Practice question

A secondary forest develops after a disturbance removes or damages an earlier forest but leaves a biological legacy, especially soil. Fire, storms, logging, shifting cultivation, or abandoned farmland can initiate this recovery. Seeds in the soil, surviving roots and stumps, nearby seed sources, microbes, nutrients, and existing soil structure allow vegetation to return faster than during primary succession on newly exposed rock. Early colonists are often fast-growing, light-demanding herbs, shrubs, and trees. As their canopy develops, shade, litter, soil moisture, and competition change, allowing more shade-tolerant species to establish. A primary forest is usually one that has not experienced recent major human clearing and has developed over a long period; “climax forest” is an older equilibrium concept, not the general name for post-disturbance regrowth. Mangrove forest is defined by intertidal habitat and salt tolerance, not by successional origin. Secondary forests can recover substantial biomass and biodiversity, but their composition may differ for decades or longer. Retained soil and propagules are therefore the mechanism linking disturbance to secondary forest formation.