, primary productivity is the rate of biomass production, which depends on plant species, nutrient availability, and various environmental factors . The sources highlight that tropical environments receive more solar energy, which directly contributes to higher productivity compared to temperate regions . Because of this abundant solar energy and relatively constant, predictable environment, tropical rain forests (such as the Amazonian rain forest) exhibit the greatest biodiversity and high productivity levels . While the annual net primary productivity of the entire biosphere is approximately 170 billion tons, the vast majority of this production occurs on land .