Beech tree masting explains the inter-annual variation in the fall and spring peaks of Ixodes ricinus ticks with different time lags

Table 6 The parameter estimates from the best model (model 2 in Table 5) are shown

Type	Name	Estimate	SE	z	P
Intercept	Low site	2.477	0.160	15.459	< 2e−16
Contrast 1	Medium–Low	−0.260	0.175	−1.486	0.137
Contrast 2	High–Low	−0.076	0.177	−0.429	0.668
Contrast 3	Top–Low	−1.064	0.192	−5.529	< 0.001
Contrast 4	Fall–Spring	0.693	0.264	2.629	0.009
Slope 1	BM[2,1]	0.245	0.018	13.288	< 2e−16
Slope 2	Year (for Low site)	0.057	0.014	3.999	< 0.001
Contrast 5	Medium site: Year	−0.006	0.020	−0.317	0.751
Contrast 6	High site: Year	−0.082	0.020	−4.016	< 0.001
Contrast 7	Top site: Year	−0.162	0.022	−7.226	< 0.001

Smooth terms	Edf	Ref. df	F	P
s(Day)—Low site	7.734	8.590	297.400	< 2e−16
s(Day)—Medium site	6.786	7.904	347.900	< 2e−16
s(Day)—High site	6.823	7.918	237.900	< 2e−16
s(Day)—Top site	5.909	7.043	182.300	< 2e−16

In this best model, the DON response variable was modelled as a function of elevation site (low, medium, high, and top), nymphal peak (spring and fall), covariate beech mast index with different time lags for the spring peak and fall peak (BM[2,1]), and covariate year (rescaled as 1, 2, …, 14). Interactions are indicated by colons (:); for example, the parameter estimates for the site:year interaction are indicated by the terms Medium site: Year, High site: Year, and Top site: Year. For each parameter, the parameter type, parameter name, parameter estimate on the log scale, standard error on the log scale (SE), z value (z), and P-values (P) are shown. To model the bimodal phenology of the DON, a site-specific smoother function was applied to the calendar day. For each of the four site-specific smoother functions of the calendar day, the effective degrees of freedom (Edf), reference degrees of freedom (Ref. df), F-statistic (F), and P-value (P) are shown

ISSN: 1756-3305