COMMUNITY INTERACTIONS – SEVERAL SPECIES LIVING TOGETHER!

Ch. 4

What determines world climate? Sunlight and precip!

Niche -

A range of conditions in which a species lives, survives in and hopefully reproduces.

Competitive Exclusion Principle: Species partition Resources so they Are not competing Against each other And all can survive!

Symbiosis – Any relationship where 2 species live closely together.

There are 3 main classes: Mutualism +/+ Both benefit Commensalism + / 0 One benefits, the

other is neither helped nor harmed. Parasitism +/- One benefits while the

other is harmed. Look at the following photos and write M,

C or P for each relationship:

A squirrel living in an oak:

Cleaner wrasse and eel:

Ramora and shark:

Flea and dog:

Bee pollinating flower:

Bromeliad on tree:(epiphyte)

Sea lamprey and fish:

Blind shrimp and Gobi:

Tomato hornworm and wasp pupa:

Barnacle and whale:

Acacia tree and ants:

Clown fish and anenome:

Tapeworm and human:

Cattle egret and water buffalo:

This crustacean devours the fish tongue and takes its’ place.

Greenland shark and copepod:

Toxoplasma in rats/cats:

http://v.youku.com/v_show/id_XMjk1OTYxMTg0.html

Succession – over time, ecosystems change

Primary – a land ecosystem that has been destroyed to the point that not even soil remains. Ex: glaciers, volcanoes

Pioneer species come in first (lichens, fungi) to break up rock and create soil. Soon plants can get a foothold and the area changes as soil nutrients build up - plants bring ani mals and decomposers etc…

Secondary Succession:

An ecosystem is disturbed, but soil remains and new life can come back quickly. First smaller plants and then over time larger plants, animals etc… until a CLIMAX community (mature thriving species) is created.

Ex: fire in Yellowstone Park 1988

Aquatic areas go through successtion too!

Keystone species -

Not the most numerous or “biggest” organism in the ecosystem, but one that is key to other organisms success in that same environment. If something happens to it, other things will go too.

Ex: Prairie dogs, otters

Major biomes: Terrestrial

Acquatic biomes:

Freshwater:

1. Rivers and streams – lots of oxygen, few plants.

2. Lakes/ponds – plankton, fish Phyto- light so producers Zoo – animal so consumers

3. Wetlands – part of the year. Cattails/red winged blackbirds.

Marine: Oceans

Intertidal – covered by water and exposed to air. Barnacles, seaweed, starfish.

Coastal – shallow water – highly productive because light shines here. Kelp and coral reefs.

Open ocean – 500 – 10,000 meters. Many creatures, can be large (whales), few nutrients and producers.