Primary Succession vs Secondary Succession

What is the first step in primary succession?

• Growth of large trees

• Colonization by pioneer species

• Soil erosion

• Formation of a climax community

Answer explanation

The first step in primary succession is colonization by pioneer species, which are the first organisms to inhabit a barren environment, paving the way for further ecological development.

What is an example of a location currently undergoing primary succession?

• A forest recovering from a fire

• A newly formed volcanic island

• A field after farming

• A riverbank after flooding

Answer explanation

A newly formed volcanic island is an example of primary succession because it starts from bare rock, where life begins to colonize for the first time. Other options involve areas that have existing soil and life.

What type of species often dominates primary succession?

• Large trees

• Grasses and shrubs

• Pioneer species like lichens

• Animals

Answer explanation

Pioneer species like lichens are the first organisms to colonize barren environments during primary succession. They help create soil, allowing other plants to establish later, making them crucial for ecosystem development.

After a forest fire, an ecosystem would start regrowth through -

• primary succession

• secondary succession

• climax community

• limiting factors

Tags

NGSS.MS-LS2-3

Natural disturbances, such as fires or hurricanes, can result in

• A.parasitism.

• B.competition.

• C.commensalism.

• D.succession.

Tags

NGSS.MS-LS2-2

NGSS.MS-LS2-4

Which of the following events can trigger primary succession?

• A forest fire

• A volcanic eruption

• A hurricane

• Deforestation

Answer explanation

A volcanic eruption can create new land and environments, allowing life to start from bare rock, which is characteristic of primary succession. Other events like forest fires and hurricanes may lead to secondary succession.

What role do pioneer species play in soil formation?

• They consume all nutrients

• They break down rocks and contribute organic material

• They prevent other species from growing

• They have no effect on soil

Answer explanation

Pioneer species play a crucial role in soil formation by breaking down rocks through physical and chemical processes, and they contribute organic material as they die and decompose, enriching the soil for future plant growth.

After a disturbance, why is secondary succession generally faster?

• More sunlight is available

• Soil is already present

• There is less competition

• Water is more abundant

Answer explanation

Secondary succession is faster because soil is already present, providing nutrients and a substrate for new plants to grow. This contrasts with primary succession, where soil must form from bare rock.

Which of the following is a sign of secondary succession?

• Bare rock

• Rapid regrowth of plants

• No vegetation

• Only pioneer species present

Answer explanation

Secondary succession occurs in areas where a disturbance has cleared existing vegetation but soil remains. Rapid regrowth of plants indicates recovery, unlike bare rock or only pioneer species, which are signs of primary succession.

What is the main difference between primary and secondary succession?

• Primary succession starts on bare rock, while secondary succession starts on existing soil.

• Primary succession occurs after a disturbance, while secondary succession occurs on new land.

• Primary succession involves only plants, while secondary succession involves animals.

• Primary succession is faster than secondary succession.