DENDROLOGY

Detailed explanation-1: -Primary succession occurs after a volcanic eruption or earthquake; it involves the breakdown of rocks by lichens to create new, nutrient-rich soils. The first species to colonize an area after a major disturbance are called pioneer species; they help to form the new environment.

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: -Secondary Succession This type of succession is faster because the soil is already in place. In this case, the pioneer species are plants such as grasses, birch trees, and fireweed.