Ecosystem Structure and Trophic Levels Flashcards

Ecosystem Fundamentals

• An ecosystem serves as the primary unit for studying how biotic (living) and abiotic (nonliving) components interact and support life.
• The sun is the primary energy source for over $99\%$ of life on Earth; remaining life forms, such as those near underwater volcanic extrusions, utilize alternative energy sources.

Trophic Structure and Feeding Levels

• Primary Producers (Autotrophs): Mostly green plants that capture energy through photosynthesis at the base of the food chain.
• Primary Consumers: Herbivores that feed directly on primary producers.
• Consumer Hierarchy: Secondary consumers feed on herbivores, while tertiary and quaternary consumers feed on subsequent levels of the chain.

Decomposition and Nutrient Cycling

• Detritivores (Detritus Feeders/Decomposers): Includes bacteria, fungi, and insects that feed on dead and decaying material.
• Primary Function: They return essential nutrition to the soil and surroundings, enabling the ecosystem to cycle matter and support new growth.