1. Natural Resources
Chapter 23

2. Living Things as Natural Resources

3. What are Natural Resources?
Natural resources are usable materials that man can obtain from he physical world.
Examples: plants, animals, land, water, coal, oil, gems, metals, hills, prairies, and coastlines

4. Natural Resources It can not be replenished It can “replace” itself
Renewable
Nonrenewable
It can “replace” itself
It can not be replenished
Trees
Oil

5. Living Things as Resources
There are three types of living organisms that we rely on
1. producer organisms
2. consumer organisms
3. decomposer organisms

6. Producer Organism
Producer organisms trap energy from the sun and convert the energy into food.
Plants also produce fibers for clothing, materials for building and some medicines

7. Consumer Organisms
Labor
Clothing
Food
Transportation

8. Decomposer Organisms
Remove and recycle wastes
Example- microorganisms decompose a compost pile

9. Abuse of Wildlife
When something becomes popular, such as beaver furs in 1600 and 1700s, man sometimes exploits an organism for personal gain.
Beavers almost became extinct because beaver furs were in fashion
Extinct- when no members of that species are left alive on earth

10. Why are Beavers Not Extinct?
Beavers are still around today because some people and made laws in some areas against beaver trapping.
We have learned to be better stewards of what God has provided for us
Some animals are now raised on special farms so as not to harm the natural population
Rabbit Farm

11. Farming
Caring for a concentrated group of plants or animals so that they can be used to supply human needs

12. Domesticated Animal Living things man raises primarily for his own use
+ Donkey
Living things man raises primarily for his own use
After they are domesticated, man usually breeds them for the characteristics he wants
Remember Mendel and his peas?
Mules were bred for work
Horse
= Mule

13. Agriculture- the science of growing crops and livestock
Agriculture and Soil
Agriculture- the science of growing crops and livestock

14. Harvest
Farmers have known for a long time that some soil is better than others
The sciences of agriculture came about when scientists started experimenting with soil to find the best options
They have increased the harvest to be between 10 and 50% more productive than fifty years ago

15. Loss of Productivity
Silo
After several crops, using the same soil, the amount produced becomes less and less
In the Bible, God commanded the children of Israel to let their land rest on the seventh year… guess He knew what he was talking about!
Modern version of food storage

16. Land Loses Productivity in Several Ways
Depletion- loss of soil nutrients
Normally a plant dies and replenishes the soil but, in farming, the harvest is gathered.

17. Fertilizer Today farmers add fertilizer to replenish the soil
Fertilizers are specific to the soil and the crop
Fertilizers are natural (poop) or made in a lab (chemicals)

18. Some Plants Add Nutrients to Soil
Alfalfa
Clover, alfalfa, soybeans and other legumes have bacteria living in their roots
These plants are planted just to be tilled under to supply the soil with nitrogen

19. Crop Rotation
Farmer changes the kind of crops grown in each field each year
This works because some crops need a particular nutrient while others need more of another
Each nutrient has a chance to “rebuild”

20. No-Till Agriculture
Seeds are planted among remains of the previous crop
The soil is not opened to erosion and the old plant material (dead leaves and stalks) enriches the soil

21. Man’s Role in the Ecosystem

22. Human Population Time of Christ- 0.25 billion people
Notice a trend???
Population did not double again in the mid-nineties but is projected to do so around 2025

23. How Does a Population Grow?
Birthrate and death rate of a population affect the growth rate
If birthrate and death rate are even there will be zero population growth.
Population Increase- more births than deaths
Population Decrease-more deaths than births

24. What’s the Trend Right Now?
Decrease in deaths and in births but the population is still growing
There is a decrease in deaths right now due to medical advancements and improved standards of living
Death rates have decreased so dramatically that there is still an increase in population

25. Planning for the Future

26. Future Population
It is hard to predict the future population because we can’t account for wars, epidemics, natural disasters etc.
Japanese Tsunami
Bubonic plague
Some people estimate that, with careful planning, the earth could sustain 100 billion people.

27. Some Terms to Know
Conservation- the preservation and wise use of natural resources
Pollution- addition of impurities to an ecosystem
Biodegradable- substances that living organisms break down