A rocky island appears as oceanic waters recede. Which of the following forms of vegetation would probably appear first on the bare rocks?
A. Shrubs.
B. Weeds.
C. Lichens.
D. Pioneer trees.
A lichen is an example of a pioneer organism, one of the first organisms to inhabit an area. Succession on land usually starts with lichen on bare rock, which will build up soil, allowing weeds to grow. The weeds soon get crowded out by the shrubs, which then get overpowered by the trees.