Whereas rare, special and elusive fauna are understandably in the limelight at Orokonui, the plant life creates habitat in the ecosanctuary - food, fibre, shelter as well as roosting and nesting sites.
Soon after the fence was built and the predators - no fewer than 12 species - were removed, a resurgence in plant life could be seen. This natural regeneration has been aided by the planting by a small army of volunteers of more than 10,000 native plants.
The ecosanctuary spans an elevational gradient from 60m above sea level to just over 360m above sea level at the highest part on the slopes of Mopanui.
The wide elevational range incorporates a gradient from remnants of dry podocarp forest with matai, lowland totara, kahikatea, and kowhai at low elevation in Marie's Block (gifted by Graham and Marie Bennett), to montane podocarp/broadleaved forest dominated by rimu, miro, pokaka, and Hall's totara on the upper slopes of the ecosanctuary.
There is even a hint of cloud forest, with a few examples of pahautea (a native cedar) emerging from the upper forest.
More than 250 plant species have been recorded within the ecosanctuary, and a healthy 175 of these (70%) are native to the site.
The exotic species are mainly grasses and herbs found in open sites, and exotic trees including the mountain ash (Eucalyptus regnans) and radiata pine stands at the base of the valley.
A feature of the native vegetation is the presence within the ecosanctuary of all of the native emergent tree species that are found in the Dunedin area.
It is possible the ecosanctuary is the only place in Dunedin where mature individuals of lowland totara, Hall's totara, rimu, miro, matai, kahikatea, pokaka, and pahautea can be found at the same site. One at-risk plant species occurs naturally within the ecosanctuary, a naturally uncommon hooked sedge, Uncinia purpurata.
In addition, a range of nationally threatened and at-risk plant species have been planted in a rare plants garden maintained by volunteers Graeme and Judy Cook.
This garden has been formed to showcase some of the threatened and uncommon plant species found in Otago, including the tree daisies Olearia hectorii and O. fragrantissima, a nationally threatened hooked sedge (Uncinia strictissima), inland beauties such as the showy East Otago endemic Gingidia grisea, and coastal species such as pikao and Euphorbia glauca. It is a great place to see these species up close.
The ecosanctuary is also host to two translocations of threatened plant species, the nationally vulnerable grass Simplicia laxa, and nationally endangered sedge Carex inopinata. Both species are found beneath rock outcrops in Otago, but we suspect that historically they would have been found in forest where the canopy was not too thick.
A trial is under way to establish these species beneath a light kanuka canopy in the upper part of the ecosanctuary, using plants propagated by Valerie Fay.
Results to date have shown good survival and growth and provided a good indication of the optimal microhabitats for these species.
A network of 52 permanent plots was set up on conservation land within the ecosanctuary prior to pest eradication.
Among other measurements, seedlings were counted in each of these plots - about 22,000 in total - and if funding can be obtained for a re-survey of plots, it will be interesting to see if the removal of pests such as possums and rodents has resulted in an increase in native regeneration.
High densities of wineberry on track margins suggest that regeneration may well have been limited by possums and other browsing animals in the past.
• Dr Kelvin Lloyd is a plant ecologist and a trustee of the Orokonui project. The Wild Ways column runs on the first Saturday of the month.
