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AUBURN RESEARCHERS ASSISTING SMITHSONIAN INSTITUTION
AUBURN, Ala.__--When the Smithsonian Institution needs help protecting
a national treasure, who do they call? Auburn University scientists,
that's who.
That was certainly the case when the Smithsonian and the National Park
Service became concerned about the impact visitors might be having on
the stately elm trees at the Capitol Mall in Washington, D.C.
The Mall, around which are located many of Washington's choice attractions
including the Smithsonian Institution, is visited annually by great
numbers of tourists. The Mall also often serves as the hub for various
festivals and special events that periodically draw tremendous crowds.
In recent years, horticulturists have suspected a decline in the vigor
of elm trees planted there, trees which are considered national treasures.
They have speculated that visitors walking through the Mall may actually
be damaging the trees by compacting the soil, which can impeded root
growth.
To establish any correlation between foot traffic and the decline of
the elms, representatives of the Smithsonian asked Hugo Rogers, a USDA-ARS
researcher with the National Soil Dynamics Lab in Auburn, to do a cursory
evaluation.
"Hundreds of thousands of people visit the national Mall annually,"
he said. "But there has not been an analysis of the impact of that
traffic at the Mall."
Rogers assembled a team of scientists to look at various aspects of
the soil situation. The team did the evaluation this past summer, just
before and just following the Folk Life Festival held there in July.
Included on the team are scientists working with the USDA and with the
Alabama Agricultural Experiment Station (AAES) at Auburn University.
The researchers are: Stephen Prior, a plant physiologist with the USDA;
Brett Runion, a USDA plant pathologist; Bob Mitchell, a ecophysiologist
in the School of Forestry working with the AAES; and Wesley Wood, an
AAES soil fertility researcher in Auburn's Department of Agronomy and
Soils.
Wood noted that the soil in the Mall is a hodge-podge of soil types,
a situation that can complicate analysis. He added that tree growth
cannot be evaluated over such a short time period. Instead the researchers
took samples from 36 sites before and after the Festival. These will
be analyzed to see if any changes occurred in the soil profile of the
area following the onslaught of thousands of visitors to the Folk Life
Festival.
"Some of the things we are evaluating include soil compaction,
soil density, hydraulic conductivity, tree root growth, pathogens, potential
contamination by heavy metals and nutrition," said Wood.
"To know what the effects of this foot traffic really are, we will
have to continue sampling year after year for several years," said
Rogers. He noted that results of these initial samplings will not be
conclusive, but they will be a step toward understanding the impact
of foot traffic on plant life. And it may help horticulturists get the
jump on future problems for the elms. -30-
By:
Katie Smith
December 3, 1991
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