Brodie Wild Site Plan

Version 1.6, 2005/9/5

Table of Contents

  1. Table of Contents
  2. Summary
  3. Partners
  4. History
  5. Current State
    1. Summary
    2. Description
    3. Plant Species List
  6. Project Plan
    1. Summary
    2. Education
    3. Restoration
    4. Timeline
  7. Bibliography
  8. Contributors

Summary

Brodie Wild is a Water Quality Protection Land (WQPL) received by the City of Austin in exchange for other property.  The property is part of the environmentally sensitive Barton Springs Recharge Zone.

Brodie Wild can be described as a degraded savanna tending toward woodland.  Due to the removal of fire and grazing (bison historically and cattle in settled times) from the natural processes of the ecosystem, this site would probably transition from savanna to woodland and from woodland to forest, decreasing the biodiversity of flora on the site [7].  The non-native invasive plant species would also increase, which would result in a loss of habitat for urban wildlife.

The goals of the project are to:
  1. Educate citizens in and around the environmentally sensitive Barton Springs Recharge Zone about how native plants contribute to water quality, help conserve water, and how they may be incorporated into local urban and rural landscapes.
  2. Manage the site to benefit water quality.
The activities to meet goals will include:
  1. Education via field trips, handouts, and a kiosk
  2. Restoration of the site and maintenance of the site as a savanna.
All parties involved will adhere to the agreements in the document "Memorandum of Agreement  Between City of Austin Water Utility Wildland Conservation Division and Native Prairies Association of Texas".  This document can be found at this link.

Partners

Current partners in the project are:
  1. City of Austin, Austin Water Utility, Wildland Conservation Division (also referred to as the City in this document)
  2. Native Prairies Association of Texas (NPAT): Planning, advice, coordination
  3. Native Plant Society of Texas - Austin chapter (NPSOT-Austin): Cash and in-kind donations, planning, plants, volunteer time
  4. National Park Service: Challenge Cost Share Program Grant
  5. A-Z Rental: Equipment rental donation
In the future, we would like to approach the following groups about participating in the project:
  1. Shady Hollow Neighborhood Association
  2. WQPL Slaughter Tract volunteers
  3. Travis Audubon
  4. UT Austin - Botany, Ecology, Restoration
  5. Lady Bird Johnson Wildflower Center

History

Residents of the area recollect (1960 forward) that the Brodie Wild area was more open with fewer trees in the past [11].  Several people have stated that their interest in native plants and nature were greatly influenced by the wildflowers and other native plants they found in the area of Brodie Wild [11].

In the future, we will research the history of the site further.  We will attempt to obtain past photographs of the site for comparison.  In addition, we will also attempt to discover any other relevant historical information (such as land surveys and when livestock were added to and removed from the site).

[TODO: research past land uses and public land surveys for more certain information.]

Current State

Summary

As of summer 2005, the state of the site can be described as a degraded savanna transitioning to woodland.  It appears that woody species and brush are increasing, with some species of forbs becoming stressed due to increasing canopy cover and the resulting shade.  A savanna typically mixes both sun and shade species resulting in high diversity.  If the trend towards woodland continues, we expect many shade intolerant species will decrease or disappear from the site.

Description

General

Brodie Wild lies at the SW corner of intersection of Slaughter Land and Brodie Lane.  The site is appoximately 4.4 acres in size.  The property is roughly triangular in shape, with the following approximate points of the triangle:
An aerial view of the site (date unknown) taken prior to the construction of CVS Pharmacy (NW corner of Brodie and Slaughter) and the plaza (NE corner) from 2001 or later:

Brodie Wild Arial Map

Vegetative Region

The greater Austin area lies at the intersection of the Blackland Prairie, Cross Timbers and Prairies, and Edwards Plateau vegetative regions [2], leading to many interesting graduations between these areas [15].  The Edwards Plateau supports a number of endemic species, and many species are at or near their northern, southern, or eastern limits of distribution, leading to a high degree of diversity [17].  Travis County itself contains a high number of endemic Texas species [21].

