A tree-fall gap in a mature forest often leads to the growth of which type of plants?

• A. Shade-tolerant species
• B. Shade-intolerant species
• C. Aquatic plants
• D. Epiphytic plants on trees

Answer: (B)

A tree-fall gap suddenly increases light and space on the forest floor, creating a bright, open environment. In that light, fast-growing, sun-loving plants establish quickly, so shade-intolerant species are the ones that dominate the new openings. Shade-tolerant plants are built to grow under dimmer conditions and tend to be slower to colonize a bright gap, so they aren’t the immediate responders. The gap also favors species that can complete their growth cycle rapidly and produce many seeds, traits typical of shade-intolerant or pioneer plants. Epiphytic plants on trees and aquatic plants aren’t the primary players in this new ground-level light niche, so they don’t best explain the immediate response to a canopy opening.