What is Ecological Succession?

A volcanic eruption creates a new island of bare lava rock. Describe the succession that follows.

This is primary succession because there is no soil at the start.
Lichens and mosses arrive first as pioneer species and break down the rock.
Dead lichen matter mixes with rock particles to form thin soil.
Grasses, then shrubs, then trees colonize as soil deepens and matures.
A climax forest community eventually stabilizes on the island.

A forest fire burns through a woodland but leaves the soil intact. What type of succession occurs, and how does it differ from succession on bare rock?

Because soil, seeds, and roots already exist, this is secondary succession.
Secondary succession skips the slow soil-building stage of primary succession.
Fast-growing grasses and weeds appear within months.
Shrubs and fast-growing trees follow within a few years.
A climax community re-establishes much faster than primary succession, often in decades rather than centuries.

An abandoned farm field is left untouched. Rank the order in which grasses, shrubs, and forest trees are expected to appear.

This is secondary succession since farmland already has soil.
Order of appearance: grasses and weeds first (fast-growing, sun-loving).
Then shrubs and small sun-tolerant trees establish.
Finally, shade-tolerant trees grow up and form a mature forest, the climax community.