A Method for Analyzing Ecosystem Stability Based on Multi-Species Coupled Dynamics Modeling

In order to better analyze the impacts of agrochemicals such as pesticides and herbicides on ecosystems, and to address the ecological imbalance in the transition zone of the Amazon rainforest, this paper proposes a methodology for analyzing the stability of ecosystems based on a multi-species coupled dynamics model. First, an ecosystem composed of soil microorganisms (D), forest area (S), farmland (F), pests (I), birds (B), and bats (Bat) was constructed, and ecosystem managers were given the power to regulate logging rates (L) and pesticide use rates (P). Second, an ecological dynamics model containing multiple differential equations was developed based on the Lotka-Volterra framework, and simulated by controlling key variables such as forest natural growth rate, predation efficiency, energy transfer efficiency and pesticide toxicity coefficient. Finally, the following conclusions were drawn through long-term field data validation: (1) when pesticide use exceeds the critical threshold, the system will experience significant bifurcation, leading to a sharp decline in the population size of key species; and (2) the model maintains good stability over a wide range of parameter perturbations, which provides a quantitative tool for the assessment of ecological risk in the agrarian transformation of tropical rainforests.