Soil variations along a climatic gradient in an Andean agro-ecosystem

Soil development along mountainous slopes is often affected by pronounced altitudinal variations of climatic parameters. This research was conducted to study the effects of climate-induced pedological differences on the properties of agricultural soils in an agro-ecosystem that stretches from 2400 to 3300 m above sea level in the Andes of northern Ecuador. Example profiles of the two major soil types were pedologically characterized, a number of soil fertility parameters were analyzed for 100 agricultural fields, and runoff-erosion behaviour was tested in rainfall simulation experiments on 15 agricultural topsoils. It turned out that the climate-dependent soil development significantly affects the altitudinal distribution of many important soil properties, such as texture, organic matter content, pH, cation exchange capacity, phosphate sorption and phosphorus availability, as well as susceptibility/resistance to runoff generation and soil erosion. The present altitudinal patterns are likely to be altered by future climate change in the region.