Table 4.

Summary statistics of GAMM models relating Jaccard's distance and percentage matching between the composition of EPTO communities inferred from morphology and metabarcoding, in relation to subsampling day and DNA extraction methods

Jaccard's Distance	Family				Species
Parametric coefficients	Estimate	SE	z‐value	p	Estimate	SE	t‐value	p
Intersect	0.610	0.058	10.42	<2 × 10−16 ***	0.731	0.052	14.123	<2 × 10−16 ***
TISSUE	0.034	0.021	1.596	0.111ns	0.031	0.019	1.622	0.106ns
SOIL	0.067	0.022	2.987	0.003**	0.060	0.020	2.992	0.003**
Smooth terms	edf		F‐value	p	edf		F‐value	p
s(day): BEAD	1.000		7.411	0.007**	1		13.550	2.6 × 10−4 ***
s(day): TISSUE	2.205		21.612	5.5 × 10−10 ***	2.455		26.190	3.3 × 10−12 ***
s(day): SOIL	2.032		16.302	1.2 × 10−7 ***	1.381		31.240	1.5 × 10−8 ***

Percentage Matching	Family				Species
Parametric coefficients	Estimate	SE	z‐value	p	Estimate	SE	t‐value	p
Intersect	0.520	0.068	7.685	1.2 × 10−13 ***	0.303	0.057	5.277	2.1 × 10−7 ***
TISSUE	−0.052	0.032	−1.634	0.103 ns	−0.048	0.026	−1.839	0.067 ns
SOIL	−0.098	0.033	−2.997	0.003**	−0.094	0.027	−3.514	4.9 × 10−4 ***
Smooth terms	edf		F‐value	p	edf		F‐value	p
s(day): BEAD	1		5.565	0.019*	1		17.270	3.9 × 10−5 ***
s(day): TISSUE	2.315		26.032	2.9 × 10−12 ***	2.458		34.130	7.7 × 10−16 ***
s(day): SOIL	2.173		23.066	1.2 × 10−10 ***	1.822		28.600	4.0 × 10−9 ***

Extractions were performed from the ethanol used to preserve five unprocessed freshwater macroinvertebrate bulk samples and subsampled on days 1, 2, 3, 5, 7 and 14 after field sampling, using three DNA extraction methods (BEAD, TISSUE and SOIL). For each model, we provide the parameter estimates, standard errors (SE) and statistical significance of parametric terms, and the effective degrees of freedom (edf) and approximate significance of smooth terms. The shape of the smooth terms is provided in Figure 4. The matrix used to build the models excluded rare species with a percentage read count <0.01% from each sample; models build using alternative criteria for dealing with rare species are given in Tables S7 and S8.

^*** p < 0.001.

^** p < 0.01.

^* p < 0.05.

^ns p > 0.05.