B.11B Ecological Succession 🏖️

___ are the first organisms to colonize an area and begin the process of ecological succession.

• foundational organisms

• introductory organisms

• primary organisms

• pioneer species

The picture shows what type of succession?

• primary

• secondary

• tertiary

• pond succession

The picture shows what type of succession?

• primary

• secondary

• tertiary

• quaternary

Between 2005 and 2016 Kenai Fjords in Alaska experienced an increase in exposed rock due to melting ice. The rock formations are known as "nunataks" which are the tips of mountains that were left uncovered by glaciers in the last ice age. Nunataks are shown in the image.

Which time line describes how plant diversity on the nunataks will change over time?

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The table shows the predominant plant types on a piece of land in the years following a disturbance.

Based on the data in the table, which disturbance most likely led to this progression?

• A glacier retreat

• A volcanic island formed

• A plowed field was abandoned

• A new sand dune was formed

After a wheat field is cleared, wild grasses and weeds begin growing.

This process is considered--

• Primary succession because pioneer species appear

• Primary succession because there are no large trees

• Secondary succession because soil is already present

• Secondary succession because the field contains inorganic matter

Sand dunes along the coast are formed of bare sand. Eventually, grasses take root on the dunes. Over time, larger plants such as shrubs and trees are able to grow at the edge of the sand dune ecosystem.

This gradual change in plant communities of a sand dune ecosystem can result in --

• reduced symbiotic relationships between producers and bacteria

• reduced energy absorption by consumers

• greater erosion rates

• greater species diversity

During secondary succession, which of these best describes why decomposing pioneer plants give way to larger, more complex plant species, such as hardwood trees?

• Increased amounts of sunlight are able to reach the ground while the pioneer species are decomposing

• Increases soil temperatures from decomposing pioneer species help tree seeds germinate more quickly

• Increased amounts of decomposing pioneer species remove nutrients that tree seedlings need to grow and mature

• Increased amounts of soil from decomposing pioneer species allow plants with more extensive root systems to become stablished

Grasslands ecosystems in Texas have evolved to depend on periodic fires to return nutrients to the soil and encourage plant production. Humans have prevented fires in many of these grassland areas, resulting in plant and animal communities with little diversity. Wildlife biologists often recommend purposefully starting fires called prescribed burns, which are monitored and controlled, in grassland ecosystems every 3-4 years. These biologists observe greater diversity in plant and animal life in the years following a prescribed burn.

What natural processes are the biologists attempting to imitate?

• Biomagnification

• Succession

• Population bottleneck

• Species extinction

Match the following

• secondary sucession

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• pioneer species

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• Primary succession

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• climax community

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