Property Evaluation

Bexar County 1

Acreage:  47

County:    Bexar

Nearest Town: San Antonio

General Property Location:  Located approximately 4 miles northwest of San Antonio, TX

Photo Points:

Photo 1:  Perennial Creek with floodplain

Photo 2:  Steep slope above creek – recently cleared

Photo 3:  Spring at head of creek

Photo 4:  Oak savanna uplands

Site Description

This 47 acre site is located in northwestern Bexar County approximately 4 miles northwest of San Antonio. Babcock Road forms the northern boundary of this roughly rectangular property. Lee Creek begins as a nearly perennial stream and flows continuously through the site, maintained by a spring near the northeastern corner. The creek delineates a sharp change in topography. North of the creek, slopes are moderate and rolling. This area lies in a U-shaped valley surrounded by hills. South of the creek, slopes become extremely steep as the site moves up the side of one of the surrounding hills. The low point on the site is where Lee Creek exits at approximately 1220 ft above MSL. The property rises on either side of the creek, reaching 1300 ft above MSL in the northwestern corner along Babcock Road, and 1340 ft above MSL along the eastern boundary. A steep canyon cuts through the southern portion of the site.

Habitat Description

This site is a combination of diverse woody vegetation along Lee Creek, with a contrast in uplands on either side of the creek. North of the creek has been and is currently being disturbed with construction of a tank, heavy clearing, and mowing along the floodplain. South of the creek, the native grass savanna of the hilltop and mixed-oak woodland of the canyon have seen little disturbance.

The area immediately surrounding the creek has an extremely diverse canopy and midstory. Cedar elm (Ulmus crassifolia), escarpment black cherry (Prunus serotina), Texas oak (Quercus buckleyi), hackberry (Celtis spp.), redbud (Cercis canadensis), rough-leaf dogwood (Cornus drummondii), red and yellow buckeye (Aesculus pavia pavia and A. pavia flavescens), Texas mountain laurel (Sophora secundiflora), persimmon (Diospyros texana), evergreen sumac (Rhus virens), wafer ash (Ptelea trifoliolata), greenbriar (Smilax bona-nox), mustang grape (Vitis mustangensis) and Virginia creeper (Parthenocissus quinquefolia) were all present. Some small stands of Chinese tallow (Sapium sabiferum) occupied the banks. Large pecan trees (Carya illinoiensis) shade the floodplain just north of the creek. Herbaceous vegetation is somewhat scattered under the dense canopy along the banks, but is quite heavy on the north side of the creek where the canopy is lighter. Species include long-leaf chasmanthium (Chasmanthium latifolium), Canada wildrye (Elymus Canadensis), bushy bluestem (Andropogon glomeratus), plains bristlegrass (Setaria leucopila), sideoats grama (Bouteloua curtipendula), Lindheimer muhly (Muhlenbergia lindheimeri), frostweed (Verbesina virginica), turk’s cap (Malvaviscus arboreus), zexmania (Zexmania hispida), and coneflower (Ratibida columnifera). There are signs of heavy browse pressure on desirable plants along the creek as well as heavy feral hog damage.

The upland areas south of the creek are dominated by native warm season grasses with scattered clumps of live oak (Quercus fusiformis), Texas oak, and associated shrubs such Texas mountain laurel, agarita (Berberis trifoliolata), and persimmon. Grass cover is fairly continuous and includes little bluestem (Schizachyrium scoparium), silver bluestem (Bothriochloa saccharoides), plains bristlegrass, slim tridens (Tridens muticus), hairy grama (Bouteloua hirsute), threeawns (Aristida spp.), and patches of King Ranch bluestem (Bothriochloa ischaemum). Forbs include lindheimer senna (Cassia lindheimeri), zexmania, and snow-on-the-mountain (Euphorbia marginata).

The canyon and extreme southern end of the site are a dense oak-juniper woodland with Texas oak, live oak, escarpment black cherry, cedar elm, and Ashe juniper. This is potential habitat for a variety of neotropical songbirds and offers opportunities to compare use of the woodland and nearby native and disturbed savanna habitats.

Soil Types

The site contains 2 soil types:

1. TaD – Eckrant-rock outcrop complex, 15 to 60 percent slopes

2. Kr – Krum clay, 1 to 5 percent slopes

Krum clay lines the creek and floodplain with Eckrant-rock outcrop on the slopes above the creek on either side.

Eckrant soils are shallow, well drained, slightly alkaline, cobbly clay soils from 8-20 inches deep. Soil permeability is moderately slow. Rock outcrop is a non-soil area that makes up 17 percent of the map unit. Map unit TaD is classified in the Steep Rocky range site. Climax vegetation is Texas, live, and shin oak; ash, redbud, kidneywood, sumac, juniper; with little bluestem, sideoats grama, indiangrass, big bluestem, green sprangletop, bushsunflower, orange zexmenia, daleas, gayfeather, halfshrub sundrop, and bundleflower.

Krum clay is a deep, well-drained, moderately alkaline clay. Soil depth is >60 inches with high natural fertility, medium to high water holding capacity, fair to good plant-soil-moisture relationship, and high production potential. It is classified in the Clay Loam range site. Climax vegetation includes big and little bluestem, indiangrass, switchgrass, wildrye, and sideoats grama, with maximilian sunflower, Engelmann daisy, penstemon, gayfeather, sundrops, and other forbs. Pecan, hackberry, elm, oaks, bumelia, and sumac are sparse inhabitants.

Research Potential

This site offers opportunities for investigations into resilience and restoration of narrow riparian areas affected by non-native vegetation and mammals. The site could also potentially serve as a sample site for determining the effects of in stream and upland juniper management on spring flows. Comparisons of the highly manicured northern section with the relatively undisturbed southern section may help understanding of species composition in Hill Country habitats of varying quality. Monitoring of the spread of non-native warm season grasses is possible due to its currently limited presence on the upland areas south of the creek. Monitoring for species of concern in this area may be important as San Antonio continues to spread outward and encroach upon the area. Ongoing census data would be valuable for determining displacement of species and sensitivity to urban sprawl. The presence of both red and yellow buckeye offers an interesting opportunity for genetic studies of these two subspecies.

Shane Kiefer

Senior Wildlife Biologist

Plateau Land & Wildlife Management

August 29, 2005