AP BIOLOGY

Detailed explanation-1: -Secondary succession begins in areas where natural biotic communities have been destroyed, such as in abandoned farmlands, burned or cut forests, lands that have been flooded. Since some soil or sediment is present, secondary succession is faster than primary succession.

Detailed explanation-2: -The process of primary succession can take hundreds, if not thousands, of years. In contrast, the process of secondary succession can reestablish an ecosystem’s climax communities in as few as 50 years. The ecosystem’s animal populations are also established more quickly during secondary succession.

Detailed explanation-3: -Secondary succession is more common and usually occurs faster than primary succession because the substrate is already present. Secondary succession occurs on a surface where an ecosystem has previously existed. This happens after some sort of disturbance.

Detailed explanation-4: -Secondary succession is usually faster than primary succession because soil and nutrients are already present due to ‘normalization’ by previous pioneer species, and because roots, seeds and other biotic organisms may still be present within the substrate.