Cedar Elm Research Articles

Remnant Grasslands of the Fayette Prairie, Texas

Twenty-five remnant grasslands from across the Fayette Prairie of SE Texas were sampled for species frequency and basal cover as well as selected soil and topographic properties. Polar ordination was used to elucidate stand and species patterns and plant-environmental interrelationships. Three major topo-edapho-vegetation complexes were defined. Upland clay soils (Vertisols and Mollisols) were characterized by Andropogon gerardii var. gerardil, Bouteloua curtipendula var. curtipendula and Carex microdonta. Upland sandy clay loam and clay loam soils (Alfisols) had Paspalum plicatulum, Coelorachis cylindrica and Fimbristylis puberula var. puberula as characteristic species. Schizachyrium scoparium var. frequens and Sorghastrum nutans were ubiquitous dominants or codominants in all upland communities. Panicum virgatum and Tripsacum dactyloides dominated lowland clay soils (Vertisols). The Fayette Prairie should be classified as a southern extension of the True Prairie Grassland Association. INTRODUCTION The Fayette Prairie is located in SE Texas (Fig. 1). It is isolated from the Blackland Prairie to the N and the Coastal Prairie to the S by narrow strips of Post Oak Savanna. To the E it borders on the southeastern Evergreen Forest (Braun, 1950) and to the W it grades into the South Texas Plains (Godfrey et al., 1970). It once contained approximately 1.5 million ha of native grassland (Godfrey et al., 1970), but little undisturbed vegetation remains (Johnson, 1931; Launchbaugh, 1955). No quantitative analysis of the vegetation exists for the area and, as a result, available data are insufficient to adequately describe or classify the prairie. The purpose of this study is to: (1) provide a quantitative ecological analysis of remnant vegetation and soil; (2) relate differences in vegetational composition to edaphic and topographic factors, and (3) evaluate ecological affinities and determine the appropriate classification of the prairie. STUDY AREA The Fayette Prairie is characterized by a flat to gently rolling topography. Two rivers, the Brazos and the Colorado, cross the area. Uplands were historically prairie although Quercus stellata and Q. virginiana occurred occasionally as scattered individuals or in small clumps. Lowlands were dominated by stands of hardwood forest including Q. stellata, Ulmus crassifolia, Fraxinus spp. and Carya illinoiensis. Current land use is primarily for native and tame pasture with limited cropland. Geologically, the Fayette Prairie consists of material deposited in the middle to upper Miocene (Geol. Atlas Tex., 1974). Three major formations occur: the Fleming, Oakville Sandstone and Cook Mountain (Fig. 1). The Fleming formation underlies most of the area except the western margin. Laid down in the upper Miocene, it consists of a 400-m-thick layer of calcareous silty clay sediment with some medium to coarse grained sandstone. The Oakville Sandstone is slightly older. It is found as a narrow strip on the NW side and in the S-central portion of the prairie, and consists of a

Control of Oaks (Quercusspp.) and Associated Woody Species on Rangeland with Tebuthiuron

Aerial applications of 20% tebuthiuron {N-[5-(1,1-dimethylethyl)-1,3,4-thiadiazol-2-yl]-N,N-dimethylurea} pellets at 2.2 kg/ha (ai) in the spring effectively controlled post oak (Quercus stellataWangenh.), blackjack oak (Q. marilandicaMuenchh.), water oak (Q. nigraL.), yaupon (Ilex vomitoriaAit.), winged elm (Ulmus alataMichx.), downy hawthorn (Crataegus mollisScheele), gum bumelia [Bumelia lanuginosa(Michx.) Pers.], and willow baccharis (Baccharis salicinaTorr. & Gray) in the Post Oak Savannah of Texas. Tree huckleberry (Vaccinium arboreumMarsh.), black hickory (Carya texanaBuckl.), honeylocust (Gleditsia triachanthosL.) and cedar elm (Ulmus crassifoliaNutt.) were partially controlled by 2.2 kg/ha of tebuthiuron. Canopies of buckbrush (Symphoricarpos orbiculatusMoench), southern dewberry (Rubus trivialisMichx.), American beautyberry (Callicarpa americanaL.), and persimmon (Diospyros virginianaL.) were reduced for about two growing seasons after which the woody species recovered. American beautyberry appeared to increase in abundance by the third growing season after control of the other woody species. Honey mesquite [Prosopis juliflora(Swartz) DC. var.glandulosa(Torr.) Cockerell], eastern redcedar (Juniperus virginianaL.), and Texas persimmon (Diospyros texanaScheele) were not controlled by tebuthiuron at 2.2 or 4.4 kg/ha, and saw greenbrier (Similax bona-noxL.) and peppervine [Ampelopsis arborea(L.) Koehne] apparently increased following application of tebuthiuron.

Notes on the biology of Pheidole lamia (Hymenoptera: Formicidae) at its type locality (Austin, Texas).

Notes on the biology of Pheidole lamia (Hymenoptera: Formicidae) at its type locality (Austin, Texas).

A Comparison of Some Woody Upland and Riparian Plant Communities of the Southern Edwards Plateau

Vegetation of the southern Edwards Plateau in northwestern Bexar County and northeastern Medina County, Texas, was analyzed using the point- centered-quarter method to determine major community relationships. Two geo- logically different areas were studied, including outcroppings of the Buda forma- tion and Quaternary deposits or creekbottoms. Although the total acreage occupied by the Quaternary deposits and intermittent creeks was small compared to the overall area studied, many species were found only in the creekbottoms. A total of 35 woody species was encountered; 49% were found only in riparian habitats, 14% were exclusively upland, and 37% were common. Dominants on the Buda formation were Mexican juniper (Juniperus ashei), live oak (Quercus fusiformis), and Texas persimmon (Diospyros texana), while Mexican juniper, cedar elm (Ulmus crassifolia), sycamore (Platanus occidentalis), and Texas persimmon were dominants in the creekbottoms. The number of species, total density and the sum of average dominance values were statistically different in the two communities. There were 30% more species in the creekbottoms and total density was almost three times greater on the Buda; however, the sum of the average dominance values was eight times greater in the creekbottoms. The Edwards Plateau region (Gould 1969) is located in west central Texas (Fig. 1). It is bounded rather sharply by the Balcones Escarp- ment on the east and south, grades gradually into the Rolling Plains and High Plains on the north, and the Trans-Pecos region on the west. Thorthwaite (1948) considers the eastern half as dry subhumid and the western half as semiarid. However, both are mesothermal. Rainfall varies from approximately 38 cm/yr in the west to approxi- mately 84 cm/yr in the east. with peaks occurring in the spring and fall. The soils are typically shallow and calcareous Tarrant-Brackett Association Soils for the upland sites with the deeper Venus-Frio-