Primary productivity is the rate at which plants, algae, and other photosynthetic organisms convert solar energy into organic materials through photosynthesis. It is a key process in ecosystems as it forms the base of the food chain, providing energy for all other organisms. Primary productivity can be measured as the amount of biomass produced per unit area per unit time, and it is influenced by factors such as temperature, sunlight, and nutrient availability. Understanding primary productivity is important for assessing ecosystem health, biodiversity, and the impacts of climate change.