Succession has helped people to understand that natural disasters; for example, tornadoes, melting of glaciers, hurricanes, volcanoes, etc., are not always bad things to happen. Even though these disasters may bring destruction, devastation, and death, the final outcome after the effect of succession usually means new life. Primary succession and secondary succession are two types of succession that effect the environment.
"Primary succession is the change in species composition over time in a previously uninhabited environment" (Raven & Berg, 2006). In figure 4-4 of the text the pictures are showing the changes of Glacier Bay, Alaska. In the beginning photograph it is showing what the land looked like after the retreating of the glacier. The land was uninhabited and very desolate with rock, dirt and very little plant life. In the second picture is the showing how dwarf plants and shrubs are beginning to cover the land. The last picture is showing how larger spruces are colonizing trees.
These photographs are showing the gradual change in the environment due to primary succession.
"Secondary succession is the change in species composition that takes place after some disturbance destroys the existing vegetation; soil is already present" (Raven & Berg, 2006). In figure 4-5 of the text the picture is showing the gradual change in vegetation after a fire or desertion of land. If the land is deserted and not taken care of or the land is taken over by fire all the vegetation is lost. Gradually over time the vegetation will slowly come back and grow just a fully as it was before or sometimes even more. Scientists were excited to be able to observe secondary succession in 1988 because they were going to be able to observe how secondary succession worked after the fire in Yellowstone National Park. They were able...