AP BIOLOGY

Detailed explanation-1: -Pioneer species help in ecological succession by preparing an environment for later species. In primary succession, pioneer species move into barren, rocky landscapes that cannot support other living species. They help to break down rocks into soil and then enrich the soil with decaying organic matter when they die.

Detailed explanation-2: -Lichens are considered as pioneer species in primary succession on rocks because they can easily grow on rocks where other plants cannot grow. They produce oxalic acid which induced the weathering of rocks and thus soil is formed.

Detailed explanation-3: -The Importance of Pioneer Species Because pioneer species are the first to return after a disturbance, they are the first stage of succession, and their presence increases the diversity in a region. They are usually a hardy plant, algae or moss that can withstand a hostile environment.

Detailed explanation-4: -The first organisms appearing in the regions of primary succession are pioneer species (usually lichens or mosses). They are the first species present. They must be strong and hardy. The development of a new community is succession.

Detailed explanation-5: -Pioneer species are important to the evolution of an ecosystem. The presence of barren land means the land cannot change into soil without the life processes of pioneer species. This is why lichens are such successful pioneers. As the lichens colonize bare rock, they secrete acids that slowly break down rock.