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First Annual Report, Environmental Assessment of Tandy Hills Park, 1989

Author: L. Wayne Clark, Fort Worth Nature Center and Refuge


  1. Study area

  2. Results

  3. Plant list

  4. Future management

  5. Introduction

  6.  Educational and recreational potential


The environmental assessment in the following pages began in the summer of 1987 and was formally proposed by the Director of Park and Recreation, Ralph W. Emerson, to the Park and Recreation Advisory Board on February 11, 1988. The assessment also updates the preliminary report requested by Assistant Director of Programs, Jack Ashworth, in May 1987.

The questions to be asked in regards to the Tandy Hills/Stratford area are: “What is actually in the parks? Is it a special natural area? How might the natural areas be managed?” These questions will be addressed in the following report, but first let us consider the natural history of the Fort Worth region.

Although there is an incredible array of plants, animals, and natural communities, which may be found in Texas, natural scientists generally recognize ten vegetational areas, or bio-geographic areas, which represent the broad changes in plants and animals across the state. The areas are as follows: 1. Pineywoods 2. Gulf Prairies and Marshes 3. Post Oak Savana 4. Blackland Prairie 5. Crosstimbers and Prairies 6. Rio Grande Plains 7. Edwards Plateau 8. Rolling Plains 9. High Plains 10. Trans- Pecos, Mountains and Basins. Fort Worth is situated in region 5, Crosstimbers and Prairies.

The Crosstimbers and Prairies consist of two vegetational types: Post Oak/Blackjack Oak woodlands and Prairie grasslands. The Crosstimbers border the eastern and western edges of Fort Worth and runs north and south from Central Texas to the Red River. The Prairie runs between these two belts of woodlands. The Trinity River crosses through the Crosstimbers and Prairies and in its basin creates riverbottom forests. The major part of the Fort Worth city limits is in the Prairie region which is sometimes referred to as the Fort Worth Prairie. Tandy Hills/Stratford parks are in the eastern portion of the Fort Worth Prairie.

What are grasslands and prairies? Grasslands occur on all continents and together with the grazing animals that co-evolved with them, constitute one of the world’s major natural ecosystems as well as forming the basis of our agriculture. Natural grasslands (prior to industrial man) once covered nearly 40% of the earth’s surface. Today, much of that grassland is used for crop production and the remainder has been greatly altered by domestic livestock, suppression of fire, and development. Grasslands are plant communities dominated by graminoids (grasses, sedges, rushes) but with forbs (wildflowers) present and sometimes seasonally dominant. Trees and shrubs may be present but would be scattered in the grassland. Grasses and wildflowers of the grasslands are well adapted to the environment in which they exist where periods of defoliation or limitations of growth may occur due to climatic limitations, herbivore consumption, or removal of fire. Grasses have two unique features that make them more tolerant of defoliation and subsequent regrowth than most other plants. The meristem or growing point of grass tends to be close to the ground or beneath allowing it to resist defoliation, normal grazing, and other stresses while allowing for regrowth. Grasses have a finely divided dense root system, which allows them to efficiently capture water and nutrients from a large volume of soil. This also contributes to their ability to bind soil particles together and reduce erosion. There is a general relationship in that taller grasses tend to have deeper root systems while shorter grasses have shallower root systems. Grasses are typically classified as to their height at maturity; tall grasses greater than four feet high, mid grasses two to four feet high, short grasses less than two feet. Grasslands are then grouped into classifications such as tall grass prairie, etc.

In comparison to forested ecosystems, grasslands have large annual temperature variations, high evaporation-precipitation ratios, and relatively low precipitation rates. The annual phenomenon of seasonal drought (July, August, September for our area) as well as periodic droughts that may last for more than one year are characteristics of grasslands. Climate alone does not adequately identify why a particular grassland exists at a given time and place. Other factors including soil conditions, fire and grazing animals interact to create and maintain grasslands. Generally as we go east to west in Texas the climate tends to have less precipitation and is more conducive to grasslands but we see woodland in grassland regions due to disturbance by man (overgrazing, farming, etc.)

To fully appreciate a grassland community it must be observed an entire year since it changes its character from season to season as each of its components species responds to the varying photoperiod (hours of sunlight), temperature, and moisture regimes. Studying a particular grassland is like reading a book, as each page is turned more of the story is revealed.

