New York State 8th Grade Science - Ecology Key Terms

1. Ecosystem & Environment

• Ecosystem – A community of living (biotic) and non-living (abiotic) things interacting in an environment.

• Biotic Factors – The living parts of an ecosystem (e.g., plants, animals, bacteria).

• Abiotic Factors – The non-living parts of an ecosystem (e.g., water, air, temperature, sunlight).

• Habitat – The specific place where an organism lives.

• Niche – The role an organism plays in its environment, including what it eats and how it interacts.

2. Energy Flow & Cycles

• Producer (Autotroph) – An organism (like plants) that makes its own food using sunlight (photosynthesis).

• Consumer (Heterotroph) – An organism that eats other organisms for energy.

  • Herbivore – Eats only plants.

  • Carnivore – Eats only animals.

  • Omnivore – Eats both plants and animals.

• Decomposer – Organisms (like bacteria & fungi) that break down dead organisms and recycle nutrients.

• Food Chain – A sequence that shows how energy moves from one organism to another.

• Food Web – A network of interconnected food chains in an ecosystem.

• Trophic Levels – The levels in a food chain (producers, primary consumers, secondary consumers, etc.).

• Energy Pyramid – A diagram showing energy loss as it moves up trophic levels (only about 10% of energy transfers).

• Photosynthesis – The process in which plants use sunlight, water, and carbon dioxide to make food (glucose) and oxygen.

3. Population & Community Interactions

• Population – A group of the same species living in the same area.

• Community – All the different populations that live together in an area.

• Carrying Capacity – The maximum number of organisms an ecosystem can support.

• Limiting Factor – Something that restricts population growth (e.g., food, water, space).

• Predator – An animal that hunts and eats other animals.

• Prey – The animal that is eaten by a predator.

• Competition – When organisms fight for the same resources (food, water, shelter).

• Symbiosis – A close relationship between two species:

  • Mutualism – Both species benefit (+/+)

  • Commensalism – One benefits, the other is unaffected (+/0)

  • Parasitism – One benefits, the other is harmed (+/-)

4. Human Impact & Environmental Issues

• Biodiversity – The variety of life in an area; greater biodiversity makes ecosystems more stable.

• Invasive Species – Non-native species that cause harm to an ecosystem.

• Deforestation – The removal of forests, which leads to habitat loss and climate changes.

• Pollution – Harmful substances introduced into the environment (air, water, soil pollution).

• Global Warming/Climate Change – The increase in Earth's temperature due to greenhouse gases (like CO₂).

• Renewable Resources – Resources that can be replenished naturally (e.g., solar, wind, water).

• Nonrenewable Resources – Resources that cannot be easily replaced (e.g., fossil fuels).