Soil as component of landscapes and ecosystems

Landscape is a three dimensional section of the Earth’s surface with specific pattern of topography, rocks, soil, water and flora and fauna. E. Schlichting (1923-1988) proposed that soils in different positions in the landscape (or catena) exchange materials through transport processes which could be compared to the transfer processes between horizons in a soil profile (Schlichting, 1964). Landscape pedology is an emerging science focusing on soil as part of the landscape particularly on the variability of soil properties at the landscape scale (1-10km) (Sommer, 2006).

Ecosystem is a natural system consisting of a biosystem (community of organisms) interacting with the geosystem (its physical environment). The geosystem includes soil, water, relief, and climate. Soil is a major component of geosystem in that it provides nutrients, water and living space to the organisms in the ecosystem. Two emerging fields of science are ecopedology and geoecology. The former focuses on the ecological role of soil while the latter on the geosystem (soil, rock, water) component of ecosystems.

The two major types of ecosystems are the terrestrial ecosystem (or ecosystem on land) and aquatic ecosystems. In the humid tropics, a common landscape consists of the following terrestrial ecosystem types: forest, agricultural (agro-ecosystem), wetland, urban and mangrove. All the terrestrial ecosystem types are linked by the soil. The transfer of water, nutrients and soil material occurs largely in the soil. The soil also determines to a great extent the biological system that develops in each terrestrial ecosystem type. Further, degradation of the soil in the terrestrial ecosystem also affects the health of the aquatic ecosystem nearby. For instance, in many places in the Philippines, severe soil erosion in the uplands causes heavy siltation of the nearby marine area and thus affecting the survival of marine organisms.

References

Schlichting, E. 1964. Einführung in die Bodenkunde. Verlag Paul Parey, Hamburg, 93pp.

Sommer M. 2006. Influence of soil pattern on matter transport in and from terrestrial biogeosystems- a new concept for landscape pedology. Geoderma 133: 107-123.