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
