recap

53.1 recap

Ecology is the scientific study of the interrelationships among organisms and the environment. Ecology is studied at multiple levels of organization, from individuals to the biosphere. Ecologists use a mixture of observations, experiments, and models to test ecological theories.

learning outcomes

You should be able to:

  • Distinguish between ecology and environmentalism, and include examples of each.

  • Describe the methods of study used by ecologists, and identify how and why ecological studies might differ from studies in other scientific fields.

Question 1

How does ecology differ from environmentalism? Give a reason why ecology is a useful scientific enterprise.

Ecology is the study of the interrelationships among organisms and the physical environment, while environmentalism is the use of that ecological knowledge (as well as social and ethical concerns) to inform personal and public policy related to stewardship of the natural world. Ecology is a useful scientific enterprise because it can allow us to better anticipate how our actions may have negative consequences for ourselves and the natural world.

Question 2

Using observations, experiments, and models at different levels of organization, describe how you might test the hypothesis that the widespread death of the ochre sea star (Pisaster ochraceus) (shown in Figure 53.1) is the result of a disease.

You could conduct observational surveys in the field to look for disease prevalence in live and dead sea stars. If multiple individuals were surveyed at multiple sites, then you might be able to make inferences of the prevalence of the disease at population and metapopulation scales. You could conduct an experiment in which you expose sea stars to the suspected pathogen to determine if they contract and die from the disease. Finally, you could create a population model to simulate how death from the disease would affect the populations of sea stars and compare the results with your observational data.

We will begin our study of ecology in the spirit of the discipline in Haeckel’s time, focusing on variations in the distribution and abundance of organisms worldwide and the factors that determine these patterns. Our first step will be to examine attributes of the physical environment, which is the ultimate determinant for where organisms can live. We’ll begin with climate.