Parts of an Ecosystem
A Joshua tree can only be pollinated by one kind of moth, and that moth can only raise its young inside a Joshua tree. Neither one survives without the other. An ecosystem is full of connections like this, between living things and the nonliving world around them.
What You'll Be Able to Do
By the end of this lesson, you will be able to:
- State what students will be able to do.
- Set a clear target before content begins.
- Goal setting
- Advance organizers
- Understand to Analyze
- DOK 1 to 3
- Plain "I can" statements
- Standard code shown for reference
- Short, scannable cards
Words You'll Meet
Choose a card to see what each word means.
- Front-load the terms students will meet.
- Lower the language barrier before reading.
- Pre-teaching vocabulary
- Reduced extraneous load
- Remember to Understand
- DOK 1
- One card open at a time
- Click to reveal, no hover
- Plain, short definitions
A Tree and a Moth That Need Each Other
In Joshua Tree National Park, the desert looks empty at first. But every living thing there is tied to the others and to the nonliving world around it. One pair shows this better than any other.
Partners for Survival
The Joshua tree can only be pollinated by the yucca moth. The yucca moth can only lay its eggs inside a Joshua tree flower, where its young will feed. If one disappears, so does the other. Around them, coyotes hunt jackrabbits, lizards hide under rocks from the Sun, and roots reach for scarce water. Why are the living things in one place so tied to each other and to the nonliving world?
The best answer is A. The Joshua tree needs the moth to move its pollen, and the moth needs the tree as a place to raise its young. This is one kind of close relationship between species. An ecosystem is built from many such connections, between living things and between living things and the nonliving world. To understand them, we first have to name the parts of an ecosystem.
- Anchor the lesson in a striking real relationship.
- Raise a question students will want answered.
- Curiosity gap
- Phenomenon-based learning
- Understand
- DOK 2
- Concrete, labeled example
- Short framing text
- Visual anchor
The Two Kinds of Parts
Every ecosystem is made of two kinds of parts. Some parts are alive or were once alive. The rest were never alive at all. Both kinds matter.
An ecosystem is all of the living and nonliving parts of the environment in a given area. A pond, a forest, and a stretch of desert are all ecosystems.
The living parts and the nonliving parts are always interacting. A plant needs sunlight and water. An animal needs other living things to eat and a place to shelter. Change one part and the others feel it.
- The living or once-living parts of an environment
- Includes plants, animals, fungi, and microbes
- Examples: Joshua tree, coyote, lizard, cactus
- The nonliving parts of an environment
- Things that were never alive
- Examples: sunlight, water, soil, rock, temperature
An ecosystem is the living and nonliving parts of one area. A biome is much larger. It is a geographic region on Earth that contains many ecosystems with similar living and nonliving features. A desert is a biome, and Joshua Tree National Park is one ecosystem inside it.
- Define ecosystem and sort it into biotic and abiotic parts.
- Separate ecosystem from the larger biome.
- Categorization
- Comparison and contrast
- Understand to Apply
- DOK 1 to 2
- Two short, parallel cards
- Plain living vs nonliving framing
- Key terms in bold
Levels of Organization
Scientists study living things at different scales. Starting from one organism, each level adds more, until we reach a whole biome. Click a level to zoom out one step.
- Order the levels of organization from small to large.
- Show each level nested inside the next.
- Dual coding with the nested diagram
- Sequencing and hierarchy
- Chunking
- Remember to Understand
- DOK 1 to 2
- Click to reveal each level, no hover
- Labeled diagram paired with text
- Numbered, ordered levels
Where It Lives, What It Does
Each species fits into its ecosystem in two ways. There is the place it lives, and there is the job it does. These are not the same thing.
A habitat is the place within an ecosystem that gives an organism the biotic and abiotic factors it needs to survive and reproduce. It is the organism's home.
A coyote's habitat provides shelter among rocks and brush, prey to hunt, and water to drink. If the habitat cannot meet those needs, the organism cannot live there.
A niche is the role a species plays in its environment. It is the way a species interacts with biotic and abiotic factors to get food, find shelter, and meet its needs. If a habitat is an organism's address, its niche is its job.
Two species can share a habitat but fill different niches. A hawk and a lizard might both live among the same rocks, but the hawk hunts from the air during the day while the lizard hunts insects close to the ground.
Because their niches differ, they do not need the exact same resources at the same time, so they can share the same space.
- Separate where an organism lives from what it does.
