NGS barcoding reveals high resistance of a hyperdiverse chironomid (Diptera) swamp fauna against invasion from adjacent freshwater reservoirs

Table 1 Linear mixed effects model to determine the relationships between three response variables (species richness, Shannon index, and Simpson index) in separate models and the continuous physicochemical variables and one categorical variable in 28 Nee Soon Swamp Forest sites

	Species richness		Shannon index		Simpson index
Term	% Adj. R²	P	% Adj. R²	P	% Adj. R²	P
Conductivity	64.8	ns	69.8	*	78.8	*
Width	0	ns	0	ns	0	ns
Dissolved oxygen	15.6	ns	14.08	ns	6	ns
pH	0	ns	5.02	ns	15.2	ns
Presence of reservoir species	0	ns	0	ns	0	ns
Stream depth	0	–	0	–	0	–
Stream order	19.6	–	11.1	–	0	–
Stream discharge	0	–	0	–	0	–
Turbidity	0	–	0	–	0	–
Average velocity	0	–	0	–	0	–
Temperature	0	–	0	–	0	–
Total variance explained (Adj. R²)	0.12		0.27		0.17

The relative contribution (%) of each term in explaining model variance was calculated as % difference in adjusted R² comparing the full refined model and the model with each term removed. Stream depth, stream order, stream discharge, turbidity, average velocity, and the temperature were removed during model refinement. Symbols indicate the presence or the significance of the term within the refined model: 0, negative adjusted R² values; −, not present in the refined model; ns, not significant, * = P < 0.05

ISSN: 1742-9994