What is a pioneer plant?

According to Hope College, pioneer plants are those species that can only grow in cleared forested areas or otherwise disturbed areas where light penetrates to the ground in unusual amounts. These plants rely upon the disturbance of a rainforest canopy, for example, to establish themselves; they are considered pioneers because they are often the first plants to reestablish in an area cleared by events such as forest fires or logging.

Pioneer plants colonize in areas that have recently been deprived of tall trees, dense brush and other plant matter that blocks sunshine. These plants take advantage of the new sunny areas, but they cannot compete in heavily shaded areas.