Primary & Secondary Succession

This week in science, we talked about primary and secondary succession. Primary succession is when there is no soil left after a natural or man-made disaster. For example, if a volcano erupted and covered 5 miles with lava, when the lava died down there would be no soil. This would be primary succession. Another example is if a glacier is melting or slowly receding, what would be left would be just rocks, which is also primary succession. Pioneer species play a big part in primary succession. A pioneer species is the first thing to grow somewhere such as moss, lichen or algae. They will eat away at the rock and form soil where there was no soil, allowing the second stage of growth to happen such as grass, weeds and small plants. The third stage of growth would be small bushes, shrubs and bigger plants like ferns and tall grasses. The fourth stage would be small trees like aspen or dune trees, bigger bushes. The fifth stage would be small pine trees, beech and birch trees. The last stage would be bigger pines and oaks.

Secondary succession is when there is soil left after a natural or man-made disaster. For example, after a tornado trees could be ripped up but there would still be soil left. Another example is after a flood, all of the trees and bushes might be wiped out but there would still be soil. The first stage of secondary succession is weeds and grasses start to grow. The second stage is small shrubs and bigger plants start to grow. The third stage is that small trees and bigger bushes start to grow. The fourth stage is small pines, beech and birch trees. The fifth stage is oak trees and bigger pines. Did you notice that pioneer species are not included in secondary succession? This is because there is already soil, so no soil needs to be formed.