🌱 Ecosystem Organization
What is one individual living thing called?
An organism
What is the original source of energy for most ecosystems?
The Sun
What is a species called when it naturally occurs in a particular ecosystem or region?
A native species
What is the gradual change in species and communities in an ecosystem over time called?
Ecological succession
What term means the variety of living organisms within an ecosystem or area?
Biodiversity
What do we call a group of organisms of the same species living in the same area?
A population
What role do plants usually have in a food chain, and why?
Producers, because they capture energy and make their own food.
True or False:
Every nonnative species is invasive.
False. A nonnative species becomes invasive when it establishes/spreads and causes harm.
What do we call the early organisms that are among the first to establish during succession?
Pioneer species
Name two factors that can contribute to biodiversity loss.
Any two of:
Habitat loss • Pollution • Invasive species • Overuse of resources • Disease • Catastrophic events • Environmental changes
Deer, birds, trees, mushrooms, and insects are all living in the same forest. Together, these different populations make up what level of organization?
A community
Use this food chain:
Grass → Grasshopper → Frog → Snake → Hawk
What does the arrow between the grasshopper and frog represent?
Energy is transferred from the grasshopper to the frog when the frog eats the grasshopper.
A new fish is introduced into a lake from another part of the world. It survives in the lake but does not spread rapidly or harm native organisms.
Is it native, nonnative, or invasive?
Nonnative
A volcanic eruption creates an area of bare rock with no developed soil community.
What type of succession would begin?
Primary succession
What is the difference between an endangered species and an extinct species?
An endangered species is at serious risk of extinction. An extinct species no longer exists.
Put these levels in order from smallest to largest:
Organism → Population → Community → Ecosystem → Biome → Biosphere
In an energy pyramid, approximately what percentage of energy at one trophic level is transferred to the next trophic level?
About 10%
An introduced snake reproduces rapidly, has few natural predators, eats native birds and mammals, and spreads throughout an ecosystem.
What evidence makes this species invasive rather than simply nonnative?
It establishes/spreads and causes ecological harm, including declines in native organisms.
A wildfire burns a forest. Most vegetation is destroyed, but the soil remains.
What type of succession would most likely occur?
Secondary succession
An invasive species competes with several native species for food and habitat. Native populations begin declining.
Explain how this could eventually cause biodiversity loss.
If native populations continue declining or species disappear, the variety of living organisms in the ecosystem decreases.
A pond contains fish, frogs, algae, bacteria, water, rocks, sunlight, and dissolved oxygen. Why is the pond considered an ecosystem rather than just a community?
Because an ecosystem includes both biotic and abiotic factors interacting, while a community includes only the living populations.
A disease causes most of the frogs in an ecosystem to disappear. Frogs normally eat grasshoppers and are eaten by snakes.
Predict one effect on the grasshopper population and one effect on the snake population.
Grasshoppers would likely increase because fewer frogs are eating them, while snakes could decrease because they have less available prey.
An invasive predator causes a native bird population to decline. The native birds normally eat insects.
Predict an indirect effect the invasive predator could have on the ecosystem.
Some insect populations could increase because fewer native birds are available to eat them.
Put these events in the correct order:
Changing Communities • New Equilibrium • Disturbance • Succession • Original Equilibrium
Original Equilibrium → Disturbance → Succession → Changing Communities → New Equilibrium
Conservationists protect habitat, remove an invasive predator, monitor native populations, and help endangered animals reproduce.
What is the overall goal of these actions?
To protect species and habitats, prevent further biodiversity loss, and help vulnerable populations recover