Positive Periodic Solution of Phytoplankton–Zooplankton Model on Time Scales

This paper addresses a phytoplankton–zooplankton model on time scales. Based on a fixed point theorem of strict-set-contraction, some sufficient conditions are established for global existence of positive periodic solution to the considered system. Finally, two examples are presented to illustrate effectiveness of the results. The main purpose of this paper is to study a more general class of biological system and to investigate the existence of positive solutions for the aforementioned system using strict-set-contraction theory. It is interesting that the results of this paper are applicable to both discrete and continuous systems. Periodic behavior is widely present in biological systems and also reflects symmetry in nature. Therefore, studying the periodic solutions of biological systems can help us better understand the dynamic behavior of biological systems.