Tropical and Subtropical Grasslands, Savannas, and Shrublands

Longitude:10 to 30

Names of Regions: Africa, India, Northern parts of South America and Australia, and Southern parts of the United States

Area is defined by its humid summers and warm dry winters.

Abiotic Factors

Average Precipitation: 300 to 1500 milliliters of rain per year

Average Temperature: 27 to 30 Degrees Celsius

Wind Patterns: The area is influenced by trade winds. It moves to the west and down, they come from the east. As the heat rises the moisture within the air evaporates creating a dry and arid region.

Soil Composition: Most soil is porous and extremely thin which allows rain to drain quickly. There are some exceptions where there are clayish and shallow soils though. It is usually rich in nutrients and minerals.

Abiotic Factors

There are two levels: a grassy ground level and a woody plants

Limiting Factors: The lack of rainfall prevents the upper layer from becoming dominate Fires and grazing keep the grass level dominate. The grassy level depends on summer rainfall. Most species can survive through fires with only 10% of plants being killed. Also, they are experiencing a heavy conversion to agriculture.

Climatogram

Displays the rainfall and temperature of this region.

Biodiversity

Autotrophs: Trees- Oaks, Cottonwoods, and Willows; Grasses- Purple Needlegrass, Blue Garma, Buffalo Grass, and Galleta; Flowers- Asters, Blazing stars, Coneflowers, Goldenrods, Sunflowers, Clovers, Psoraleas, and Wild Indigos

Heterotrophs: Gazelles, Zebras, Rhinoceroses, Wild Horses, Lions, Wolves, Prairie Dogs, Jack Rabbits, Deer, Mice, Coyotes, Foxes, Skunks, Badgers, Grouses, Meadowlarks, Quails, Sparrows, Hawks, Owls, and Snakes.

Biodiversity

Threatened Species: Zebra and Wildebeest are declining in population because of environmental changes which have forced them to alter their hunting and migratory patterns.

Concerns

There are concerns involving temperate grasslands because many are becoming farms or grazing land because the land is flat, tree less, and rich in soil.

Cattle grazing, particularly in Australia, has caused a huge detriment to the land quality.

Vegetation has also become thicker causing less fires. Introduction of native mammals have caused other species to decrease in population.

Hope?

Savannas are successfully being protected because the Kruger and Kalahari Gemsbok National parks protect the land. There are other reserves suchs as Etosha, Gemsbok, Chobe and Hwange National Parks, and Central Kalahari Game Reserve.

Groups

Biodiversity Support Program

SAFE

WWF

NRCS

Biblography

http://www.bcgrasslands.org/grasslands/communitiesandhabitats.htm

http://www.plantzafrica.com/vegetation/savanna.htm

http://www.wri.org/publication/content/8269

http://www.nationmaster.com/encyclopedia/Shrubland