Which biome most diverse of all biomes with canopy and understory vegetation?

The biome that is the most diverse of all biomes with canopy and understory vegetation is the tropical rainforest. Tropical rainforests are known for their extremely high levels of biodiversity, with an estimated 50-90% of all the world's plant and animal species living in these lush, complex ecosystems.

The canopy of a tropical rainforest is typically composed of tall, broadleaved trees that form a dense, almost continuous layer of vegetation. This layer can reach heights of up to 100 meters (330 feet) or more, and is home to a wide variety of plant and animal species, including epiphytes (plants that grow on other plants), lianas (woody vines), and numerous species of birds, insects, and mammals. The understory vegetation in a tropical rainforest is also incredibly diverse, with a variety of shrubs, saplings, and herbaceous plants growing beneath the canopy.

Tropical rainforests are found in a narrow band around the Earth's equator, in regions with high temperatures and abundant rainfall. They are primarily located in South America, Africa, Southeast Asia, and Central America, and cover an area of approximately 14% of the world's land surface.

Due to their tremendous biodiversity and ecological importance, tropical rainforests are considered to be one of the most valuable ecosystems on Earth. However, these forests are also facing a variety of threats, including deforestation, climate change, and hunting, which are causing significant loss of habitat and species extinction.