The branches and leaves of gigantic trees form the intricate canopy of the tropical rainforest. Trees searching for light create the canopy, and the canopy in turn limits evaporation of moisture from lower levels of the ecosystem. Many creatures live their entire lives in the upper reaches of the rainforest, never venturing down to the sweltering forest floor where there is no wind and little light. The world will be a much poorer place if these magnificent forests are lost.