Ecosystems and Communities Ch. 4

What is Climate? Temperature, weather (rain, snow, windy, etc…), amount of sunlight, etc… Climate the average temperature/precipitation over long periods of time What abiotic factors effect climate? Greenhouse gasses CO2, CH4, and H2O help trap heat from the sun inside the Earth’s atmosphere Latitude Earth spins at 23o angle, so northern and southern areas get less sunlight while near the equator the amount of sunlight is the same all year long

What is Climate? 3) Wind and Water Currents hotter air at the equator and cooler air everywhere else creates wind currents that move heat around the Earth Same effect in water; warm water rises and cold air sinks Areas along these current paths gain warmer temperatures (more energy)

Niches and Community Interactions What is a habitat? Place an organism spends most their life Organisms have a Range of Tolerance flexible conditions that it CAN survive All habitats must fit somewhere in an organism’s range What is a niche? Specific way an organism interacts with the environment (gets recourses, reproduces, etc…) What is the special rule about niches?

Competitive Exclusion Principle No two species can have the same niche; competition will eliminate the weaker species Intraspecific competition between same species IntRA = same Interspecific competition between different species IntER = different How do organisms limit the effects of competition? Organisms get resources in many ways

Resources in Cycles Predator-Prey relationship one animal (predator) eats another animal (prey); number of predators changes with the number of prey Herbivore-Prey Relationships one animal (herbivore) eats producers; plants density changes with herbivore density In both systems there is always a Keystone Species Species, if removed, that would have the greatest effect on the ecosystem

Interactions Produce Symbioses Symbiosis close interaction between two or more species 3 types: Mutualism both animal benefit from relationship; ex. Clown fish and Sea anemone Parasitism one benefits and one is weakened (not killed); ex. Tape worm Commensalism one benefits and one is not affected; ex. Barnacles on Whales

Major Shifts in an Ecosystem Ecological Successions: Primary Succession first life (pioneer species) in an area of only freshly exposed land Volcano forms an island Secondary Succession after massive destruction, surviving life spreads quickly into new space Growth after a forest fire After a succession, populations grow until a Climax Community is obtained Studying successions and climax rate tells scientists about the history of the ecosystem

Marine Ecosystems Oceans/Seas are divided into 3 zones: Intertidal Zone: major temperature changes as waves move in and out with the tide; organisms live with lots of sunlight and air exposer Costal Ocean: area between lowest tide and continental shelf (edge of continent); lots of life in nutrient rich water Open Ocean: rest of the ocean; little life but common migration routes

Photic Zones Open ocean can be divided into zones based on light exposure Photic Zone: upper levels of ocean based on phytoplankton (single-celled organisms) Aphotic Zone: lower levels of ocean too deep to receive light based on chemosynthetic primary producers One of the last unexplored areas on Earth; contains thousands of new species

Homework Finish reading Ch. 4 and Start reading Ch. 5 Ch. 4 “Apply Vocab” and questions #1-18 on p 103-104 all due Friday Morning Presentations on 2 Biomes next Monday How to present: Everyone in your group speaks Must have a good PPT: Text is easy to read NO PARAGRAPHS! Use Pictures to help explain yourself Good Presentations: NO READING! Speak clearly and loudly Talk to the students, NOT to me! STAY IN YOUR TIME LIMIT: 5 minutes! If you go over your time, I will stop your group and you will lose points YOU GET 1 CLASS TO DO THESE PRESENTATIONS!!!!!!!!!!!!!!!!!!!