From: Driving forces for changes in geographical distribution of Ixodes ricinus ticks in Europe
 |  |  |  | Impact on spread or abundance at | ||
---|---|---|---|---|---|---|
KEY DRIVER | Driver | Mode of action of driver | Impact on tick biology | altitude | latitude | endemic zones |
Climate | Temperature | Increased temperature during winter months | Increased winter survival | X | X | Â |
 |  | Overall increased temperature (winter and summer) | Extended development period | X | X |  |
 | Rainfall | Increased humidity | Extended development period, increased survival |  |  |  |
 | Snow cover | insulation, preventing ground temperature falling below 0°C | Increased winter survival | X | X |  |
 | Extended vegetation period (increased temperature and reduced snow cover) | Altitudinal and latitudinal expansion of deciduous woodland creating suitable conditions for Ixodes ricinus | Improved microclimate with increased tick survival, and development | X | X |  |
 |  | Dispersal of roe deer at higher altitude and latitude | Enhanced dispersal and reproduction | X | X |  |
Anthropogenic | Wildlife management | Increased habitat for Ixodes ricinus | Enhanced dispersal | X | X | Â |
 |  | Increased habitat for hosts | Enhanced dispersal | X | X |  |
 |  | Increased host abundance | Enhanced reproduction |  |  | X |
 | Changes in land use patterns | Increased habitat for Ixodes ricinus | Enhanced dispersal |  |  | X |
 |  | increased habitat for hosts | Enhanced dispersal |  |  | X |
 |  | Increased host abundance | Enhanced reproduction |  |  | X |
 | Forest management | Reforestation, creation of suitable habitats |  | X | X | X |
Ecological / geographical factors | Habitat structure and connectivity | Increase in suitable environment | Enhanced reproduction and development | Â | Â | X |
 |  | Improved hosts dispersal | Enhanced dispersal |  |  | X |
 | Orientation of mountain slopes | Impact on microclimate | Impact on survival, development | X |  |  |
 | Host dispersal | Behaviour adaptation of roe deer to human presence | Enhanced tick reproduction and dispersal |  |  | X |