TY - JOUR T1 - Effects of traffic on soil physical characteristics and vegetative resources of the national mall JF - Journal of Soil and Water Conservation SP - 389 LP - 393 VL - 48 IS - 5 AU - G.B. Runion AU - H. H. Rogers AU - C. W. Wood AU - S. A. Prior AU - R. J. Mitchell Y1 - 1993/09/01 UR - http://www.jswconline.org/content/48/5/389.abstract N2 - SURROUNDED by the Capitol, the Washington Monument, the Smithsonian Institution and other museums, the National Mall is used as a recreational area by those who live and work in the metropolitan Washington, D.C. area and is a popular picnic and relaxation spot for tourists visiting the US. capital. In addition, the Mall is the site of a variety of national celebration events, demonstrations, and marches. The National Park Service (NPS) maintains the Mall and recently has been concerned that the intensity of use threatens the sustainability of this national resource. Compaction of urban soils, in general and specifically on the National Mall, has been a concern for some time (4, 12, 13). It is noteworthy that the decision to use elm trees in this area was a fortuitous choice as elms are known to be more tolerant of poor soil aeration than many other tree species (17, 18) and should be better able to withstand higher levels of soil compaction. The NPS is particularly concerned with special event traffic which occurs when large numbers of people visit the … ER -