Ecological Interactions
Unit Plan
Ecological Interactions
Objectives
In this unit, students will learn that all species, including humans, are part of an interconnected global food web. A balance of these ecological interactions within a system is essential to the health and sustainability of the ecosystem. This unit explores the interdependence between biotic and abiotic components of an ecosystem. Students will:
- describe how living organisms affect the survival of one another.
- explain the biotic and abiotic parts of an ecosystem and their interactions.
- predict how limiting factors such as physical, biological, chemical factors, etc. can affect organisms.
- use evidence to explain how patterns in populations affect natural systems.
Essential Questions
Related Unit and Lesson Plans
Related Materials & Resources
The possible inclusion of commercial websites below is not an implied endorsement of their products, which are not free, and are not required for this lesson plan.
- National Aeronautics and Space Administration http://www.nasa.gov/home/index.html
- National Oceanic and Atmospheric Administration: http://www.noaa.gov/
- Google Earth: http://earth.google.com/
Formative Assessment
-
View
Multiple Choice Items:
1. Which two biomes are the most similar with regard to rainfall?
A tundra and taiga
B tundra and desert
C rain forest and savanna
D temperate forest and prairie2. Which biome is characterized by a layer of permafrost?
A taiga
B savanna
C chaparral
D tundra3. Biodiversity is greatest in which biome?
A taiga
B polar
C rain forest
D savanna4. The eastern portion of the United States is dominated by which biome?
A temperate forest
B desert
C taiga
D prairie5. In which biome of Africa would you find lions, giraffes, and elephants?
A savanna
B chaparral
C desert
D tropical rain forest6. All the different species of an ecosystem are referred to as the:
A biome
B community
C population
D abiotic factors7. Which of the following would represent an ecosystem?
A lake
B fish tank
C prairie
D all of these8. All the nonliving parts of an ecosystem are referred to as:
A the community
B biotic factors
C abiotic factors
D biomes9. Which of the following would be a biotic factor in an ecosystem?
A bacteria
B soil
C temperature
D rainfall10. The types and numbers of species in a given area are most greatly determined by the area’s:
A biotic factors
B precipitation
C climate
D biodiversity11. A population that is growing exponentially in the absence of limiting factors can be illustrated by a(n) ________.
A S-shaped curve
B J-shaped curve
C curve that terminates in a plateau phase
D tolerance curve12. All the populations of different species that occupy and are adapted to a given area, are referred to as a(n) ________.
A ecosystem
B community
C biosphere
D niche13. A one-way relationship in which one species benefits at the expense of another is called ________.
A commensalism
B competitive exclusion
C parasitism
D an obligatory relationship14. A symbiotic relationship in which both species benefit is best described as ________.
A commensalism
B competitive exclusion
C mutualism
D parasitism15. In a natural community, the primary consumers are ________.
A herbivores
B carnivores
C scavengers
D decomposers16. Which of the following is a primary consumer?
A cow
B dog
C hawk
D bear17. The biome concept illustrates:
A dominant plant communities
B insect populations
C old field succession
D temperature and precipitation similarities in an area
18. ________ is the least influential in determining the distribution of terrestrial biomes.
A light intensity
B rainfall
C salinity
D temperature
19. The ________ of a species describes the trophic role it fills in its environment.
A niche
B habitat
C carrying capacity
D biotic potential20. Bacteria and fungi act as ________ within an ecosystem.
A primary producers
B primary consumers
C secondary consumers
D decomposers21. A study of a meadow ecosystem revealed the following trophic relationships: sweet clover---grasshoppers--toads---snakes. The primary producer (s) in the meadow is (are)________.
A sweet clover
B grasshoppers
C toads
D snakes22. Which of the following is an example of secondary succession?
A appearance of mosses and weeds on an exposed rock fence
B abandoned farm field covered with weeds and shrubs
C former pond now supporting growth of shrubs and trees
D establishment of plants on a newly-formed island23. The ecosystems concept includes both abiotic (nonliving) and biotic factors (living) with a defined area.