The last aspect to understand about grasslands is the climax community. Within a given climatic region a particular habitat can be expected to develop a relatively stable community, which is called a climax community. This community is not static but rather exhibits a state of dynamic equilibrium, that is, it varies around a mean set of conditions. If abnormal conditions occur, such as overgrazing, the community can be expected to change. If the disturbance factor is removed and if the community is not deteriorated, then the community will tend to go back to climax condition. This recovery to climax condition is dependent on a number of factors: 1. Soil seed reserves 2. Persistence of vegetative portions of plants 3. Degree of soil deterioration 4. Degree of growth form shift (grasses versus woody species) 5. Other variables.

Now we might ask, what is a prairie? A prairie is a grassland in humid (greater than 25 inches annual precipitation) regions dominated by tall grasses and having a diversity of associated forbs (wildflowers). Typically the topography consists of gently rolling hills. Plains are typically drier and flat.

Hopefully this mini-course in grassland ecology will help one to understand the results of the Tandy Hills study and also its importance in the Fort Worth region.

Study Area and Methods

The areas considered in this study are the 105.25-acre Tandy Hills Park, 50-acre Stratford Park, and the adjoining lands east and west of Tandy Hills Park. Elevations range from 643 to 525 ft. The study area is situated in the Fort Worth section of the Grand Prairie where it approaches the Trinity River bottoms.

Soils of our region generally determine what plant community should exist. Soils that have a clay loam or clay surface layer are indicative of mid and tall grass prairies. Soils that have a fine sand or fine sandy loam are indicative of oak forests. Three soil types are found at the study area: Aledo-Bolar-Urban land complex on 3% to 20% slopes; Aledo-Urban land complex on 1% to 8% slopes; Frio silty clay frequently flooded. Most of the soils in the study belong to the Aledo-Bolar series and are primarily found on the slopes and hillsides. The Aledo soil is the next most abundant soil and is found primarily on the flat hilltop areas. A small portion of the study area soils is the Frio silty clay loam and is located in the creek bottoms near Interstate 30. The Aledo and Aledo-Bolar soils are indicators (among other soils) of Prairie in Tarrant County. The Frio soil is indicative of creek bottom. So in just examining the soil survey of Tarrant County one has expectations of most of the park being in grass.

The two parks belong to the City of Fort Worth and are operated by the Park and Recreation Department’s south zone park operations. The private property to the east belongs to the Sagamore Hill Baptist Church. A real estate company currently lists the private property to the west and this author has not determined the owner.

Methods used in the study involved weekly visits during spring and early summer to every two weeks in mid-summer and fall. Visits consisted of walking through most of the park and observing the plant species in bloom, the numbers of individual species, making note of general topography, disturbed sites, and off road vehicle activity. Ninety- five percent of the time spent at the study was in the Tandy Hills portion. Other methods used were examining aerial photographs, interviewing Lewis Tandy, searching for scientific papers, and trips to other prairie areas for comparison.
See Fig. 1 for map of park boundaries.

Study Results

As stated in the introduction, Fort Worth is found in the prairie area of the Crosstimbers and Prairies vegetational region. The major study of the Fort Worth Prairie was prepared by E. J. Dyksterhuis in 1946, published in Ecological Monographs vol. 16, number 1. Much of the background information for this study was provided by this valuable work on the prairie and was also used as a standard for evaluating Tandy Hills.

Much of the prairie that existed in the Fort Worth Prairie was still intact in the 1870s but by 1900 most of the prairie had disappeared, been degraded, or had declined. Overgrazing by domestic livestock and farming of wheat and cotton were the major factors leading to the demise of the prairie. In many areas where prairie still exists the land is situated on slopes that were less desirable for livestock and unsuitable for farming;

this is the case with Tandy Hills. Examining aerial photos from the early 1940s indicate that Tandy Hills was in excellent shape and at that time had less woody growth whereas the Stratford Park area was already very woody. It is interesting to note that both Tandy Hills and Stratford have basically the same degree of slope and the same soil types but Stratford is dominated by woody vegetation (see fig. 2). This reflects differences in land use before 1940. Conversations with Lewis Tandy (the family owned the land from before the turn of the century until the 1930s) support the fact that Tandy Hills was never abused like much of the surrounding land.

