Researchers at the Institute of Applied Ecology of the Chinese Academy of Sciences have introduced a theoretical and methodological framework for assessing the coordination of composite systems, a concept used to describe complex systems formed through interactions between natural processes and human activities.

The study was published in both Chinese and English in the Bulletin of Chinese Academy of Sciences. The article was later selected as one of the “Top 10 Most Popular Science Articles of 2025” on the journal’s public science communication platform.

Composite systems are widely found across the Earth’s surface where ecological processes and human activities intersect. Examples include large-scale ecological governance frameworks such as “mountains, rivers, forests, farmlands, lakes, grasslands, and deserts,” a holistic framework that emphasizes the integrated management of multiple ecological systems. In such systems, different subsystems interact through exchanges of matter, energy, and information. Scientists use the concept known as the coordination degree of composite systems (CDoCS) to measure how effectively these subsystems function together. A higher coordination degree generally indicates that ecological, economic, and social components operate in a balanced way, which is important for long-term environmental stability and sustainable development.

Previous studies have attempted to quantify coordination within complex systems, but the researchers note that definitions and measurement approaches have often been inconsistent. This lack of clarity has made it difficult to explain how coordination emerges among subsystems or to design practical strategies for managing large-scale ecological systems that combine environmental and socioeconomic factors.

To address these challenges, senior researcher ZHU Jiaojun, postdoctoral researcher QI Ke, and their colleagues developed a research framework that combines theoretical analysis, methodological innovation, and practical application. The researchers first clarified the conceptual meaning of coordination in composite systems. They then proposed a new method to quantify coordination in a way that reflects the underlying concept more accurately than traditional approaches.

Based on this method, the team developed what they describe as a “coordination degree and constraint” mechanism model. The model analyzes how cooperative interactions among subsystems are influenced by limiting factors such as resource availability and environmental capacity. According to the researchers, understanding both coordination and constraints is necessary to explain how complex ecological systems operate and how they can be optimized.

Building on these findings, the researchers outlined a four-step application framework for managing composite systems. The framework includes defining the conceptual scope of coordination, conducting quantitative assessment, identifying system constraints, and implementing optimized management strategies. Each step is associated with specific analytical tools and operational procedures intended to support decision-making in composite system governance.

Using integrated ecological management systems as an example, the researchers also summarized five major challenges commonly encountered in composite system governance. The study suggests practical pathways for addressing these challenges, such as redefining governance priorities around coordinated management, dividing ecological governance areas into scientifically defined units, and designing resource allocation strategies based on the coordination–constraint analytical model.

A certificate recognizing the “Top 10 Most Popular Science Articles of 2025” selected by the Bulletin of Chinese Academy of Sciences