Auswirkungen langfristiger Immissionen eines Kaliwerkes auf Boden und Vegetation

1996

S. 39-45

12 Lit. Ang.

Unselbständiges Werk

200057066

The forest areas of the Forest Office Ziegelroda, Forest District Wendelstein, had been exposed to ash. HCl, SO2, Cl2 and dust of salts by the Rossleben Potassium Plant from 1907 to 1991. In the vicinity of the plant the extent of the damage done to young and old growth stock led to a denudation of an area now mainly covered with Calamagrositis epigejos. Outside the centre of immission impact approximately 200 plant species coud be identified in the field layer. In the central area the number of plants of continental origin was larger. All attempts to reforest this denuded area have been failing so far. Following the plant's closure the conditions of sites, stands and vegetation have been thoroughly investigated, in order to obtain a basis for reference as for the future development as well as a foundation for silvicultural measures. In the central parts of the damage zone there was an overall increase of salt-enduring plants but hardly any halophytes grew there. In the Forest District the height growth of beech appeared to be more suppressed than its radial growth, which caused the height/diameter ratio to diminish inversely proportional to the emitter's distance. Pot and field surveys refealed the nutrition of deciduous trees to be sufficient. In addition to European black pine (Pinus nigra) and lucust (Robinia pseudoacacia) probably common oak (Quercus robur) and, moreover, in the fringe areas also beech are supposed to be suitable for reforestation. A pH increase of the soil substrates (due to ash input, maximum value 9.5), dependent on the distance from the emitter, could be evidenced, however, due to increased levels of acid stress after the improved processes of ash filtration pH has not notably increased over the past few years. The salts and thus Na-, Cl- as well as SO4- and K-ions are accumulated in a soil layer 50cm below the soil surface which is rich in silt and clay, and may readily be removed by soil moisture, Referring to 40mg Cl/100g of soil the max. salt concentration was found to be approx. 0,5% The soil developed above red sandstone overlain by a layer of loess loam as cambisol. Subsequent to subsoil salt leaching the bare areas are supposed to recover to normal growth conditions again, as the main damage of trees was incurred via the assimilative organs, and, except for the salt, no other growth-limiting factors of soil could be proven.