Bumper sticker of the day: "Make it idiot proof and someone will make a better idiot."

Review of Lecture 10: The big apple: The ecosystem.

1. Ecology: the study of relationships of organisms to each other and to the environment.

2. Community ecology -- study of all the organisms and how they interact within an ecosystem; Population ecology -- study of populations of species within an ecosystem; Physiological ecology -- study of the physical environment affecting an ecosystem.

3. Different types of ecosystems exist in different environments (e.g., the ecosystem on top of a mountain is different than a desert ecosystem or a tropical rainforest ecosystem).

4. Ecosystems are characterized by limiting factors that affect plant growth: light, water, nutrients, temperature, etc.

5. Dominants: plants that characterize a community, but they may not be the most abundant. For example, in a Sonoran Desert ecosystem the giant saguaro cactus might be considered a dominant even though it is not the most abundant plant that grows there.

6. Biodiversity: estimated # spp on Earth is 30 million or more; estimated # spp in tropical rainforests is 10 million; at rate of tropical deforestation, extinction rate is estimated at 27,000 spp per year (normal rate estimated at 10 spp per year).

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Last updated January 29, 1999.