Cc. Ogle et al., Impact of an exotic vine Clematis vitalba (F. Ranunculaceae) and of control measures on plant biodiversity in indigenous forest, Taihape, New Zealand, AUSTRAL EC, 25(5), 2000, pp. 539-551
The exotic vine, Clematis vitalba L. (F. Ranunculaceae), has been in forest
reserves around Taihape in the Rangitikei Ecological Region of the central
North Island, New Zealand, for about 70 years. Before this weed was abunda
nt, Taihape forests were rich in species of indigenous vascular plants, esp
ecially woody species. Clematis vitalba and its control are contributing to
a loss of forest structure and of indigenous biodiversity at the ecosystem
and species levels, to a lack of recruitment of indigenous species, to an
influx of other weeds and to changes in growth forms of indigenous shrubs.
Species that have disappeared or become uncommon in forest with C. vitalba
tend to be those that are nationally threatened or uncommon, have restricte
d distributions or are biogeographically significant. Current control of C.
vitalba in the Taihape forest is piecemeal and long-term. It is based on m
echanical and chemical methods, followed by grazing with sheep to prevent r
egeneration. Recommendations are made for rapid removal of C. vitalba from
all untreated parts of the reserve, followed by manual control or spot-spra
ying, permanent removal of sheep, control of other serious weeds and implem
entation of a restoration programme.