How do trees compete for light in tropical rainforests?

In tropical rainforests, light is a critical and limited resource, with only about 1 percent of sunlight reaching the forest floor. Trees and other plants compete for this energy through several distinct strategies:1

• Canopy Gaps: Most tree species require openings in the canopy to receive enough light to reach maturity. When a large tree falls—often due to storms or the weight of epiphytes—it creates a gap that allows solar radiation to reach the lower levels, triggering rapid growth among seedlings and saplings.213
• Life-History Trade-offs: Tree species have evolved along a continuum of light requirements. Pioneer species, such as balsa, grow rapidly in high-light conditions but have high mortality in the shade. Conversely, shade-tolerant species grow slowly and can persist in low-light environments until a gap provides the opportunity to emerge.21
• Structural Adaptations: Many plants avoid the energy-intensive process of developing large trunks by using other trees for support. Lianas are woody vines that climb toward the canopy to place their leaves in well-lit areas. Stranglers, such as the strangler fig, begin life as epiphytes in the canopy and grow roots downward, eventually shading out and outcompeting their host tree for light.14