Transcript Chapter 3
Chapter 3 Important Info Definition of Environment • All the conditions such as air, water and soil that affect life; physical factors that influence the existence or development of a living organism. We have always lived in an environment. • Our environment has always met our requirements. We used trees to make our houses. We killed animals to eat. But now, with technology and the ever increasing population growth, we are using resources at an unprecedented rate. We should consider ourselves on “Spaceship Earth” ---the only resources we have are the ones we have now. Resource Management • Managing our natural resources must become a priority for us. We must take care of our environment. • Collecting data about the health of the ecosystem will help us to know how to take care of our environment. (See the Deer example on page 43.) • If an ecosystem has been damaged (or polluted), we must take steps to help it heal (or clean it up). Resources • Everything we use or could potentially use is a resource. • Nonexhaustible resources can last forever regardless of human activities. Ex: Sunlight, wind power, surface water. • Renewable resources can be replaced by human efforts. Ex: a forest, fish and wildlife. However, just because it renewable doesn’t mean that it could be around forever (if we use it too quickly, we could use it up). • Exhaustible resources (also called nonrenewable resources)—they exist in finite amounts. Once we use them up, they are gone. Ex: fossil fuels, soil. Is nature balanced? • No—nature is not balanced. It changes. Balance implies no change. Some plant and animal species become extinct, new species are found. The overall temperature of the atmosphere increases (global warming) and decreases (ice ages). As long as the changes are slow, we have time to adapt. Carrying Capacity • Population level—the number of given species of plant or animal in a given area at a particular point in time. • Carrying capacity—the ability of an ecosystem to provide food and shelter for a given population level. • When a population exceeds its ecosystem’s carrying capacity, then diseases, predators, or starvation reduce the population level. Human Population • Around 2000 years ago, the human population of the world was about 300 million. Now we are above 6 BILLION! See the graph on page 49. • What is the carrying capacity for humans? Are we there yet? (discuss) Conservation and Preservation • Conservation--the practice of protecting natural resources against harm and waste. In conservation, resources can be used, just not overused or harmed. • Preservation-- protecting natural resources just for the sake of having them. Preservationists would prefer that we leave these resources alone. • Multiple Use—a somewhat new idea…using our resources so that we get more than one benefit out of it. Using a lake for flood control, drinking water and fishing, for example. Biotechnology • Scientists in this field are altering the genetic makeup of living organisms to help researchers in many fields, including medicine, agriculture, and environmental sciences. • Genetic engineering is one part of Biotechnology. The genes of an organism are modified to enable them to do something or live longer or prevent pests, etc. • Is genetic engineering safe? (discuss) Pollution • Water Quality-keeping water clean. There are some laws that we’ll talk about in a chapter down the road that helped us (forgive the pun! ) “clean up our act” when it came to water. • Air Quality- acid rain, smog (clouds of polluted air) and car exhaust: all things we should work on trying to reduce to keep the air we breathe clean!