Four major climax grasses occur in the Fort Worth Prairie: Little Bluestem, Sideoat Gramma (our state grass), Indian Grass, and Big Bluestem. All of these grasses occur in the park and in the manner described by Dyksterhuis; shorter grasses on the shallow soil on the hilltops with the taller grasses on the slopes. One peculiarity of the Fort Worth Prairie is the occurrence of flat, bench-like regions dominated by the prairie grass Seep Muhly. These are referred to as Muhly benches. Tandy Hills has many of the benches and all are in good shape except where used for previous vehicular travel. In regards to prairie grasses in an undisturbed state, the slopes of Tandy Hills Park are among the best in the county and I believe the best anywhere in the City of Fort Worth (including the Nature Center). The area in the park that has been maintained by mowing has the fewest climax grasses although some have survived. The decreased mowing helped identify the grasses that had survived as well as numerous wildflowers.

Wildflowers are what really make Tandy Hills a special area. Although many areas have the climax grasses for our region, few have many wildflowers. The scarcity of wildflowers can be attributed to overgrazing and their inability to recover from grazing. Most wildflowers are very palatable to livestock at different stages and these forbs make up an important part of the diet of livestock. So even though there are large areas of native prairie west of Fort Worth they have a low diversity of wildflowers (though most species can be found if you look in a large area for a long time).

Tandy Hills wildflowers are in the right place and the right amounts (almost all pioneer accounts mention the beauty and numbers of wildflowers) and it is from my observations the best place in Fort Worth for native wildflowers. Although there are many species of flowering plants at Tandy Hills (see plant list) some stand out in either their numbers or their rarity. Purple Paintbrush abounds in the park particularly near View Street as does a red Winecup that is found in its rare white form. On the edge of the slopes the Engleman’s Sage is numerous and in greater number than I have seen anywhere (if occurs only in 3 or 4 Texas counties). Dog Tooth Violet is too numerous to count and are uncommon in the rest of the county. Compass Plant and Rosin Weed are considered prairie indicators anywhere in the prairie states. These two plants are numerous and occur side by side (a condition I have not seen elsewhere). Purple Prairie Clover, White Prairie Clover, Purple Coneflower, and Prairie Celestial occur in impressive numbers. One plant identified has not been located anywhere else in North Texas and is uncommon in Central Texas. This plant has no common name, its scientific name is Tomanthera Multiflora. This colony that was found has thousands of individuals. All plants were identified by use of the Manual of the Vascular Plant of

Texas and Shinner’s Manual of the Flora of North Central Texas. Dora Sylvester of the Botanical Research Institute of Texas verified many of the findings. The Tomanathera, was confirmed by Dr. Mahler of SMU.

The damage done by off road vehicles, four wheel drives, motorcycles, and water department activities are certainly noticeable. Many of the roads and trails have been in place for many years and some are recent. Examining aerial photos of 1981 and 1987 indicate at least a 100% increase in damage to the park. There were few times when I surveyed the park that I did not see evidence of this activity. Many times I would see the offender but could never get to them in time to catch them.

Vehicle usage in the park appears to have decreased a small amount recently. Areas where roads and trails exist are showing little signs of recovery. This takes a long time and since this year was a hot one with little rain recovery would be slower. Vehicle entry is still on the western and eastern sides. The activity in the park by the survey company that the Water Department had contracted for was noticeable in the summer 1988, and I understand that it is now completed. The Water Department will need to advise the park staff of any proposed activity in the future.

Little time was spent in Stratford Park but I though that Tandy Hills warranted the most attention. Time was spent on the church property and in general what can be said for Tandy Hills can be said for this property also, because the areas on that property are contiguous with the prime areas of Tandy Hills. Stratford Park warrants further study in the future.

Tandy Park Plant List

The following plant list was prepared from summer of 1987 through the winter of 1988. This is not a complete list of all species in the park and does not include the woody plants. Most are considered prairie species. Entries are also not in alphabetical order; due to the way they were entered on our computer.


  1. Schizarachyrium scoparium ---- Little Bluestem

  2. Sorghastrum nutans ---- Indian Grass

  3. Andropogon furcatus ---- Big Bluestem

  4. Panicum virgatum ---- Switch Grass

  5. Bouteloua hirsuta ---- Hairy Gramma

  6. Bouteloua curtipendula ---- Sideoats Gramma (state grass of Texas)

  7. Muhlenbergia reverchonii ---- Seep Muhly

  8. Stipa leucotrica ---- Texas Wintergrass

  9. Buchloe dactyloides ---- Buffalo Grass


10. Dyschoriste linerasis ---- Snake Herb
11. Ruellia humilis ---- Wild Petunia
12. Ruellia caroliniensis ---- Wild Petunia 13. Rhus toxicodendron ---- Poison Ivy
14. Cooperia drumundii ---- Brazos Rainlilly 15. Amsonia ciliaa ---- Bluestar

