ordination

Human impacts in Aotearoa New Zealand have considerably damaged native ecosystems, and conservation efforts must therefore preserve remaining ecosystems and restore degraded areas. However, restoration efforts must address several challenges including species authenticity, plant survival and seedling regeneration in the presence of exotic competition, browsing mammals, and vagaries of climate. Styx Mill Conservation Reserve (SMCR), Christchurch, contains a remnant freshwater wetland in a floodplain complex where restoration activities were initiated in 2000 under a 40-year plan.

Habitat disturbance is a significant factor contributing to biodiversity decline worldwide. Amphibians are particularly vulnerable because of their specific microclimatic and microhabitat requirements. In Aotearoa New Zealand, Archey’s frogs (Leiopelma archeyi) have shown some degree of resilience to severe habitat disturbance historically. However, it is unknown how much L. archeyi populations are currently being impacted by historical and ongoing mining activities and development within their range.

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).

The vegetation of Campbell Island and its offshore islets was sampled quantitatively at 140 sites. Data from the 134 sites with more than one vascular plant species were subjected to multivariate analysis. Out of a total of 140 indigenous and widespread adventive species known from the island group, 124 vascular species were recorded; 85 non-vascular cryptogams or species aggregates play a major role in the vegetation. Up to 19 factors of the physical environment were recorded or derived for each site.