1. 4-2 What Shapes an Ecosystem?
Some basic questions to ask about organisms are: Where does it live? Why does it live there?

2. Ecological address
A. Tells you about the climate the organism experiences, the neighbors it would most likely have and the kinds of things that will influence its survival.
2. Those things that may influence the organisms survival can be
Biotic or abiotic factors.

3. 3. Environment is separated into two classes
A. Biotic factors – (bio = living) living parts of the ecosystem
1. Plants, animals, bacteria, fungus
B. Abiotic factors – (a = non) nonliving parts of the ecosystem
1. Temperature, humidity, pH, salinity, O2 concentration, amount of sunlight, available nitrogen, precipitation, soil, water, rocks
2. Temperature is most important – varies
the most.

4. A. An area where the organism lives is called its habitat.
4. Biotic and abiotic factors determine the survival and growth of an organism and the productivity of the ecosystem in which the organism lives.
A. An area where the organism lives is called its habitat.
B. Habitat includes biotic and abiotic factors

5. What is abiotic, what is biotic?

6. A. Organism must be able to survive within a wide range of conditions.
5. Response to Changing Environment
A. Organism must be able to survive within a wide range of conditions.
1. Temperature changes, weather changes,
variations in sunlight (shade).
2. No organism can withstand the extreme
variations – they are adapted for a specific
range of condition.
B. Acclimation
1. Adjusting their tolerance to the environment around them.

7. 6. Control of Internal Conditions
A. Conformers are organisms that do not regulate their internal conditions (cold blooded)
1. Conform to the environments conditions.
2. Example – lizards body temperatures
fluctuate with outside temperature.
B. Regulators are organisms that use energy to control some of their internal conditions
1. Regulate without regard to environment
conditions (warm blooded)
2. Example – humans body temperature
remains constant (unless you are sick)

8. 7. Escape from Unsuitable Conditions
A. Some species can survive unfavorable conditions by escaping them temporarily
B. Desert species – active at night when temperatures are much lower
C. Dormancy – state of reduced activity during periods of unfavorable conditions
1. Reptiles and amphibians hide underground
until conditions become favorable again.
D. Migration – some organisms move somewhere else for periods of unfavorable conditions.

9. 8. Resources – energy and materials a species needs.
A. Examples – food, energy, nesting sites, water, sunlight
1. Resource Partitioning – Certain birds called warblers, share different areas on a tree so each type of warbler feeds either on the top, the middle or the bottom of the tree, not crossing another warblers feeding area. This allows different types of birds to survive and live successfully in the same tree.
a. Competitive exclusion principle- no 2 organisms can occupy the same niche in the same habitat at the same time.

10. 9. Niche is the full range of physical and biological conditions in which an organism lives and the way in which the organism uses those conditions
A.Includes:
1. The range of conditions that the species can tolerate.
2. Methods by which it obtains needed resources.
3. The number of offspring it has,
4. Its time of reproduction
5. All of its interactions with its environment

11. C. Realized Niche – the resource a species will actually consume.
B. Fundamental Niche – range of conditions that a species can potentially tolerate and the range of resources it can potentially use.
C. Realized Niche – the resource a species will actually consume. .

12. A. Generalists are species with broad niches.
10. Niche Differences – Species niche can change within a single generation.
A. Generalists are species with broad niches.
1. Can tolerate a broad range of conditions.
2. Use a variety of resources
B. Specialists are species that have narrow niches. (very specific eating habits)
1. Koala – eucalyptus leaves only

13. 11. Community interactions
A. Competition, predation and various forms of symbiosis can affect an ecosystem.
1. Resource – anything that is necessary for life, water, light, food etc.
a. Predation – one organism captures and feeds on another.
b. Symbiosis – 2 species live closely together.
c. Mutualism – both benefit from the relationship.
d. Commensalism – one benefits the other is not harmed or affected.
e. Parasitism – organism lives on or inside harming the organism.

14. 12. Ecological Succession
A. Ecosystem are constantly changing in response to natural disturbances. Older habitants are replaced by new causing further changes in the community.
1. Primary succession – growth or succession that occurs on surfaces where there is no soil.
A. Pioneer Species - the first plants that will grow in a primary succession area. These plants are Lichen (fungus and alga) that help break up rocks when they grow and add nutrients to the broken rock when they die, so other plants can begin to develop.

15. 1) Characteristics of pioneer species plants.
A) Small
B) Fast growing
C) Reproduce quickly, covering a large area.

16. 2. Secondary Succession – Growth after a disturbance in the area such as a storm, flood, or fire. Since there is usually soil left the growth is faster and the plants that grow there are different.
3. Climax Community –Plants that have stabilized in growth and have matured.

17. Microclimate
A microclimate is a climate within another climate that surrounds it.
Many time these environments are man made and contained and controlled by man.
Roof gardening
Zoo’s
Some natural parks