Creating and testing a geometric soil-landscape model in dry steeplands using a very low sampling density

作者：Peter D. McIntosh, I. H. Lynn, Peter D Johnstone · 发表于：Soil Research · 年份：2000 · DOI：10.1071/sr99029 · 被引用次数：24 · 研究领域：Soil Carbon and Nitrogen Dynamics、Soil Geostatistics and Mapping、Soil and Water Nutrient Dynamics

The aim of this study was to determine whether a predictive geometric soil-landscape model, potentially applicable to 400 000 ha of seasonally dry greywacke steeplands in New Zealand, could be created for 29 soil properties, using a very low soil sampling density. We postulated that in these deeply dissected steeplands which have relatively uniform geology and slope form, landscape geometry (through its effects on microclimate), rather than vegetation, geology, or slope form will control the soil pattern. To create and test the soil-landscape model we sampled the 26 000 ha Benmore Range, South Canterbury, New Zealand, in a formally stratified way so that trends of soil carbon, soil nutrients, and profile characteristics could be established for predominant slopes, at various altitudes and aspects. We used a factorial sampling system (3 land systems × 3 altitudes × 4 aspects × 2 slope positions), giving 72 sampling sites in total, and a sampling density of one site per 360 ha. Altitude and aspect had significant ( P < 0.05) effects on many topsoil characteristics, particularly those likely to be related to soil moisture status, leaching, and weathering (e.g. topsoil pH, carbon, nitrogen, and phosphate retention). For most soil properties the effect of slope position was not significant ( P > 0.05). The soil-landscape model was tested by comparing predicted and actual soil properties at a further 22 sites. Soil properties that were laboratory-determined were generally satisfact...