Ecology 101 Energy Transfer

The Sun The sun is the source of energy needed for plants to produce their own food. Therefore, it is the source of energy for almost all living things. In this transfer of energy, living things are divided into two categories: autotrophs and heterotrophs.

Autotrophs organisms that can use the energy in sunlight to produce their own food (glucose) autotrophs are also called Producers because they produce their own food all food chains start with an autotroph examples include plants, algae and some bacteria

Chemotrophs autotrophs that get their energy from inorganic substances, such as salt, iron and sulfur Ex. Bacteria and Deep Sea Worms

Heterotrophs Organisms that do not make their own food Another term for heterotroph is consumer because they consume other organisms in order to live There are 5 types of heterotrophs: scavengers, herbivores, carnivores, omnivores and decomposers.

Scavengers – feed on the tissue of dead organisms (both plants and animals); they are also known as detritivores Ex. – Vultures, Crows, and Shrimp

Herbivores – consumers that feed only on plant material Ex: cows, elephants, rabbits

Carnivore – consumers that feed only on meat Ex: sharks, tigers, wolves

Omnivore – consumers that eat both plant and animal material Ex: bears, raccoons, humans

Decomposer – organisms that consume wastes and dead organisms; they help recycle once-living matter by breaking it down into simple, energy-rich substances. Ex: fungi and bacteria

Energy Transfer In an ecosystem there is energy, and this is what allows the organisms to live. This energy mainly comes from one original source: the sun. Plants use this solar energy to produce carbohydrates which serves as fuel for living things. When one organism eats another, only some of this energy can be transferred because it has to be used by the organism that was eaten.

Conservation of Energy Energy cannot be created or destroyed, it just changes forms.

Food Chains The energy flow from one trophic (feeding) level to the other is known as a food chain A food chain is simple and direct. It involves one organism at each trophic level

Trophic Levels Producer – produce their own food

Trophic Levels Producer Primary Consumer – eats producers

Food Chains Secondary Consumer – eats primary consumers Producer

Food Chains Tertiary Consumer – eats secondary consumers Producer Primary Consumer Secondary Consumer Tertiary Consumer – eats secondary consumers

Food Chains Tertiary Consumer Producer Primary Consumer Secondary Consumer Decomposer - bacteria and fungi that break down dead organisms and recycle the material back into the environment

Food Chains Tertiary Consumer Producer Primary Consumer Secondary Consumer Decomposer

Food Webs Interconnected food chains in a community Identify the following: Producers plants Primary Consumers grasshopper, mouse, rabbit, squirrel Secondary Consumers fox, mouse, frog, snake Tertiary Consumers owl, fox, snake Herbivores grasshopper, rabbit, squirrel Carnivores fox, owl, snake, frog Omnivore mouse What element is missing? decomposers

Ecological Pyramid Shows the relative amounts of energy or matter contained at each trophic level The Pyramid shows which level has the most energy and the highest number of organisms