New Zealand Ultramafics

摘要: Ultramafic rocks comprise less than 0.1% of the New Zealand land surface but their occurrence in areas contrasting climate and glacial history has produced a wide range plant habitats. Compared with other soils, ultramafic ranging from deeply weathered laterites to youthful skeletal regoliths, have low concentrations most major nutrients, Mg/Ca quotient, high nickel, chromium cobalt, pH. vegetation, while often strikingly different that on adjoining rock types, close floristic physiognomic similarities communities edaphically extreme soils. Forest soils is restricted lowland montane sites higher rainfall, drier an open mixed shrubland isolated stunted trees appears be maximum vegetation development. With increasing elevation declining soil conditions, becomes more open, sparse greater proportion low-growing, microphyllous shrubs several small grasses. Most families genera representatives soil. At present 34 taxa are considered endemics distributions limited outcrops which escaped direct effects Pleistocene glaciations. Studies ecotypic differentiation, element accumulation species response amendment suggest adopt diverse strategies achieve tolerance.