Primary & Secondary Succession
This type of succession occurs after a wildfire where soil is still present.
Secondary Succession
An organism that eats only plants is called this.
Herbivore
This term describes the variety of species in an ecosystem.
Biodiversity
This organism makes its own food using sunlight.
Producer
This process allows plants to convert sunlight into chemical energy.
Photosynthesis
This type of succession begins on bare rock with no soil.
Primary Succession
An organism that eats both plants and animals is called this.
Omnivore
An ecosystem with high biodiversity is generally more or less stable?
More stable
What is the original source of energy in most ecosystems?
The Sun
A nonliving factor in an ecosystem is called this.
Abiotic factor
These organisms are the first to grow during primary succession and help create soil.
Pioneer Species (lichens & mosses)
In a food chain: Grass → Rabbit → Snake → Hawk
What type of consumer is the snake?
Secondary Consumer / Carnivore
Explain why having many species of plants helps an ecosystem survive a drought.
Some plant species may survive and continue providing energy, keeping the food web functioning.
Why do food webs show a more accurate picture of energy transfer than food chains?
Because organisms have multiple feeding relationships, not just one pathway.
Name one human activity that can disrupt ecosystems.
Examples: deforestation, pollution, overfishing, urban development.
A glacier melts and exposes rock. It takes many years before trees appear. Explain why this ecosystem takes longer to develop than one after a forest fire.
Because primary succession begins without soil and must first build soil before larger plants can grow.
If primary consumers decrease in an ecosystem, explain what will likely happen to secondary consumers.
Secondary consumers will likely decrease because less energy is available to them.
Two ecosystems experience the same flood. One has 20 species. One has 4 species.
Predict which ecosystem will recover faster and explain why.
The one with 20 species, because more species increases resilience and energy pathways.
In a food web, grass decreases significantly.
Explain how this affects higher trophic levels.
Less energy enters the system, so herbivores decrease, followed by predators.
After a forest fire, species diversity increases over time and then levels off.
What is the stable final stage called?
Climax community
Two ecosystems are disturbed:
One by a volcanic eruption
One by a hurricane
Both lose trees. Predict which ecosystem will recover faster and justify your reasoning.
The hurricane ecosystem will recover faster because soil remains, allowing secondary succession to occur.
A disease removes most of the top predators in an ecosystem.
Describe two possible effects this could have on lower trophic levels.
Herbivore populations may increase; producers may decrease due to overgrazing; energy balance becomes disrupted.
Explain how biodiversity affects energy transfer when a disruption removes one species from a food web.
High biodiversity provides alternate energy pathways; low biodiversity can cause energy transfer to collapse if one species is removed.
In an energy pyramid, only about 10% of energy transfers to the next level.
Explain why top predators have smaller populations than producers.
Because energy decreases at each level, less energy is available to support large populations at higher trophic levels.
Explain how human activities can both decrease biodiversity and disrupt energy transfer in a food web.
Removing species reduces biodiversity and eliminates energy pathways, decreasing stability and disrupting trophic relationships.