Tear off the SIGNED portion of the brochure January 18, 2012 Tear off the SIGNED portion of the brochure Concept: Ecological Succession Instruction: Cornell Notes bell ringer Assignment: succession sequence card sort

Nature’s Recovery The land around Mount Saint Helens once was a thriving forest. But the mountain is an active volcano. It erupted on May 17, 1980, spewing rock, ash, and steam. For a few weeks, the land near the volcano seemed as Barren and empty as the Moon. Yet living things eventually grew there again. Often fireweed, the plant shown in the photo, is the first plant to appear after a forest has been destroyed. 1. Other than a volcanic eruption, what types of events could destroy a forest? 2. Could animals live on the land shown here? Explain. 3. Do you think this land will ever be a forest again? Could animals return? Discuss.

Set your next right side for Cornell notes Set your next right side for Cornell notes. Title: Ecological Succession

Ecological succession is the process of one ecological community gradually changing into another. Ecological succession occurs in a series of steps. These steps can usually be predicted. For example, small plants usually grow in an ecosystem before trees do.

The final stage of ecological succession in a land ecosystem is a climax community—a stable community that no longer goes through major ecological changes. Climax communities differ depending on the type of biome they are in. In a grassland biome, mature grassland is the climax community. Climax communities are usually stable over hundreds of years. As plants die, new plants of the same species grow as long as the climate stays the same.

Primary Succession What do you think happens to a lava-filled landscape when a volcanic eruption is over? Volcanic lava eventually becomes new soil. This new soil supports plant growth. Ecological succession in new areas of land with little or no soil, such as on a lava flow, a sand dune, or exposed rock, is called primary succession. The first species that colonize new or undisturbed land are pioneer species. Lichens and mosses are pioneer species.

Secondary Succession Secondary succession occurs in areas where existing ecosystems have been disturbed or destroyed. One example is forestland in New England. Early colonists cleared land hundreds of years ago. Some of the cleared land was not planted with crops. This land gradually grew back to a climax forest community of beech and maple trees.

During a volcanic eruption, molten lava flows over the ground and into the water. After the eruption is over, the lava cools and hardens into bare rock.

Lichen spores carried on the wind settle on the rock Lichen spores carried on the wind settle on the rock. Lichens release acid that helps break down the rock and create soil. Lichens add nutrients to the soil as they die and decay.

Airborne spores from mosses and ferns settle on the thin soil and add to the soil when they die. The soil becomes thick enough to hold water. Insects and other small organisms begin living in the area.

After many years, the soil is deep and has enough nutrients for grasses, wildflowers, shrubs, and trees to grow. The new ecosystem provides habitats for animals. Eventually, a climax community develops.

Settlers in North America cleared many acres of forests to plant their crops. On land where people stopped planting crops, the forests began to grow back.

Seeds of grasses, wildflowers, and other plants began to sprout and grow. Young shrubs and trees also started growing. These plants were habitats for insects and other small animals, such as mice.

White pines and poplars were the first trees in the area to grow tall White pines and poplars were the first trees in the area to grow tall. They provided shade and protection to trees that grow slower, such as beeches and maples.

Eventually, a climax community of beech and maple trees developed Eventually, a climax community of beech and maple trees developed. As older trees die, new beech and maple trees grow and replace them.

The climax community in the area of Michigan is a beech-maple forest The climax community in the area of Michigan is a beech-maple forest. After the ponds are filled in, the area will undergo another series of stages of succession. This is illustrated below. Briefly explain what is happening in the diagram. ____________________________________________________________