A BOTANICAL INVENTORY OF SAN ANTONIO MISSIONS NATIONAL HISTORICAL PARK PART I FOR THE PORTION IN BEXAR COUNTY, TEXAS RESULTS OF A 2001-2002 BOTANICAL INVENTORY AND RELATED RESEARCH AND REVIEWS FINAL REPORT 24 DECEMBER, 2003 REPORT PREPARED BY WILLIAM R. CARR, BOTANIST TEXAS CONSERVATION DATA CENTER THE NATURE CONSERVANCY Submitted under cooperative agreement number H5028 01 0268 to U.S. National Park Service by Mark Gallyoun Program Coordinator Texas Conservation Data Center The Nature Conservancy P.O. Box 1440 San Antonio, Texas 78295-1440 TABLE OF CONTENTS THE NATIONAL PARK SERVICE INVENTORY AND MONITORING PROGRAM ....................................1 SETTING .....................................................................................................................................................................1 MACROHABITATS...................................................................................................................................................2 OLD FIELD.................................................................................................................................................................2 UPLAND WOODLAND ................................................................................................................................................3 RIPARIAN WOODLAND ..............................................................................................................................................3 OTHER HABITATS ......................................................................................................................................................4 SAMPLING METHODS ............................................................................................................................................4 RESULTS AND ANALYSIS ......................................................................................................................................5 CONCLUSION ............................................................................................................................................................6 SELECTED REFERENCES ......................................................................................................................................7 APPENDIX 1: ANNOTATED LIST OF THE VASCULAR PLANTS OF SAN ANTONIO MISSIONS NATIONAL HISTORICAL PARK, BEXAR COUNTY, TEXAS ...............................................................................................................................12 LITERATURE CITED IN APPENDIX 1 ...............................................................................................................51 APPENDIX 2. TABULAR LIST OF THE VASCULAR PLANTS OF SAN ANTONIO MISSIONS NATIONAL HISTORICAL PARK, BEXAR COUNTY, TEXAS ...............................................................................................................................52 LITERATURE CITED IN APPENDIX 2 ................................................................................................................80 LIST OF TABLES Table 1. Soils of San Antonio Missions National Historical Park. Source: Taylor, Hailey & Richmond, 1962; information about classification was taken from Batte (1984), Taylor (1977) and Werchan, Lowther & Ramsey (1974)………………….. 8 Table 2. Transects, macrohabitats represented, and dates of surveys. Locations of transects are indicated in Figure 1………………………………………………….. 9 LIST OF FIGURES Figure 1. Location of 23 transects utilized during botanical survey of San Antonio Missions National Historical Park ………………………………………………… 11 i THE NATIONAL PARK SERVICE INVENTORY AND MONITORING PROGRAM The National Park Service (NPS) Inventory and Monitoring (I&M) Program seeks to obtain baseline inventories of biotic and abiotic natural resource elements represented within each National Park Service unit. The inventories have 12 components and include such features as occurrence and distribution of vertebrate and invertebrate animals, soils, hydrology, and geology. Padre Island National Seashore (PAIS), Palo Alto Battlefield National Historic Site (PAAL), and San Antonio Missions National Historical Park (SAAN) are all included as part of the Gulf Coast Inventory and Monitoring Network (GCN). Under a cooperative agreement, the NPS has contracted the Texas Conservation Data Center (TxCDC) of The Nature Conservancy to conduct a comprehensive vascular plant species inventory for SAAN, and baseline herpetofaunal inventories for PAIS, PAAL, and SAAN. Two sections of this report address the plant inventory at SAAN, and a separate report addresses the herpetofaunal inventories. The botanical inventory of SAAN was undertaken from July 2001 through October 2002 following the protocol outlined in