PARENT SESSION
Oral Session # 37: Invasive Species III: Grasses and Shrubs.
Presiding: C Lortie
Tuesday, August 5. 1:30 PM to 5:00 PM, SITCC Meeting Room 205.
The Barberry Eradication Program in Whitman County, Washington: A reassessment.
Foster, Sara*,1, Mack, Richard1, Black, R. Alan1, 1 Washington State University, Pullman, WA
ABSTRACT- The eradication of an invasive alien species, i.e., the total destruction of all individuals at least below the level of detection, remains the most desirable but a seldom attained goal in combating biological invasions. Eradication usually is possible only with small populations within well-defined boundaries. However, the most ambitious alien plant removal campaign ever undertaken, the Barberry Eradication Program, sought to extirpate Berberis vulgaris, the alternate host for Puccinia graminis (stem rust), across much of the northern U.S. In Whitman County, Washington, Barberry removal was both thorough and apparently exhaustive, as recorded in the Program's exceptionally detailed field survey records dating from 1944 until 1978. Eradication teams searched the surroundings of all buildings of hundreds of farms and wood-lots in the county, seeking to destroy all barberry, regardless of size or reproductive state. Barberries were initially destroyed with applications of salt, kerosene, and later with ammonium sulfamate, 2,4-D and 2,4,5-T. The Program ultimately destroyed 48,673 barberry plants on 1,373 properties in the county. Relying on the original field survey records, in 2002-2003 we re-visited 100 sites that had supported barberry as recently as 1978. We detected only eight shrubs at four sites, representing a remarkably low level of occurrence 25 years after cessation of the removal program for an invasive species that was once widespread and abundant in the county. Virtually total eradication of a widespread plant invader can be attained, provided a straightforward protocol is scrupulously followed: exhaustive and comprehensive field surveys, rapid destruction of all plants upon their detection, and long-term, repeated searches for remaining or newly emergent plants.
Key words: Puccinia graminis, Berberis vulgaris, eradication, non-native