1. Human Ecology

2. Exponential Growth Exponential growth: will occur under ideal conditions with unlimited resources J-shaped graph

3. Limiting factors: –Factors that stop or control population growth –Examples: Food, light, water, space, parasitism and disease, predators, energy resources, oxygen, accumulation of waste products, competition, disasters – fire, floods, drought, etc.

4. Carrying Capacity and Logistic Growth Logistic Growth: –Exponential at first  then levels off as it reaches carrying capacity –S-shaped graph Carrying Capacity: –Maximum population that environment can support

5. Population Growth of Humans

6. Factors affecting human population growth Agricultural revolution/food production Increase in knowledge of diseases Better health care and hygiene/sanitation Advances in Medicine and technology Resulting in a decrease in death rate, a longer life span, and an increased birth rate in some areas

7. Limiting Factors Space, food, water, oxygen, presence of disease Energy resources: –Renewable energy Resources Can be replaced Food supply, solar energy, wind/air, water, soil, living things (trees), geothermal energy, nuclear energy –Non-Renewable Energy Resources cannot be replaced in one’s lifetime fossil fuels

8. Source: United Nations, World Population Prospects, The 1998 Revision; and estimates by the Population Reference Bureau. Human population is estimated to rise over 9 billion by the year 2150. Many think it will then level off or decline at this point. If growth continues, may result in population crash due to overcrowding and competition for food. May also result in famines, disease and wars.

9. Human Population Growth and the Environment As the human population grows- we take up more space consume more resources and produce more wastes

10. Disruption of Existing Ecosystems Urbanization –Shift from rural (farming) areas to cities –Increased Industrialization –Destruction of farmland and deforestation –Results in Decreased amount of space for other species Loss of habitats Decreased biodiversity Disruption of ecosystem by introducing new species into an area w/no known predator

11. Poor Farming Practices Over farming and over grazing – result in areas w/o a cover of vegetation –No plants…no roots to hold soil –Leads to soil erosion: removal of soil by wind or water and desertification Deforestation – can also lead to soil erosion, washing away of nutrients

12. Pollution Noise Water – ex. Sewage, animal wastes, toxic chemicals (DDT, fertilizers), thermal pollution Air – ex. burning of fossil fuels leads to increased levels of carbon dioxide, acid rain, smog Land – ex. solid wastes, garbage

13. RESTORING ENVIRONMENT PRESERVING RESOURCES: 3 R’s –Reduce: avoid using resource, ex. Walk, bike, carpooling –Reuse: use product over again instead of throwing it out, ex. Dishes instead of paper plates –Recycle: using a product to make another product, ex. Paper, metal, plastic, glass

14. Reduce amount of Non- renewable Energy Used Use renewable energy sources – sun, geothermal, nuclear, hydroelectric Carpool, use mass transit, use bikes

15. Control birthrate Birth control Education

16. Use biological pest control, not pesticides – ex. Using lady bugs to control aphids –Use phermones – sex hormones to attract pests

17. Compost heaps: –natural recycling of nutrients, no need for chemical fertilizers, reduces amount of waste in landfill

18. Complete lab pgs 1-3