Bamberger Ranch Research
Recovery of the Texas Snowbell (Styrax platanifolius var. texanus) (UPDATED JUNE 2008)
The snowbell is a beautiful under-story tree that inhabits the limestone cliffs of the southwestern corner of the Edwards Plateau. This delicate, heart-shaped leafed tree grows 10-15 feet and blooms white bell-shaped flowers in mid-April. Found mostly on cliffs associated with deeply cut waterways, only 39 plants from seven scattered populations were known to exist in Edwards, Val Verde and Real Counties on the southwestern edge of the Edwards Plateau of Texas when this species was listed as endangered by the State of Texas in January 1987. The main problem, scientists believe, is in the location of the trees; leaning out from high cliffs, most seeds ripen and fall into streams below and are carried away. Most of the seedlings that do survive are quickly eaten by herbivores, especially browsers such as deer, goats and sheep, killed by drought, or swept away in the next big flood.
The objective of the recovery plan is to have the plant "de-listed" and to know that a good number of plants are protected in healthy colonies that will continue to grow in size. We also need to have seeds secure in several "seed banks", so there will be viable seeds from which new colonies could be started if disaster strikes their home area of Texas. We have continued to search for previously unknown colonies as we find new private landowners that are willing to cooperate with us. Learning more about the biology and ecology of Snowbells is important for making management decisions.
A "Recovery Team" of landowners, agency personnel, botanists, volunteers, horticulturists and other stakeholders has been formed to help the Bamberger Ranch with planning, growing plants, and putting them in appropriate and protected places in the watershed from which the seeds were collected. Large corrals of heavy gage wire surround the plants offer protection from all critters (except insects and small mammals) and enough space for new seedlings to sprout and grow.
Several grants have been awarded to the Bamberger Ranch to help with the 5-year plan to re-establish the Texas Snowbell in its original home territory. U. S. Fish and Wildlife Foundation helped with Phase 1. The Texas Parks and Wildlife’s Landowner Incentive Program helped with Phase 2, which is almost completed (June, 2008).
J. David reports that there were several minor setbacks in the past year with the reintroduction project. First high water on the Nueces River took out 6 plants on one ranch. On another property that was part of the project the ownership changed hands and the new owner had a bulldozer operator remove 15 protective corrals and destroy the 15 plants they held that were 2 to 3 feet tall.
Here at Selah in the "George Beere Greenhouse" we have over a thousand plants that should be ready for introduction this fall. We plan to finish this phase of the project before the year is out. We now have 682 plants in protective corrals. In November and December the team will mount a major effort to get all the plants out in the ground. Instead of metal corrals to protect them, they will be surrounded by enough brush to protect them from animals.
We’re looking for physical help for this massive "volunteer" planting effort. If you are interested please call J. David at 830-868-7303. --- Or you can send an e-mail to Selah and if for any reason that doesn’t work then please send to Colleen. Please include a phone number so we can contact you. If you are only available on weekends let us know that too.
Steven Fulton, ranch Biologist, is working on his master’s degree, and he will receive assistance from a Section 6 Federal Research Grant to continue the research he has started on the Texas Snowbell.
In his research Steven hopes to answer, with scientific data supporting his findings, the following questions:
Which insects are the effective pollinator(s)?
- By putting excluder nets on some 15 branches of plants that we have observed to bloom and produce seeds, he will keep out all insects until he is there to observe.
- When the buds are opening he will temporarily remove the net from a branch and watch to see who visits the plant. Before leaving he will replace the netting so that those branches that were visited (and the visitors recorded) will have the chance to produce seeds.
- In the summer the netting will be removed.
- In the fall he will determine which branches on which plants produce seeds. This spring Steven had excluded 17 branches on plants. Bumblebees, except for one small native solitary bee, visited all branches.
Can Texas Snowbells be manually pollinated?
- Steven also manually pollinated 20 or 30 blossoms on each plant. In some cases he used pollen from the same plant, and in others from a different plant.
- In the fall he will determine if seeds were produced.
Who likes to eat Snowbells?
- Steven has set up motion cameras to see who visits the plants. He often sees coons, and squirrel or two, a few birds, and the major culprit--- Aoudad sheep.
How does water affect seed viability?
- Steven will set up experiments to see if immersion in water kills seeds, hurts their viability, or perhaps even enhances their viability.
What animals eat Texas Snowbell seeds?
- This fall Steven would like to find out if seeds are eaten by wildlife.