Figure 3.

Mean values (± st. error) of variables for nematode trophic group abundances and results of PERMANOVA associated with “treatment” (T) and “duration of treatment” (D) on these parameters. Different letters (a, b) indicate significant differences of pairwise comparisons among treatments (Control, C₂₅ and C₅₀). The results of principal component analysis (PCA), depicting the ordination of samples and variables are presented in Figure 4. The first axis explained 54.4% of the data variability, while the second one explained 17.5% (71.9% in total). Samples of the C₅₀ for both durations were ordinated at the left part of the first axis showing a positive correlation mostly to Gram−, Gram+, fungi, and bacterial-feeding nematodes. The samples of control and C₂₅ of 15DAA were placed at the right side of the first axis showing a positive correlation to plant-feeding nematodes. Samples of 15DAA were separated along the second axis from all other samples and were ordinated in the lower part, showing a positive correlation to urease, dehydrogenase and alkaline phosphatase activities.