Researchers working to devise plan for Palo Alto Battlefield Restoration

Drs. Steven Whisenant and Ben Wu and graduate student Michael Margo are charged with devising a plan that would re-create the vegetative appearance of the 1846 Palo Alto battlefield in Brownsville - the site of the first Mexican-American war.

"The historical aspect of this project is something new and exciting to us as ecologists," Wu said.

Putting a 156-year-old battlefield back to its original appearance takes a lot more than one would think. The challenges? Consider it's been grazed by livestock and some of it farmed-up until the 1990s. And throw in the fact that the researchers have only had to rely on old aerial photographs, historical accounts and topography maps to help them vision the landscape where the U.S. army was victorious May 8, 1846.

By performing experiments on the range and studying the vegetation and hydrological makeup of the soil, the group says they will be able to come up with a restoration model they can present to the National Parks Foundation, which commissioned the $116,900 study.

There are two components to the research. First, the group will try to restore native Gulf Cord grass on the previously cultivated portions of the battlefield. The thick sections of cord grass served as camouflage for the soldiers.

"According to one historical account, the soldiers would hide in it," Margo said. "It had needle-point leaves and would poke their legs. It can dominate when in a healthy stage."

However, the grass can't be re-established by seed. "The saline soils crust over. It's a tough environment for seed," Whisenant said.

But it can be done by transplanting stems. Margo said current experiments involving both till and no-till planting methods in different seasons have been attempted.

The second component of the research involves reshaping the resacas (Spanish for oxbow lakes), a key location of the battle. The wetlands (resaca) terrain has undergone much change through the years, including ditches along the banks and stock tanks across the channel that were dug to collect fresh water for livestock. The wetlands area will be one of the most intensely studied.

"The most important thing about wetlands is hydrology, hydrology, hydrology," Wu said. Hydrology dictates vegetation structure, and according to Wu, "that's what's interesting to us and so challenging."

To study this, Wu said, a series of shallow PVC wells will be dug between 8-12 feet to monitor how the hydrology fluctuates throughout the year. By altering the hydrology of the ground through restoring the shape of the resaca channel, Wu said, the group can study how it will influence the vegetation structure.

"But this is a challenge because we don't have prior knowledge or data on this," he said.

And any disturbance of the soil by machinery is a concern as well.

"The real challenge has been implying manipulative field experiments, while still respecting the significant cultural-archeological value," Whisenant said.

This is the second year of the three-year study. The formation of the park officially began in 1978 when Congress authorized its establishment two miles north of the Brownsville city limits. The National Park Service has overseen the project, and following Congressional approval in 1978, an archeological study began. But it was later deemed incomplete for planning purposes.

In 1992, Congress passed the Palo Alto Battlefield National Historic Site Act, allowing for a more thorough assessment of the site.

Land acquisition continues as the national park that will include a lookout tower to view the actual battlefield, visitor's center, museum, trails and administrative offices.

"They want people standing on the viewing platform to see something very similar to what these generals were seeing," Whisenant said. "They also want to show both sides culturally and not play up just the battle."

Editor's Note: For a historical look at the battle of Palo Alto, refer to "On the Prairie of Palo Alto: Historical Archaeology of the U.S.-Mexican War Battlefield" by Charles M. Haecker and Jeffrey G. Mauck, Texas A&M University Press, College Station.

Additional information is available on the Web at http://www.nps.gov/paal/home.htm