A. Plant > Herbivore > Carnivore

1. Plant- called the primary producer - ex: corn -Energy comes from the sun and is changed into form consumable by animals through process of photosynthesis

2. Herbivore- called the primary consumer - ex: mouse

3. Carnivore- called the secondary consumer - ex: rat snake

B. We are now referring to the food chain as food webs

1. Partially because omnivores (eat plants and meat) do not fit in above definition

2. Assimilation energy limits the length of the chain

a. Assimilation energy is the amount of what is eaten that becomes new energy

b. Herbivores assimilate 20% to 60% of what is eaten

c. Carnivores assimilate 50% to 90% of what is eaten

C. The "food chain" is Mother Nature's system of checks and balances

1. Loss of predator species leads to increased population of the prey species

a. Increased damage to vegetation

b. Increased accidents (deer / car accidents in Virginia)

c. Eventually the system can not support the high numbers of prey species either

D. Knowledge of food webs is important because it can help us formulate management solutions. Ex: pest management