Ecosystems – It includes all ofthe populations that live in anarea and everything that affectsthem.

Ecosystems & Types ofInteractions

Interactions with the Environment

Limiting Factors – limits the size of apopulation. Ex. – Food becomes alimiting factor when a populationbecomes so large that there is notenough food.

Any resource can be a limiting factor,ex. Habitat, food, space, mates

Interactions with the Environment Carry Capacity – The largest

population that can live in the samearea for a long time.

After a population grows larger thanthe carry capacity, limiting factorscause the population to get smaller.Ex. Rainy seasons affecting plantgrowth.

Community – All the species in anarea.

There are 4 different waysorganisms in a community interactwith each other.

Interactions with the Environment

Competition – When two or more individuals orpopulations try to use the same limitedresource. Ex. Food, water, sunlight, etc.

Competition can also occur within populations.Ex. – Elk in Yellowstone National Park competewith each other for the same food plants andfor living space.

Competition can also occur betweenpopulations of different species. Ex. Severalkinds of trees are competing for sunlight.

Interactions with the Environment

Predator and Prey – Animalsthat are eaten are the prey.Predators are the animalsthat eat the prey.

Predator adaptations –Predators must have aadaptations that enablethem to be able to catchtheir prey. Ex. – Cheetahruns fast, Goldenrod spidercamouflage.

Interactions with the Environment

Prey Adaptations – Toavoid becoming prey,organisms can run away – Ex. Rabbits stay in groups – Ex. Small

fish, antelopes, buffaloes camouflage themselves -

flounder poisonous- fire

salamanders

Interactions with the Environment

Symbiosis Symbiosis is a close, long term

association between two or morespecies that can be helped, harmedor unaffected by the relationship.

1. Mutualism – When both organisms arehelped. Ex. Clownfish and the SeaAnemone

2. Commensalism – When oneorganism is helped and the other isneither helped nor harmed. Ex. Sharksand Remoras

3. Parasitism – When one organism ishelped and the other is harmed. Ex.Dogs and Ticks