Figure 4: An analysis of the long-term changes in climate suitability for the tick Ixodes ricinus in Europe (1900–1999). A temporally extensively gridded dataset was subjected to a temporal analysis to understand how climate has changed in 100 years and how this trend affected the climate suitability for the tick. Areas are divided into suitable and unsuitable (the last, without colors in the figure). In the panel “A,” the area marked as suitable and stable means no changes in suitability for the tick. Deterministic increase or decrease means a continued trend towards increasing or decreasing climate suitability. Panel B shows the areas where random walk trend has been observed. These areas are subjected to periodic cycles of climate, thus allowing cycles of increasing or decreasing climate suitability for the tick. (Estrada-Peña and Venzal 2006 [50], with permission from Ecohealth).