300 likes | 462 Vues
Ch. 4. Community Interactions – several species living together!. 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
E N D
Ch. 4 Community Interactions – several species living together!
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:
This crustacean devours the fish tongue and takes its’ place.
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 animals 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
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
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.