A true
B false
24. What is the term for the maximum number of individuals that an area can support indefinitely?
A biotic potential
B carrying capacity
C niche
D maximum density25. Which of the following represents the most complex level?
A community
B species
C ecosystem
D population26. Which of the following lists include only abiotic environmental factors?
A food, temperature, fire, wind
B soil minerals, oxygen level, light, predators
C wind, rainfall, temperature, soil minerals
D light, food, predators, competitors27. All of the same species of organisms living in a particular area make up ________.
A a food chain
B a population
C a biological community
D a biosphere28. An organism’s “trophic” level refers to ________.
A the rate at which it uses energy
B where it lives
C what it eats
D whether it is early or late in ecological successionMultiple-Choice Answer Key:
1. B
2. D
3. C
4. A
5. A
6. B
7. D
8. C
9. A
10. C
11. B
12. B
13. C
14. C
15. A
16. A
17. D
18. C
19. A
20. D
21. A
22. B
23. A
24. B
25. C
26. C
27. B
28. C
Short-Answer Items
29. Two species or populations are competing for the exact same resource in an ecosystem. Describe three possible scenarios or results of this competition. Use ecological terms in your answer.
30. What would you predict as the effect of removing a large portion of the population of fir trees from an island where the dominant species were the wolves, moose, and fir trees? Outline three possible effects of fir tree removal on this ecosystem.
31. Interactions within ecosystems are necessary for the ecosystem to function properly. Identify and describe one specific type of ecosystem and two types of ecological interactions that might occur within this ecosystem. Why are the interactions you identified necessary in this ecosystem?
Short-answer key and Scoring Rubrics:
Students should demonstrate understanding when communicating scientific information. Students should use appropriate scientific language, a range of communication modes, and the most appropriate communication format.
Points
Description
5-6
In question 29, the student accurately communicates three scenarios, using scientific language correctly.
In question 30, the student accurately outlines three possible effects, using scientific language correctly.
In question 31, the student accurately describes one ecosystem and two ecological interactions, using scientific language correctly.
3-4
In question 29, the student accurately communicates some scenarios, using scientific language correctly.
In question 30, the student accurately outlines some possible effects and uses scientific language correctly.
In question 31, the student partly describes an ecosystem and two ecological interactions and uses scientific language correctly.
1-2
In question 29, the student accurately communicates some scenarios, using scientific language incorrectly.
In question 30, the student accurately outlines some possible effects and uses scientific language incorrectly.
In question 31, the student partly describes an ecosystem and ecological interactions and uses scientific language incorrectly.
0
In questions 29-31, the student does not reach a standard described by any of the descriptors above.
Performance Assessment:
The Challenge: Create a Critter
Imagine that a new planet has been discovered—a planet similar to earth in many aspects, but also very different. Your job is to design an animal that could live on this newly discovered planet. That’s what the “Create-a-Critter” project is all about.
You are to design an animal for the imaginary planet of Khoumon. It’s a chance to let your imagination run wild, or maybe we should say “run wildlife,” and to apply the ecological concepts we have learned in this unit. Read the information provided about what kind of world Khoumon is and learn about the strange life forms living there. Design an animal species that could survive on Khoumon.
The whole idea of this project is to use your imagination but still make good ecological sense. The creature you design should have adaptations that prepare it well in body and behavior to thrive in one of Khoumon’s biomes. For example, if your critter lived in the tropics, would it need a defense against a swarm of Snitters? As you read about Khoumon, you’ll find examples of creatures that could prey on your critter or be preyed on by it. The question is: How will your critter cope? What adaptations will it have?
