1. “Land Biomes of the World” Mrs. Hartge’s Science Class

2. The biosphere is the total of all of Earth's ecosystems
The global ecosystem is called the biosphere
It is the sum of all the Earth's ecosystems
The biosphere is the most complex level in ecology
Figure 34.2A

3. The biosphere is self-contained
except for energy obtained from the sun and heat lost to space
Each habitat has a unique community of species
Figure 34.2B

4. Abiotic Factors Abiotic factors are those non-living physical and chemical factors which affect the ability of organisms to survive and reproduce.   

5. Abiotic Factors
Abiotic factors vary in the environment and determining the types and numbers of organisms that exist in that environment.
light intensity
temperature range
type of soil or rock
pH level (acidity or alkalinity)
water availability
dissolved gases
level of pollutant

6. Physical and chemical factors influence life in the biosphere
The most important abiotic factors that determine the biosphere's structure and dynamics include
solar energy
water
temperature

7. Disturbances such as fires, hurricanes, and volcanic eruptions are also abiotic factors
Figure 34.4

8. Biotic Factors
Biotic factors are all the living things or their materials that directly or indirectly affect an organism in its environment.   This would include organisms, their presence, parts, interaction, and wastes.  Factors such as parasitism, disease, and predation (one animal eating another) would also be classified as biotic factors.

9. Natural selection adapts organisms to abiotic and biotic factors
Organisms are adapted to abiotic and biotic factors by natural selection
The presence and success of a species in a particular place depends upon its ability to adapt
Natural selection adapts organisms to abiotic and biotic factors
Biotic factors include predation and competition
Figure 34.5

10. Regional climate influences the distribution of biological communities
Climate often determines the distribution of communities
Earth's global climate patterns are largely determined by the input of solar energy and the planet's movement in space

11. Most climatic variations are due to the uneven heating of Earth's surface
This is a result of the variation in solar radiation at different latitudes
North Pole
60º N
Low angle of incoming sunlight
30º N
Tropic of Cancer
Sunlight directly overhead
0º (equator)
Tropic of Capricorn
30º S
Low angle of incoming sunlight
60º S
Atmosphere
South Pole
Figure 34.6A

12. The seasons of the year result from the permanent tilt of the plant on its axis as it orbits the sun
MARCH EQUINOX (equator faces sun directly)
JUNE SOLSTICE (Northern Hemisphere tilts toward sun)
DECEMBER SOLSTICE (Northern Hemisphere tilts away from sun)
SEPTEMBER EQUINOX
Figure 34.6B

13. What is a Biome?
Plants and animals don't live in isolation, but they live together with other plants and animals in an interdependent group called an ecological community. If you think about it for a moment, you will realize that all of the plants and animals in a particular ecological community must be adapted to the same climate so that they can all live in the same location.

14. A distinct ecological community of plants and animals living together in a particular climate is called a "biome." Scientists have divided the broad spectrum of climates and ecological communities found on Earth into biomes in different ways - some with many divisions, some with only a few.

15. Major terrestrial biomes
30º N
Equator
30º S
Tropical forest
Polar and high-mountain ice
Temperate deciduous forest
Savanna
Chaparral
Coniferous forest
Desert
Temperate grassland
Tundra (arctic and alpine)
Figure 34.9

16. Tropical forests cluster near the equator
Several types of tropical forests occur in the warm, moist belt along the equator Tropical Rainforest
Figure 34.10

17. Savannas are grasslands with scattered trees
Drier, tropical areas and some nontropical areas are characterized by the savanna Tropical Savannah
Figure 34.12

18. Deserts are defined by their dryness
Deserts are the driest of all terrestrial biomes
They are characterized by low and unpredictable rainfall Desert
Desertification is a significant environmental problem
Figure 34.13

19. Temperate grasslands include the North American prairie
Temperate grasslands are found in the interiors of the continents, where winters are cold
Drought, fires, and grazing animals prevent trees from growing
Farms have replaced most of North America's temperate grasslands
Figure 34.15

20. Deciduous trees dominate temperate forests
Temperate deciduous forests grow where there is sufficient moisture to support the growth of large trees Deciduous Forest
Nearly all of the original deciduous forests in North America have been drastically altered by agriculture and urban development
Figure 34.16

21. Coniferous forests are often dominated by a few species of trees
The northern coniferous forest, or taiga, is the largest terrestrial biome on Earth Taiga
Figure 34.17

22. The taiga is characterized by long, cold winters and short, wet summers
Coastal coniferous forests of the Pacific Northwest are actually temperate rain forests

23. Long, bitter-cold winters characterize the tundra
The arctic tundra lies between the taiga and the permanently frozen polar regions Arctic Tundra
It is a treeless biome characterized by extreme cold, wind, and permafrost
Permafrost is continuously frozen subsoil
Figure 34.18