Chi2:Chi-square test (P > 0.05 indicates
absence of significant discrepancy between the data and the model); *:
p<0.05; **: p<0.01; ***: p<0.001
Species richness showed significant positive direct effect on FEve (β =
0.53; P < 0.001; Table 3), which also showed positive
and significant effect (β = 0.62; P < 0.001; Table 3;
Figure 4a) on AGB. Therefore, species richness, through FEve had a
positive significant effect on AGB (β = 0.53*0.62 = 0.39). Similarly,
species richness, through structural diversity (CV DBH and CV Npb)
showed positive significant effects on AGB (Table 3; Fig. 4b-c).
However, when comparing the three SEMs, we found that the variation in
AGB explained was greater for FEve (r2=0.39) than for
CV DBH (r2=0.20) and CV Npb
(r2=0.24). Further, when we combined functional
evenness, CV DBH and CV Npb in the integrative SEM, only FEve showed
significant mediation role in linking species richness to AGB (Table 3;
Fig. 4d).
Table 3. Results of the SEMs testing the direct and indirect
effects of species richness on AGB via functional evenness and
structural diversity. Fit statistics are presented in Figure 3