Primary producers, primarily plants and some microorganisms, play a vital role in an ecosystem by converting solar energy into chemical energy through photosynthesis. By synthesizing organic compounds, they form the base of the food web, supporting herbivores and subsequently higher trophic levels. Primary producers also contribute to the oxygen content of the atmosphere, which is essential for the survival of aerobic organisms. Their health and abundance influence overall ecosystem productivity and biodiversity, making them critical for maintaining ecological balance and supporting life on Earth.