Effects of Weathering, Erosion and Deposition Texas Ecoregions Effects of Weathering, Erosion and Deposition

Factors Affecting Our Ecoregions Weathering – chemical and physical break down of rocks into sediment Erosion – the movement of sediment from one place to another Deposition – the placement of sediment after being carried from place of origin

1. Piney Woods This ecoregion is found in Southeast Texas. It is the wettest region of the state. This allows for a high rate of decomposition to occur resulting in healthy, nutrient-rich soils. The topography is gently rolling to near flat through out the region. Pine trees, woody vines, and hardwood trees dominate the vegetation. It is a fire climax system. Fire is necessary in order for pines to maintain dominance in the area. Unless an area has been clear-cut of vegetation for construction, the amount of trees and plants can prevent too much wind and water erosion. Main cities include Tyler & Huntsville

2-3. Blackland Prairie & Oak Woods These areas have nutrient-rich soils and receive good amounts of rainfall through the year. If the land is clear-cut of natural vegetation for construction, nutrients can easily be eroded by wind and water. If the land is used for farming and it is not managed well, nutrients will be quickly used up. Main cities include DFW, Midlothian, Cleburne, Bonham

4-5. Western Gulf Coastal Plain Soil in the region is primarily sand-based. If there isn’t enough vegetation to keep the soil in place, rainfall received can cause severe water erosion. Catastrophic events such as hurricanes can increase wave erosion and deposition. Main cities are Galveston, Houston, and Corpus Christi

6. South Texas Plains The area is known as “Brush Country” due to the shorter trees and many shrubs. Overgrazing of the land has allowed nutrient-rich topsoil to erode way. Rocky, dry soil cannot support grasses, trees can thrive because of their deeper root system. Wind erosion is very common here. Cities include Brownsville, Laredo, and San Antonio

7-8. Edwards Plateau Llano Uplift This region is located between dry western plains and moist prairies and woods. Unfortunately, wind and gravitational erosion has left most of the region with very shallow soils (less than 10 inches) lined with limestone rock layers. High amounts of rain in a short amount of time can cause flash flooding and water erosion. Main cities include: Austin, Enchanted Rock, Garner

9. Rolling Plains (Panhandle) This region is part of the Great Plains of the central United States. Soils in this area are most fertile and sought after for crop production. Periods of drought and then sudden increase in rainfall causes large amounts of wind and water erosion and deplete the soil of nutrients. Main cities include: Abilene, Lubbock

10. High Plains “Texas Panhandle” Largest and most completely flat areas of it size in the world! The region extends to the Palo Duro Canyon-the nation’s 2nd largest canyon. Palo Duro Canyon was formed by water erosion from the Prairie Dog Town Fork of the Red River. The water deepens the canyon by moving sediment downstream. Wind and water erosion gradually widen the canyon. Main cities include: Amarillo, Possum Kingdom

11. Trans-Pecos Rain does not fall evenly over the area. “Desert portion” of Texas. The weathered bedrock in this area has high amounts of calcium. As a result of gravity, water, & wind erosion and deposition in the area, the soil has high amounts of calcium called caliche. Main cities include: Big Bend, Fort Lancaster, Midland, Odessa