Henderson discusses the various definitions of savanna, including "less than 50% tree canopy" and "grading into both forest and prairie" [9].  If we use this definition, plant species present, and the information gathered from longtime residents so far, we can generally characterize the site as degraded savanna transitioning to woodland.  If left alone in the future, the savanna would become woodland, and the woodland becomes forest, decreasing biodiversity [1].

Using the Kuchler Potential Natural Vegetation Types [18, 19], the site may be a degraded state of the Mesquite-Oak Savanna PNV type (USDA Forest Service K087) of the Texas Savanna PNV group (USDA Forest Service Group 35) [18] which occurs in the Edwards Plateau area [12]. 

From the EPA Kuchler Potential Natural Vegetation of the Conterminous United States with updated species names (from the USDA NRCS PLANTS database [20]), and species present at Brodie Wild underlined:

NAME PHYSIOGNOMY DOMINANTS OTHER COMPONENTS OCCURRENCE
87 Mesquite - oak savanna (prosopis - quercus - andropogon) Low to medium tall grass with broadleaf deciduous shrubs and low trees scattered openly to densely Little bluestem (Schizachyrium scoparium), Mesquite (Prosopis julifora var. glandulosa), Oak (Quercus spp.) Aloysia gratissima, Andropogon spp.,  Aristida longispica var. geniculata, A. purpurea, Bothriochloa barbinodis, Bouteloua curtipendula, B. hirsuta, B. rigidiseta, Buchloë dactyloides,
Diospyros texana, Juniperus ashei, Quercus marilandica, Q. stellata, Ulmus crassifolia 		Central Texas

The site also shares many dominant and some component species with the Juniper-Oak Savanna PNV type (USDA Forest Service K086) of the Texas Savanna PNV group (USDA Forest Service Group 35) [18].

NAME PHYSIOGNOMY DOMINANTS OTHER COMPONENTS OCCURRENCE
86 Juniper - oak savanna (juniperus - quercus - andropogon) Savanna with a dense to very open synusia of broadleaf deciduous and evergreen low trees and shrubs and needleleaf evergreen low trees and shrubs Little bluestem (Schizachyrium scoparium), Ashe juniper (Juniperus ashei), Live oak (Quercus virginiana) Andropogon gerardi (eastern part), Aristida intermedia, A. longispica, Bouteloua curtipendula (western part), B. hirsuta, Buchloë dactyloides, Cercis canadensis var. texensis (eastern part), Erioneuron pilosum, Fraxinus texensis, Hilaria belangeri (western part), Leptochloa dubia (western part), Panicum obtusum (western part), Quercus sinuata var. breviloba, Q. texana, Sorghastrum nutans (eastern part), Sporobolus spp. Central Texas

The site also shares many dominant and component species with the Blackland Prairie PNV type (USDA Forest Service K076) of the Prairie PNV group (USDA Forest Service Group 33) [18].

NAME PHYSIOGNOMY DOMINANTS OTHER COMPONENTS OCCURRENCE
76 Blackland prairie (andropogon - stipa) Medium tall, rather dense grassland Little bluestem (Schizachyrium scoparium), Texas needlegrass (Nassella leucotricha) Andropogon gerardi, Aristida purpurea,
Bothriochloa saccharoides,
Bouteloua curtipendula, B. hirsuta, B. rigidiseta, Buchloë dactyloides, Panicum virgatum, Sorghastrum nutans, Sporobolus compositus 		Texas

[TODO: Research plant communities and associations more, especially the National Vegetation Classification System via NatureServe Explorer.] 

Soil

By aligning Sheet Number 68 of the USDA NRCS Soil Survey of Travis County [16] as an overlay on Google Earth [28] at the location of Brodie Wild, we see that the survey found two soil types on the site: "Tarrant Soils, rolling" (TaD) and "Speck stony clay loams, 1 to 5 percent slopes" (SsC).  The survey notes that the "Tarrant Soils, rolling" (TaD) soil type is one of the soils in the survey that is more variable and studied in less detail than others in the survey.

