The effect of planting Pinus pinaster Ait. on populations of soil microarthropods and on litter decomposition at Gnangara,Western Australia

Litter decomposition rates and the population densities of soil microarthropods were measured in three Pinus pinaster stands thirty-one, twenty-three and eighteen years old, and on an area of native vegetation on sandy soil at Gnangara, W.A. Litter decomposition was faster in the soil than within the litter layer and was slowest at the litter surface. Decomposition was rapid in cool wet seasons and slow in hot, dry summers. Microarthropod population densities were similar on all sites (77–100 × 10³/m²) but species diversity was greatest under native vegetation and least under the youngest pine stand. The impoverished soil micro-fauna of the pine stands is unable to decompose pine or sclerophyll litter as fast as the full complement of soil microfauna in native vegetation.