Soil Survey of Karnes County, Texas - Soil Data Mart - US ...

86 Soil Survey
lovegrass grow near the edge of the areas.
Buffalograss can appear when the areas are dry for
long periods.
The composition by weight is 95 percent grasses
and 5 percent forbs. No woody plants are present on
this site in its climax stage.
The predominant grass is Hartweg paspalum. Other
grasses better suited to moist areas include
switchgrass, white tridens, knotroot bristlegrass, spike
lovegrass, and sedges and rushes. These species
generally are present in smaller amounts.
As the site is overused, mesquite, huisache, and
retama invade and form a dense canopy. Other
common invaders include spiny aster, sesbania,
bermudagrass, and annual forbs.
Loamy Bottomland range site. The Odem, Sinton,
and Zunker soils, map units Od, St, and Zu, are in the
Loamy Bottomland range site. The climax plant
community is a tall grass savannah. Trees shade about
20 percent of the ground. The overstory consists of
oaks, pecan, hackberry, elm, cottonwood, and hickory
or ash. The understory is hawthorns, greenbriar,
honeysuckle, grapes, and peppervines. Cool-season
grasses and sedges dominate the shaded areas, and
warm-season grasses dominate the other areas. The
composition by weight is 80 percent grasses, 15
percent woody plants, and 5 percent forbs.
Switchgrass, fourflowered trichloris, big cenchrus,
little bluestem, and southwestern bristlegrass grow in
the open areas and make up most of the plant
community, followed by vine-mesquite, sideoats
grama, low panicums, pink pappusgrass, buffalograss,
plains bristlegrass, and other grasses. Virginia wildrye,
Texas wintergrass, sedges, and white tridens grow in
the shaded and wet areas, and comprise a lesser
amount of the total grass composition. The forbs are
bundleflower, lespedeza, Engelmanndaisy, hairy
ruellia, partridge pea, and gayfeather.
This site is preferred by livestock. The warm season
grasses and forbs are reduced by overgrazing and fire
suppression, which increase the tree and brush
canopy. Shade-tolerant grasses and forbs then
dominate and forage production is drastically reduced.
Loamy Sand range site. The Papalote soil, map
unit PaB, makes up the Loamy Sand range site. The
climax plant community is an open grassland. Some
mesquite and live oak are present. Tall grasses grow
between the oaks. The composition by weight is 85
percent grasses, 10 percent woody plants, and 5
percent forbs.
The predominant grasses on this site are little
bluestem, switchgrass, and crinkleawn, followed by
brownseed paspalum, tanglehead, and sideoats
grama. Other grasses adapted to this site are
cottontop, feathery bluestem, spike and plains
bristlegrass, hooded windmillgrass, and other low
panicums and paspalums.
With overgrazing, this site loses decreaser plants,
such as bluestems, crinkleawn, and switchgrass.
These plants are replaced by many annual forbs, red
lovegrass, hairy grama, signalgrass, threeawns, and
grassbur. Mesquite, spiny hackberry, pricklypear, and
lantana also increase with continued overuse.
Rolling Blackland range site. The Coy, Eloso,
Monteola, Rosenbrock, and Tordia soils, map units
CoA, CoB, CoC, EsB, EsC, MoA, MoB, MoC, MoD,
RoA, RoB, Rr, TrB, and TrC, are in the Rolling
Blackland range site.
The climax plant community is an open prairie. This
site is dominated by mid and short grasses. The
composition by weight is 95 percent grasses and 5
percent forbs. Woody plants are present only in small
amounts.
The dominant decreaser grasses are sideoats
grama, vine-mesquite, bristlegrass species, Texas
wintergrass, and Arizona cottontop. Other desirable
grasses, present in lesser amounts, are Texas
cupgrass, pinhole and silver bluestem, buffalograss,
and the trichloris species.
As retrogression occurs, Texas wintergrass, plains
bristlegrass, curly mesquite, and buffalograss are
likely to increase. With continued deterioration, invader
plants, such as red grama, red threeawn, Texas
grama, and windmillgrasses, can dominate the site.
Mesquite, spiny hackberry, whitebrush, agarita, and
pricklypear frequently increase or invade and can
eventually dominate the site.
Sandstone Hills range site. The Weigang-Gillette
complex, map unit WtF, is in the Sandstone Hills range
site. The climax plant community is a savannah of
moderate size with stunted post oak and blackjack in
association with an open stand of mid to tall grasses.
Grasses are spaced to use the limited moisture. The
composition by weight is 80 percent grasses, 5
percent forbs, and 15 percent woody plants.
Little bluestem is the dominant grass under climax
conditions. Open areas are dominated by grasses,
such as little bluestem, Indiangrass, sand lovegrass,
tanglehead, and silver bluestem. Shaded areas are
dominated by bluestems, purpletop, and Canada
wildrye. Forbs, legumes, woody vines, and shrubs add
variety to the climax plant community.
As retrogression occurs, the surface soil compacts
and sheet erosion can occur as the amount of bare
ground increases. The tall grasses decrease and are
replaced by less palatable and robust plants, such as
annual threeawan, red lovegrass, and gummy
lovegrass. Understory brush, such as American