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Population Ecology. HABITAT = The area where an organism lives “address” NICHE = place it lives PLUS the biotic and abiotic interactions it has in that place “occupation”. http://animals.timduru.org/dirlist/snake/animalwild089-RattleSnake-FaceCloseup.jpg
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HABITAT = The area where an organism lives “address” NICHE = place it lives PLUS the biotic and abiotic interactions it has in that place “occupation” http://animals.timduru.org/dirlist/snake/animalwild089-RattleSnake-FaceCloseup.jpg http://www.electricwomen.com/hunterspoint/images/21-street-sign-moreell.jpg http://www.rvstogophx.com/images/arizona_desert_sm.jpg http://resmedicinae.sourceforge.net/logos/doctor.png http://www.michcampgrounds.com/yogibears/yogi-picnic-cartoon.jpg
Competitive Exclusion • Two species cannot coexist in a community if their niches are identical-one will be eliminated • How do the organisms solve the dilemma? • Realized niche vs. Fundamental niche
Realized vs. Fundamental niche • Fundamental – where a species CAN possibly live • Disregard predation & limiting factors • Realized –where the species actually DOES live • because predators, limiting factors, etc. have forced it to leave parts of the fundamental niche
CARRYING CAPACITY (K) • Maximum population size environment can support http://www.algebralab.org/img/cb07ae0c-5106-416c-8407-38da526923c6.gif
Limiting Factors element in short supply or cycles slowly LIMITS the growth of the population http://www.wspa-international.org/exhibition/gallery/large_DeadKenyan%20droughtSPANA.jpg
Population size is affected by: Levels of competition Predatory defense mechanisms Resistance to disease and parasites Ability to migrate • Environmental conditions • Birth rate • Realized vs. Fundamental niche • Food supply • Habitat
Exponential Growth (J curve) • Occurs when populations are introduced into new niche • May occur when numbers have been reduced due to a catastrophic event and population is rebounding • Differences in birth and death rate are high
Logistical Growth (S Curve) Slide by Kim Foglia • Rapid reproduction phase • Then slower growth rate as population increases