January 1989, by L.Wayne Clark, FW-PARD
Prospectus on Tandy Hills Stratford Natural Area Tandy Hills/Stratford Natural Area
In 1987 citizens began to urge the City of Fort Worth Park and Recreation Department to protect the Tandy Hills/Stratford Natural Area (TH/SNA) from off-road vehicles and dumping, and to determine the value of this area in terms of its natural history. Staff from the Fort Worth Nature Center and Refuge (FWNC&R) were asked by Fort Worth Park and Recreation Department (FWP&RD) to examine the two parks to determine if the land warranted special consideration as a natural area. After four initial visits the FWNC&R staff recommended that the two parks did merit status as a natural area and suggested further study.
The initial Environmental Assessment of Tandy Hills Park was completed in 1989 and shortly thereafter the FWP&RD recommended to the Park Board that protective cable be installed on the park perimeter and that management of the park be turned over to the Nature Center staff. The addition of Tandy Hills/Stratford Park to the Nature Center added 160 acres to the 3500 of urban natural area or approximately 1/3 of existing parkland in Fort Worth. Continual surveying of flora and fauna, trail routing, land condition and research into methodology of natural area managerial and restoration have been the major effort by FWNC&R staff since 1990.
Natural Area and the Mission of FWP&RD
What was once commonplace 150 years ago is now a rarity, and much like artifacts in a museum, Tandy Hills is desirable for preservation and viewing by the public. The preservation and management of Tandy Hills/Stratford Park is congruent with the mission of FWP&RD, to enrich the lives of our citizens through the stewardship of our resources and the responsive provision of recreational, cultural, and educational opportunities. It is also consistent with the goal of conservation and preservation, “to effectively and efficiently plan for the managed natural and developed areas.” TH/SNA can fulfill a part of the mission and goals of FWP&RD by providing a valuable natural resource, providing recreation through trails and related activities, and with educational programming. Due to the inherent differences between natural areas and other parks within the system, a land use plan must use appropriate methods that will protect and enhance Fort Worth natural areas and remain consistent with the mission.
Which activities any given natural area can tolerate depends on how large the tract is, how resilient and sensitive to disturbance its native habitats and components are, how much disturbance has already occurred, and what kinds of monitoring and habitat protection capabilities the managing entity has. Some natural areas (or parts of) are fragile enough to justify allowing no public access at all while others may allow access only by guided tour. Many natural areas restrict access to include only people and do not allow pets of any kind--leashed or loose. Other tracts may allow limited access to pets and may require them to be leashed. Ecological impacts from visitor use can vary widely depending on many factors. The impacts can be foremost in a plan for a natural area such as TH/SNA is that the resource must be protected based on sound and current management techniques using site-specific survey data to the site protection. Public access must be secondary.
Description of TH/SNA
TH/SNA is a 160-acre area of public land that is owned by the City of Fort Worth and is situated on prairie land which gently slopes northward draining toward the Trinity River. Tandy Hills is a relic of the original Grand or Fort Worth Prairie showing minimal disturbance with most of the original plant species intact. Stratford has had a different land use history from that of Tandy Hills; most of the original prairie is replaced by invasive tree species. The range of ecological quality requires a distinct management plan for each site.
Three soil types are found at TH/SNA: Aledo, Aledo-Bolar and Frio. Each of these soil types has a characteristic natural plant community (as determined by the U.S. Soil Conservation Service) which gives the base line for judging the condition of each site and determines the disturbance (if any). The Aledo soil is situated on the upper shelves of high ground. The climax plant community should be a prairie of mid and tall grasses interspersed with an abundance of forbs (wildflowers). By weight, the composition is 95% grasses, 5% forbs, and 0% trees. Little bluestem makes up about 45% of the composition and Indian grass, big bluestem, and switchgrass make up 15%. Other grasses are sideoats grama, tall dropseed, slim tridens, silver bluestem, Texas cupgrass, hairy grama, buffalo grass, Texas wintergrass, and vine-mesquite. Forbs are numerous and include purple paintbrush, Engleman daisy, prairie clover, Maximillian sunflower, heath aster, compass plant, golden dalea, penstemen, and gay feather occurring as some of the more noticeable species.
