Tropical Rainforests and Biodiversity

How Rainforests Improve Global Environmental Health

Tropical Rainforest Canopy

DreamPictures/Shannon Faulk , Getty Images

Biodiversity is a term biologists and ecologists use to describe natural biotic variety. The numbers of animal and plant species plus the richness of gene pools and living ecosystems all make for sustained, healthy, and diverse ecosystems.

Plants, mammals, birds, reptiles, amphibians, fish, invertebrates, bacteria, and fungi all live together with non-living elements like soil, water, and air to make a functioning ecosystem. A healthy tropical rainforest is the world's most spectacular example of a living, functioning ecosystem and the ultimate example of biodiversity.

Just How Diverse are Tropical Rainforests?

Rainforests have been around a long time, even on a geological scale. Some existing rainforests have evolved over 65 million years. This time-enhanced stability has in the past allowed these forests greater opportunities for biological perfection. Future tropical rainforest stability is now not so certain as human populations have exploded, rainforest products are in demand, and countries struggle to balance the environmental issues with the needs of citizens living off these products.

Rainforests by their very nature harbor the greatest biological gene pool in the world. The gene is a basic building block of living things and every species is evolved by various combinations of these blocks. The tropical rainforest has nurtured this "pool" for millions of years to become the exclusive home for 170,000 of the world's 250,000 known plant species.

What Is Tropical Rainforest Biodiversity?

Tropical rainforests support higher land area units (acres or hectares) of biodiversity when compared to temperate or arid forest ecosystems. There are some educated guesses by experts that tropical rainforests on our planet contain about 50% of the world’s terrestrial plant and animal species. The most common estimate of the size of total rainforests amount to approximately 6% of the world’s land area. 

While tropical rainforests around the world have many similarities in their climates and soil composition, each regional rainforest is unique. You will not find precisely the same species living in all the tropical rainforests around the world. For example, the species in African tropical rainforests are not the same as the species living in the tropical rainforests of Central America. However, the different species play similar roles within their specific regional rainforest.

Biodiversity can be measured on three levels. The National Wildlife Federation lists these levers as:
1) Species diversity - "being the sheer variety of living things, from microscopic bacteria and fungi to towering redwoods and enormous blue whales." 2) Ecosystem diversity - "being tropical rainforests, deserts, swamps, tundra, and everything in between." 3) Genetic diversity - "being the variety of genes within a single species, which give rise to the variations that cause species to evolve and adapt over time."

Two Fantastic Rainforest/Temperate Forest Comparisons

To comprehend just how marvelous this biodiversity is, you have to make a comparison or two:

One study in a Brazilian rainforest found 487 tree species growing on a single hectare (2.5 acres), while the US and Canada combined only have 700 species on millions of acres.
There are approximately 320 butterfly species in all of Europe. Just one park in a Peruvian rainforest, The Manu National Park, has 1300 species.

Top Biodiverse Rainforest Countries:

According to Rhett Butler at, the following ten countries are home to the most biodiverse tropical rainforests on Earth. The United States is included only because of Hawaii's protected forests. The countries in order of diversity are:

  1. Brazil
  2. Colombia
  3. Indonesia
  4. China
  5. Mexico
  6. South Africa
  7. Venezuela
  8. Ecuador
  9. Peru
  10. United States