VEGETATION-ENVIRONMENT RELATIONSHIPS AT WAIPOUA FOREST, NORTHLAND, NEW-ZEALAND

The Waipoua Forest Sanctuary and Waipoua Kauri Management and Research Area together form a large (approx. 13 000 ha), continuous protected natural area on the west coast of Northland, New Zealand. This reserve complex contains comparatively unmodified examples of Northland fores t including large areas dominated by the tall conifer kauri (Agathis a ustralis). It also includes substantial areas of ''heathland'' scrub d ominated by manuka (Leptospermum scoparium) and Dracophyllum lessonian um. Landscape-scale vegetation patterns are described from 294 vegetat ion samples located in both forest and scrub, and their relationships with the environment are examined using indirect gradient analysis tec hniques. Results suggest that vegetation patterns in both forest and s crub are determined largely by topographically linked variation in soi l fertility and soil moisture and by altitudinally determined temperat ure and precipitation gradients. Conifers tend to occur on the inferti le soils often found on ridges, whereas broadleaved species, though no t excluded from ridge-top sites, dominate on the more fertile lower sl opes and in gullies.