Brodie Wild Soil Map:

Brodie Wild Soil Map

Excerpt of Table 3 Estimated Soil Properties from the USDA NRCS Soil Survey of Travis County [16]:

Symbol
 Soil series
 Depth to bedrock (inches)
 Depth from surface (inches)
TaD Tarrant Soils, rolling 4-14
 0-8 Clay
8-12 Limestone
SsC Speck stony clay loams, 1 to 5 percent slopes 14-18
 0-14 Clay Loam
14-18 Gravelly clay
18-20 Limestone rock

"Tarrant Soils, rolling" (TaD) occupy areas with complex slopes dominantly 5 to 12 percent, and typically contains random outcroppings of limestone and areas of limestone gravel and Bracket soils [16].  "Speck stony clay loams, 1 to 5 percent slopes" (SsC) occur on smooth, undulating topography with complex slopes dominantly 1.5 to 3.5 percent.  Reddish-brown chert pebbles and cobblestones cover 30 to 50 percent (and up to 80 percent) of the surface [16].

Plant Species

In general, a surprising variety of native plants are present on the site, especially given the site's location within a developed area.  The low number of non-native and invasive species is also pleasantly surprising.

Texas Wintergrass (Nassella leucotricha, syn.  Stipa leucotricha) is the most common grass on the site.  It is a common winter grass in this region and adapted to a variety of soils, and is frequently an indicator of overgrazed rangelands [10].  This could be an indication that the site was overgrazed in the past before livestock were removed.

Some native species, especially prairie species, seem to be gradually decreasing due to increasing shade.  Big Bluestem (Andropogon gerardii), Indiangrass (Sorghastrum nutans), and Standing Winecup (Callirhoe pedata) are some examples.

Many non-native plant species have become established in the disturbed areas along both the north and west sides of the site (bordering Slaughter Lane and Brodie Lane).  This was likely caused by road construction, sidewalk installation, and other construction.

Non-native and native woody species are increasing canopy cover and brush on the site, and may have been controlled by livestock grazing in the past.

Also, many native woody species are expanding on the site and increasing the amount of canopy cover, leading to transition from savanna towards woodland.  These species include Ashe Juniper (Juniperus ashei), Western Soapberry (Sapindus saponaria), Live Oak (Quercus virginiana), and Honey Mesquite (Prosopis glandulosa).

Miscellaneous

An emerging sink hole is also present on the site (see the location on the map below).  [TODO: Kevin, do you have any more information?  Does it lead to Edwards Aquifer?]

Due to the streets, businesses, and residential areas bordering the site, trash tends to blow into the site and stay there.  Also, the storm runoff area at the northwest corner of the property tends to wash trash into the site.

Disturbance from construction (likely either the street side or water right of way) appears to have disturbed the roots of  Western Soapberry (Sapindus saponaria), leading to the beginning of a thicket.

The City water utility posesses a right of way diagonally through the property, from approximately the northwest corner to the southeast corner.  This has led to some disturbance of the site in this area, but it appears mainly native species have revegetated the area.

Starting at the storm water drainage at the northwest corner of the site, the west edge appears to be seasonally wet (labeled "Riparian Area" in the map).  This area supports some species that prefer extra moisture, such as Eastern Cottonwood (Populus deltoides).  It also appears to be disturbed periodically due to the force of the water, with a large area of Giant Ragweed (Ambrosia trifida var. texana) present.

Plant Species List

Due to length, the plant species list is included in this document by reference.  The list of plant species can be found at this link.

Project Plan

Summary

The projects education goals will be accomplished by directed education (mainly field trips) and restoration.

All work will be reviewed and approved by the City before commencing.  All volunteer work hours will be tracked for grant reporting purposes.

The following map shows the main features for education and restoration:
Brodie Wild Map

Education

One goal of the project is to educte citizens in and around the environmentally sensitive Barton Springs Recharge Zone about how native plants contribute to water quality, help conserve water, and how they may be incorporated into local urban and rural landscapes.

While the site will accomodate public access, it will not be advertised as a park and unsupervised visitation will not be promoted.

The following parts of the project will meet the education goal:
  1. Field Trips
  2. Volunteer Work
  3. Fence
  4. Kiosk
  5. Signs
  6. Handout
  7. Demonstration Area
  8. Other Areas
  9. Trail
Field Trips:  The Austin chapter of NPSOT and other volunteers will lead field trips to the site approximately four times a year.  Knowledgable field trip leaders will talk about how native plants contribute to water quality, help conserve water, and how they may be incorporated into local urban and rural landscapes.  Specific plants will be identified and their use in urbal and rural landscapes explained.

