Influence of environmental conditions and some soil chemical properties on the carbon and nitrogen contents of some tropical Australian rainforest soils

Abstract

Concentrations of carbon, total nitrogen, total phosphorus, soil pH, the sum of the exchangeable basic cations, clay and dithionite-extractable iron were examined in the surface soils of 72 rainforest sites from north-eastern tropical Queensland. Soils derived from basalt had higher levels of most of the above properties than those formed on other parent materials. Differences between the carbon status of soils formed from basalt and those formed from other parent materials may be related to the higher free iron levels and phosphorus status of the former group. Excluding the soils of basalt origin, both carbon and nitrogen are positively related to clay content. In contrast, within the soils of basaltic origin, carbon concentrations are negatively related to clay contents through interactions with free iron oxides. Separate univariate regression relationships were established between carbon and nitrogen concentrations and site temperature and precipitation for soils derived from basaltic and combined granitic and acid volcanic parent materials. Coefficients relating both nitrogen and carbon to temperature differed between these groupings. The importance of topography in controlling carbon levels is demonstrated in soils that are poorly drained or formed on ridges, while the importance of soil age is demonstrated by a juvenile soil formed on weakly weathered basalt.

Influence of Environmental Conditions on Carbon and Nitrogen Content in Serbian Rendzina Soils

“…Decarbonated Rendzinas have greatest content of C and N in southeast and central Serbia, while the amount of nitrogen in humus is the greatest in west and central Serbia. Similar inconsistent results have been reported in other regions [21,22].…”

Fertility and acidity status of latossolos (oxisols) under pasture in the Brazilian Cerrado

“…The results of this study corroborate those presented by Zinn et al (2005), who suggested that the sum of silt and clay levels may be used as an indication of C stocks in the soils of the Cerrado region. Other authors have also noted a positive correlation between levels of organic carbon and clay in soil (Schimel et al 1985, Spain 1990, attributing this result to the fact that the absorption of organic molecules at clay surfaces provides a mechanism for stabilization and protection against microbial attack (Ladd et al 1996).…”

Effects of land use, climate, topography and soil properties on regional soil organic carbon and total nitrogen in the Upstream Watershed of Miyun Reservoir, North China

“…In general, SOC and TN increase with decreasing temperature and increasing precipitation (Burke et al, 1989;Miller et al, 2004), but there have been some notable exceptions. For example, SOC decreased with decreasing temperature in a mountainous forested region of Western Oregon (Homann et al, 1995) and with increasing precipitation in Australian tropical rainforests (Spain, 1990). Topographical factors, such as elevation, slope and aspect, influence SOM levels by controlling soil water balance and thus plant litter production and decomposition, as well as soil erosion and geologic deposition processes (Birkeland, 1984).…”