Biology Reference
In-Depth Information
may be an order of magnitude less, although they offer no data or case histories to
support their assertion.
Simberloff (2002, 2003a, b) as well as Mack and Lonsdale (2002) and Mack and
Foster (2004) have offered counterpoint to these somewhat pessimistic (or at least
conservative) views on the feasibility of plant eradications. They cite a growing
array of studies that demonstrate eradication, or at least containment to the cusp of
eradication, for a taxonomically diverse array of plants in terrestrial, freshwater,
and even brackish environments and in new ranges > 1,000 ha. We dissect here case
histories for which adequate information is available on the tactics and strategies
employed (sensu Moody and Mack 1988) as we seek generalities that consistently
distinguish successful from failed eradication efforts.
3.2 Early Attempts at Eradication
The attraction of being permanently rid of a problem is basic to human values; it is
not surprising then that attempts at eradicating an invasive plant, as opposed to
controlling its damage, or even enduring its on-going damage, have a long history.
Deliberate, if poorly documented, attempts to clean grain of extraneous and poten-
tially weedy species stretch back into antiquity (Leviticus 19:19). We have chosen
to explore the history of alien plant eradication, in terms of known deliberate action,
only from the late nineteenth century onward, although there are likely older, scat-
tered attempts at eradication.
As agriculture in the US grew both in geographic extent and the collective value
of agricultural products, the US Department of Agriculture (U.S.D.A.) by the late
nineteenth century began to systematically report the spread of destructive alien
plants (Dewey 1897). The U.S.D.A. was alarmed to see that in addition to a well
known list of alien plants combated by farmers for > 200 years (Mack 2003), new
invaders were appearing. One of the earliest to attract federal attention was
Salsola
iberica
(Russian thistle), a native of western and central Asia, which reputedly
arrived in the US in the mid-nineteenth century as a seed contaminant.
Salsola
iberica
is a weed in cereal crops, and it rapidly began appearing in cereal fields in
the Northern Great Plains. Within two decades after its putative entry near Scotland,
South Dakota, it had become established at numerous locales in Iowa, Minnesota,
South Dakota, Nebraska, and North Dakota (Dewey 1894).
Although Russian thistle already occurred in five-states by 1892, the initial fed-
eral goal was its eradication because it provides fuel for wildfires in addition to
competition for cereal crops. Russian thistle's still local distribution (e.g. cereal
fields, along railroad-right-of ways) probably contributed to the guarded optimism
that eradication, rather than control, was possible, and various “remedies” were
proposed for curbing its spread and persistence (Dewey 1894). Furthermore, action
was taken to eliminate new foci of the invasion. For example, Russian thistle rap-
idly rode the rails and soon appeared in the western US. Piper (1894a, b) waged a
determined but short-lived campaign in all towns and their connecting rail-lines in
