environmental factors

Relationships between composition of secondary vegetation and environment were studied in central North Island, New Zealand. A classification procedure was used to identify broad compositional groups which included forest, broadleaved scrub, shrub-fernland, sclerophyllous scrub and shrubland, and tussock-shrubland. Generalised additive models (GAMs) were used to examine relationships between species' distributions and mean annual temperature and rainfall, stand age, distance from intact forest, slope, topography, and drainage.

Soil temperature, soil moisture and soil fertility were determined empirically at 63 predominantly hill sites in the South Island, New Zealand. Soil temperatures were measured at a depth of 0.5 m in four seasons and gave a standard deviation of mean annual temperature between sites of 2.2-degrees-C. Soil moisture levels, as available water in a 0-0.5 m profile, measured seasonally, gave a standard deviation between sites of 49 mm water.