vegetation

Feral goats (Capra aegagrus hircus) were eradicated from Auckland Island, a National Nature Reserve and World Heritage site, between 1989 and 1991. Goats had established on the main Auckland Island following several releases in the 19th century. The population, amongst the most southerly ever recorded, was restricted to the northernmost areas of the island, with environmental conditions appearing unfavourable for southward spread, and the population stable at c. 100 individuals during scientific studies in the 1970s and 1980s.

Feral sheep were eradicated from Campbell Island (Motu Ihupuku) – a National Reserve, Nature Reserve and UNESCO World Heritage Site in subantarctic New Zealand – in three distinct stages from 1970 to 1991. The sheep derived from farming attempts on the island, starting in 1895 and abandoned by 1931. The potential genetic and commercial value of the isolated sheep population meant proposed eradication plans were not wholly supported.

Relying solely on public conservation lands for habitat provision will be inadequate for achieving national conservation goals. Production landscapes in New Zealand make up 60% of the land area and contain potential conservation habitat; however, the amount of native vegetation they contain is poorly known. While there have been previous assessments of native vegetation cover in New Zealand, no study has undertaken a national-scale assessment of multiple native vegetation cover types on different land uses. This absence limits the potential to manage production landscapes for conservation.

Black-fronted terns/tarapirohe (Chlidonias albostriatus) are highly adapted to nesting on clear shingle areas of the braided rivers in the South Island, New Zealand. They are nationally and internationally classified as endangered. Ongoing threats, primarily an interaction of predation and habitat degradation or loss, have resulted in population decline. Conservation management in the form of control of introduced mammalian predators has proven partially successful.

[First paragraph(s)...]
Lake Te Anau and Lake Manapouri, the two largest lakes in Fiordland National Park, are connected by the Upper Waiau River (Fig. 1). They have been the centre of a decade-long controversy involving the harnessing of their large hydro-electric potential—primarily to smelt bauxite brought from Weipa in Queensland, Australia to the smelter at Bluff.

Changes in the vegetation of Flat Top Hill, a highly modified conservation area in semi;arid Central Otago, New Zealand, are described four years after the cessation of sheep and rabbit grazing. Unusually moist weather conditions coincide with the four-year period of change in response to the cessation of grazing. Between 1993 and 1997, the average richness and diversity (H') of species increased, and the average proportion of native species decreased significantly.

Despite the importance of forest edges in ecology, only one study has previously been carried out in New Zealand on the modification of climate across forest edges. We measured light exposure, wind speed, air and soil temperature, and vapour pressure deficit (VPD) perpendicular to a north-south aligned, mature, edge of native broadleaf rainforest adjoining grazed pasture. At a point 80 m into the forest from the edge, light was only c. 0.7% and wind speed c. 20% of that in the open, and there was much less diurnal fluctuation in soil temperature, air temperature and VPD.

Fragments of kahikatea (Dacrycarpus dacrydioides) forest provide a major opportunity for conservation of indigenous biodiversity in the heavily deforested landscape of the Waikato Basin, New Zealand. However, there is little documented information on what indigenous fauna survives in these fragments.

We analysed biomass allocation of Pleurophyllum speciosum (Asteraceae) and Anisotome latifolia (Apiaceae) to explore the 'megaherb' phenomenon, the apparent importance of large-leaved, colourful forbs on southern oceanic offshore islands. The two species had similar shoot dry weights, with high leaf:stem ratios. Even within the megaherb form there are differences in shoot allocations, with Pleurophyllum investing more biomass in rhizome than foliage, compared with Anisotome.

The effects of environment and management on the composition of short-tussock grasslands and the abundance of the invasive weed Hieracium pilosella were investigated in two small catchments. Species composition and site factors were recorded on a total of 182 plots and the management history of each catchment was reviewed. H. pilosella was present on >80% of all plots, but was at an early stage of invasion in one catchment (<5% cover) and dominant in the other (25% cover).