Locations+&+History

=**th Period**= The Blackland Prairie spans approximately 6.1 million hectares from the Red River on the north to near San Antonio in south Texas. It is part of a tallgrass prairie continuum that stretches from Manitoba to the Texas coast. The main belt of the Blackland Prairie is divided into four narrow, geomorphic areas aligned in a north-south direction. These include–from west to east–the Eagle Ford Prairie, the White Rock Cuesta, the Taylor Black Prairie, and the Eastern Marginal Prairie.
 * Where are Blackland Prairies found?**

-Overgrazing (3) -Cultivation (3) -Mowing (3) -Plowing (tractors) (3) -Settlers’ natural desire to eliminate fires (3) -Invasion of woody plants (3)
 * Why are they disappearing?**

-The original biodiversity of Blackland Prairies was far greater than its northern tall grass counterpart. (1) -The prairies protect watershed, increase water filtration and water yield, increase water supply by decreasing erosion and reservoir sedimentation, increase water quality by decreasing fertilizers, pesticides, and herbicides. (2) -Prairies are habitats for grassland birds and native pollinators. (2) -The main plant community of Blackland Prairies are highly threatened. (2) -The diverse nature of Blackland Prairies produce large amounts of carbon and can help reduce global warming.(2) -Prairies provide educational opportunities, open space, and natural exposure. Children can learn about how natural prairies actually look like and learn about prairie lifestyle and heritage and the different species in prairies in addition to the history of humans and prairies.(2)
 * What is their value?**

==== ~Prior to European settlement (1825 for the southern half and 1845 for the northern half), there were infrequently (every 5 to 10 years) large intense wildfires that made the plants more fire resistant and vigorous. Fire is useful for returning nutrients to the soil and for spreading the growth of the prairie. In addition to this, the prairies were used by large herbivores, primarily bison and prong horn antelope, for grazing. (4) ====  ~IN the early days of settling the prairie, mules were used as the primary labor. Settlers would clear the land for a hay meadow to be used for pasture, all the way until the 1930s. However, as the United States became more industrialized, tractors were used to plow these prairies and pastures for the use of agriculture and also for development. (3)
 * What is their history?**


 * Sources**
 * 1.** [|__http://www.eoearth.org/article/Texas_blackland_prairies__]
 * 2.**[| __http://texasprairie.org/index.php/main/educator_resources/why_protect_and_restore_prairie/__]
 * 3. **<span style="background-color: transparent; color: #000099; font-family: Arial; font-size: 11pt; vertical-align: baseline;">[|__http://www.seedsource.com/medicine/history3.asp__]
 * <span style="background-color: transparent; color: #000099; font-family: Arial; font-size: 11pt; vertical-align: baseline;">__4.__ **<span style="background-color: transparent; color: #000099; font-family: Arial; font-size: 11pt; vertical-align: baseline;">[|__http://www.worldwildlife.org/wildworld/profiles/terrestrial/na/na0814_full.html__]

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=**7th Period**= - Texas (roughly from the Red River in North Texas to San Antonio in the south) - Urbanization (most dangerous threat because the prairies follow a line of urban development stretching between Dallas, Austin, and San Antonio) - Invasion of exotic species (african bermuda grass and lovegrass, Eurasian "King Ranch bluestem," and Mediterranean Johnson grass (3)) - row-crop agriculture (long-term mowing, businesses are depleting the prairie's resources for profit) - fragmentation (humans produce habitat fragmentation chiefly from agricultural land conversion, urbanization, pollution, deforestation, and introduction of alien species) - loss of landscape-scale processes (especially fire and grazing by large herbivores) - a high degree of plant biodiversity - rich in resources - greater representation of soil orders - are habitat for more than 500 native fauna including 327 species of bird, 7 reptile, and 15 bird species are considered imperiled (ranging from state "watch listed" to federally endangered). - Pre-European settlers: the moist eastern prairies of Texas were dominated by the tall grasses andd rivers, streams, and bottomland hardwoods. - Today: mor<span style="font-family: Arial,Helvetica,sans-serif;">e than 90% has been plowed <span style="font-family: Arial,Helvetica,sans-serif;">- 1970: a survey was conducted by graduate students of Texas A&M University across the main belt of the Blackland Prairie: approximately 100 ungrazed, excellent condition prairies were located, most of the sites were small, but a few were as large as 700 acres <span style="font-family: Arial,Helvetica,sans-serif;">- 1980: the number of sites had decreased from 100 to 35, and the total area from 5000 to 2000 acres 1. [] 2. [] 3.[]
 * Where are Blackland Prairies located? (1)**
 * Why are they disappearing? (2)**
 * What is their value? (2)**
 * History**
 * Source:**