Wetlands are very sensitive ecosystems, functioning as habitat for many organisms. Protection and regeneration of wetlands are of great importance in ecological research and in nature conservation. A great amount of research has been done on the hydrology, plants and animals in wetlands. Knowledge on soil organisms and soil ecological processes of wetlands is still lacking. This knowledge is highly needed for landscape planning purposes or climate change predictions. For climate change, trace gas emissions from wetlands are of great interest. The authors provide an overview of state-of-the-art on soil ecology of wetlands. The book is divided in the following main chapters: "Wetlands as habitats for soil organisms", "Soil ecological processes in fens and floodplains", "Carbon and nitrogen dynamics in soils with different water regimes" and "Trace gas emissions".