ILLUSTRATED FLORA OF EAST TEXAS - Brit - Botanical Research ...

More documents

Recommendations

Info

SOILS OF THE PINEYWOODS UPLANDS Uplands cover large areas of East Texas east of the Trinity River. Ultisols are the most dominant soil order on the Wilcox, Reklaw, Queen City, Sparta, and Willis formations and on significant portions of the Carrizo Formation; they occur as gently sloping interstream divides to steeply sloping side slopes above drainage ways. Soil types occurring in the Carrizo, Queen City, Sparta and Willis formations generally have sandy surface layers over reddish to yellowish loamy subsurface layers. Soils developing in the Wilcox and Reklaw formations are typically loamy over more clayey subsurface layers. Pinus taeda (loblolly pine) and Pinus echinata (shortleaf pine), with a scattering of Quercus spp. (oaks) dominate most of the canopy. However, on the Willis and adjacent formations, Pinus palustris (longleaf pine) predominates. Where the Carrizo overlays the relatively impermeable Wilcox, there are large flowing springs which support a diverse vegetative cover. Alfisols occur in a number of upland areas and tend to be dominant on the Yegua formation, most of the Jackson Group, the Fleming formation, and the flatwoods part of the Lissie and Beaumont formations. There are soils on the Yegua formation and part of the Jackson Group and the flatwoods part of the Lissie formation that have unique characteristics and properties. These soils do not have a high pH but are high in salts (i.e., calcium sulfate [gypsum]) that do not raise the pH appreciably. This condition, coupled with a nearly level topography and a degree of wetness, supports a large population of prairie crayfish which keep the soil profile churned. There is also a belt of Alfisols in the Weches Formation. They are typically very red soils high in oxidized iron. In areas where calcareous marine shells occur near the soil surface, hardwoods are dominant and unique plant communities may exist. In some areas on the Weches, isolated pockets of prairie vegetation may occur. Vertisols and Alfisols with vertic properties (soils that crack open/turn) occur in the Beaumont, Fleming, and Cook Mountain formations, and in the Manning Formation of the Jackson Group. The shrink-swell properties of these soils cause pines to undergo extreme stress as the clayey soil exerts pressure on the roots. Pines growing under such stress do not compete well with other species and result in poor quality timber products (in part because the trunks often become crooked). On a related topic, many red-cockaded woodpecker colonies are located in these stressed trees. As a result of the negative soil effects on pines, oaks may be dominant in these areas. Some soils in the Beaumont formation have developed under deep rooted prairie vegetation and are dark gray to black in color to depths of 10 inches (25 cm) or more due to the accumulation of organic material. These are classified as Mollisols. SOILS OF THE POST OAK SAVANNAH UPLANDS SOILS, PINEYWOODS UPLANDS, POST OAK SAVANNAH UPLANDS/INTRODUCTION 49 The soils of the Post Oak Savannah uplands are typically sandy or loamy. They are generally old, with highly developed horizons, and are typically moderately acid to neutral in reaction. Exceptions include limited areas of calcareous deposits which have developed more basic soils (Brown et al. 1969) and restricted sites with unusual mineral or rock deposits (e.g., glauconite, iron ore, lignite). In general, the soils of the Post Oak Savannah “developed under moderately high rainfall (30 to 45 inches/year) and deciduous and coniferous forests” (Brown et al. 1969). One soil order, Alfisols, dominates the sandy and loamy Post Oak Savannah. Alfisols can form under a number of conditions, but characteristically develop under forests. Because of their often brownish color and the fact that they often develop under broad-leaf trees, they are sometimes referred to as brown forest soils (Woodward 1996). The brown color derives from the relatively high humus content, which is the result of the breakdown of leaves and their incorporation into the upper soil horizons (Woodward 1996). As a result of their relatively high fertility, until the invention of the steel plow in the 1800s allowed the breaking of the prairie sod and the cultivation of its rich Mollisols and Vertisols, the Alfisols were considered the most fertile, easily worked, and easily cleared of northern hemisphere temperate zone soils (Woodward 1996).
