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Chapter 5 Populations. Section 5-2 Limits To Growth. Limiting Factors. Cause Population Growth to DECREASE! Competition Predation Parasitism & Disease Climate Extremes Human Disturbances. Density Dependent Factors : differ with the biome/environment Amount food Disease Competition
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Chapter 5Populations Section 5-2 Limits To Growth
Limiting Factors • Cause Population Growth to DECREASE! • Competition • Predation • Parasitism & Disease • Climate Extremes • Human Disturbances
Density Dependent Factors: • differ with the biome/environment • Amount food • Disease • Competition • Parasites • Versus Independent: • Abiotic factors • Habitat disruption
Density-Dependent Factors Are Limiting Factors that depend on increased population size (density) for activation. competition predation parasitism disease
Competition Between different species is a major force behind evolutionary change Results in the formation ofNICHES
Predation • Predator/Prey Relationship • Balances, Stabilizes Populations • Wolves & Moose • 50 kg Wolf needs 2700 kg Moose per year • Average Moose is 385 kg • How many Moose need to be eaten each year?
Predation • 2700/385 = 7.01 Moose per Year • A pack of 8 wolves will kill how many Moose per year?
Parasitism & Disease Weaken Host Makes Host Susceptible To Predation May Kill Host.
Density-Independent Factors • Affect population regardless of size. • Unusual Weather • Natural Disasters • Seasonal Cycles • Human Activities • Dams • Clear Cutting
Density-Independent Factors Result in crash in population size May result in extinction