Chapter 5 Section 2 Limits to Growth Objectives: -Identify factors that limit population growth -Differentiate between density-dependent and density-independent limiting factors

Limiting Factor: Causes population growth to decrease How is this similar to the addition of a limiting nutrient to an ecosystem?

Exponential growth Rapid decline Steady population Steady population Peak population Rapid decline Steady population Steady population

Density-Dependent limiting factor – Limiting factor that depends on population size Operate more strongly when a population is large and dense

Density-Dependent Factors: A: Competition Occurs with members of the same species or among members of different species Two species can compete for food, water, space, etc. When these factors are become limited, populations will decrease

Density-Dependent Factors: B: Predator–Prey Relationship: Mechanism of population control in which a population is regulated by predation

Wolf and Moose Populations Wolves Wolf and Moose Populations

Density-Dependent Factors: C: Parasitism and Disease

Density – Independent Factors: Affects all populations in similar ways, regardless of population size. Results in crash of population size A: unusual weather B: natural disasters C: seasonal cycles D: certain human activities (damming rivers, clear-cutting, etc)