The rules
I. Once you establish your group, you cannot change it.
II. You must keep the biome you were assigned in Lesson 3. No biome trades.
III. No magical powers allowed! Your critter must be biologically believable.
IV. The project includes the following three components:
A. A five-paragraph essay explaining your critter and its adaptations.
B. A detailed map of your critter’s specific habitat within its ecosystem.
C. The presentation, which includes:
1. A full explanation of the biome your critter is from.
a. Location on the planet
b. Climate (e.g., precipitation, temperature range)
c. Types of plant and animal life typically found there
d. Map of habitat
2. A food web of your critter’s ecosystem.
a. Critter’s niche (primary or secondary consumer)
b. Organisms your critter eats
c. Organisms that eat your critter
3. A drawing or diagram of your critter that clearly illustrates at least four adaptations specific to your critter’s ecosystem.
a. At least one body-covering adaptation
b. At least one behavioral adaptation (e.g., hunting technique, mating ritual, social behavior, etc.)
c. Two additional adaptations of your choice – you can be creative here
4. Each adaptation must be explained in terms of how it helps your critter survive in its environment.
V. Your critter must be unique! (It should not resemble any animal native to Earth. It should not resemble a cartoon or comic book character.)
VI. Project must be completed by ____________________
The Planet khoumon
Planetary Conditions:
Atmosphere: Similar to Earth
Gravity: The planet is about the same size as Earth, so the gravitational conditions are similar.
Climate: The planet has biomes similar to the biomes found on Earth (see map).
Organisms: The plant and animal species are strikingly different from Earth’s; however, they are well adapted to their respective ecosystems.
Regional Conditions: (see map)
Khoumon Map with Area Detail:
Brief History:
Khoumon is the fourth planet in the Alpha Leonis system. It was discovered by the 5th Consolidated Expeditionary Force of 2481, under the command of Admiral Michelle Polovenski (born on Mars in 2426). Admiral Polovenski found that Khoumon had a vast variety of plant and animal species, including a few that have some intelligence.
One interesting feature is the extreme tilt of the planet’s axis. This makes the seasonal changes more extreme than on Earth and encourages a wide variety of seasonal adaptations used by Khoumon’s species. In 2488, Earth sent a team of biologists to study the plants and animals of the whole planet. A startling biodiversity was found, with each species adapted to the ecosystem in its own specific ways. The major classifications of life turned out to be remarkably similar to those on Earth. Among the more unusual species described so far are those highlighted throughout this report
The following was written by erik rensberger
Khoumon Plant and Animal Species Classified:
Name: Elauos Sandsliders
Habitat: Sandy regions of North Elauos.
These reptilian animals resemble Earth snakes but have six legs that they keep tucked inside sand-proof flaps of skin. Each leg has a scooplike claw, which is used for digging. The six legs help Sandsliders cope with Khoumon’s strong gravitational pull when walking. Sandsliders eat succulent plants, insects, very small desert mammals, and even bird eggs. They are not very aggressive. They spend the frigid nights buried up to the tips of their noses in warm sand.
Will your critter find food in this palm tree or seek shelter under its broad leaves?
Name: Lesser Khoumon Palms
Habitat: Temperate Zafrana.
Although these trees look like Earth palms, they are not true palms. Lesser Khoumon Palms average about 18 to 20 meters in height. The lower 90 percent of the trunk is covered with tough plates of barklike material. Its strong, tightly woven fibers are very difficult to cut through. They shield the soft, protein-rich inner wood. At the top Lesser Khoumon Palms sport large spreads of thick, broad leaves averaging 10 meters across.
Name: Great Khoumon Palms
Habitat: Tropical rainforest of Hasvakoor.
Huge but rare versions of the Lesser Khoumon Palms, these giants can reach 40 meters, with their bushy tops spreading out in a rough disk 15 meters across. The bark of this tree is as durable as that of its lesser cousins.
Name: Macrobes
Habitat: Deep, cool regions of all oceans
These creatures look something like amoebae except that Macrobes weigh nearly 20 kilograms. They swim by rippling their bodies in the manner of manta rays on Earth. They kill prey by engulfing it and suffocating it. Very little is known about these bizarre creatures, as living Macrobes have been sighted only briefly on two occasions.
Name: Polovenski’s Snitters
Habitat: Subtropical South Elauos and Hasvakoor
Snitters are tiny insect-like creatures no more than half a centimeter long. They often appear from the brush, hopping like overgrown fleas, in swarms of up to a few hundred. They feed on the blood of mammals. The front two legs of each Snitter are lengthened to nearly a centimeter. Tiny grasping pinchers allow Snitters to hang onto a host creature long enough for their slashing jaws to gash its skin. They lap up as much blood as possible before releasing their hold and jumping away.
