Sunday, October 11, 2009

The Magical North Central Texas that Used To Be



North Central Texas is composed of three major ecosystems, the Cross Timbers, Black Prairie, and Fort Worth Prarie. Less than 150 years ago, sparkling streams were abundant with trout, perch, and catfish...and alligators! Indeed, Kendall (1845) found alligators along the San Gabriel in the southern Blackland Prairie as "too plentiful for any useful purposes." Black bear were also common, along with mountain lion. Brooke (1848) reports gray wolves as far east as McLennan County, ocelot in bottoms of Brazos River near Waco in McLennan County. The last jaguar record was a large male killed in Mills County (Lampasas Cut Plain) in 1903.

Other vanished creaturs out of this Noah's Ark world include river otter, ringtail (a cat-like creature), badger, javalina (collared peccary), bison, pronghorn antelope, turkeys, and prarie chickens. Many of these animals still persist in zoos or mountains out west, but some cannot be found anywhere on the planet. For example, both the ivorybilled woodpecker and the carolina parakeet, once found near modern day Dallas/Ft. Worth, are extinct.

Estimates of the destruction of the Blackland Prairie ecosystem range from 98% (Hatch et al 1990) to 99% (Riskind and Collins 1975) to more than 99.9% (Burleson 1993). Some of the last remnants can still be seen at the Nature Conservancy's Clymer Meadow Preserve. Slightly more Fort Worth Prarie and Cross Timbers survive. Dyksterhuis (1946) studied relics of the Fort Worth Prairie, and, surprisingly, Cross Timbers are still one of the largest relatively unaltered forest vegetation types in the eastern United States (Stahle &Hehr 1984), but there are more in Oklahoma, for example, Pontotoc Ridge Preserve. Examples of old-growth Cross Timbers forests in North Texas are found in Comanche County (Leon River), Tarrant County (Fort Worth Nature Center), and Throckmorton County (Nichols Ranch).

Prairie remnants are threatened by eastern red cedar (Juniperus virginiana) and cedar elm (Ulmus crassifolia) because of a lack of natural fire. Results include reduction in broad-leaved plants and increased abundance of grasses. (Diamond & Meins 1993). Over much of the slope-lands, as muich as three feet of soil have been eroded, exposing barren rock where once was prairie soil (Hayward &Yelderman 1991). So, although remnants remain, they are often degraded by various human activities such as heavy grazing or selective cutting and their authenticity is rarely noticed or protected.....I wonder how many people realize what used to be?

Much of this text, and the image, are from Shinner's and Mahler's Illustrated Flora of North Central Texas, published by Botanical Research Institute of Texas.

More great info about Texas Native Plants, from the Plant Resources Center at UT - Austin.

1 comment:

亚历山德拉 said...

see http://www.birds.cornell.edu/ivory/

and the PDF at http://www.birds.cornell.edu/ivory/evidence/

for a recount of the purportedly extant yet elusive Ivory-Billed Woodpecker...in Arkansas no less. eain't that near Texas?