Physical Geography by Alan Arbogast Chapter 10 con

1
Physical Geographyby Alan ArbogastChapter 10
cont
Biomes
Lawrence McGlinn Department of Geography State
University of New York - New Paltz
2
Geography of Biomes
3
Grassland Biomes

• Midlatitude Grassland dominant vegetation is
  grass dry parts Dfa, Dwa, Dfb, Dwb climates,
  and Bsk climate central N. America, South
  Africa, eastern Europe, central Asia, Argentina

4
Midlatitude Grassland

• Precipitation great enough to support grasses and
  some trees, but not forests.
• Drought and fire prevent large forests from
  growing.
• Fires are very common in the grassland biome.
• Grasses can survive fires because they grow from
  the bottom instead of the top.
• Soils found in grasslands are some of the most
  fertile in the world, though.
• Tallgrass and shortgrass prairie in U.S.

5
Midlatitude Grassland Biome
Shortgrass prairie
Tallgrass Prairie
6
Geography of Biomes
7
Deserts

• Where are they located?
• Continental areas
• Areas dominated by STHP
• Rainshadows (leeward sides of mountains)

8
Deserts

• Most animals are nocturnal to avoid high
  temperatures
• Many cold-blooded animals
• Low organic content of the soil high salt
  content
• Warm deserts tropics, subtropics
• Cold deserts midlatitudes

9
Desert Biome

• Types of plants in deserts
• All generally classified as Xerophytes
• Phreatophytes plants that grow along water
  courses (deep tap roots)
• Ephemerals plants that wait years for rainfall
  events
• Succulents plants that store water for long
  periods to survive continued aridity
• Halophytes plants specifically adapted to the
  very salty environment often found in deserts

10
Desert Biomes

• Hot Dry Desert subtropical, centered on 30º N
  S Bwh climate Sahara, Kalahari, Mohave
  Deserts bare ground to xerophytic plants

11
Warm Desert and Semidesert

• Caused by the low precipitation and dry air of
  subtropical high pressure
• These areas are under the influence of high
  pressure 8 to 12 months of the year
• Coastal deserts, such as the Atacama, western
  Sahara, and Namib Deserts receive precipitation
  in the form of sea mist and fog

12
Desert Biomes

• Semi-Arid Cold Desert western N. America
  central Asia Bwk climate bare patches to low,
  spiny, wooly plants, e.g. mesquite, sagebrush,
  creosote bush

13
Cold Desert and Semidesert

• Occur at higher latitudes
• Affected by subtropical high pressure less than 6
  months of the year
• Rainshadow and interior location produced the
  cold deserts of the Great Basin.
• Light winter snow can occur over cold deserts
• Many of these deserts were former shortgrass
  prairies ? overgrazing

14
Desertification

• Expansion of the desert
• Occurs along the margins of semiarid and arid
  lands
• Caused by poor agricultural practices, such as
  overgrazing, soil overuse/abuse, improper
  management of soil moisture, erosion,
  salinization, deforestation, and climate change.

15
Geography of Biomes
16
Tundra Biome

• Borders Arctic Ocean across N. American Russia
  ET climate grasses, shrubs, sedges, mosses,
  lichens all short easily damaged

17
Arctic Tundra
Figure 20.18
18
Arctic Tundra

• Associated with high latitudes
• Found in extreme northern Russia, North America,
  Europe, and Greenland
• 60-80 day growing seasons
• No trees, dwarf plants, soggy ground
• Low temperatures, precipitation, and evaporation
• Poorly developed soils underlain by permafrost

19
Arctic Tundra

• Tundra vegetation mosses, sedges, snow lichen,
  arctic meadow grass
• Important breeding ground for migratory birds
  geese, swans, waterfowl

20
Alpine Tundra
Figure 20.19
21
Alpine Tundra

• Associated with high elevations above timberline
• Similar composition to Arctic Tundra
• No permafrost, better drainage
• Andes, White Mts of California, Alps, Himalayas
• Vegetation grasses, herbs, stunted shrubs