144. Tropics Overview

Warm, moist, tropical rainforests support the world’s most diverse and ecologically complex plant communities. In this fiercely competitive environment, many plants have adapted in intriguing ways. 

Tropical rainforests have several layers, including the forest floor, understory, canopy, and the emergent layer. Each layer presents its own survival challenges—and different species, or those in different life stages, grow in different layers.  

Notice the drip tips on many leaves that allow water to run off to reduce algal growth on their surfaces. In the shadier understory—where shorter plants grow beneath the tree canopy—you can see that many plants have large leaves to maximize capturing light for photosynthesis.

The soils of the rainforest are shallow and relatively poor. Under humid, warm conditions, plants that die and fall to the soil decompose rapidly. Their nutrients are quickly absorbed by the roots of other plants.  

Increasingly, development drives rapid deforestation in many tropical areas. This threatens indigenous people, survival of rare species, and earth’s climate.