Tools of environmental science Chapter 2 Tools of environmental science

Introduction How is thinking scientifically similar to how you usually think about things? What values do people consider when making a decision about the environment?

Chapter 2 Section 1 Objectives: 1. What is meant by the experimental method? 2. Define hypothesis. 3. Explain why a good hypothesis is not simply a guess. 4. Why do scientists write predictions? 5. Name the two essential parts of a good experiment.

6. What is the difference between the experimental group and the control group in an experiment? 7. Define variable. 8. What is the purpose of the control in an experiment? 9. Describe how scientists study subjects in which experiments are not possible.

10. Why is it important that scientists repeat their experiments? 11. Explain the importance of curiosity and imagination in science.

The experimental method Define the problem Collect information on the problem (observe) Form a hypothesis; make a prediction Conduct an experiment to test the hypothesis Record data from the experiment State a conclusion Communicate the results

Controlled experiment Involves two groups, the control group and the experimental group Involves a control, the standard for comparison Involves a variable, the one condition being changed in the experiment

Variables Independent Variable The one factor that is manipulated by the scientist It causes the change in the dependent variable Dependent variable The change that occurs because of the independent variable

Smithers thinks that a special juice will increase the productivity of workers. He creates two groups of 50 workers each and assigns each group the same task (in this case, they're supposed to staple a set of papers). Group A is given the special juice to drink while they work. Group B is not given the special juice. After an hour, Smithers counts how many stacks of papers each group has made. Group A made 1,587 stacks, Group B made 2,113 stacks.

The correlation method Used when questions cannot be answered by experimentation Does not necessarily prove cause-and-effect relationships between two variables Not reliable

Scientific habits of mind Curiosity The habit of skepticism Openness to new ideas Intellectual honesty Imagination and creativity

Chapter 2 section 2 objectives 1. Define statistics. 2. Explain how scientists use statistics. 3. Explain why sample size is important in determining probability. 4. What is mean? 5. List four types of models commonly used by scientists. 6. Explain the relationship between probability and risk.

How scientists use statistics Scientists rely on statistics to summarize, characterize, analyze, and compare data. Scientists uses statistics to describe statistical populations. A statistical population is a group of similar things that a scientist is interested in learning about.

What is the Average? Although statistical populations are composed of similar individuals, these individuals often have different characteristics. For example, in the population of students in this classroom, each student has a different height, weight, and so on. The mean is the number obtained by adding up the data for a given characteristic and dividing this sum by the number of individuals. Another term for mean is average.

Distribution Curve The relative arrangement of the members of a statical population A normal distribution forms a bell-shaped curve around the mean

What is Probability? The chance that something will happen (like flipping a coin) Often determined by observing ratios or patterns

Models Physical Graphical Conceptual Mathematical

Chapter 2 - Section 3 Objectives: 1. Define value. 2. List and define three values that people consider when making decisions about the environment. 3. List the four steps in a simple environmental decision-making model. 4. Describe in a short paragraph examples of two situations in which environmental values come into conflict with other values.

Ch 2 Section 3 Values and the Environment Values are principles or standards that an individual considers to be important.

An Environmental Decision-Making Model A decision-making model is a conceptual model that provides a systematic process for making decisions.

Decision-Making Model

A Hypothetical Situation The golden-cheeked warbler population is declining in Valley County. The town of Pleasanton, in Valley County, is growing rapidly, and much of the new development is occurring outside the city limits. Biologists who have been studying the warbler warn county officials that if they do not take action, the state fish and wildlife service may list the bird as an endangered species.

Several groups join together to propose that the county buy several hundred acres of land where the birds are known to breed and save the land as a nature preserve.

The group also proposes limiting development on land surrounding the preserve. The group obtains enough petitions to put the issue to a vote, and the public begins to discuss the proposal.

People who own property within the proposed preserve oppose the plan. These property owners have an economic interest in the situation. They believe that they will lose money if they are forced to sell their land to the county instead of developing it. Other residents do not like the idea of more government regulations on how private property can be used.

Other landowners support the plan and fear that without the preserve the warbler will be listed as an endangered species. Once listed as endangered, the state will impose a plan to protect the bird that will require even stricter limits on land development. People who have land near the preserve think that their land will increase in value. Many residents also look forward to hiking and camping in the preserve.

How to Use the Decision-Making Model The hypothetical situation in Pleasanton can be used to illustrate how to use the decision-making model. Michael Price is a voter in Valley County who will vote on whether the county should create the nature preserve. The steps Michael took to make his decision follow.

Gather Information Michael studied the warbler issue thoroughly by watching local news reports, reading the newspaper, learning more about the golden-cheeked warblers from various Websites, and attended forums where the issue was discussed. Several of the arguments on both sides made sense to him.

Gather information Michael also gathered scientific information that included graphs of the decline of the warbler population.

Consider Values Michael made a table to help him clarify his thoughts and values. Michael considered the environmental, economic, and recreational values of the preserve. He believed these to be important, but someone else might have thought other values were more important to consider.

Should the Valley County Set Aside a Nature Preserve?

Explore consequences Michael decides that in the short term, the positive and negative consequences listed in his table were almost equally balanced. For example, some people would suffer financially from the plan, but others would benefit. Also, taxpayers would have to pay for the preserve, yet all residents would have access the previously private property.

Explore consequences It was the long term consequences that allowed Michael to make his decision. Michael realized that the environmental values were an important factor in his decision. The thought of the warbler becoming extinct distressed him, and protecting the habitat now would be less costly that protecting it later under a state imposed plan.

Explore consequences Michael considered that there were long term benefits as well. He had read that property values were rising rapidly in counties where land was preserved for recreation. He also found that people would pay more to live in counties that have open spaces.

Explore consequences Because the county contained little preserved land, Michael thought that creating the preserve would bring the county long-term economic benefits. He also highly valued the aesthetic and recreational benefits of the preserve, such as walking trails.

Make a Decision Michael chose to vote in favor of the nature preserve. However, someone else who looked at the same table of pros and cons might have voted differently. If you lived in Valley County, how would you have voted