A classic example of secondary succession is an abandoned farm field gradually returning to forest over the course of decades. Unlike primary succession, which starts on bare rock or new land with no soil at all, secondary succession begins where soil, seeds, and root systems already exist. This head start means life returns much faster, often visibly within a single growing season.
Abandoned Farmland: A Step-by-Step Example
When a farmer stops plowing a field and walks away, the land doesn’t stay bare for long. The sequence that follows has been closely studied in the Virginia Piedmont region of the eastern United States, and it unfolds in a remarkably predictable pattern.
In the first two years, fast-growing annual plants like crabgrass and horseweed blanket the field. These species thrive on bare soil and full sunlight, and they sprout quickly from seeds already sitting in the ground. By year three, a perennial grass called broomsedge takes over and dominates the field. Around year five, scattered pine seedlings, eastern redcedar, and blackberry bushes begin appearing, as long as mature trees nearby can supply seeds. Over the next several decades, those pines grow into a dense canopy that shades out the grasses and sun-loving plants beneath them. Eventually the pines themselves start dying off, replaced by slower-growing hardwood trees like white oak and mockernut hickory. After roughly 200 years, what started as an empty farm field has become a mature hardwood forest.
Why Secondary Succession Moves So Fast
The key difference between secondary and primary succession is what’s already in the ground. After a disturbance like farming, fire, or a storm, the soil still contains organic matter, nutrients, fungal networks, and a bank of dormant seeds waiting for the right conditions. Pioneer species of secondary succession encounter a resource-rich environment where competition has been temporarily reduced. That combination of available nutrients and open space lets plants establish rapidly.
Pioneer species share a few traits that make them first on the scene. They grow fast, reproduce quickly, and need full sunlight. Some of the fastest-growing plant species on Earth are pioneer herbs and shrubs, many of which are familiar as agricultural weeds. But that speed comes with a tradeoff: pioneers grow well in bright, open conditions but can’t survive in shade. Once taller species move in and block the light, the pioneers disappear. This built-in limitation is what keeps succession rolling forward rather than stalling at the first stage.
Yellowstone After the 1988 Fires
The massive wildfires that burned through Yellowstone National Park in 1988 offer one of the best-documented examples of secondary succession on a large scale. Before the fires, the park’s high volcanic plateau was covered in dense stands of tall, straight pine trees, broken up by grassy river meadows and occasional brush plains. After the fires swept through, those forests were reduced to charred trees and blackened grasses.
Recovery began almost immediately. In the first few growing seasons, grasses and wildflowers sprang up from the ashes. Over the following years, tiny pine seedlings took root among the new ground cover and began growing toward the canopy. By 2019, thirty-one years after the fires, much of the burned area was covered again by trees and vegetation, though the burn scars were still visible from satellite imagery. NASA scientists tracking the recovery noted that in Yellowstone’s environment, it will take additional decades for the forest to fully reach its former state. The soil, seeds, and root systems that survived underground gave the ecosystem a foundation that bare rock never could have provided.
Other Common Examples
Secondary succession happens in many different settings, not just forests. A few common scenarios:
- After logging: Clearcut forests regrow through the same grass-to-shrub-to-tree sequence, though the timeline depends heavily on soil health. Near Mount St. Helens, areas that had been clearcut before the 1980 eruption and lost their topsoil were still largely barren decades later, while areas with intact soil recovered far more quickly.
- After hurricanes or windstorms: When a storm topples mature trees, sunlight floods the forest floor and triggers a burst of growth from shade-suppressed seedlings and dormant seeds. In tropical forests, treefalls create canopy gaps where pioneer tree species rapidly colonize the opening.
- After flooding: River floodplains that get scoured by major floods regrow riparian vegetation once water levels recede. On California’s Cosumnes River, reconnecting the river to its historical floodplain led to renewed flooding that promoted natural riparian vegetation establishment across the landscape.
What a Climax Community Looks Like
The endpoint of succession is sometimes called a climax community. This is the relatively stable collection of species that persists once the ecosystem matures, assuming no new major disturbance resets the clock. In the eastern United States, that typically means a hardwood forest dominated by oaks and hickories. In central southern Florida, the climax community on sandy soils is a scrub-pine forest. The specific species depend on climate, soil type, and geography.
In reality, most ecosystems never sit perfectly still at their climax stage. Insect outbreaks, disease, small fires, and storms periodically knock back portions of even mature forests, creating a patchwork of areas at different stages of succession happening simultaneously. A “climax” forest is better understood as a general state the ecosystem tends toward rather than a fixed destination it reaches and never leaves.