Ecosystem Basics
What is an ecosystem?
A community of living (biotic) and non-living (abiotic) things that interact in an environment.
What is succession?
The gradual process by which ecosystems change and develop over time.
What is an invasive species?
A non-native species that spreads rapidly and harms the ecosystem.
What is biomass?
The total mass of living organisms in a given area.
What are greenhouse gases?
Gases that trap heat in Earth’s atmosphere.
Name 2 biotic and 2 abiotic factors in an ecosystem.
Biotic: plants, animals. Abiotic: sunlight, water.
What is primary succession?
Succession that begins in an area with no soil or life (e.g., after a volcanic eruption).
What is an endangered species?
A species at risk of extinction.
In a biomass pyramid, which level has the most biomass?
The producers (bottom level).
Name two examples of greenhouse gases.
Carbon dioxide (CO₂), methane (CH₄), nitrous oxide (N₂O)
Which term describes all living things in an ecosystem?
Biotic factors.
What is secondary succession?
Succession that occurs after a disturbance but soil remains (e.g., after a forest fire).
What is biodiversity?
The variety of life in an ecosystem.
Give an example of a biomass pyramid from bottom to top.
Grass → Grasshopper → Frog → Snake → Hawk
What is the greenhouse effect?
The process where greenhouse gases trap heat, keeping Earth warm.
What happens to an ecosystem if abiotic conditions like temperature or water availability change drastically?
It can disrupt populations, causing species to move, die, or adapt.
What is the main difference between primary and secondary succession?
Primary starts with no soil; secondary starts with soil.
What is carrying capacity?
The maximum number of individuals an environment can support sustainably.
Why does the amount of biomass decrease at higher trophic levels?
Energy is lost as heat through each level of consumption.
How do human activities increase the greenhouse effect?
Burning fossil fuels, deforestation, and agriculture release more greenhouse gases.
Give an example of how biotic and abiotic factors interact in an ecosystem.
Example: Plants (biotic) need sunlight and water (abiotic) for photosynthesis.
What is a climax community?
The stable, final stage of succession in an ecosystem.
What factors affect carrying capacity?
Availability of food, water, space, and limiting factors like disease or predation.
What is the energy transfer efficiency between trophic levels?
About 10% of energy is passed on to the next level.
Scientists have discovered what percentage of all species on Earth?
About 10–20% (12.5%) of all species are currently known.