Biology Reference
In-Depth Information
eastern Washington (>1,500 km from the locales where it was first detected, Dewey
1894), so as to detect and destroy all Russian thistle.
These late nineteenth century attempts at eradication, even locally, failed, con-
sequences of the feeble methods (usually excavation and burning of the plants) and
total lack of a discernible strategy for destroying many plants across a growing new
range. In fairness to these early would-be plant eradicators, the ease with which
Russian thistle was carried throughout the US along the rail lines plus its broad
ecological amplitude and abundant seed production would have presented difficult
challenges for eradication even today.
Salsola iberica
remains widespread and
locally abundant in the western half of the US (Whitson et al. 1996), despite the
short-lived campaign against it in the 1890s.
Eichhornia crassipes
(water hyacinth) arrived in the US almost contemporane-
ously with Russian thistle and also attracted early federal interest in eradication.
The circumstances surrounding the entry of this subtropical/tropical South America
macrophyte have been repeatedly reported (Klorer 1909; Barrett 1989): it likely
first arrived as a deliberate introduction at the World's Industrial and Cotton
Centennial Exposition in New Orleans in 1884, and many attendees reputedly
returned home with cuttings of this showy aquatic plant (Klorer 1909). Within a
decade the plant had escaped repeatedly into rivers in the southern US, most nota-
bly in Louisiana and Florida (Webber 1897; Klorer 1909). Water hyacinth produces
dense, floating vegetative mats that render boat traffic difficult to impossible. Its
invasion triggers a cascade of environmental changes that affect the native biota,
and it has also been linked to serving as a habitat for the water-residing vectors of
human parasites (Barrett 1989).
Here again, tools available more than 100 years ago for combating this invader
were meager, although there was clear public support for eradicating, not simply
reducing water hyacinth (Klorer 1909). Control consisted of mechanical dredging of
the vegetative mats. But these mats soon regrew, thanks to the plant's high productiv-
ity. Even then it was known that natural enemies could have a devastating effect on
alien plants, Webber (1897) suggested that practical hope of destroying water hya-
cinth could lie with detecting such a parasite in water hyacinth's native range.
Despite these setbacks, these early eradication advocates had recognized a key
ingredient to any eradication effort - public cooperation (Dewey 1894; Klorer 1909).
Unless the public supported the endeavor, eradication could not be achieved.
3.3 The Campaign Against
Berberis vulgaris
3.3.1 Barberry Eradication on a Continental Scale
Given the failure of even local extermination, much less eradication of Russian
thistle and water hyacinth, the likelihood that the US would embark on a continent-
wide eradication campaign early in the twentieth century would seem nil. Yet just
