apes unit 2 slide show 4

What is ecological succession?

A series of predictable stages of growth that an ecosystem (like a forest) goes through.

What are the two main types of succession?

Primary succession and secondary succession.

What is primary succession?

Succession that starts from bare rock and an area with no soil.

What organisms typically begin primary succession?

Early organisms like mosses and lichens.

How do mosses and lichens contribute to soil formation?

They secrete acids that break down rock, releasing minerals (N, P, K) and combining with organic matter to form shallow soil.

What minerals do mosses and lichens release?

Nitrogen, phosphorus, and potassium (N/P/K).

What is a pioneer species?

Organisms that appear when the ground is bare and mostly rock after a disturbance.

What disturbances lead to pioneer species colonization?

Volcanic eruptions, mining pits, glacial retreats.

What are characteristics of pioneer species?

Fast growing, tolerant of shallow/no soil, need full sunlight.

What are examples of pioneer species?

Mosses, lichens, wildflowers, raspberries, grasses.

What are mid-successional species?

Species that appear after soil has developed and nutrients have accumulated.

What are characteristics of mid-successional species?

Fast growing, larger plants that need nutrient-rich soil and deeper roots.

What are examples of mid-successional species?

Bushes, shrubs, aspen, cherry, pine.

What are late successional (climax community) species?

Species that appear last when soil is nutrient-rich and deep.

What are characteristics of late successional species?

Large, slow-growing, shade tolerant, need deep soil for big root systems.

What are examples of late successional species?

Maples, oaks, and other large trees.

What is secondary succession?

Succession that occurs in areas with established soil where most plant life has been removed by disturbances.

How do pioneer species colonize in secondary succession?

By wind dispersal and seeds of larger plants that take root in the existing soil.

How can fire affect secondary succession?

Leaves nutrient-rich ash that enriches soil, speeding recovery.

What is a keystone species?

A species that is critical to ecosystem function; without it, the system may collapse.

What are examples of keystone species?

Otters (control sea urchins), elephants (maintain savanna by trampling).

What is a foundation species?

A species that creates and maintains habitat for other species (“ecosystem engineers”).

What are examples of foundation species?

Beavers and kelp.

What is an indicator species?

A species that reveals environmental changes in an ecosystem.

What are examples of indicator species?

Crayfish (freshwater quality), oysters and other filter feeders, frogs.