Prairie in the 20th Century
overgrazing and cultivation were the most dramatic disruptions
of the natural prairie ecosystem, there have been a number of
simultaneously occurring phenomena which have contributed to
the destruction of all but a few isolated prairie relicts, and
to the degeneration of many of these surviving remnants.
In the early
days of cultivation of the Blackland Prairie, mules were the
source of power. Many farms maintained a hay meadow where the
native grasses were cut for hay or used for pasture. As late
as 1930 the practice of maintaining these hay meadows was still
common. And although the mowing and grazing altered the species
composition of these small "prairies," their root
systems and seed banks still contained a living map of the complex
prairie ecosystem that had once spanned the continent from north
to south, and covered more than 13 million hectares in Texas
alone. However, with the advent of tractors most of these meadows
and pastures were plowed.
very significant early disturbance was the settlers' natural
desire to eliminate fires. Periodic prairie fires had for centuries
kept woody species to a minimum and had cleared the ground of
dead vegetation, enabling the tall grasses to thrive and creating
new opportunities for secondary and tertiary grasses and forbs
to establish themselves. Once the fires were eliminated, a rapid
invasion of woody plants followed.
the prairie remnants found today are those in out-of-the-way
places, difficult to cultivate. These too are often invaded
by woody species, along with exotic non-native plants which
have been cultivated or allowed to spread on nearby land, and
then introduced by wildlife or carried on the winds to these
otherwise native areas. The Kachina Prairie in Ennis is a typical
example of these surviving remnants, and is in the process of
being managed back to health through controlled burning and
selective weed control in the hope that it can serve as a seed
source for prairie restoration efforts on land acquired for
the Superconducting Super Collider Laboratory.
Blackland Prairie: Situation Critical
Before the European settlers arrived, the moist eastern prairies
of Texas were dominated by the tall grasses such as big bluestem,
Indian grass, little bluestem, eastern gamagrass and switch
grass. The short grasses such as buffalograss, blue grama and
common curly mesquite were dominant in the drier western regions.
And in between, mid-grasses such as sideoats grama, little bluestem,
silver bluestem and Texas cupgrass were abundant. Running through
these belts of grasslands were the Post Oak Belt to the East,
and the East and West Cross Timbers to the west of the Blackland
Prairie. Throughout the Blacklands, as well, could be found
rivers, streams, and bottomland hardwoods.
than 90% of the area of the main belt of the Blackland Prairie
of Texas has been plowed. Many areas, because of exhaustion
of the soil or soil erosion, have been returned to permanent
grass. But in most cases these lands have been planted to exotic
pasture species such as African bermuda grass and lovegrass,
Eurasian "King Ranch bluestem," and Mediterranean
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 prairie relicts were located,
totaling nearly 5000 acres in all. Most of the sites were small,
but a few were as large as 700 acres.
the area was resurveyed. The number of sites had decreased from
100 to 35, and the area from 5000 to 2000 acres.
and associated prairies and woodlands in Texas contain four
out of the ten most threatened or endangered plant community
series in the United States, as recognized by the Natural Heritage
Commission. The total area of fair or better condition plant
communities is lowest for the Blackland Prairie, at 0.004% of
the area originally covered by this complex ecosystem.
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