HILLSLOPE SOIL LANDSCAPES
Improving the accuracy of rangeland soil maps will rely on remote sensing, and digital soil mapping techniques, with the prospect of machine learning of the existing soil data as well. Challenges to improving rangeland soil mapping include identifying the scale of soil variability and characterizing subsoil properties remotely. Identifying the major drivers of soil variability and their proxies will aid in the prediction of soil landscape patterns.
We do have some conceptual models which can aid in identifying in particularly the scale and patterns of soil variability on hillslopes such as weathering limited /transport limited hillslopes, soil catenary relations and the concept of spatial and temporally controlled soil landscapes.
Spatially controlled soil landscapes are those where the soils are sufficiently stable that slope orientation slope position, and lithology exert a control on the pattern of soil variability. Temporally controlled soil landscapes are those where the main driver for soil variability is the age of the soil, common in areas with high erosion and deposition rates.
Examples of two types of soil landscapes are discussed, a geomorphically active drainage in the Southern Alps of NZ, Camp Creek, and two drainages in the foothills of the Ladrone Mts in the Rio Grande Rift.