A dynamic disequilibrium hypothesis for terrestrial carbon cycle

The dynamic equilibrium of mass and energy movement in ecosystems is an important basis for the Earth system to nurture and maintain biodiversity. Since the Industrial Revolution, human activities have caused the carbon exchange between terrestrial ecosystems and the atmosphere to be at dynamic disequilibrium. This paper examines a dynamic disequilibrium hypothesis for the carbon cycle of terrestrial ecosystems. The hypothesis suggests that the dynamic disequilibrium is caused by interactions of four basic properties of internal processes of the terrestrial carbon cycle with five types of external drivers. Based on these internal properties and external drivers, this paper summarizes the expression phenomena of the dynamic disequilibrium of terrestrial carbon cycle at different time and space scales, and discusses its detection methods from the perspective of observations, experiments and models. The dynamic disequilibrium hypothesis for terrestrial carbon cycle not only helps us understand the complex terrestrial carbon-cycle phenomenon, but also provides a new theoretical framework for predicting the future terrestrial carbon sink dynamics.