Join us from 6:30-8:00pm, Georgetown Public Library, Classroom • NPAT Executive Director, Pat Merkord, will preside over the NPAT…Read more of this >>
2nd Annual Savage Cabbage BashSaturday from 9:00 a.m. to NoonCome out to support our wildflowers!Join students in this “invasive species public awareness event”. Location: Trinity…Read more of this >>
Saturday and Sunday—NPAT’s “Open Preserve” Location: Rolling Plains on NPAT’s Maddin…Read more of this >>
The Trans Pecos region of extreme western Texas and the Stockton Plateau and the Sand Hills near the southeast comer of New Mexico is perhaps the most complex of all the regions. Elevations range from 2,500 to more than 8,500 feet. This is a region of strongly diverse habitats and vegetation, varying from desert valleys and plateaus to wooded mountain slopes. Even the mountains vary, with some composed of volcanic rocks, and others of limestone.
Over most of the area average annual rainfall is less than 12 inches. Precipitation may be as high as 20 inches at higher elevations. July and August are usually the high rainfall months.
The soils of the Trans Pecos are based on Mountain outwash materials. They are generally alkaline and have poor drainage in some areas.
The most important plant communities are creosote-tarbush desert shrub, grama grassland, yucca and juniper savannahs, pinon pine and oak forests, and a limited amount of ponderosa pine forests. Saline sites support salt brush (Atriplex spp.), alkali sacaton (Sporobolous airoides) and other salt tolerant plants.
Some of the important climax forage plants are Bothriochloa spp., sideoats grama, green sprangletop (Leptochloa dubia), Arizona cottontop, bush muhly (Muhlenbergia Porteri), plains bristlegrass (Setaria macrostachya), Indian grass, alkali sacaton, vine-mesquite (Panicum obtusum), dropseeds, blue grama, black grama, chinograss (Bouteloua ramosa) and other species of grama, tobosa, sacaton and three awns. Common invader grasses are burro grass (Scleropogon brevifolius), fluffgrass ( Erioneuron pulchellum ), Erioneuron pilosum, ear muhly (Muhlenbergia arenacea), and sand muhly (M. arenicola). Other commonly invading plants are Croton dioicus, snakeweeds (Xanthocephalum spp.) and Cactaceae.
About one out of twelve species of the Texas flora occurs in the Trans-Pecos and nowhere else in Texas (Correll and Johnson). On the eastern edge along the Pecos River is a region of low rainfall and high evaporation where the principal growth consists of such shrubs as lechuguilla (Agave lecheguilla), ocotillo (Fouquieria splendens), several species of Yucca, cenizo and other arid-land plants. In the more arid areas, chino and tobosa grasses prevail. In places creosote bush ( Larrea tridentata ) and tarbush ( Flourensia cernua) grow with tussocks of burro and salt grasses (Correll and Johnson).