
LaLatitude (m)
ClimateTAvg annual mean temp (°C)10.2 (1.6)8.0–12.7
TrAnnual temp range (TJL − TJN) (°C)13.0 (1.2)11.4–14.9
FdAvg no. of annual frost days49.1 (30.0)7.9–104.5
PAvg annual rainfall (mm)1,248.3 (120.3)1,028.0–1,344.3
MP24Avg maximum precipitation in 24 h (mm)148.6 (20.9)120.1–186.8
MPrRelative maximum precipitation (MP24/P)0.09 (0.01)0.07–0.12
AHrAnnual air humidity range (HJL − HJN) (%)9.1 (2.9)3.4–12.1
ETaAvg annual actual evapotranspiration (mm)648.4 (41.1)596.8–725.8
SoilFForest coverage (%)0.25 (0.7)0–2
SVScarce vegetation coverage (%)22 (12.4)3–37
GGrassland coverage (%)3.8 (6.0)0–18
NDVIaMean annual normalized difference vegetation indexb7,039.9 (374.7)6,265.4–7,400.7
NDVIcCurrent NDVI (measured on 25 June 2004)b8,404.3 (581.5)7,280.9–9,098.4
NDVIsNDVI seasonality0.17 (0.07)0.07–0.27
HostsCabCattle abundance index (no. of 10-m transects positive for host dung in 100 m)0.37 (0.03)0–0.60
HabHorse abundance index (no. of 10-m transects positive for host dung in 100 m)0.03 (0.01)0–0.23
DabDeer abundance index (no. of 10-m transects positive for host dung in 100 m)0.05 (0.01)0–0.27
  • a The table shows the mean value for each variable at the study sites (except for site PI) and its associated standard error (SE) as well as the observed range (minimum to maximum) of values for each variable at the surveyed sites. TJL, average mean temperature in July; TJN, average mean temperature in January; HJL, average air humidity range in July; HJN, average air humidity range in January.

  • b NDVI values were divided by a scale factor of 0.0001.