1. 4.2 Human Population Human Population Growth
Chapter 4
Population Ecology
4.2 Human Population
Human Population Growth
The study of human population size, density, distribution, movement, and birth and death rates is demography. 1

2. Technological Advances
Chapter 4
Population Ecology
4.2 Human Population
Technological Advances
For thousands of years, environmental conditions kept the size of the human population at a relatively constant number below the environment’s carrying capacity.
Humans have learned to alter the environment in ways that appear to have changed its carrying capacity. 2

3. Human Population Growth Rate
Chapter 4
Population Ecology
4.2 Human Population
Human Population Growth Rate
Although the human population is still growing, the rate of its growth has slowed. 3

4. Trends in Human Population Growth
Chapter 4
Population Ecology
4.2 Human Population
Trends in Human Population Growth
Population trends can be altered by events such as disease and war.
Human population
growth is not the same in all countries. 4

5. Zero Population Growth
Chapter 4
Population Ecology
4.2 Human Population
Zero Population Growth
Zero population growth (ZPG) occurs when the birthrate equals the death rate.
The age structure eventually should be more balanced with numbers at pre-reproductive, reproductive, and post-reproductive ages being approximately equal. 5

6. pre-reproductive stage, reproductive stage, and post-
Chapter 4
Population Ecology
4.2 Human Population
Age Structure
A population’s age structure is the number of males and females in each of three age groups:
pre-reproductive stage, reproductive stage, and post-
reproductive stage. 6

7. Invasive Species An invasive species is defined as a species that is:
1) non-native (or alien) to the ecosystem under consideration and
2) whose introduction causes or is likely to cause economic or environmental harm or harm to human health.
Invasive species can be plants, animals, and other organisms (e.g., microbes). Human actions are the primary means of invasive species introductions.

8. Emerald Ash Borer (EAB)
INVASIVE SPECIES-not native to Michigan
Came to Metro Detroit in packaging crates from China
Only eats ASH trees in USA
Ash trees-used for firewood, furniture, baseball bats, packing material etc…
Arrived around 1992-population rapidly increased (no natural predator) and by 2002 it was a noticeable problem
woodpeckers (we don’t have many left) are starting to prey on them
Has already killed 15 million Ash trees

9. Has spread to other states-Ohio, Indiana, Illinois, Maryland, and even Canada
Follow Insect Life Cycle = Metamorphosis
Adult, Egg, Larva, Pupa
1-2 years for adults to emerge
Larva bores into tree and eats the inside-killing the tree in 1-2 years
AS OF NOW THE ONLY SOLUTION IS TO LIMIT THE FOOD SOURCE-REMOVE ASH TREES and BURN ALL INFECTED WOOD
DNR-working on traps (they seem to like purple)
POTENTIALLY-$1 + BILLION PROBLEM

14. Asian Carp Two species – Bighead and Silver
Imported by catfish farmers in the 70’s to remove algae from ponds
During massive floods in the 90’s, catfish farmer’s ponds overflowed and released the carp into the waterways.
Now they are the most abundant species in some parts of the Mississippi River.

15. Asian Carp and the Great Lakes
Asian carp eat a tremendous amount of food, taking away from other species of fish. They can weigh up to 100 lbs.
They are very capable of surviving in the Great Lakes due to the fact that the lakes resemble their habitat in Asia.
Researchers predict the demise of the Great Lakes Ecosystem if these fish are allowed to thrive.

20. Population Quiz! Covers chapter 4 (Sections 1 and 2)
Focuses mostly on the graphs they show
Exponential and Logistic Growth
Human Population, Age Structure, etc.
Study bookwork from Section 4.1 and 4.2 / Read over sections
Quiz is about 10 questions long and is fill in the blank
PowerPoints will be online by tonight