Volunteer work: The volunteer work for restoration will also serve an educational purpose, teaching those involved more about native plants and water quality.

Fence: A bollard fence will be installed on the Slaughter Land and Brodie Lane sides (North and East) of the site to prevent vehicles using the site as a shortcut.  It will also help demarcate the site visually, separating it as a natural area.  The City is providing the fence.

Kiosk:  The kiosk will contain information about the site, the partners, the handout, a plant list and any other species lists volunteers may develop (such as bird or butterfly lists), and any other relevant information.  Handouts will also be available at the kiosk.  The NPS grant is funding the purchase of the kiosk.  [TODO: Exact location and contents of kiosk.  Perhaps in demonstration area?]

Signs: Signs around the street sides of the site will state the site name, an abbreviated purpose of the project, and a list of the partners involved in the project.   City of Austin, Austin Water (Kevin Theusan) has offered to obtain the signs.  Installation will be discussed.   At least one sign will be placed at the corner near the intersection of Slaughter Land and Brodie Lane since it is visible to vehicle, cyclist, and pedestrian traffic.  [TODO: Sign locations and text.]

Handout: The handout, available from the kiosk, will contain the purpose of the project, a list of the partners involved in the project, a plant list, a link to the project web site, and other site information.  Volunteers will periodically restock the handouts.

Demonstration Area: This area will be planted with showy forbs during restoration to "show off" the native plants.  A formal garden would require too much volunteer time to maintain and maintenance would likely fall behind, so the decision was made to make this a showy natural area instead of a demonstration garden bed.

Other Areas: Trees will be cut to make a "Quiet Lecture Area" for use during field trips.  The "Prairie Meadow" contains several species of native prairie grasses and will be used to teach about them.

Trail: Optionally, a short trail may be installed and maintained to enable ease of use by younger children and older adults.  It may also improve ascetics of the site and increase neighborhood acceptance of a natural-looking area.  The wastewater line area may be used for the trail since it already could be disturbed. Another concern is that without a trail people walking nearby may cut across the property as a shortcut and make their own trail, whereas if a trail existed it would be used instead.  However, a trail may increase non-supervised access to the site which is discouraged.  The optional installation of a trail is dependent on obtaining funds and volunteer time for installation and maintenance.

Issues and Concerns

No parking is available on site.  Suggestions have included 1-3 small, primitive parking spaces or asking neighboring businesses if visitors may make limited use of their parking areas.  Crosswalks with signal lights are present at the street corners, allowing access from other sides of the streets.

The NPS grant ends in October, so all funds from the grant (mainly the kiosk) must be used by that time.

Restoration

The restoration goal is to restore and maintain the site as an savanna, maintaining a canopy cover of 50% or less.

Structural control of some woody native species to simulate the effects of fire will also be necessary to prevent the savanna from transitioning to woodland and then to forest.  Controlled burns have not been recommended due to the high traffic intersection, and the church and school nearby, and grazing is impractical on such a small scale.  Physical simulation of these missing ecological processes is partially possible due to small size of the site and will be done as much as possible, given the limits of reasonable effort and volunteer time.

Physical alternatives (hand removal and pruning, mowing) will be used to simulate the effects of fire will be used.  Other physical alternatives (haying and grazing) may be researched later but are likely impractical.  All of these methods may have problems that may need researched and dealt with, such as thatch buildup, lack of bare ground for seed ground contact, and species needing fire to stimulate a fire response. 

Herbicide use will be avoided except as neccessary to eliminate problem species when another effective method is not available.  Any herbicide used must be approved by the City for water quality reasons, and will only be used as directed by the instructions.  A licensed applicator shall apply the herbicide after permission has been obtained.

Control of woody species will need to be done with methods other than controlled burning, such as cutting followed by treatment with approved herbicide for re-sprouting species.  Preventing understory shrubs from acting as a nursery for trees and expanding the size of woody plant areas will be a challenge and needs to be researched further.  Hand cutting may be needed.  Mechanically assisted cutting may be investigated. 