the cooperative agreement. An inventory of the Rancho de las Cabras site, an administrative attachment of SAAN, was conducted concurrently. The results of that inventory are reported separately. SETTING SAAN is a discontinuous collection of small tracts located along a six-mile stretch of the San Antonio River, on the southern side of the city of San Antonio in south central Bexar County, Texas. The area lies on the San Antonio East and Southton quadrangles (both USGS, 1973). The park is focused around four eighteenth-century Spanish missions: Mission San José y San Miguel de Aguayo (built during the 1720's), Mission Nuestra Señora de la Purísma Concepción de Acuña (built early 1730's); Mission San Juan Capistrano (early 1730's), and Mission San Francisco de la Espada (early 1730's) (Torres, undated). In addition to the grounds of these four missions, the park includes considerable acreage of picnic grounds, abandoned cropland, homeless camps, and urban wastelands. A separate unit of SAAN is the Rancho de las Cabras, also located along the San Antonio River but quite removed from the urban park. It occupies about 99 acres along the southwest bank of the river just south of Floresville in west-central Wilson County, Texas. The site is closed to the public except during occasional guided tours. SAAN is located almost entirely on Quaternary alluvium of the historic and contemporary floodplains of the San Antonio River. This part of Bexar County is located southeast of (coastward from) the Cretaceous deposits that characterize the Edwards Plateau to the north and west, and no limestone outcrops occur within the park. Surface geology just beyond the river floodplain consists instead of Eocene mudstones, clays, and sandstones of the Wilcox and Midway groups, but outcrops of these rocks are scarce within the park proper. The Leona Formation, a collection of gravels and other outwash alluvium from Quaternary streams draining the Edwards Plateau, mantles a few higher spots along the edge of the floodplain (Brown, et al., 1983). Topography in the area is more or less level except within the immediate vicinity of old river channels. (The current channel has been highly modified for flood control and is maintained by the San Antonio River Authority; it is not part of the park.) Elevation ranges from about 500 feet above mean sea level along an old river channel river near Mission Espada to about 600 feet on the grounds of Mission Concepción, the northernmost of the missions. Soils of the park are mapped on sheets 63 and 71 of the soil survey of Bexar County (Taylor, Hailey & Richmond, 1962). A small portion of an old athletic field west of Mission Concepción may lie on the northeast corner of sheet 62. Seven mapping units representing four range sites have been identified (Table 1). Soils in closest proximity to the river are mapped as Frio clay loam, a deep, friable, limy soil that is well drained except locally in depressions of old stream channels. This mapping unit is assigned to the Loamy Bottomland range site. Soils of older floodplain terraces are mapped as Lewisville silty clay, 1 to 3 percent slopes; Venus clay loam, 0 to 1 percent slopes or 1 to 3 percent slopes; or Karnes loam, 3 to 5 percent slopes. All are deep, well drained, calcareous soils assigned to the Clay Loam range site. Patrick soils, 3 to 5 percent slopes, are found on low escarpments between primary and secondary terraces along the river. These are shallow, dark, calcareous soils with a surface layer that varies from loam to gravelly loam or silty clay; they are assigned to the Shallow range site. The last mapping unit, Hilly gravelly land, is restricted to abandoned channels that presumably represent outwash of the Leona Formation; these channels occur on higher positions on the Missions area landscape. The unit consists of beds of caliche and strongly calcareous loamy soils; it is assigned to the Shallow Ridge range site. MACROHABITATS For the purposes of this survey, three macrohabitats were recognized: Old Field, Upland Woodland, and Riparian Woodland. Each is described below. Old Field This term applies to various agricultural fields on deep alluvial soils (primarily Frio clay loam and Venus clay loam) of essentially level river terraces. Most have probably been in some sort of cultivation or another for most of the last 200 years. Most are currently utilized as exotic hay meadow rather than cropland; most are planted to Bermudagrass (Cynodon dactylon) or Johnsongrass (Sorghum halepense) or both, and are harvested on an irregular basis. Some have not been harvested in several years and are now invaded by woody legumes, most notably mesquite (Prosopis glandulosa) and huisache (Acacia minuata), and other trees and shrubs such as hackberry (Celtis