Unit 8: Environmental Stewardship · Lesson 7
Environmental Stewardship - Lesson 7
What this lesson is for
- Students will explore and observe Environmental Stewardship - Lesson 7
- Students will describe what they learned about God's creation
For by him were all things created, that are in heaven, and that are in earth, visible and invisible.
Colossians 1:16
Invasive Species Management
An invasive species is a non-native organism introduced (intentionally or accidentally) to an area where it has no natural predators, competitors, or pathogens — allowing it to spread aggressively and damage native ecosystems.
Why invasions succeed: Native species evolve in balance with their enemies. Without those controls, invasives can grow unchecked. The "enemy release hypothesis" explains why so many invasives thrive abroad but are controlled at home.
Famous examples:
- Kudzu in the American Southeast: Imported from Japan for erosion control. Now covers millions of acres, smothering native vegetation at a rate of 150,000 acres/year.
- Zebra mussels in the Great Lakes: Arrived in ballast water from Eastern Europe (1988). Filter phytoplankton so efficiently they starve native fish larvae; clog water intake pipes; cause billions in damage annually.
- Cane toad in Australia: Introduced to control cane beetles (1935). Highly toxic, no native predators. Now 200+ million spread across tropical Australia, poisoning native predators who try to eat them.
- Brown tree snake in Guam: Accidentally introduced after WWII. Has driven 12 of 22 native forest bird species extinct on the island.
- Asian carp in the Mississippi River basin: Threaten to enter and devastate the Great Lakes fishery.
Management approaches:
- Prevention: Border inspections, ballast water treatment, pet trade regulation
- Mechanical removal: Hand-pulling, trapping, physical barriers
- Chemical control: Targeted herbicides/pesticides (risk of non-target effects)
- Biological control: Introducing natural enemies from the home range (requires years of study to avoid creating new invasion problems)
Christian stewardship angle: Introducing species carelessly is a failure of stewardship. The same "dominion" mandate that authorizes responsible use of creation also calls us to careful management.
Practice: Research one invasive species in your region. What is being done to control it?
Homework
Write a short paragraph about Environmental stewardship - lesson 7.
Note for the parent
Today's lesson covers Environmental Stewardship - Lesson 7. Estimated time: 50 minutes. Encourage independent work but be available for questions.
The first three of this lesson's 10 questions
The 'enemy release hypothesis' explains why invasive species often thrive in new regions because:
Show the answer
Answer: In their native range they are controlled by predators, diseases, and competitors — which are absent in the new region
Kudzu was imported to the American Southeast from Japan for:
Show the answer
Answer: Erosion control — but it now covers millions of acres smothering native vegetation
Zebra mussels in the Great Lakes cause damage primarily by:
Show the answer
Answer: Filtering phytoplankton so efficiently that native fish larvae starve; also clogging water intake pipes
Another 7 questions follow in the lesson itself, each one graded the moment it is answered.