Biology Reference
In-Depth Information
degradation of French Polynesia's native communities and biodiversity (Meyer and
Florence 1996).
M. calvescens
was introduced as an ornamental into Hawai'i (on Oahu) in 1961;
similar to its history on Tahiti, a botanical garden was at least one site of its early
introduction (Medeiros et al. 1997). Wagner et al. (1990) noted Miconia as becom-
ing naturalized locally and cautioned about its future potential for spread. Much
stronger signals of the invasive potential of Miconia had already been received,
informally by the early 1970s (Meyer and Florence 1996) with repeated warnings
through the 1980s, based on the environmental disaster unfolding in French
Polynesia. The local press did sound an alarm as early as 1991 about the potential
damage that could be caused by Miconia (Altonn 1991 as cited in Medeiros et al.
1997), but these public alerts unfortunately did not spark a concerted search-and-
destroy campaign. Instead plants were removed on Maui, Oahu, and Hawaii begin-
ning in the mid-1990s, even as new foci of the invasion were being detected
(Medeiros et al. 1997).
Action on Maui exemplifies the consequences of not moving rapidly into an
eradication mode. For example, by May 1991 on East Maui, any response was
“still in the information-gathering stage” (Loope et al. 1992), while a coopera-
tive effort to eradicate Miconia was being developed (Gagne et al. 1991 as cited
in Loope et al. 1992). However, in all likelihood the invasion on Maui by that
time was far greater than then perceived - a consequence of a limited survey for
the invader on the island. Effective control, much less eradication, is hamstrung
without accurate information on the geographic boundaries of the invasion
(Panetta and Lawes 2005) (cf. successful campaign against
B. scoparia
in
Australia). As much more extensive reconnaissance took place, beginning in
approximately 1995, the investigators found many more foci of
Miconia
spread
across a much wider area than detected earlier (Medeiros et al. 1997,
J. Gooding, pers. comm.). A concerted plant removal effort in the last 10 years
has probably curbed further wholesale range expansion by destroying fruiting
trees in outlier populations. But large infestations, such as two populations
(400 ha and 800 ha each) on the north side of Maui near Hana remain, in addi-
tion to innumerable outliers. Although the opportunity for eradication on Maui
may not be irretrievably lost, the chances have been lowered appreciably
through a combination of inadequate early detection/rapid response, erratic
financial support and the difficult search terrain (numerous steep, isolated val-
leys with dense vegetation). Public cooperation and understanding of the threat
held by an unchecked
Miconia
invasion is, however, encouragingly high
(J. Gooding, pers. comm.).
Whether eradication is still feasible for all islands in Hawai'i is likely subject
to an island-by-island assessment and, of course, the intensity of the eradication
effort. Clearly, the cost/benefit ratio, using the fate of French Polynesia as a
worse case scenario, strongly favors a much more intensive eradication cam-
paign than has been employed for the past 10-15 years. Ironically, the current
expenditures to combat Miconia may not even be containing the invader
statewide, much less achieving eradication. On the basis of an economic model,