50 INTRODUCTION/SOIL-RELATED GEOLOGY, PINEYWOODS, POST OAK SAVANNAH SOIL-RELATED GEOLOGY OF THE PINEYWOODS AND POST OAK SAVANNAH While there are almost innumerable soil types that occur in the Pineywoods and Post Oak Savannah and their detailed discussion is beyond the scope of this book, a number of the geologic layers reaching the surface develop soils that have special characteristics which profoundly influence the vegetation. Brief mention will be made of a few of these special circumstances, with the underlying geologic strata of the Holocene, Pleistocene, and Tertiary listed from youngest to oldest. Geologists divide the various strata they find into categories called groups and subdivide these groups into formations. In the discussion below, while we generally focus on formations, in several cases these subdivisions do not warrant detailed treatment and the group is discussed as a whole (i.e., Jackson, Wilcox, and Midway groups). Figure 17 provides further information on the various strata found in East Texas. HOLOCENE AGE ALLUVIAL FILLS—These occur in stream bottomlands that flood during periods of high intensity rainfall. Sediments eroded from uplands are deposited in such bottomlands during floods. Sand particles, which are heavier than silt or clay, are deposited first in the upper reaches of streams where the gradient is steeper. Clay-sized particles are deposited in the larger streams where the water flow is much slower. “The alluvial surfaces are continuous with and graded to alluvial surfaces downstream” (Arnow 1988). Soils of the alluvial flood plains may have profiles with layers of various textures, as the sediments of the different layers are dependent upon the deposited material. Generally, the smaller streams have soils with a loamy texture and the larger streams have a clayey-textured profile. Entisols occur mainly on the smaller streams and Inceptisols on the larger stream flood plains. QUATERNARY (PLEISTOCENE AGE) STREAM TERRACES AND EOLIAN (= WIND-BORNE) DEPOSITS—Various areas adjacent to large streams in East Texas are the result of terraces or eolian deposits of Quaternary Period (Pleistocene Epoch) age. A number of different terrace levels may occur within one general area. Soils of the stream terraces have a loamy soil profile that is high in very fine sand and silt, particles of sizes that can be moved by wind. Most of these soils are Alfisols, have a high available water capacity, and are relatively fertile. They are easy to cultivate and have a variety of plant communities. Mounded soils also occur in these areas. The mounds are known as “pimple mounds” or “mima mounds” and range from the coast in the vicinity of Corpus Christi into East Texas as far north as the Red River. These mounds, thought by many to be wind-deposited, are widely known north to Minnesota, east into Louisiana and west to Colorado, California, Washington, and Oregon. For the most part, the mound material seems to be Pleistocene or Early Holocene in age, regardless of the age of the geologic substrate underlying the mounds. The mounds vary from 1 m (3.28 feet) to more typically 6 m (20 feet) to 15 m (50 feet) in diameter and are rarely more than 1.5 m (5 feet) in height (Arnow 1988). Since the slightly higher mounds are relatively better drained than immediately adjacent areas, they significantly increase the number of plant species which can grow in their vicinity. See further discussion of mima mound formation on page 65. PLEISTOCENE AND TERTIARY SEDIMENTARY MARINE AND FLUVIAL DEPOSITED GEOLOGIC GROUPS AND FORMATIONS BEAUMONT FORMATION—This is a Pleistocene formation of usually calcareous clays interbedded with more or less continuous lenses of sand (Smeins et al. 1982). It represents levee, delta, and interdelta deposits associated with shifting Ice Age rivers (Sellards et al. 1932). The Beaumont weathers into rich dark soils that are crossed by low, meandering ridges of sand (Solis 1981). While clay predominates, because of the mixture of components in the parent material, soils ranging from sandy to clayey are derived from the Beaumont, with extensive areas of clay soils in depressions and flats (Sellards et al. 1932). The black clay soils are sometimes referred to as “gumbo” and are noted for trapping surface water—some have been converted for rice cultivation (Block 2002). As most of this formation originally had a cover of
Page 1 and 2:
ILLUSTRATED FLORA OF EAST TEXAS
Page 3 and 4:
ALLDREDGE, LINDA & JACK BATTERBAE,
