The primary determinant of ecosystem dynamics is the interaction between biotic (living) and abiotic (non-living) components. These interactions shape processes such as energy flow, nutrient cycling, and species interactions within an ecosystem. Factors like climate, soil type, and water availability significantly influence which species thrive in a given area, thereby driving ecological relationships and community structures. Understanding these dynamics is crucial for effective conservation and management, allowing for the prediction of ecosystem responses to various changes, including climate change and human impact.