ILMAX - Managing Experience Knowledge of the river Ilm

The river Ilm (in Thuringia in Germany) is 130 km long with a catchment area of 1043 square km and a mean-flow discharge at the mouth of 5.9 m³ s^-1. The region at the headwater is 75% woodland but the proportion used for agriculture increases along the stream, reaching 95% in the mouth area. The rainfall decreases from the hilly spring region, with 1200 mm a^-1, down to 550 mm a^-1 in the lowland mouth region. In the catchment there are approximately 180,000 residents, living in rather small villages and settlements.
		After the political reunification of Germany in 1990, many industrial production sites were shut down and modern waste-water treatment plants were built. This improved the water quality rapidly and the regeneration of the aquatic ecosystem has been investigated since then.
Regeneration of an Ecosystem
Many ecosystem communities are affected by activities of humans or have even been degraded for many years. The types of disturbance range from mechanical influences to chemical contamination of the ecosystem. The appearance of the adapted community differs profoundly from the natural one.
		When, after many years, the degradation is ameliorated, the community will respond to this change with a succession. This process is not influenced by humans and is therefore called regeneration of the ecosystem. The subject of the ecological investigation project mentioned here is whether the ecosystem can attain its natural state again and how the regeneration can be influenced.