Levels & Components
These are the hierarchical levels used when ecologists study life from individual organisms up to the entire planet.
What are the levels of organization (organism, population, community, ecosystem, biome, biosphere)?
Producers occupy this base level in a trophic pyramid.
What are primary producers (or producers)?
These organisms, like fungi and bacteria, break down dead materials,
What are decomposers?
A close, long-term interaction between species that can be mutualism, commensalism, or parasitism.
What is symbiosis?
Soil is called this because it forms the thin outer layer of Earth and supports most terrestrial life.
What is the "skin of the Earth"?
Any living part of an ecosystem — examples include plants, animals, fungi, and bacteria.
What are biotic factors?
These consumers eat only plants — examples include rabbits and many insects.
What are herbivores (or primary consumers)?
This process describes increasing concentration of toxins as they move up trophic levels
What is biomagnification?
Competition between members of the same species for resources like mates, territory, or food.
What is intraspecific competition?
This term describes the long‑term storage of carbon in soils, plants, and geologic reservoirs.
What is sequestration?
Nonliving components such as sunlight, temperature, water, and soil that influence ecosystems.
What are abiotic factors?
Consumers that eat other animals (meat-eaters) — examples include hawks and lions.
What are carnivores (or secondary/tertiary consumers depending on context)?
These substances that bioaccumulate and biomagnify in ecosystems.
What are persistent organic pollutants (e.g., DDT, PCBs)?
Competition between different species, for example wolves and coyotes competing for similar prey.
What is interspecific competition?
One sustainable soil management practice that reduces erosion, adds organic matter, and can improve structure — often done between cash crops.
What is cover cropping?
This diagram shows multiple interconnected feeding relationships in an ecosystem and is built from many single sequences.
What is a food web?
The rule that states roughly this fraction of energy is passed from one trophic level to the next.
What is the 10% rule (about 10% energy transfer)?
These loops amplify changes in an ecosystem (example: melting ice reduces albedo, increasing warming).
What are positive feedback loops?
One species benefits, while the other is harmed.
What is parasitism?
This element is called the building block of life because its chemistry forms the backbone of organic molecules like proteins, lipids, carbohydrates, and nucleic acids
What is carbon?
This single linear sequence shows who eats whom, usually beginning with a producer and ending with a top predator.
What is a food chain?
If milkweed captures 10,000 Calories and energy transfer is 10% per level, this many Calories are available to chickadees two trophic steps up (milkweed → caterpillar → chickadee).
What is 100 Calories?
These loops reduce change and help maintain stability (example: predator–prey relationships that regulate population sizes).
What are negative feedback loops?
Monarch butterfly larvae feed off the milkweed's sap, while the milkweed's flowers get cross-pollinated.
What is mutualism?
A key nitrogen process where atmospheric N2 is converted into biologically usable ammonia or related compounds by bacteria.
What is nitrogen fixation?