Historical Ecology

We're situated in the ecological/vegetational region known as the South Texas Plains, also known as the South Texas Brush Country or Tamaulipan Thornscrub. The South Texas Plains is level to gently rolling with elevations ranging from sea level to about 1000 feet. Soils are diverse and range from clays to fine sands. The average annual rainfall is 16 to 35 inches increasing from west to east.

Thorny brush is the predominant vegetation type in the region. Brush Country has a greater diversity of animal life than any other in Texas. It is home for many near-tropical species prevalent in Mexico, many grassland species that range northward, and some desert species commonly found in the Trans-Pecos. Some ecologists refer to the entire South Texas-Northern Mexico scrubland region as the Tamaulipan Biotic Province.

The pre-settlement vegetation was open grassland or savannah along the coastal plains and brushy chaparral-grassland in the uplands (Johnston 1963). Dense thickets of oak, mesquite and other brushy species occurred only on the ridges, with oak, pecan, and ash common along streams (Inglis 1964).
Historically, the South Texas Plains was one of the reasons why San Antonio appealed to all, from the earliest Native Americans to the Spanish explorers. General Teran de los Rios and Father Manzanet who camped near San Pedro springs in 1691 and those who followed saw that the springs and the San Antonio River were, of course, a primary asset - but they also viewed the prairies and savannahs of the plains as invaluable. The abundant game present on the savannah provided a food source. Deer, bison, and even antelope were recorded during early times. These Plains regions also served as a location for the outpost ranches of the Spanish missions, providing grazing for the livestock.