1. Chapter 12: Interactions Within Ecosystems
12.1: Groups of living things interact within ecosystems
12.2: Organisms can interact in different ways
12.3: Ecosystems are always changing

2. How can you estimate population in an area. Is this accurate
How can you estimate population in an area? Is this accurate? Limitations?

3. Organisms occupy specific living areas
Living things in an ecosystem depend on their environment to meet their needs
Area characteristics help determine the types of living things you will find in that area
Recall: Species: organisms grouped according to shared characteristics
Same species: can mate and reproduce

4. Population
Vibrio Tubiashii
A group of organisms of the same species that live in a particular area
People in a city/town
Group of plants/animals/bacteria/fungi/etc.

5. Habitats and Niches
Habitat: physical location where plants and animals live
Ex: island, woods, etc
Specific physical characteristics describes them
Precipitation, temperature range, soil quality
Filled with many different species
Characteristics determine plant life
Which determines the other (ex: animal) life there
Interaction between species leads to energy and matter flow through the ecosystem
Galapagos: cacti captures sunlight, (stores) water, and CO2  produces O2 and food for the iguana (eats leaves)
Each has a role to play in the habitat = “niche”

6. Niches
Habitat – specific characteristics control what species will be found

7. Communities Ex: school- has students, teachers, etc
Work together to help each other
Occupy the same space
“Biological community”: group of populations that live in a particular area and interact

8. The environment can be organized into five levels
Biome
general climate and types of plants found in similar places on the planet
Ecosystem
a biome contains many ecosystem
Living and nonliving factors form a stable system
Only organisms and their local environment
Community
the living components
Plants, animals, and other organisms interact
Population
group of organisms of the same species living in the same area
Organism
A single individual animal, plant, fungus, etc

9. (Organism)

10. Patterns exist in populations
Patterns in living space
Individuals may be crowded together, spread far apart, or live in small groups
Ex: Creosote bushes in California’s Mojave desert
Evenly spaced because the roots of each bush release a toxin preventing the roots of other bushes from growing
Enough spacing for animal food supply and raise young
Closely compacted: group safety

11. Patterns exist in populations
Patterns in Time:
Numbers of individuals may rise and fall, depending on season or other condition
In spring and throughout summer, a queen wasp lays eggs
Population grows throughout the summer and fall
In winter, all wasps die except the queen
Some birds fly south for the winter

12. Cicadas- every 17 years adults lay eggs for the next generation
Young hatch and grow underground over the next 17 years
cicadas video
video2