Primary and Secondary Succession
Primary succession usually occurs where there has been no previous life. A few examples of these places include newly exposed rock areas, sand dunes, newly created ponds, and lava flows. Simple species that can handle living in these harsh conditions are the species that arise first. Secondary succession is when an area retains some life but it has been denuded in some way. A farmers field could be an example of secondary succession. There could have been a forest that used to be where the field is now.
The picture to the left is an example of primary succession. First, it starts out as bare rock. Then, as time goes on, mosses and lichen start to grown. When the moss and lichens die, they help form soil. The soil then develops and grasses and small plants start to grow. Next, the soil starts to thicken and then smaller shrubs begin to grow. Finally, you start seeing trees growing in these areas that once started as bare rock.
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This prairie fire is an example of secondary succession. Since the grasses have such deep roots, after the fire burns the grass on the surface, the grass starts to grow again and it never dies. The cause of succession in the temperate grasslands is the climate. Since it gets so hot, the prairies sometimes catch on fire.
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