The correct answer is: Tropical rain forest.
Tropical rain forests are the most productive ecosystems on Earth. They have a high annual net primary productivity (NPP), which is the amount of energy that is stored in plant biomass each year. This is due to a number of factors, including the warm, wet climate, the high diversity of plant species, and the lack of seasonality.
Tropical deciduous forests are also productive ecosystems, but they have a lower NPP than tropical rain forests. This is because they experience a dry season, which limits plant growth.
Temperate deciduous forests are less productive than tropical forests. This is because they have a cooler climate, which limits plant growth. They also experience a seasonal cycle, which means that plant growth is not as continuous as in tropical forests.
Temperate evergreen forests are the least productive ecosystems on Earth. This is because they have a cool, dry climate, which limits plant growth. They also experience a seasonal cycle, which means that plant growth is not as continuous as in tropical forests.
In conclusion, tropical rain forests have the highest annual net primary productivity. This is due to a number of factors, including the warm, wet climate, the high diversity of plant species, and the lack of seasonality.