Final answer:
Terrestrial ecosystems have varying productivity levels, while freshwater ecosystems are diverse despite their small surface area. Marine ecosystems cover most of Earth's surface, with areas of high productivity due to coral reefs and phytoplankton, which perform a significant portion of Earth's photosynthesis.
Step-by-step explanation:
Terrestrial ecosystems, which occupy about 33% of Earth's surface, demonstrate varying levels of productivity depending on factors such as climate, water availability, and sunlight, with certain biomes like tropical rainforests having high productivity. In contrast, aquatic ecosystems, covering approximately 75% of the planet, also exhibit diverse productivity levels. Freshwater ecosystems, though only 1.8% of Earth's surface, support a diverse range of life. Marine ecosystems, which form the largest portion of Earth's surface, contain regions of high productivity such as shallow ocean areas with coral reefs and zones with robust phytoplankton activity that perform 40 percent of all photosynthesis on Earth. Despite the vastness of the oceans, marine biodiversity is less evenly distributed, with some deep ocean areas being less diverse than terrestrial or shallow marine environments.