Rapid glacial retreat in the last 200 years at Glacier Bay, Alaska, has created a natural laboratory for the study of primary succession. The plant succession at Glacier Bay is accompanied by other ecological changes, such as soil development. Primary Succession in the tundra would probably begin after a glacier has retreated. In primary succession pioneer species like mosses, lichen, algae and fungus as well as other abiotic factors like wind and water start to "normalize" the habitat. When the earth warmed the glaciers retreated and left behind land that was lifeless and rocky. It took a very long time before pioneer plants like lichen started to grow on these rocks. In time, rocks broken down by the lichens mixed with decaying lichens and formed the first soil. Wind also blew dust, which congregated in small cracks in rocks where moss and small plants started to grow. Like lichens, moss obtains water by absorbing moisture in the air. Soon, more moss and more soil forms. Decaying moss mixes with rock chips and dust to form more soil. Because of this, grass begins to grow in the area. As soil becomes more plentiful, more and more plants begin to grow. These stages of soil and plant sophistication are called primary succession. A good example of primary succession is a receding glacier because land is continually being exposed as the face of the glacier moves back. The glacier that composes much of the head of Glacier Bay, Alaska, has receded some 100 km (62 mi) over the last 200 years.
Secondary Succession in the Glacier Bay would begin after a tundra fire. Tundra fires are rare because they must reach a certain threshold before spreading. The sparse vegetation makes it difficult for fires to take hold. When an event, like a fire or a hurricane, reduces an already established ecosystem, but the soil remains and succession then follows. This is faster than primary succession because the soil is already present. In the tundra this could occur after a fire or a mudslide.
Humans have a big impact on the succession of Glacier Bay and it is very vulnerable to the human impact. A lot of people that visit the park do not dispose of waster properly and this causes an effect on the campers and wildlife. The action of these people impact the behavior and habitats of the animals. Also people hunt and fish which can cause low population and maybe even extinction of an animal. This can cause an animal to be removed from the food web. All of the things can be avoided if everyone is more careful when camping in the park.