Community Interactions Community Interactions

Community Interactions

• Community interactions, such as competition, predation, and various forms of symbiosis, can powerfully affect an ecosystem.

• Competition – when organisms attempt to use a resource at the same place and the same time.

• Predation – when one organism captures and feeds on another organism.

Symbiosis

• In a symbiotic relationship at least one of the organisms directly benefits from its close association with the other organism. There are three types of symbiosis.

Symbiotic Relationships

A symbiotic relationship where both organisms benefit

EX: Cowbirds eat the bugs off of a cow’s back

A symbiotic relationship where 1 organism benefits and the other is unaffected

Ex: When cows walk through a field it stirs up bugs and birds eat the bugs

A symbiotic relationship where 1 organism benefits and the other is harmed.

Ex: A tick feeds on the blood of a dog

Commensalism

• One species benefits and the other gets no real benefit or harm.

Commensalism

Bromiliad and tree – the higher the bromiliad on the branches, the more sun

Commensalism

Shark and Remora – remora eats food scraps from sharks meals.

Commensalism

Barnacles and Whale – Barnacles are moved to feeding grounds by riding on the whales.

Mutualism

• Both species benefit from the relationship

Mutualism

Clownfish gets – protection and home

Anemone gets – cleaned and brought food

Mutualism

Eel gets cleaned by removal of parasites

Shrimp gets food

Mutualism

Same as before

Parasitism

• One species (the parasite) benefits, but in doing so, harms the other (the host).

Parasitism

Mosquito – takes blood for food

Humans – loss of blood and possible infection

Parasitism

Tick – blood for food

Mammal – loss of blood and possible infection

Parasitism

Mistletoe – takes nutrients from the tree.

Tree – loss of nutrients and loss of leaves, possible disease.