The quantity and nature of the forest floor and topsoil under some indigenous forests and nearby areas converted toPinus radiataplantations in South Island New Zealand

Abstract

In a comparative study, the quantity of accumulated organic matter in, and the nutrient composition of the forest floor and topsoil (0-20 cm) of indigenous (beech or podocarp) forests and nearby Pinus radiata plantations in five widely separated forest sites in the South Island of New Zealand were measured. Total mass of forest floors in native and radiata plantation stands ranged from 25 to 464 and 9 to 79 t/ha, respectively. Native forest stands apparently accumulated larger amounts than nearby radiata pine stands, especially in the West Coast forests. In exotic plantations, the nett accumulation was modified by management practices such as burning, during the process of converting native forests to pine plantations, and stand thinning.Except in Nelson forests, forest floors in native stands had larger contents of carbon and nutrients than those of nearby radiata pine sites. No consistent differences were found in carbon and nutrient concentrations in topsoils of native and exotic forests except in the 9-year-old radiata pine stand in the Hochstetter forest, where they were lower than those under the native forest. However, levels of exchangeable cations and Bray-P in topsoils under radiata pine stands were higher than those of native stands. Concentrations of etherextractable components (lipids), water-soluble carbohydrates and polyphenols in the forest floors under native forest were generally higher than those under radiata pine stands. Consistent differences between concentrations of lipid components and polyphenols in the topsoil under native and exotic forest were not found.

Conversion of a natural broad-leafed evergreen forest into pure plantation forests in a subtropical area: Effects on carbon storage

“…In the top 20 cm of soil, the carbon concentration was higher in the NF and lower in the plantations, suggesting that conversion of native forest and subsequent slashing and burning was accompanied by some carbon loss from the topsoil. Similar results have been reported in a variety of studies [15,16,34,41,42].…”

Effects of clearfell logging and clearfell logging and burning of aNothofagusforest on soil nutrient dynamics in South Island, New Zealand — changes in forest floor organic matter and nutrient status

“…Consideration must be given to the bulk density of the material. No measurements of litter bulk density were made in the present study, but Goh & Heng (1987) reported the average bulk, density of mixed beech litter to be approximately 0.06 g/era 3. Using this value the two methods gave reasonably similar estimates overall for the loss of organic matter during burning.…”

“…Weight of the forest floor at three biomass sampling periods (Table 3) shows that results obtained were in the medium range of forest floor weights reported for other West Coast beech forests (Goh & Heng 1987). There were few significant differences in the weights between different treatments.…”

“…The total carbon (C) was determined only for humus samples by combusting the sample at 900~ in a stream of oxygen in a Thomas Micro-Carbon Hydrogen Analyzer (Goh & Heng 1987). Biomass samples for determining total N, P, Ca, Mg, and K were digested according to the wet oxidation method (Parkinson & Allen 1975).…”

“…Water-soluble polyphenols were extracted by hot water (Allen et al 1974) and determined using FolinCiocalteau phenol reagent at 725 nm (Goh & Heng 1987). The humus pH was measured with a combination glass electrode using distilled water or 0.1M CaCI2 with the humus:extractant ratio of 1:10 (Blakemore et al 1977).…”