The Aledo-Bolar soil is on the slopes with occurrences of Aledo soils (described above) within Bolar soils. The Bolar soil climax plant community is true prairie consisting mainly of tall grasses. The composition by weight is about 90% grass, 5% forbs, and 5% woody plants (trees or shrubs). Little bluestem, switchgrass, big bluestem and Indian grass make up about 70% of the vegetation. Other grasses are wild rye, sideoats gramma, Texas wintergrass, vine mesquite, Texas cupgrass, white tridens, meadow and tall dropseed, and silver bluestem. Forbs include Engleman daisy, Maximillian sunflower, prairie clover, heath aster, salvia, purple coneflower, golden dalea, big top dalea, gay feather, and bundle flower. Woody vegetation includes elm, hackberry, plum, live oak, aromatic sumac, New Jersey tea, and white honeysuckle.
The Frio soil occurs in the creek bottom in the lower reaches of the TH/SNA. The climax plant community for the Frio soil is mid and tall grass with a tree canopy of pecan, elm, bur oak, cottonwood, and others shading about 25% of the ground. The vegetation is 70% grasses, 20% woody plants, and 5% forbs. Little bluestem, big bluestem, Indian grass, switchgrass, purple top tridens, and wild rye make up most of the grasses. The rest of the grasses are tall and meadow dropseed, vine mesquite, Texas blue grass, and beaked panicum. Forbs include Engleman daisy, maximillian sunflower, gay feather, dalea, penstemen, and tick clover.
The preceding plant community descriptions are not restoration models but do give an approximate view of the original landscape and provide a starting point for site specific plant and ecological monitoring.
Model for Ecological Monitoring
The natural resources found in Fort Worth natural areas include, complex organisms, processes, and systems. Because the understanding of these resources is far from complete, research, mitigation, and monitoring are used to provide information needed to make sound park management decisions.
- General Plant Survey. A general plant survey was performed in 1988-89 and compared to the classic monograph, “Vegetation of the Fort Worth Prairie”. The vegetation of Tandy Hills was found to be mostly native prairie species. Stratford was not part of this general survey and has yet to be inventoried. The general plant survey lists only the species found on site and not numbers or importance of species within the plant community.
- Plant Transects. Various techniques are used to determine the percentage of plants and their importance in the plant community. By utilizing this baseline data a view of the actual existing plant community can be developed. With this view as a point to start from, a management scenario can be formatted. All future management, climate change, visitor impact, and future changes in the natural community can be gauged against this data. The plant transects should be performed quarterly.
- Wildlife. Depending on what is considered wildlife (non-plants?), a wildlife survey is the next step after or during plant transects. Generally birds, mammals, reptiles, amphibians, fish, insects, and invertebrates are observed or sampled. Wildlife responds to changes in vegetation, management practices, and visitor density. Once a baseline wildlife inventory is developed, an initial management plan can be adjusted to accommodate the needs of wildlife. Birds are the easiest to sample because of the relative ease of viewing. Other organisms need to be captured. As with plants, this data collection must be on-going.
Disturbances to plant and animal communities comes from both natural events (flooding, drought, fire, etc.), and human-derived events (grazing, logging, vehicles, etc.). The timing of an impact or disturbance can be historical or recent. Historical disturbances are events that happened more than 30-50 years ago and recent events are those from 30 years ago to present. Both Tandy Hills and Stratford have disturbance impacts. Both sites have impacts from human sources and include grazing, vehicles, and adjacent development.
Tandy Hills is in very good shape with the main impacts or disturbances being recent vehicle traffic and invasion of tree species from light grazing and lack of fire. (Note: lack of fire in a prairie is considered a disturbance).
Stratford shows signs of an older and more severe impact. Probably by the turn of the century, it had been heavily overgrazed and the resultant tree invasion has altered the plant and wildlife communities.
