Tropical rain forests are primarily characterized by what feature?

Tropical rain forests are primarily characterized by massive biodiversity, which is one of their most defining features. These ecosystems are known for their incredible variety of plant and animal species, with estimates suggesting that they contain more than half of the world's biodiversity, despite covering only about 6% of the Earth's surface. The warm, humid climate and consistent rainfall throughout the year create ideal conditions for a wide array of organisms to thrive. This high level of biodiversity also supports complex food webs and ecological interactions, making tropical rain forests vital to global ecological health.

In contrast, high altitude is not a characteristic of tropical rain forests, as these forests are typically found at low elevations near the equator. While extreme temperatures can sometimes occur in tropical areas, the temperatures in rain forests are generally warm and consistent due to the proximity to the equator. Lastly, low rainfall is inaccurate for describing tropical rain forests; rather, these forests receive a significant amount of rainfall, often exceeding 2000 millimeters (about 79 inches) annually, which contributes to their lush vegetation and diverse ecosystems.