Which of the following is a disturbance event that could initiate succession?
A forest fire can remove vegetation, alter resource availability, and open space, thereby initiating a new successional trajectory. Depending on fire severity, soil and many belowground propagules may remain, making the subsequent process secondary succession rather than primary succession. A disturbance changes the availability of space, resources, and biological legacies, creating opportunities for colonization. Whether succession is primary or secondary depends chiefly on the starting substrate and survival of soil, not simply on the identity of the disturbance. Colonists must arrive, establish, reproduce, and interact with residents; meanwhile they alter nutrient cycling, shade, moisture, and physical structure. These feedbacks create directional replacement, although repeated disturbance or environmental change may interrupt, reverse, or redirect the sequence. In this context, the keyed term, Forest fire, identifies the relevant mechanism or quantitative relationship and links the observed pattern to its underlying ecological cause. The distinction is testable by measuring changes in organisms, resources, or process rates through time rather than relying on the label alone.
Ref: Ecology: Concepts and Applications, Molles, 9th Ed., Ch. 20