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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”. Realized vs. Fundamental niche. Fundamental – where a species CAN possibly live
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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”
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 • 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 Slide by Kim Foglia • Rapid reproduction phase • Then slower growth rate as population increases