Environmental Science: Chapter 5-4 Community Stability

Chapter 5-4: Community Stability

Multiple Choice

The organism shown in the picture is a primary consumer

• True

• False

Multiple Choice

Oxpeckers are a small bird commonly found on rhinoceroses. The oxpecker feeds on the parasites that cover the rhinoceroses’ skin. The bird gets a meal and the rhinoceros is relieved of the harmful parasites.

• mutalism

• parasitism

• commensalism

• predation

Multiple Choice

Which of the following is another word for a plant?

• autotroph
• heterotroph
• consumer

Multiple Choice

In the energy pyramid here, which organisms have the most energy available?

• Producers
• Carnivores
• Herbivores
• Top Predator

Multiple Choice

The largest group of organisms found in a food web would be:

• Primary Consumers
• Producers
• Decomposers
• Tertiary Consumers

Multiple Choice

What may happen if the snowshoe hare was removed from the food web pictured?

• The insects in the habitat would increase.
• The shrew population would decrease due to being only hawk food source.
• The willow tree population would decrease.
• Foxes would dies due to no food source. 

Lesson Objectives

• Describe what happens to a community after a disturbance

• Explain the conditions necessary for a species to become invasive

Introduction

• Disturbance: any change in a community's environment

  • can be large or small

  • Are both natural and man made

• Disturbances can modify the composition, structure, or function of an ecosystem

  • How ecosystems respond to a disturbance can reveal their stability

Ecological Succession

• A community can be in equilibrium or disequilibrium

  • Equilibrium: stable and balanced

  • Disequilibrium: Unstable and unbalanced

• If thrown into disequilibrium, a community is changed permanently

• Succession: A series of changes over time where an ecosystem follows a predictable series of changes in response to a disturbance

  • Two types

Primary Succession

• Primary Succession: Occurs when a disturbance is so severe that no vegetation or soil remains and the community is rebuilt from scratch

• Follows a certain order

  • Pioneer Species: Species that colonize newly exposed land first.

    • Lichens tend to be the first pioneer species

      • Release acids that break down rocks to make soil for other organisms

Secondary Succession

• Secondary Succession: occurs when a disturbance alters a community, but does not destroy all living things or organic matter in the soil

  • The soil from the previous ecosystem remains, so succession occurs faster than primary succession

Succession In The Water

• Primary aquatic succession: when an area fills with water for the first time

  • Over time the water becomes rich in nutrients

• Disturbances in aquatic communities can lead to secondary succession

  • Eventually, the water may fill in completely

Climax Communities

• Climax Community: A stable community that "completes" the succession process

  • Were once thought to be the end stage of a community

  • Now known to be a temporary state, still affected by small disturbances

Multiple Choice

Primary succession occurs in an area that has:

• Has Soil

• Has No Soil

• Has Some Soil

• none of these

Multiple Choice

What is the main difference between primary and secondary ecological succession?

• Primary begins WITHOUT soil; Secondary begins WITH soil

• Primary is the first state and secondary is the second stage

• Primary builds plant community; secondary builds animal community.

• Primary begins WITH soil; Secondary begins WITHOUT soil

Multiple Choice

What is the term that describes a steady and stable community?

• peak community

• turf community

• climax community

• disturbed community

Multiple Choice

Which is faster: Primary or Secondary Succession?

• Primary Succession

• Secondary Succession

• Both Take The Same Amount of Time

Multiple Choice

Which of the following organism is often a pioneer species

• Grasses

• Otters

• Lichen

• Spruces

Categorize

Options (5)

Takes a long time

Rebuilds the ecosystem from scratch

depends on pioneer species

Takes less time

starts with soil from the previous ecosystem

Organize the descriptions into primary succession or secondary succession

Primary

Secondary

Invasive Species

• Invasive Species: a nonnative organism that spreads within a community

  • A species introduced to an area that it normally would not live in

    • Has no predators to limit its growth and reproduction

  • Cause a disturbance for the ecosystem by out competing native organisms

The Zebra Mussel

• Invasive to Lake Erie

  • First introduced in 1990 by attaching themselves to boats

• Have Colonized more than 40% of the US Watershed

• Attach themselves to other organisms and hurt them

  • Produce toxins that poison larger animals

The Cane Toad

The Honeybee

• The European Honeybee was brought to the United States by settlers

• Are seen as a benefit to the people who live in the area due to their ability to pollinate crops

Multiple Choice

What is an invasive species?

• An organism that is new to an environment that has positive effects on the environment.

• An organism that is native to an environment that has negative effects on the environment.

• An organism that is new to an environment that has negative effects on the environment.

• An organism that is native to an environment that has positive effects on the environment.

Multiple Choice

Invasive species can have a major impact on the ecosystem.

• TRUE

• FALSE