How does soil differ across Earth's biomes: Great plains, coastal wetlands, deserts

According to SSSA's September monthly leader, Tom Fox, each biome has soils with characteristics unique to it. Fox is a professor at Virginia Tech University.

• Great Plains

Prairie soils are rich, soft and deep. They form under grasslands where the climate has warm summers and cold winters. When the grassland plants die back in winter, their leaves and roots remain. This is good, because the debris acts like mulch on a garden. It adds organic matter, which keeps the soil fertile, and helps the Plains states grow much of the United States' grain crops.

• Coastal Wetlands

Wetland soils often form in flat, low-lying areas or in depressions where water from rain or snow collects. The soil stays wet because it does not drain well. Wetlands are important habitats for wildlife. They protect against floods by soaking up water and holding it like a sponge. When wetlands become dry, they shrink, making them unstable platforms to build on. We need these wetlands to prevent flooding in rivers and streams.

All wetland soils share common colors and color patterns. The surface layer is often black because organic material accumulates there. The subsoil is grey with bright orange and reds where iron has oxidized or rusted. Some very wet soils may be blue, green, or purple.

• Great American Deserts

Not all deserts are sandy, but they all are dry. They form in areas that receive little rainfall or snow melt…or where the water evaporates more quickly than it can be replenished. The lack of moisture means that minerals are trapped inside the soil particles. This means there are very few minerals to support plant growth. However, we know that there are still organisms that live in desert soils, such as microbes, lichens, ants, rodents and reptiles. Desert soils are typically light in color because there is little vegetation to add organic material.

For more information, visit http://soilsmatter.wordpress.com.