Fig. 4: Conceptual model of ecological network and the temporal changes in connectance (%) and strength between nodes of ecological network of Lake Hongjiannao.

Empirical trophic classification (a) and paradigm of metaweb generated by sedDNA data (b). Trophic links represents predator–prey interactions. Non-trophic links encompass facilitation and competition. Hybrid links can be both trophic and non-trophic. All species or genera were classified into one of 13 guilds, then these links were used to constructed a conceptual ecological network. c, d Connectance (%) and average strength between the realized links of the whole ecological network. All lines are drawn based on the central point of a moving window of 6 years, used for causality detection via convergent cross mapping. e, f Connectance (%) and average strength of trophic, non-trophic and hybrid interactions. g, h Connectance (%) and average strength of bottom-up (BU) and Top-down (TD) interactions. The significant level between groups were calculated using pairwise comparisons via non-parametric Wilcoxon test.