Sunday, May 24, 2009

Research That Follows Work

The beginning of our work to rescue the federally and state listed endangered plant, Styrax platinifolius ssp. Texanus, commonly known as the Texas snowbell, was in 1994. This beautiful plant is a small tree or shrub native to the watersheds of the Nueces and Devils River of west Texas.

I spent the first five years following leads from other botanists, looking in various herbariums and going door to door (ranch to ranch) in Real, Edwards, Uvalde, Kinney and Val Verde counties. Eventually, we secured landowners interest and support to save the plant from extinction. My message was that we private landowners could demonstrate our commitment and stewardship without the government’s regulation. A number of landowners agreed. Their combined ownership exceeded 100,000 acres. During this time, we collected small quantities of seed and began propagating and growing operations here on the ranch. In 2003 we began the recovery project by introducing the first of what would become 682 plants.

All introductions, under agreement with the U.S. Fish and Wildlife Service and The Texas Parks and Wildlife Department, are planted in the watershed from where the seed was collected. Plants are all corralled (caged) with five foot high 4 x 2 horse fencing supported by six steel t-posts. Each corral is six foot wide and contains three snowbell plants. We believe these will protect the plant from herbivory for 75 years and allow room for regeneration within the structure. Doing all the very hard labor of carrying materials, water and plants into steep canyons, over rocks and through thick brush would not have been possible without the help of many volunteers. Now the project has reached a point that scientists desire more knowledge and information about the plant. Steven Fulton, our ranch biologist, has chosen to answer scientists’ questions as part of his thesis for his graduate degree at Texas State University in San Marcos. The following describes the questions that Steven’s research is designed to answer:

Review of the Recovery Plan has illuminated many questions concerning the ecology of the Texas snowbell. Some believe that the Texas snowbell is confined to such inaccessible places as cliff faces to escape herbivory; however, there is only anecdotal evidence of animals consuming Texas snowbells. Evidence gathered through observation will prove or disprove that herbivory is a threat. Others believe that the Texas snowbell grows in such places because the presence of surface water creates a microhabitat with lower temperatures and higher relative humidity; however, no site specific climatic data is available. It is presumed that Texas snowbells reproduce via outbreeding and insect-pollination; however, these assumptions have not been verified and the pollinators have not been identified. As a result of their position above or near water, many of the mature seeds drop into water. The effect submersion has on seed viability is unknown.

To aid in the management of this species there is a need to identify its pollinators, to record its microclimate characteristics, and to determine if there is a correlation between seed submersion and viability. Information obtained from Steven’s research will improve the survival rate of reintroduced plants as well as provide information and understanding concerning the ecology of the Texas snowbell.

The snowbell blooms for approximately two weeks in mid April.

A distinguishing characteristic of the Texas snowbell is the white pubescence on the underside of the leaf. This is the only apparent difference from its close cousin, the sycamore leaf snowbell which we have growing naturally here on the ranch.

Looks can be deceiving! Between Steven and the mountain in the background flows the beautiful, crystal clear Devils River. This is in Val Verde County on the Nature Conservancy’s Dolan Falls Preserve. Here Steven is unpacking some of the scientific equipment he uses to collect data.

Here are the scientific instruments Steven has installed to collect data. The instrument in the foreground collects temperature and humidity and the one in the background records rainfall. These are delicate battery powered instruments.

Steven’s 6’8” height comes in handy when mounting a motion detecting camera which will produce a photograph of any animal that might come by and choose to browse the snowbells. Early results show Aoudad sheep browsing.

All of the research is not accomplished with scientific instruments! Here Steven has shrouded branches on the plant prior to its blossoming. Notice the flowers on the unshrouded branches. Steven will remove the shrouds and sit for hours observing what insect pollinates the snowbell plant. Up until now, this is totally unknown. Because this is scientific research, it is premature to make a statement about the pollinator until the work is complete.

Another shrouded plant overhanging the Devils River.

Here Steven retrieves information from the instruments into his laptop. This set up is on the Nueces River.

Steven must visit all of his installations once a month. Sometimes it takes two or three days to travel out to replace the batteries and extract the information. He spent ten days at the beginning of his research installing the equipment.

This was a gamble! On the cliff which was inaccessible to us from the top or from below, we had discovered some very healthy plants. In an effort to collect seed we drilled into the cliff and placed ten foot rebars to support some galvanized screen. To our delight we caught over 100 seeds in our net and from these seeds we have grown some healthy plants.

Steven has another year before he will be publishing his research and defending it at the university. We will bring the results to you at that time, but feel free to communicate with us if you have further interest.

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