All non-native species will be removed or controlled as possible.  All non-native woody species will be removed or controlled if they continually appear.  Some species are difficult to eliminate or kill and may require continual control, such as Chinaberry (Melia azedarach).

While brush and small individuals of tree species (generally less than 10' in height) will be removed to maintain a canopy cover of 50% or less, most large specimens will be maintained.  These species include Ashe Juniper (Juniperus ashei), Common Honey-Locust (Gleditsia triacanthos), Live Oak (Quercus virginiana), and Honey Mesquite (Prosopis glandulosa) (see the "Mesquite Control" area on the map).  An exception may be made for a particularly hard to control species, such as Western Soapberry (Sapindus saponaria) in the "Soapberry Thicket" area on the map.

The City an pick up woody brush for composting or shredding if we contact Kevin after piles are made.

In addition, to simulate the effects of fire killing lower limbs of larger trees, these limbs may be removed by cutting.  This will approximate the extra sunlight that fire allowed under the canopy [6], increasing the space available to savanna species.

Non-native grasses and forbs, such as Johnsongrass (Sorghum halepense), Bermudagrass (Cynodon dactylon), and King Ranch Bluestem (Bothriochloa ischaemum) shall either be removed or controlled.  Some species may be impossible to eliminate, but we will make a good effort to control them.  Some species may be removed by approved herbicide.  Other species may be removed by hand, or some combination of these methods.  We may have to rely on native species out competing some of these non-native species as a form of control, and we will likely be stuck with continual control of some non-native species.

As part of savanna restoration and to increase the floral biodiversity of the site, we will add plants of appropriate native species to the site.  We will also increase the number of specimens of pre-existing native species appropriate to the site.   Plants will be added via pre-grown individual plants and by seeding.  Volunteers from NPSOT and NPAT will grow these plants to add to the site, and will collect seed to grow or use on site.  We may also contract with growers or accept donations of appropriate plant material.  Volunteers will also plant the specimens and apply seed.  Plant specimens will be planted during times of the year when they can survive with minimal care (late Fall, Winter, and early Spring) and become established before high heat and lack of moisture occur.

All plant species added to the site must be native and appropriate to the site and a savanna ecosystem.  All plant material (seeds, or plants grown from seeds or cuttings) must come from within 100 miles of the site to maintain local provenance of the genetics of the plant species.  Native plants from Bill Carr's "Annotated Checklist of the Vascular Plants of Travis County, Texas" will be used as the primary checklist of eligible native plants for use on the site [5], and Shinners & Mahler's Illustrated Flora of North Central Texas will be used as an additional reference [2].

We will attempt to greatly increase the amount of  Little Bluestem (Schizachyrium scoparium) on the site since it is a dominant grass of local savannas.  Other grass species we will attempt to increase on the site include Big Bluestem (Andropogon gerardii), Indian Grass (Sorghastrum nutans), and Sideoats Grama (Bouteloua curtipendula). 

We will also add and increase appropriate forb species, such as Standing Winecup (Callirhoe pedata), Englemann Daisy (Englemannia pinnatifida), Velvet Leaf Mallow (Allowissadula holosericea), Paintbrush (Castilleja purpurea),  Turk's Cap (Malvaviscus arboreus), and Liatris (Liatris mucronata).

The "Prairie Meadow" area on the map contains several species of native prairie grasses and will be used during field trips to teach about native grasses. We will concentrate on this area at first when adding more species of these grasses to the site.

Starting at the storm water drainage at the northwest corner of the site, the west edge appears to be seasonally wet (labeled "Riparian Area" in the map).  This area supports some species that prefer extra moisture.  We may try native species that need more moisture in this area, such as Obedient Plant (Physostegia intermedia).

The "More Xeric Area" appears to support species that prefer drier conditions, so appropriate species will be planted in this area.  Live oak (Quercus virginiana) sprouts in this area may need to be controlled to preserve Lace Hedgehog Cactus (Echinocereus reichenbachii) on the site.

