Ecology

1. Ecology Upward Bound

2. Ecology The study of interactions that take place between organisms and their environment

3. Ecological Research Involves using descriptive and quantitative methods

4. Biotic Factors All the living organisms that inhabit an environment

5. Abiotic Factors Nonliving parts of an organism’s environment including air currents, temperature, moisture, light, nutrients, and soil

6. Obtaining energy The ultimate source of all energy within ecosystems comes from the sun

7. Autotrophs Autotrophs (producers) are organisms that use light energy to make energy-rich compounds (food) Examples of autotrophs include plants and algae

8. Heterotrophs: The consumers • A heterotroph is an organism that cannot make its own food and must feed on other organisms • Herbivore – feeds only on plants • Carnivores – feed on other heterotrophs • Scavengers – feed on dead heterotrophs • Omnivores – feed on plants and animals • Decomposers – break down complex compounds of dead and decaying plants and animals into simpler molecules to be absorbed

9. Carnivore

11. Scavenger

12. Flow of matter and energy in ecosystems Food chains – a simple model that scientists use to show how matter and energy move through an ecosystem Arrows indicate the direction in which energy is transferred from one organism to the next

13. Trophic Levels in food chains • Each organism in a food chain represents a feeding step or trophic level describing the passage of energy and materials

14. Ecological Pyramids • A model used to show how energy flows through an ecosystem • The first level represents autotrophs • The next level represents primary consumers • The next level represents secondary consumers and so on. . .

15. Ecological pyramids • Pyramids of energy illustrate the energy decrease at each successive trophic level • Only ten percent is available for use in metabolism, building tissue, and giving off heat • Population sizes decrease at each successive trophic level (usually) • Biomass – total weight of matter at each trophic level decreases

16. Food Web Food webs are models that represent all the possible feeding relationships at each trophic level in a community

17. The biosphere Cells 10 µm Organs and organ systems Cell Ecosystems Organelles Communities 1 µm Fig. 1-4 Atoms Tissues 50 µm Molecules Populations Organisms

18. Levels of Organization • Biosphere • Ecosystem – The community of organisms and how they relate to each other and the abiotic environment • Community – The set of interacting populations in a defined place and time • Population - a group of organisms, all the same species which interbreed and live in the same area at the same time • Organism

19. Habitat • The place where an organism lives out its life • Niche – all strategies and adaptations a species uses in its environment, how it meets needs for food, shelter, survival, and reproduction