Mixed decidious forest

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The plantation is located in the hindmost half of the photograph.

Objective

A safe and simple method for the reforestation of woods is to leave them to natural succession. This natural reforestation, however, takes much longer than the legally determined time frame allows for. Therefore, the area to be restorated was sown with a mix of various tree and shrub species in cooperation with the local forest authority.

Context

Layers of the upper white Jurassic are being extracted in several quarries in the area of Blaubeuren. The Schelklingen cement plant obtains its raw materials from the Vohenbronnen quarry located near-by. Since the proportion of forests in this re¬gion is high, the extraction of minerals inevitably affects large areas of the forests, which are predominantly copper beech forests. Permission for the conversion of the forest for the purpose of extracting minerals is only granted for a limited time. This means that a cleared area must be reforested in due form until a certain point in time. As the humus-rich topsoil is limited in thickness and cannot sufficiently cover the locations, the natural soil structure is replaced by raw soil.

Solutions

Although the composition of the seed does not exactly allow for the monitoring of the composi¬tion of the targeted forest, the resulting wood stands are very well adapted to the lo¬cation. This is due to the fact that not all selected species and plant individuals ger¬minate and some do not thrive. The sowing and the different locational conditions also result in highly species-rich forest stands featuring a multitude of structures. It is essential to ensure that the seed mix contains an adequate share of quickly germinating spe¬cies which can also tolerate extreme locational conditions. The following measures have been implemented:

Covering of the parent with about 50 cm of non-compressed subsoil (clay, marl) without topsoil,
Buying native seeds from local forests (provenance) with seven tree species and six shrub species,
Preparation of the seeds according to the demands of the respective wood spe¬cies, for instance by cold/wet treatment. This is especially important when so¬wing in spring,
The seed was sown by hand and broadly distributed without a cover sheet, using an amount of 80-100 kg per hectare.

Results

The project demonstrates not only the successful restoration of the quarry adequate for the habitat, but is also a destination for numerous tours organised for NGOs, representatives of the administration, and the general public. By showing the successfully sown plantations it can be demonstrated that even forests can successfully be re-established.