Species To Control:

Common Name
 Scientific Name
 Exotic?
 Control Method For This Site
 General Control Methods
Woody Species



Chinaberry Melia azedarach
 X
 Cut-stump and basal bark applications of triclopyr-based herbicide (brand names Garlon, Pathfinder II, others) [3]
Japanese privet
Ligustrum japonicum X
 Immediately after cutting stems at or near ground level, apply a 25% solution triclopyr to the cut stump [4] Immediately after cutting stems at or near ground level, apply a 25% solution of glyphosate and water or triclopyr and water to the cut stump [4]
Ashe juniper Juniperus ashei
Mechanical control (removal).  Since prescribed burns are not recommended at the site, continued mechanical control of seedlings from seed bank in later years will be required. [23] Mechanical control (removal) followed by burning brush piles vastly reduced subsequent regrowth.  Since prescribed burns are not recommended at the site, continued mechanical control of seedlings from seed bank in later years will be required. [23]
Soapberry Sapindus saponaria

20% Roundup, 40% Amitrol-T, or 20% Tordon 22K resulted in death. [27]
Honey Mesquite Prosopis glandulosa

Mechanical control requires removal of above ground growth and destruction of roots by plowing or grubbing to prevent quick resprout.  Chemical control with 0.75% solution of clopyralid applied in June, July, August or September, caused 100% top-kill and no resprouts were observed the following year [22].
Live Oak Quercus virginiana

Vigorously resprouts from roots after cutting, but we can not use soil-applied herbicide, tebuthiuron, recommended for control.  Deer ate resprouts in some cases.  [26]  Precautions to avoid oak wilt shall be taken, such as disinfecting tools before use on each tree and applying pruning spray to wounds when needed.
Common Honey-Locust  Gleditsia triacanthos
Cutting of trees and 50% Triclopyr applied to cut surface effective [24] [25].  Cutting of trees followed by cutting of any resprouts for several years effective. Cutting of trees followed by cutting of any resprouts for several years effective.  Garlon 3A (a formulation of triclopyr) at rate of 50% water applied to cut surface effective [25].  Susceptible to triclopyr and to a mixture of picloram and 2,4,-D  [24]
Grasses, Sedges, Rushes



King Ranch Bluestem Bothriochloa ischaemum X
Plateau? Roundup?  Solarization?
Rescuegrass Bromus catharticus X
 Removal.  Solarization.  Replanting area with aggressive native annuals/perrenials. ?
Soft brome
 Bromus hordeaceus
 X
 Removal.  Solarization.  Replanting area with aggressive native annuals/perrenials. ?
Bermudagrass Cynodon dactylon X
Physical removal.  Tall competing vegetation.  No disturbed areas.  Glyphosate (Roundup) at 2% concentration.  [14]
Japanese brome Bromus japonicus X
 Removal.  Solarization.  Replanting area with aggressive native annuals/perrenials. ?
Vaseygrass Paspalum urvillei X
Plateau? Roundup?  Solarization?
Canarygrass
 Phalaris canariensis X
Rodeo, Roundup, or Amitrol - foliar spray [1 p253]
Johnsongrass Sorghum halepense X
Roundup - foliar spray [1 p253].  No disturbed areas. Repeated yearly application of glyphosate (Roundup) and dalapon (Dowpon). [13]
Forbs



Maltese star thistle
Centaurea melitensis X
Plateau? Roundup?  Solarization?

Approved herbicides are:
  1. The City has a mix of vegetable oil and 25% triclopyr that Kevin said is approved for use.
  2. [TODO: Kevin, can you help us check the herbicides in the list above for approved ones or approved substitutes?]

Issues and Concerns

Vehicles have used the site as a shortcut between Slaughter Lane and Brodie Lane in the past.  For this reason, the kiosk and all restoration will not start until the fence has been installed to prevent driving across the site.

We will avoid any significant effort in the right of ways (the street edges and the City water utility right of way), since that area could be disturbed by utility work.  We will mostly allow Texas Wintergrass to stay in this area, and may add other species by interseeding. 

Many non-native plant species have become established in and dominate the disturbed areas along both the north and west sides of the site (bordering Slaughter Lane and Brodie Lane).  This was likely caused by road construction, sidewalk installation, and other construction.  These areas will be restored, likely by solarization or spraying once with approved herbicide to kill the non-native plants, then reseeded with appropriate native species (including aggressive annuals to out compete the non-native species that will reappear from the seed present in the soil).

