Ecology Energy Flow Every organism needs energy Sunlight

Ecology: Energy Flow • Every organism needs energy. • Sunlight is the main energy source for life. • Less than 1% of sunlight is used by organisms. • Where does the rest of the sunlight go? Photograph courtesy philip. greenspun. com

Ecology: Energy Flow • photosynthesis: use of light energy to produce carbohydrates • autotrophs make their own food. • autotrophs are producers • Why?

Ecology: Energy Flow • sunlight is not available to all organisms • chemosynthesis: use of chemical energy to produce carbohydrates • most chemotrophs are bacteria and algae Deep sea hydrothermal vent worms • are they autotrophs?

Ecology: Energy Flow • • • autotroph: produces its own food heterotroph: acquires energy by eating other organisms What is a producer? What is a consumer? Are heterotrophs producers or consumers? consumers: primary secondary tertiary quaternary

Ecology: Energy Flow • • heterotrophs are consumers herbivores eat plants carnivores eat meat omnivores eat plants and meat insectivores eat _______ detritivores feed on remains decomposers break down organic matter Where are decomposers in a food chain?

Ecology: Feeding Relationships • Energy flows through an ecosystem in one direction (arrows) from the sun or inorganic compounds to producers to consumers. • Food chain: diagram that shows simple feeding relationships. • Trophic level: each step in a food chain • All food chains start with a producer.

Feeding Relationships: Food Chain squid (tertiary consumer) small fish (secondary consumer) zooplankton (primary consumer) algae (producer)

Students be careful! Remember: the arrow shows the direction energy flows in an ecosystem. In this example, the Leopard seal eats the penguin and as a result, gets the energy.

Ecology: Feeding Relationships • A food web is a network of complex feeding relationships that connects multiple food chains. • If one species is lost from a food web, all other species are affected.

Terrestrial Food Web

Aquatic Food Web

My Favorite Food Web Matt Pendley, Buford High School, Buford, GA

Ecology: Community Interactions Competition: when organisms try to use a resource in short supply at the same time and same place.

Ecology: Community Interaction Predation: when one organism captures and eats another organism.

Ecology: Community Interaction Symbiosis: any relationship in which two species live closely together.

Ecology: Symbiosis Mutualism: when both species benefit from the interaction. In this example, the sea anemone is cleaned by the clown fish, who in turn is protected by the anemone’s stinging tentacles.

Ecology: Symbiosis Commensalism: when one species benefits from the interaction and the host species is unaffected. The leafy plant is an epiphyte, growing on another plant only for support.

Ecology: Symbiosis Parasitism: interaction in which one organism benefits and the other organism (host) is harmed. Asian tiger mosquito Does the host die as a result?

Ecological Pyramids: Energy Pyramid (energy flow in a community) • each trophic level represents a different group of organisms in a food chain • about 10% of the energy available at each trophic level is transferred to organisms at the next trophic level • energy is lost as heat and in life processes

Ecological Pyramids: Biomass Pyramid • biomass is the total amount of living tissue • expressed as grams of organic matter per unit area • biomass pyramid represents the potential amount of food available at each trophic level • normally the greatest biomass is at the base

Ecological Pyramids: Numbers Pyramid • based on the numbers of individuals at each trophic level • some number pyramids look like biomass & energy pyramids, some do not • in this example, the oak tree has a large amount of energy and biomass, but it is only one organism

Laws of Ecology All things are interconnected. Everything goes somewhere. There’s no such thing as a free lunch. Nature bats last. Ecology: A Pocket Guide by Ernest Callenbach