1. NAS 107: Chapter 3 Objectives

2. Ecology 101 1.Humans are dependent on the natural world, from which basic needs are obtained (clean air, water, resources & energy). 2.Limiting factors determine what can live where, and climate is the major abiotic cause of differences between ecosystems.

3. 3.All life on Earth is composed of organic molecules…..Carbon!Carbon 4.1 st Law of Thermodynamics – Energy is neither created or destroyed (There is no free lunch). 2 nd Law – Systems will go in one direction only – toward increasing entropy (In any energy conversion, you will end up with less usable energy than you started with).

4. 5.Biogeochemical cycles describe the movement of matter through the environment. Humans have impacted all of these cycles.

5. Class Activity – Using your textbook, form a small group and identify a local nutrient cycle problem. Outline the problem (source, impact on ecosystem, impact on humans), then develop possible solutions. Report a summary to the class.