Energy in Ecosystems

Energy in Ecosystems Producer (autotroph) - get their energy from nonliving resources (make their own food) Producers provide energy for other organisms in an ecosystem Consumer (heterotroph) - get their energy by eating other living things such as plants and animals

Almost all producers obtain energy from sunlight  

Most producers on Earth use sunlight as energy source using photosynthesis. photosynthesis converts light energy (sunlight) into chemical energy (carbohydrates)

Chemosynthesis - organisms make carbohydrates using chemicals instead of sunlight found in deep-sea thermal vents, sulfur-rich marsh flats, and hydrothermal pools can be basis for thriving ecosystems

Food Chains and Food Webs Food Chain - sequence that links species by their feeding relationships. only follows connections between one producer and single chain of consumers simplest way to look at energy flow in an ecosystem

Food Web shows a complex network of feeding relationships In a Food Web - organism may have multiple feeding relationships. Stability of food web depends on presence of producers (forms base of food web)

Types of Consumers Herbivores - eat only plants Carnivores - eat only animals Omnivores - eat both plants and animals

Detritivores - organisms that eat detritus (dead organic matter)

Decomposers - break down organic matter into simpler compounds (inorganic matter) Fungi and bacteria Important to stability of ecosystem by returning nutrients (minerals) back into the environment

Organism may focus on single organism to feed (specialist), or have varying diet (generalist)

Trophic Levels - level in a food chain Quaternary consumer – carnivores that eat tertiary consumers Tertiary consumer - carnivores that eat secondary consumers Secondary consumer – carnivores that eat herbivores Primary consumers - herbivore Producers always first level

Energy Pyramid - diagram that compares energy used by each trophic level Base made up of producers   Energy lost to each succeeding trophic level Only 10% energy available to next trophic level