Part 2: Energy Flow and Nutrient cycles Support life in Ecosystem A . How energy flows in Ecosystem Biomass: Refer to the total mass of living plants, animals, fungi and bacteria in a given area . Energy Flow: Flow of energy from an ecosystem to an organism and from organism to organism Producers : Plants because produce food in the form of carbohydrate during photosynthesis Formula: CO2 + H2O + sunlight  O2 + Food (carbonhydrate) C6 H12 O6

Consumers: get energy by feeding on producers or other consumers Decomposers: break down waste and dead organisms into useable nutrients, through process of biodegradation (ex. Bacteria or fungi) Biodegradation: The action of living organisms such as bacteria to break down dead organism

B. Energy flow and energy loss in Ecosystem: we use different models to show how energy flows through ecosystems including food chain, food pyramids and food web 1. Food Chains: models which show the flow of energy from plant (producer) to animal (consumer) and from animal to animal  Trophic level: each step of the food chain

Primary producers: The 1st trophic level ; Produce food for other organism Primary consumers: The 2nd trophic level; Eat Primary producers Secondary consumers: The 3rd trophic level; Eat Primary consumers Tertiary consumers: The 4th trophic level; Eat secondary consumers; Also the top predator

Consumers in the food chain can be classified as Dung beetles feed on feces- common detrivore Consumers in the food chain can be classified as Detrivore: consumers that eat dead organisms and waste matter (ex. Beetles, worms) Herbivore: eat plants (ex. dear, grasshoppers) Carnivore: eat other animals (ex. Frogs, hawk) Omnivore: eat both plants and animals. (ex. Humans, bear Frog eats Grasshoppers- secondary consumers

2. Food Web: Most of the organism are part of many food chains Arrows in the food web represent the flow of energy and nutrients Following the arrows leads to the top carnivore

3. Food pyramids: show the changes in available energy from one trophic level to another in a food chain. They are also called ecological pyramids. Energy (from sun: energy source) enter the first trophic level (producers), where there is a large amount of biomass and therefore, a lot of energy

80& to 90% of energy taken in by consumers is used in chemical reactions in the body or is lost as heat energy. Therefore, lower trophic level has much larger population than the upper trophic levels.

Food pyramids the energy flow/ biomass, or numbers of organisms from one trophic level to another (Page 66)