Edaphic zoning and species-site matching to assist re-vegetation of indigenous species at the Styx Mill Reserve
Degree GrantorUniversity of Canterbury
Degree NameBachelor of Forestry Science
The Styx Mill Reserve is located in Belfast, Christchurch and is managed by the Christchurch City Council. Who aim to re-establish indigenous vegetation to large proportions of the area. These efforts have been successful in some sections of the Reserve; but large areas of the Reserve remain in grass and other weeds. The purpose of this investigation was to evaluate the presence of 5 hypothesised edaphic1 zones in a 10 ha study area, with a future aim of matching establishment practices to these edaphic sites. Findings indicated that all zones have significantly different vegetation and soil characteristics. Consequentially methods of native re-vegetation must be different in each zone if successful re-establishment of native species is to occur. Based on confirmed edaphic zones and client input, a site matched management plan and species list for one zone was developed. This aimed to increase the health and survival rates of plantings. Site modification followed techniques used at sites with similar conditions that have had successes in establishing woody vegetation. The effect of hydrogel on heath and survival levels was also trialled. To assess species suitability, five species were selected based on their abilities to survive the site conditions. Due to a combination of frost damage and ungulate browse, only totara survived and demonstrated good health scores. The frost factor is difficult to mitigate, hence species affected severely by frost are not recommended. The browse issue is easier to mitigate and it is felt that the two species heavily browsed, but not frosted are likely to be suitable. This resulted in ribbonwood, totara and kōhūhū being recommended. The time period did not allow assessment of the hydrogel treatment. Insufficient trial numbers exist to continue trials assessing future growth and survival rates over a longer time scale.