Both areas (particularly Tandy Hills) have been impacted by recent vehicular usage. Moderate to severe erosion and compaction has occurred in recent times on a network of trails throughout the area but has mostly diminished due to the protected boundaries. There are two utility lines that pass through the park; a water main and a sewer line. Some of the damage has been caused by the lines and related vehicular activity. Erosion continues on many sites but at a much-reduced pace.
Minor impacts are related to the surrounding residential community. Non-point source pollution from home pesticide use, domestic pets, dumping of grass clippings, escaped non-native plants, and unplanned trails are examples of this type of disturbance.
A primitive hiking trail system exists within the area on the old vehicle paths. Most of these trails traverse the land in such a manner as to enhance erosion and impact sensitive areas that may be wet (seeps and springs) or have important or sensitive plant species nearby. During the general survey work performed in the past, possible trail routes have been explored and notes taken on areas to avoid. Approximately one and one half to three miles of interpretive and hiking trails are possible within the area.
Trail routing and construction would be patterned after the trails on FWNC&R. Trails would be surfaced using the natural material on site except where special sites existed such as seeps or streams. Special drainage amendments are used to slow or eliminate trail tread erosion.
Since the initial interest in TH/SNA the FWNC&R has conducted educational programming on a limited basis. Special spring and fall tours, instruction of special interest college classes, and various newsletter articles have been the thrust of this programming.
The potential for interpretive programming and resource oriented non-structured recreation is high for TH/SNA. Considering the population of the metroplex, the increasing desire to learn about or experience the environment, and the area’s downtown location the possibilities are limited only by the FWNC&R staff time and inspiration.
Continue general plant survey and begin plant transects.
Begin general wildlife survey.
Use FWNC “TRIAGE” method for selecting management needs.
Begin brush removal in selected areas.
Access erosion areas and develop restoration plan.
Layout proposed trail system.
Produce interpretive brochure and trail map.
Conduct quarterly programs, and encourage special use by local schools.
Use signage and other methods to reduce impact by visitors and the surrounding neighborhood.
Promote TH/SNA as a local treasure to travelers visiting the City of Fort Worth.
Require prior authorization by FWNC&R staff to any activity by any city department
with the exception of real emergencies.
Continue mowing of ball field, playground, and areas adjacent (6’) to street as to
FWP&RD policy. Other mowing only as dictated by needs to protect or enhance the
plant community or special projects.
Develop a Natural Area Quality Index based on the floristic components of TH/SNA
that would allow comparison of areas within the boundaries and provide a method of accessing other natural areas in Fort Worth.
The FWNC&R is currently planning similar natural area management techniques and in general apply to TH/SNA and future natural areas in the Fort Worth region. Since the FWNC&R has had no official management plan, the work performed has been erratic and mostly accomplished with volunteers. The cost estimates will be based on the limited efforts at FWNC&R and other sources.
A general cost estimate for natural areas (based on Dallas County Open Space) is around $85-$100 an acre per year. This would amount to $13,600-$16,000 annually. This annual figure is approximately 70% labor, 20% equipment, 10% materials. In actuality the cost per acre would be higher (because each acre does not need the same amount of work) due to the labor intensive projects and special tools and supplies. A cost of $900-$1,000 per mile of trail is a rough estimate for trail construction using park personnel. If volunteers were used the costs decrease considerably. Chemicals and material cost alone could run $100-$400 per acre in areas where brush is dense.
FWNC&R staff time would average a minimum of 8 hours a week with a cost of approximately $20/hour or $8,320. Detailed study would raise the time requirements, but some of this could be done by area graduate students or other professional volunteers.
Annual (1st year, plant survey, trail layout, limited brush clearing) $14,000 Labor @ 70% (minimum 1 staff planner, limited brush clearing) $9,800 Equipment and materials @ 30% $4,200
As FWNC&R and TH/SNA projects are completed an accurate cost estimate can be developed for future management plans. Costs of interpretive programming were not included, as they have been in the past provided by FWNC&R. If four programs per year were planned for and presented that cost could be estimated at $2,000 staff time and mileage.