16. Asclepias asperula ---- Antelope Horn Milkweed 17. Asclepias viridis ---- Green Milkweed
18. Matelea biflora ---- Two-flowered Milkweed
19. Lithospermum incissum ---- Puccoon

20. Tradescantia occidentalis ---- Prairie Spiderwort 21. Centaurea americana ---- Basket Flower
22. Echinacea angustifolia ---- Purple Coneflower 23. Engelmannia pinnatifida ---- Cutleaf Daisy

24. Erigeron strigosus ---- Daisy Fleabane
25. Gallardia pulchella ---- Indian Blanket
26. Helianthus maximiliani ---- Maximilian Sunflower 27. Liatris mucronata ---- Gayfeather
28. Ratibida columnaris ---- Mexican Hat
29. Silphium lacinatum ---- Compass Plant
30. Silphium albaflorum ---- White Rosinweed
31. Sabata compestris ---- Prairie Gentian
32. Nemastylis geminiflora ---- Prairie Celestial
33. Krameria lanceolata ---- Prairie Sandbur
34. Salvia texana ---- Texas Sage
35. Salvia azurea ---- Blue Sage
36. Salvia engelmanni ---- Englemans Sage
37. Scutellaria drummondii ---- Drummonds Skullcap 38. Brazoria scutellarioides ---- Prairie Brazoria
39. Nothoscordium bivalve ---- Crow Poison
40. Desmanthus illinoensis ---- Bundleflower
41. Desmanthus velitinus ---- Shameweed
42. Crindelia microcephalla ---- Gumweed
43. Castilleja indivisa ---- Scarlet Paintbrush
44. Castilleja prupures ---- Purple Paintbrush
45. Castilleja purpura var. Lindbeimeri
46. Lupinus texensia ---- Texas Bluebonnet
47. Petalostemun purpureum ---- Purple Prairie Clover 48. Allium canadense ---- Canadian Onion
49. Allium drummondii ---- Prairie Onion
50. Linum rigidum ---- Yellow Flax
51. Linum pratense ---- Blue Flax
52. Linum sulcatum ---- Yellow Prairie Flax
53. Yucca pallada ---- Palid Yucca
54. Yucca arkansana ---- Thready Yucca
55. Callirhoe involucrata ---- Winecup

56. Calyophus serrulata ---- Day Primrose
57. Oenethera biennis ---- Common Evening Primrose 58. Oenethera missouriensis ---- Fluttermill
59. Stenosiphon linifolius ---- False Gaura
60. Ipomopsis rubra ---- Standing Cypress
61. Polygala alba ---- White Milkwort
62. Hedyotis nigricana ---- Star Violet
63. Verbena bipinnastifida ---- Prairie Verbena
64. Verbena halei ---- Slender Vervain9
65. Erodium cicutarium ---- Filaree
66. Erodium texanum ---- Stork’s Bill
67. Geranium carolinianum ---- Crane’s Bill
68. Ceanothus americanus ---- Redroot
69. Erythronium albidum ---- Dog’s Tooth Violet
70. Phylanthus polygonoides ---- Leaf Flower
71. Tragopogon dubius ---- Yellow Goat’s Beard
72. Hybanthus verticillatus ---- Green Violet
73. Cacalia plantaginea ---- Indiana Plantain
74. Vicia sativa ---- Spring Vetch
75. Schrankia uncinata ---- Sensitive Brier
76. Lindheimera texana ---- Texas Star
77. Delphinium virescens ---- Plains Larkspur
78. Astragalus mollissmus ---- Texas Loco
79. Astragalus crassicarpus ---- Ground Plum
80. Psoralea cuspidota ---- Tall Scurvy Pea
81. Psoralea linerifolia ---- Straight Leaf Psoralea
82. Palafoxia callosa ---- Small Palafoxia
83. Polytaenia nuttallii ---- Prairie Parsley
84. Eryginum leavenworthii ---- Eryngo
85. Solanum dimidiatum ---- Western Horsenettle
86. Solanum rostratum ---- Buffalo Bur
87. Penstemon cobaea ---- Wild Foxglove
88. Eustoma grandiflorum ---- Bluebells
89. Dyssodia tagetoides ---- Dogweed
90. Lygodesmaia texanna ---- Skeleton plant
91. Boerhavia coccinea ---- Scarlet Spiderling
92. Thelesperma filifolium ---- Greenthread
93. Veronia lindheimerii ---- Lindheimer’s Ironweed 94. Heliotropium tenellum ---- Teliotrope
95. Aster ericoides ---- Heath Aster
96. Hymenopappus scabiosseus ---- Old Plainsman 97. Marshallia caespitosa ---- Barbra’s Buttons
98. Euphorbia bicolor ---- Snow on the Prairie
99. Centaurium beyrichii ---- Mountain Pink
100. Sisyrinchium app. ---- Blue Eyed Grass
101. Monarda citriodora ---- Lemon Horsemint