Name: Ramius Bulbs
Habitat: Forested and open areas of South Elauos, Zafrana, and Hasvakoor.
Khoumon has few ground-cover plants. However, there are large tracts of a curious little plant known as the Ramius Bulb. They are sparkling sapphire blue, the size of a baseball, with tough leathery skin. They extract nutrients from the water and soil, and do not use photosynthesis. Inside the thick skins is soft fibrous tissue. The root system of a single plant may span almost a meter.
The following was written by erik rensberger
Khoumon Plant and Animal Species Classified (cont.):
Name: Khoumon Air Whale
Habitat: Offshore Hasvakoor and subtropical South Elauos
The Khoumon Air Whales are perhaps the most interesting life form yet discovered on the planet. They spend their entire lives airborne, supported by huge gas sacs made of thin but tough skin. When fully expanded the sacs are almost round and may be 10 meters in diameter. Each Air Whale’s small “main body” has fans below the gas sac. The Air Whales have “filter fans,” similar in purpose to the baleen of the extinct Earth whales for whom they are named.
Khoumon Air Whales normally keep their filter fans folded up against their bellies but they sometimes unfold them, like Chinese fans, and swoop low over Khoumon’s oceans to scoop up floating seaweed. Seaweed provides part of the Air Whales’ nourishment. The rest is gathered by direct conversion of solar energy through photosynthesis. This makes Air Whales photovores. They can photosynthesize because the surfaces of the gas sacs are covered with chlorophyll-rich cells.
Air Whales have been sighted above every major land mass on the planet except the coldest regions. One incidental note: Air Whales may remain airborne for weeks after their death, as the gas creeps out slowly through barely open slits.
Performance Assessment Scoring Rubric:
Students should show their understanding of the main scientific ideas and concepts of science by applying these to solve problems in familiar and unfamiliar situations. Students should develop critical-thinking skills to analyze and evaluate scientific information. Suitable assessment tasks to assess this criterion include complex questions in tests, critical analysis of case studies, and research projects or media articles on scientific issues. Assessment tasks should provide opportunities for students to demonstrate their understanding by solving problems in familiar and unfamiliar situations, and by analyzing and evaluating scientific information presented to them.
Map and Essay Rubric
Points
Description
5-6
Essay:
- Main points clearly outline the arguments of the essay with a complete sentence for each point. All relate directly to and support the thesis.
Map:
- All necessary labels are present and are carefully and accurately placed.
- All essential abiotic and biotic factors are present.
3-4
Essay:
- Main points clearly outline the arguments of the essay with a complete sentence for each point. All generally relate to the thesis.
- Main points clearly outline the arguments of the essay with less than one sentence for each point.
Map:
- All labels are present and most are accurate.
- Most essential abiotic and biotic factors are present.
1-2
Essay:
- Main points vaguely outline the arguments of the essay but do not relate to or support the thesis.
- Main points are vague or unclear.
Map:
- All but one or two labels are present. Some labels are not accurately placed.
- Abiotic and biotic factors are present.
0
Essay:
- No discernable main points.
Presentation Requirements:
1. A full explanation of the biome your critter is from, including:
- location on the planet
- climate (e.g., precipitation, temperature range)
- types of plant and animal life typically found there
- map of habitat
2. A food web of your critter’s ecosystem.
- critter’s niche (primary or secondary consumer)
- organisms your critter eats
- organisms that eat your critter
3. A drawing or diagram of your critter that clearly illustrates at least four adaptations specific to your critter’s ecosystem.
- at least one body-covering adaptation
- at least one behavioral adaptation (e.g., hunting technique, mating ritual, social behavior, etc.)
- two additional adaptations of your choice – you can be creative here
4. Each adaptation must be explained in terms of how it helps your critter survive in its environment.
Presentation Rubric
Points
Description
4
The student completes all four of the requirements.
3
The student completes three of the requirements.
2
The student completes two of the requirements.
1
The student completes one of the requirements.
0
The student demonstrates lack of understanding or does not attempt to complete the assessment.