Biology Reference
In-Depth Information
such an undertaking was initiated in 1918 across a 13-state region that eventually
encompassed six more states. The target was
Berberis vulgaris
, the European bar-
berry (Kempton 1921). Although widely known as a common escapee from cultiva-
tion - it had been used since colonial times as a source of fruit for jams, wood for
axe handles, and an ornamental hedge (Mack 2003) - these uses for the shrub paled
by comparison to the damage it wrought as the alternate host for the stem rust
(
Puccinia graminis)
of cereals, such as wheat and oats. The scientific link between
European barberry, cereals, and
P. graminis
had been conclusively demonstrated by
the end of the nineteenth century (Hutton 1927). Unfortunately by then, 300 years
of the shrub's dissemination and naturalization meant that
B. vulgaris
had become
a common resident in towns and farms throughout the northern half of the country
(Mack 2003 and references therein). During its history in the US (as well as its
much longer association with cereal crops in its native western European range),
barberry had contributed to chronic devastation of wheat. These losses reached a
crisis for the US by 1916, when it was estimated that > 180 × 10
6
bushels of wheat
had been lost to stem rust (Kempton 1921). Given that these losses would likely
grow in the future and coupled with a severe worldwide demand for wheat, the US
acted on an unprecedented scale. Since no means was known to directly attack the
stem rust fungus itself, the bold decision was made to break its life cycle by totally
eradicating its alternate host,
B. vulgaris
(Kempton 1921).
The US track record of combating invasive plants as well as the scale of the pro-
posed undertaking likely gave architects of this eradication campaign some basis
for hesitation: not only was the shrub abundantly widespread, but also was still sold
widely by nurseries, and its fruits were dispersed locally by birds (Meier 1933).
These would-be eradicators did however have reason for optimism: much of west-
ern Europe had already been rendered free of barberry in the early twentieth cen-
tury through eradication campaigns in England, Scotland, The Netherlands,
Germany, and especially Denmark. Within 10 years of the passage of a national law
prohibiting barberry, Denmark had almost totally eradicated the shrub. Even though
the scale of the project contemplated in the US dwarfed the eradication projects in
Europe, the US planners drew considerable confidence from the European outcome
(Stakman 1923).
Two early steps in the US eradication strategy proved essential to success. In 1919,
Federal Quarantine Regulation No. 38 was enacted to prohibit the interstate transport
of barberry (Meier 1933), thus eliminating an important source of reinfestation. And
from the outset, the federal government effectively proclaimed the goals and public
benefits of Regulation 38 through posters, fliers, and local talks. Even the new medium
of motion picture films was employed to reach the citizenry (Kempton 1921).
The US Barberry Eradication Program operated from 1918 to 1978 and eventu-
ally involved the thorough survey of
all
land holdings in or near agriculture in the
initial 13-state area as well as much of the terrain in those states that supported for-
ests (Michigan, Minnesota, Montana, Wisconsin) (Fig. 3.1). Lack of modern tools
of surveillance and land inspection (remote sensing, aerial photography, GIS-based
systems) was probably an advantage: the investigators instead relied totally on
ground surveys (termed in the parlance of the day, “foot-scouting') to detect barberry