102. Monarda punctata ---- Yellow Horsemint 103. Cassia romeriana ---- Two Leaf Senna 104. Dalea frutescens ---- Shruby Dalea
105. Psoralea cuspidata ---- Tall Scurvy Pea 106. Neptunia lutiea ---- Yellow Puff

107. Proboscidea lousianica ---- Devils Claw


Management of natural areas is accomplished across the nation on federal, state, city, and private lands. Although it has recently become a science instead of an art, management of natural areas has been practiced in some form or another for years. Most federal and state agencies have lands to manage and a professional staff of natural area managers, but most city governments do not usually deal with natural areas or seek the staff do so. There are exceptions. In Texas, the City of Austin has a natural preserve system and a preserve manager, which answers to Austin Park and Recreation. They also have a department of Environmental Protection with a section on environmental planning which includes a nature preserve technical advisor. Even New York City, which most Texans stereotype as a city with very little green space, has a department of natural resources.

The City of Fort Worth and its citizens must first decide the value of the natural areas within the city limits and then decide how to manage them. It is not an easy decision to make due to the current budget restraints and needs in so many areas. But it will take the time and attention of city staff to carry through any management plan. The following management scenarios are suggestions of policies that the city could implement.

  1. The “let nature take care of it” scenario: This type of management is the most commonly practiced. It consists of letting natural processes manage the areas in question. The immediate costs are little and the public gets years of use from the land. But in the long run, the area gradually degrades from what made it special in the first place. Few areas are truly untouched by man and nature will take a different course because of these disturbances. At Tandy Hills the problem is brush and tree invasion and in 20 to 50 years it will probably lose most of its special nature. When dealing with Natural Area Management and Preservation one is dealing with the next and future generations of citizens. It is a long-term process!

  2. The “save the best” scenario: This scenario involves the identification of the best parts of a proposed natural area and doing all that can be done to keep these areas in a natural condition. The areas that are considered in need of more work and restoration are left to nature and its altered course. At Tandy Hills this management plan would involve minor brush clearing, mowing, and prescribed burns. Cost would be determined by the extent of the areas selected to be managed and preserved.

3. The “restoration” scenario: This scenario is much like what would be undertaken if a Rembrandt or Renoir painting were discovered in your great uncle’s damp basement. Art lovers would be excited, museums would be excited, and restoration artists would be excited. Great care would be taken in handling the painting, molds would be carefully removed, and the exact paint pigments from Europe would be mixed and painted in the same strokes as the great masters. It would then be displayed with great pride for all to see. It may be a matter of opinion as to the value of Tandy Hills but if the city determines that the park needs to be restored, the following could be a management plan. Removal of all woody growth over many years, reseeding of disturbed areas with seeds from local genetic stock, prescribed burns as needed, transplanting wildflowers grown in the Nature Centers native plant nursery, and protecting the area from further disturbances. Then display it proudly.

All of the scenarios above assume that the park will be protected from Off Road V ehicles.

Educational and Recreational Potential

Education at Tandy Hills could be very similar to that at the Nature Center. Programs and trail walks explaining the ways of nature (ecology) and what its value to man is (environmental ethics) is a central theme in children and adult programming that is done at nature centers. Other programming would include wildflower walks, prairie ecology, and the history of “Cowtown”. Such programming would require a trail system (example in fig. 1), staff from the Nature Center and volunteers. The programs are limitless and are dependent on a varied staff at the Nature Center. The current limitations are that even at our allotted staffing level we would be hard pressed to do many programs at Tandy Hills. Travel time is about one hour, and the average tour takes almost one and one half-hours. Add briefing and debriefing of the volunteers and a staff member has spent half the day doing one tour. There is no problem spending this amount of time but it would put a strain on the Nature Center’s programs and daily operations.

Resource-oriented, non-structured recreation would be the same as that found at the Nature Center. This includes hiking at a leisurely pace, bird watching, wildflower observing, and just enjoying natural surroundings. Its location would be a benefit to citizens of the east and south sides of Fort Worth. This type of unescorted use of the park would be dependent on a properly designed trail system and the use of interpretive signs and literature.


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