Page 5 and 6:
We would like to recognize and expr
Page 7 and 8:
ISSN 0833-1475 ISBN 1-889878-12-X S
Page 9 and 10:
“DEEP EAST TEXAS IS AN OLD, QUIET
Page 11 and 12:
Elray S. Nixon E lray Nixon was bor
Page 13 and 14:
ILLUSTRATED FLORA OF EAST TEXAS TAB
Page 15 and 16: TABLE OFCONTENTS/ PAGE APPENDICES A
Page 17 and 18: Hymenocallis liriosme
Page 19 and 20: ILLUSTRATED FLORA OF EAST TEXAS OVE
Page 21 and 22: 4 INTRODUCTION/GEOGRAPHIC AREA OF E
Page 27 and 28: 10 INTRODUCTION/MAJOR RIVERS OF EAS
Page 29 and 30: 12 INTRODUCTION/PLANTS TREATED The
Page 31 and 32: 14 INTRODUCTION/GUIDE TO ARRANGEMEN
Page 33 and 34: 16 INTRODUCTION/GUIDE TO SOURCES OF
Page 35 and 36: 18 INTRODUCTION/GUIDE TO GEOGRAPHIC
Page 37 and 38: 20 INTRODUCTION/GUIDE TO ENDANGERED
Page 39 and 40: 22 INTRODUCTION/GUIDE TO GLOSSARY,
Page 41 and 42: 24 INTRODUCTION/GUIDE TO ABBREVIATI
Page 43 and 44: 26 INTRODUCTION/SUMMARY DATA ON FLO
Page 45 and 46: 28 INTRODUCTION/ACKNOWLEDGMENTS Kar
Page 47 and 48: 30 INTRODUCTION/AUTHORS’ NOTE Pre
Page 49 and 50: 32 INTRODUCTION/GENERAL GEOLOGY OF
Page 63 and 64: 46 INTRODUCTION/SOILS SOIL ORDER DE
Page 65: 48 INTRODUCTION/SOILS, EAST TEXAS B
Page 69 and 70: 52 INTRODUCTION/SOIL-RELATED GEOLOG
Page 77 and 78: 60 INTRODUCTION/SOILS OF BLACKLAND
Page 83 and 84: 66 INTRODUCTION/CLIMATE OF EAST TEX
Page 93 and 94: Forests define East Texas, and to a
Page 95 and 96: 78 INTRODUCTION/GEOLOGY OF PINEYWOO
Page 97 and 98: 80 INTRODUCTION/PRESETTLEMENT, EARL
Page 105 and 106: 88 INTRODUCTION/PRESETTLEMENT VEGET
Page 107 and 108: 90 INTRODUCTION/CURRENT VEGETATION
Page 117 and 118:
100 INTRODUCTION/CURRENT VEGETATION
Page 119 and 120:
Page 121 and 122:
Page 123 and 124:
106 INTRODUCTION/POST OAK SAVANNAH
Page 125 and 126:
Page 127 and 128:
110 INTRODUCTION/GEOLOGY AND SOILS
Page 129 and 130:
112 INTRODUCTION/SOILS, FIRE, AND T
Page 131 and 132:
114 INTRODUCTION/SOILS, FIRE, AND T
Page 133 and 134:
116 INTRODUCTION/ PRESETTLEMENT, EA
Page 135 and 136:
118 INTRODUCTION/VEGETATION OF POST
Page 137 and 138:
Page 139 and 140:
Page 141 and 142:
124 INTRODUCTION/CONDITIONS TODAY O
Page 143 and 144:
Page 145 and 146:
128 INTRODUCTION/RED RIVER AREA are
Page 147 and 148:
130 INTRODUCTION/BLACKLAND PRAIRIE
Page 149 and 150:
132 INTRODUCTION/GEOLOGY OF BLACKLA
Page 151 and 152:
134 INTRODUCTION/PRESETTLEMENT AND
Page 153 and 154:
Page 155 and 156:
Page 157 and 158:
Page 159 and 160:
Page 161 and 162:
144 INTRODUCTION/VEGETATION OF BLAC
Page 163 and 164:
146 INTRODUCTION/FUTURE OF BLACKLAN
Page 165 and 166:
148 INTRODUCTION/FUTURE OF BLACKLAN
Page 167 and 168:
150 INTRODUCTION/CADDO LAKE LOCATIO
Page 169 and 170:
152 INTRODUCTION/CADDO LAKE FIG.84/
Page 171 and 172:
154 INTRODUCTION/PRESENT AND FUTURE
Page 173 and 174:
156 INTRODUCTION/BIG THICKET THE BI
Page 175 and 176:
158 INTRODUCTION/BIG THICKET GEOGRA
Page 177 and 178:
160 INTRODUCTION/NATURAL HISTORY OF
Page 179 and 180:
Page 181 and 182:
Page 183 and 184:
Page 185 and 186:
Page 187 and 188:
Page 189 and 190:
172 INTRODUCTION/SUMMARY DEFINITION
Page 191 and 192:
Page 193 and 194:
Page 195 and 196:
Page 197 and 198:
Page 199 and 200:
Page 201 and 202:
184 INTRODUCTION/HISTORY OF BIG THI
Page 203 and 204:
Page 205 and 206:
Page 207 and 208:
190 INTRODUCTION/CONSERVATION IN BI
Page 209 and 210:
Page 211 and 212:
Page 213 and 214:
Page 215 and 216:
Page 217 and 218:
200 INTRODUCTION/ORIGIN AND DIVERSI
Page 219 and 220:
Page 221 and 222:
Page 223 and 224:
Page 225 and 226:
Page 227 and 228:
Page 229 and 230:
Page 231 and 232:
Page 233 and 234:
Page 235 and 236:
Page 237 and 238:
Page 239 and 240:
Page 241 and 242:
Page 243 and 244:
Page 245 and 246:
228 INTRODUCTION/CONSERVATION IN EA
Page 247 and 248:
Page 249 and 250:
Page 251 and 252:
234 INTRODUCTION/HISTORY OF BOTANY
Page 253 and 254:
Page 255 and 256:
Page 257 and 258:
Page 259 and 260:
Page 261 and 262:
244 INTRODUCTION/BOTANY IN NORTH CE
Page 263 and 264:
246 INTRODUCTION/BOTANY IN NORTH CE
Page 265 and 266:
248 INTRODUCTION/BOTANY AT UNIVERSI
Page 267 and 268:
250 INTRODUCTION/BOTANY AT TEXAS A&
Page 269 and 270:
252 INTRODUCTION/BOTANY AT TEXAS A&
Page 271 and 272:
254 INTRODUCTION/OTHER CONTRIBUTION
Page 273 and 274:
256 INTRODUCTION/CURRENT BOTANICAL
Page 275 and 276:
258 INTRODUCTION/BOTANICAL ART IN E
Page 277 and 278:
Page 279 and 280:
Page 281 and 282:
Page 283 and 284:
Page 285 and 286:
Page 287 and 288:
show all

ILLUSTRATED FLORA OF EAST TEXAS - Brit - Botanical Research ...

Create successful ePaper yourself

Delete template?

Save as template?