Introduction to Ecology

1. Introduction to Ecology “Ecology is the study of the interactions between organisms and the living and nonliving components of the environment. Each organism on Earth depends in some way on other living and nonliving things in the environment. Ecology involves collecting information about organisms and their environments, looking for patterns, and seeking to explain these patterns.”

2. Today’s Ecology Issues • Ecological information and understanding have always been critical for humans. For our nomadic ancestors, survival depended on practical knowledge about the environment. While our understanding has become more sophisticated, our need for understanding has become more urgent: over the past few decades, humans have changed the environment on a greater scale than ever before. • Rapid increase the number of people. • The sixth mass extinction? • The thinning of the ozone layer • Climatic changes: the greenhouse effect

3. Levels of Organization: The Heirarchy of Ecology • Individual • Population:________________________________________________________________. • Community:_______________________________________. • Ecosystem:________________________________________________________________. • Biosphere: the broadest, most inclusive level organization-__________________________________________________________________________.

4. The Key Theme of Ecology • INTERCONNECTEDNESS!! • No organism is isolated • All organisms interact ______________________________________________________________________________________________. • Survival depends on these ____________________. • Each ecosystem is a network in which organisms are linked to other organisms and to the nonliving environment. • Another word for this quality is interdependence.

5. Models • Ecosystems are complex and difficult to study. We use ______________to help us deal with these complexities. • Graphs • Diagrams • Mathematical equations • Models are simplified systems designed only to mimic the behavior of the natural world and cannot account for every influence of every variable in the environment.

6. Ecology of Organisms I • Ecologists separate the living from the nonliving. • Biotic factors:____________________________________________________________________________ • Abiotic factors: the physical and chemical characteristics of the environment. • These factors are not independent.

7. Ecology of Organisms II • Organisms are able to survive within a broad range of environmental conditions. However, individual organisms have a range of conditions to which they are well suited. • We can graph this range in a tolerance curve: __________________________________________________.

8. Ecology of Organisms III • Acclimation: _________________________________________________________. • This is NOT the same thing as adaptation– acclimation occurs within the lifetime of an organism. Adaptation is the ___________________________________________________________.

9. Ecology of Organisms IV • Control of internal conditions; how organisms deal with changes in the environment: • Conformers: __________________________________________________________________________________________________________________________. • Regulators: __________________________________________________________________________________________________________________________.

10. Ecology of Organisms V • Escape from unsuitable conditions; an ability to survive unfavorable conditions by escaping from them temporarily. • Dormancy:___________________________________________________ • _____________: moving to another, more favorable habitat

11. Ecology of Organisms VI • Resources:__________________________________________________________________. • Whether a species can survive or not in a particular habitat depends on the suitability and availability of resources. • Resources necessary for survival vary from species to species.

12. The Niche • A species way of life, or role the species plays in the environment. • Includes the range of conditions that the species can tolerate, the methods by which it obtains resources, the number of offspring it has, its time of reproduction, and all other interactions with the environment. • Fundamental niche: the range of conditions that a species can POTENTIALLY tolerate and range of resources that it can POTENTIALLY use. • Realized niche: the range of resources it ACTUALLY uses. • A species niche can vary within a single lifetime. • Generalists: species with broad niches; can tolerate a range of conditions and variety of resources. • Specialists: Species that have narrow niches.