Ecology Notes Populations

Essential Question What are limiting factors of population growth and their graphing relationships?

https://www.census.gov/popclock/ Using the above website, record the: Current world population:____________ Current U.S. population:_____________ 3 Highest populated countries: 1)_________2)__________3)__________

Population Ecology Habitat: place where an organism lives Niche: role and effects a species has in a community Species can occupy ONE niche at a time

Limiting Factors Any factor that controls the size of a population Density Dependent Factors: Limiting factors that depend on population size Ex: Predators, Disease, Competition, Overcrowding, Territory, and/or Food

Density Independent Factors: Limiting factors that affect all populations in almost the same way, regardless of size. Ex: Weather, Natural disasters

Population Growth Carrying capacity: maximum number of organisms an area can sustain

Population Growth Population Changes: Growth: birth rates > death rates Stability: birth rates = death rates Decline: birth rates < death rates

Population Changes: Immigration: individuals into a population Emigration: individuals out of a population

Population Growth Graphs Exponential (J Curve) Plenty of resources and few predators or diseases

Population Growth Graphs Logistic (S Curve) Growth slows as resources become limited

Population Growth Graphs Saw-tooth Curve Cyclical relationship between organisms (one increases, other increases and vice versa)

Graphing Relationships Positive Relationship- both variables increase at the same time

Negative Relationship (Inverse)- one variable increases while the other variable decreases

No relationship- there is no correlation between the variables

Write 2 higher level questions on the left margin of each page of notes. Write a 3 sentence summary at the end of your notes to answer the essential question. Anchor all of your papers and your notes in your folder and bring up to Mrs. Caryl (2 students at a time) Complete Predator-Prey Relationships Turn in to basket.