advertisement

Chapter 5 Populations: How they change Limits to growth Human population growth How do ecologists study populations? • • • • • Geographic range Density Distribution Age structure Growth Rate Geographic range • Where is the population found? Density • How many per unit area? What happens to density if the population size stays the same but the range increases? What happens to density if population stays the same and range decreases? Distribution- (draw each) • Random • Clumped • Uniform Age Structure • What is this? • Why is this important? Growth Rate • Equation for finding growth rate: Growth rate can be positive,negative or zero What impact does immigration have? What impact does emigration have? Exponential Growth What conditions must exist for this to take place? Examples of organisms that exhibit this: Draw an example of an exponential growth curve: Logistic Growth • Three phases: ( list and draw a curve) a) b) c) How does this compare with Exponential growth? When does this kind of growth occur? Analyzing Data- page 135 #1-2 1)Calculate 5 generations of rabbits: Create a graph on the attached sheet using the calculations from number one. Plot time ( independent variable) on the x-axis and population ( dependent variable) on the y-axis 2) What type of growth is this? Carrying Capacity • What is it? • List factors that limit it: Density dependent factors • • • • • • Competition Predation Herbivory Parasitism Disease Stress from overcrowding Density Independent Factors • Natural Disasters: ( list examples) Human Population Growth • What kind of growth curve is the human population showing? Why does population growth differ between countries? Comparing age structures • How does Nigeria’s age structure differ from the US? • What does this difference mean in terms of future population growth? Demographic Transition • This means a shift from ________ birth and death rates to ________ birth and death rates. • This happens in _______ stages. • During which phase is population growth rate the greatest?