Transcript Texas Ecoregions

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
CHEMICAL WEATHERING
• THE PROCESS THAT BREAKS DOWN
ROCKS B Y CHEMICAL CHANGES OR
REACTIONS.
Piney Woods
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This ecoregion is found in Southeast
Texas.
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It is the wettest region of the state. This
allows for a high rate of decomposition to
occur resulting in healthy, nutrient-rich
soils.
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The topography is gently rolling to near flat
through out the region.
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Pine trees, woody vines, and hardwood
trees dominate the vegetation.
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It is a fire climax system. Fire is necessary
in order for pines to maintain dominance in
the area.
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Unless an area has been clear-cut of
vegetation for construction, the amount of
trees and plants can prevent erosion.
Gulf Coastal Plain
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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 erosion.
Catastrophic events
such as hurricanes can
increase wave erosion
and deposition.
Blackland Prairie &
Post Oak Savannah
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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.
If the land is used for
farming and it is not
managed well, nutrients
will be quickly used up.
Edwards Plateau
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This region is located
between dry western
plains and moist prairies
and woods.
Unfortunately, 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.
Rolling Plains
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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 erosion
and deplete the soil of
nutrients.
Western and Eastern
Cross Timbers
• This is a small, thin
region running North to
South on either side of
the prairies and plains.
• The soil is not as prone
to flooding because it
allows water to infiltrate
very easily.
• The region is described
as rough, hilly terrain.
High Plains
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“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.
South Texas
Plains
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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.
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 erosion
and deposition in the
area, the soil has high
amounts of calcium
called caliche.
Mountain Forest /
West Texas
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Home of the tallest
mountain in Texas,
Guadalupe Peak.
Elevation is 8,749 feet.
Pines and Oaks dominate
the tree species.
Soils are shallow and
rocky. Weathering
continues to play a role in
developing soil and will
for thousands of years to
come.
Soils in the canyon
bottoms and valleys are
deeper as a result of
deposition.