The primary factor influencing the distribution of organisms in an ecosystem is environmental factors, including abiotic and biotic components. Abiotic factors encompass non-living elements such as temperature, soil type, water availability, and climate. Biotic factors include relationships with other organisms, such as competition, predation, and symbiosis. These factors together shape habitats, determine species' survival, and influence community structure within ecosystems. Understanding these influences is crucial for conservation efforts and ecosystem management, as changes in environmental conditions can significantly impact biodiversity.