1. Domain 2 Ecology

2. What is Ecology?
Ecology is the scientific study of interactions between organisms and their environments.
Ecology reveals relationships between the nonliving and the living parts of an ecosystem.
Abiotic factors are non-living chemical and physical factors in the environment such as water, atmospheric gases, soil, temperature, light, space, shelter, and wind.
The biotic factors include all of the living organisms with which an organism might interact.
Each organism in an ecosystem lives in a particular place (habitat) and plays a particular role (niche).
There are many type of interactions including competition, predation, and symbiosis.

3. Types of Symbiosis
Mutualism-both species benefit from the relationship.
Commensalism-one organism benefits and the other is not affected.
Parasitism-one organism lives inside or on another organism and harms it.

4. Predation Predation occurs when one organism (the predator) kills
and consumes another
organism (prey) or uses its
nutrients without killing it.

5. On the graph, when predators are fewer in number, the
numbers of prey rise. Predators respond by reproducing
more. As the population of predators rises, more prey
are killed and their numbers fall. Many of the predators
then die. Video Clip

6. Matter and Energy Sunlight is the main energy
source for life on Earth. The
need for energy to power
life’s processes drives every
organism’s interaction with
its environment.

7. Matter and Energy Flow in Ecosystems
A food chain is one path of matter and energy flow in an ecosystem. Each level of consumption in a food chain is called a trophic level.
a. The source of all food is photosynthesis by autotrophs, mainly plants. They are called producers because only they can manufacture food from inorganic raw materials.
b. Food produced by autotrophs is consumed by
heterotrophs . Heterotrophs are known by other names.
herbivores eat plants and are called primary consumers.
carnivores feed on herbivores and are called secondary consumers.
carnivores that feed on other carnivores are tertiary consumers.
omnivores eat both herbivores and carnivores
decomposers are organisms which break down and consume
dead organisms and their wastes

9. Food Web
all the possible feeding relationships at each trophic level in a community
interconnected food chains

10. Food Web
What is missing from this food web?
decomposers

11. Ecological Pyramid
A graphical representation of the trophic levels within an ecosystem.
The producer level is at the base of the pyramid with the consumer levels above.
Video

12. Energy Pyramid
compares the total amount of energy available in each trophic level.
Approximately 10% of the energy available is passed from one level to the next.
90% is used by the organisms for their life activities or lost as heat to the environment.

14. Biomass Pyramid
compares the total weight of the organisms in each trophic level Video Clip

15. Numbers Pyramid
compares the number of individuals in each trophic level.
Video Clip

16. Exponential Growth
individuals in a population reproduce at a constant rate.
occurs under ideal conditions
Will show a j-shaped curve

17. Logistic Growth
occurs when a population’s growth slows or stops following a period of exponential growth.
occurs when resources become less available
Will show a s-shaped curve

18. Logistic Growth

19. Biomes: areas with similar abiotic factors (temperature, rain, soil), plant, and animal species
Dominant plants
Dominant animals
Climate
Interesting facts
Tundra
Lichens and mosses
caribou
dry, cold; short growing season
permafrost
Taiga
coniferous forest (pine, spruce, fir trees)
moose, elk, snowy owl
long, dark, snowy winters and warm, short summers
Area south of the tundra
Temperate forest
deciduous trees (oak, hickory, and maple)
Squirrels, deer
4 distinct seasons; moderate rainfall
covers much of the U.S. and Europe
Desert
cacti
reptiles, nocturnal mammals
hot days, cold nights; very little rainfall
sandy soil
Grassland
grasses
Prairie dogs, bison
long periods of drought
Savannah, steppes
Tropical rainforest
orchids
sloths, and birds
lots of rainfall; constant warm temperature
most biodiversity

20. Comparison of Rainfall in the
Major Land Biomes