Fig. 9
Effect of the total snowpack in year y − 1 (SNY1) on the density of nymphs (DON) is shown for the four elevation sites: (a) low site, (b) medium site, (c) high site, and (d) top site. The DON is an estimate of the number of questing I. ricinus nymphs per 100 m2 sampled by the dragging method each month. The SNY1 refers to the total snowpack in the previous year as the DON (i.e., a time lag of 1 year). The SNY1 has units of cm and was measured at 200 cm above the ground by two weather stations near the field site. The DON is predicted for the range of SNY1 values that occur at each elevation site. The effect of SNY1 on the DON differs among the four elevation sites. The predicted values were calculated using model 1 in Additional file 1: Table S5. The reference conditions were as follows: season = Spring, BM[2,1]  = 1, year = 2004, field-measured temperature = 15 °C, and calendar day was 15 April