Ecology: Population Dynamics, Growth Models, and Survivorship Curves

Exponential Growth

Fast J-curve.

Logistic Growth

S-curve, slows at carrying capacity.

Type I Survivorship Curve

Live long, few young.

Type II Survivorship Curve

Steady death rate.

Type III Survivorship Curve

Many die young, few survive.

Humans

Type I survivorship curve.

Birds

Type II survivorship curve.

Fish/Plants

Type III survivorship curve.

Invasive Species

Harmful non-native species.

Biological Control

Natural predator to control pests.

Population Growth Rate in Developed Countries

Almost zero growth.

Population Density Calculation

Population ÷ area.

Older Population Structure

Top-heavy.

Rapidly Increasing Population Structure

Wide base.

Stable Population Structure

Rectangle/balanced.

Population Patterns Over Time

Grow, then level off at carrying capacity.

Red-Cockaded Woodpecker Population Changes

Down = habitat loss; Up = protection and habitat management.

Mongoose

Small carnivore; used to control pests.

Population Definition

Group of same species in one area.

Human Population Growth History

Exponential growth; Type I survivorship; humans can act like invasive species.

Equilibrial Life History

Few offspring, high parental care, long life, stable environment.

Density Dependent Factors

Affected by population (disease, competition).

Density Independent Factors

Not affected by population (weather, fire).

IPM

Integrated Pest Management.

Logistic Growth Model at Carrying Capacity

Growth stops, stabilizes at carrying capacity.

Examples of Invasive Species

Kudzu, zebra mussels, cane toads.

Prime Carrying Capacity

Maximum population an area can sustain.

r-strategists

Many offspring, unstable environment.

K-strategists

Few offspring, stable environment.