In an ecological succession, which of the following pioneer species would most likely colonize a bare rock surface in a temperate region?
Correct: B
Pioneer species are the first organisms to colonize barren or disturbed habitats. On bare rock surfaces, lichens and mosses are the typical pioneer species because they can withstand extreme conditions, can fix nitrogen (lichens), and can break down rock to begin soil formation through weathering. Over time, they create a thin layer of soil that allows mosses and later herbaceous plants to establish. Oak trees and deciduous shrubs are part of later successional stages or climax communities, not pioneer stages.