- Address a common habitat and niche mix-up.
- Analogy (address vs job)
- Comparison and contrast
- Understand to Apply
- DOK 2
- Key terms defined in place
- Concrete desert examples
- Short paragraphs
Predation and Competition
Organisms in an ecosystem are always interacting. Two of the most common interactions are predation and competition. Both affect how many of each species can survive.
Predation is an interaction in which one organism, the predator, feeds on another organism, its prey. A coyote hunting a jackrabbit is predation.
Predation keeps prey populations in check. When prey are plentiful, predators have more food and their numbers can rise. When prey become scarce, predator numbers fall.
Competition is an interaction in which two or more organisms need the same resource at the same time. They might compete for food, water, space, or sunlight.
Competition can happen within one species, such as two coyotes after the same rabbit. It can also happen between species, such as a coyote and a hawk hunting the same small animals.
- Introduce predation and competition as core interactions.
- Connect interactions to population size.
- Cause-and-effect reasoning
- Within vs between species contrast
- Understand to Analyze
- DOK 2
- Key terms defined in place
- Familiar predator and prey examples
- Short paragraphs
Close, Long-Term Relationships
Some species live in a close relationship for a long time. We call this symbiosis. It comes in three types, sorted by who benefits and who is harmed.
Symbiosis is a close, long-term relationship between two species that usually involves an exchange of food or energy. The three major types are mutualism, commensalism, and parasitism.
Mutualism: both species benefit. The Joshua tree and the yucca moth are a classic example. The tree gets pollinated and the moth gets a place to raise its young.
Commensalism: one species benefits and the other is neither helped nor harmed. A bird building a nest in a tree gets shelter, while the tree is unaffected.
Parasitism: one species benefits and the other is harmed. A tick feeds on a deer. The tick (the parasite) benefits, and the deer (the host) is harmed.
- Define symbiosis and its three types.
- Answer the opening phenomenon directly.
- Dual coding with the plus and minus chart
- Categorization by who benefits
- Worked examples
- Understand to Analyze
- DOK 2 to 3
- Key term defined in place
- Plus, zero, and minus shown visually
- One example per type
Brain Check
Three quick questions before we put it all together. These are not graded. Pulling answers from memory now will help them stick.
- Strengthen memory through retrieval before the wrap-up.
- Surface misconceptions early.
- Retrieval practice
- Generation effect
- Productive struggle
- Understand to Apply
- DOK 1 to 2
- Ungraded and low stakes
- Immediate feedback
- Short tasks reduce load
An Ecosystem Is a Web of Parts
You started with a question: how do the living and nonliving parts of an ecosystem depend on one another? Now you can put the whole picture together.
- Tie the parts into one connected system.
- Answer the opening question directly.
- Schema building
- Elaboration
- Coherent narrative
- Understand to Analyze
- DOK 3
- Step-by-step beats
- Plain causal language
- Builds on prior sections
Check Your Understanding
Ten questions covering everything you explored, from biotic and abiotic factors to the three types of symbiosis. Answer every question, then submit.
Scientists don't just know the answer. They explain their thinking.
Write your own explanation first. Then submit your work to compare your thinking with a model answer.
In one or two sentences, explain how a change in one part of an ecosystem can affect the other parts. Follow the change from one part to the next, not just a list of parts. Use the word depend.
- End the lesson with the student constructing the central idea in their own words, not selecting it.
- Give the one place where the student generates rather than clicks.
- Generation effect and self-explanation
- Systems thinking: tracing a change through connected parts
- Self-check reveal for comparison, ungraded
- Analyze to Evaluate
- DOK 3
- Sentence-length response, not an essay
- Keyword scaffold ("depend")
- Model answer to compare against
- Check understanding against the lesson goals.
- Give students and teachers a clear signal.
- Retrieval practice
- Feedback loops
- Understand to Apply
- DOK 1 to 2
- Answer explanations provided
- Practice and classroom modes
- Plausible, evenly placed options
More Learning
The lesson is just the beginning. Dig deeper into biotic and abiotic factors, habitat and niche, and the ways species interact through predation, symbiosis, and competition.
- Offer pathways beyond the core lesson.
- Signal that learning continues past the quiz.
- Interest-driven extension
- Transfer to new contexts
- Apply to Analyze
- DOK 2 to 3
- Optional and self-paced
- Clear labels for what is available
- No penalty for skipping
Connections
Every ecosystem runs on the same parts working together. These lessons show what those parts do.