Part 3: The Prairie in the 20th Century
A Vanishing Ecosystem

Although 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.

Another 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.

Most of 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.

The Texas 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.

Today, more 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 Johnson grass.

In 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 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.

In 1980 the area was resurveyed. The number of sites had decreased from 100 to 35, and the area from 5000 to 2000 acres.

The Blackland 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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