Due to the streets, businesses, and residential areas bordering the site, trash tends to blow into the site and stay there.  Also, the storm runoff area at the northwest corner of the property tends to wash trash into the site.  Periodic removal of trash will probably be needed.  If any illegal dumping occurs, the City authorities will be called immediately.  The City can pick up bagged trash collected by volunteers if we call for a pickup afterward (arrange with Kevin).

Due to the development of the area, wild hogs are not believed to be present.  Deer are believed to be present and may present a problem due to browsing of plants.  If so, cages or other control may be needed to protect specimens of specific plant species added.

Timeline

This is a draft estimated timeline and is subject to change:

Bibliography

  1. Packard, Mutel.  1997. Tallgrass Restoration Handbook.  Island Press.
  2. Diggs, Lipscomb, O'Kennon. 1999. Shinner and Mahler's Illustrated Flora of North Central Texas.  Botanical Research Institute of Texas.
  3. Batcher. 2000.  "Element Stewardship Abstract for Melia azedarach Chinaberry, Umbrella tree"  The Nature Conservancy.
  4. Batcher, 2000.  "Element Stewardship Abstract for Ligustrum spp.Privet" The Nature Conservancy.
  5. Carr, William. 2002.  "Annotated Checklist of the Vascular Plants of Travis County, Texas"
  6. Nielsen, Kirschbaum, Haney. 2003. "Restoration of Midwest Oak Barrens: Structural Manipulation or Process-only?" Conservation Ecology 7(2): 10.
  7. DeVore. 2005. The Great Savannah.  Lady Bird Johnson Wildflower Center.
  8. Anderson, Fralish, Baskin.  1999.  "Savannas, Barrens and Rock Outcrop Plant Communities of North America."  Cambridge University Press.
  9. Henderson, Richard. Oak Savanna
  10. Noble Foundation website, Texas Wintergrass
  11. Personal interviews with Coby Dinges and Pat Merkord by Jason Spangler.  2005.
  12. Rosiere. Range Types of North America: Tallgrass Savanna.
  13. Newman.  1993. "Element Stewardship Abstract for Sorghum halepebse Johnson Grass"  The Nature Conservancy.
  14. Newman.  1992. "Element Stewardship Abstract for Cynodon dactylon Bermuda Grass" The Nature Conservancy.
  15. Riskind, Diamond.  1986.  "Plant Communities of the Edwards Plateau Region of Texas" Geological Society of America.
  16. Soil Survey of Travis County, Texas.  USDA Natural Resources Conservation Service.
  17. Johnson.  Data Sheet for CPD Site NA32, Edwards Plateau, Texas, U.S.A.  North America Regional Centre of Endemism.
  18. Kuchler, A.W. 1993. Potential Natural Vegetation of the Conterminous United States. Digital vector data in an Albers Equal Area Conic polygon network and derived raster data on a 5 km by 5 km Albers Equal Area 590x940 grid. In: Global Ecosystems Database Version 2.0. Boulder CO: NOAA National Geophysical Data Center. One independent and one dependent single - attribute spatial layer. 3,580,905 bytes in 13 files.
  19. Hardy, Bunnell.  2001.  Potential Natural Vegetation Groups.  U.S. Forest Service.
  20. PLANTS database.  USDA Natural Resources Conservation Service.
  21. Checklist of All Endemics in Travis County.  Flora of Texas Consortium.
  22. Management Considerations for Prosopis glandulosa.  USDA Forest Service.
  23. Management Considerations for Juniperus ashei.  USDA Forest Service.
  24. Management Considerations for Gleditsia triacanthos.  USDA Forest Service.
  25. Heim.  Vegetation Management Guideline for Black Locust (Robinia pseudo-acacia L.) and Honey Locust (Gleditsia triacanthos L.).  Illinois Department of Conservation.
  26. Management Considerations for Quercus virginiana.  USDA Forest Service.
  27. Santos, Kageler, Gardner, Cuddihy, Stone.  1992.  Herbicidal Control of Selected Alient Plant Species in Hawaii Volcanoes National Park.  Alien Plant Invasions in Native Ecosystems of Hawaii: Management and Research.  Cooperative National Park Resources Studies Unit, University of Hawaii. Honolulu.
  28. Google Earth.

Contributors