Physical Geography by Alan Arbogast Chapter 10 con’t Biomes Lawrence McGlinn Department of Geography State University of New York - New Paltz

Geography of Biomes

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

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. Midlatitude Grassland

Midlatitude Grassland Biome Shortgrass prairie Tallgrass Prairie

Geography of Biomes

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

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

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 Desert Biome

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

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

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

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

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.

Geography of Biomes

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

Arctic Tundra Figure 20.18

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

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

Alpine Tundra Figure 20.19

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