Bodenveränderungen und Typisierung von Fahrspuren nach physikalischer Belastung | Changes in the soil and the classification of ruts according to physical loading

In Swiss environment legislation, protection of the soil is defined by reference to the long-term maintenance of soil fertility. To fulfil this commitment, long-lasting damage to the soil must be prevented, respectively reduced to a minimum. When the forest floor is driven over with heavy logging machinery, this can lead to profound and long-lasting changes in the soil structure in the ruts thus formed. Based on driving trials under controlled conditions in the Heiteren region of the forest near Bern, investigations were made to find out whether the classification of ruts into three distinct types showing morphologically determined changes in the soil could be substantiated with the help of known values in soil physics. It was shown that the non-compacted reference soils could be clearly distinguished from all three types of rut by comparison of the stratification density, the total pore space and the saturated water permeability. In addition, the three types significantly differed from each other. Damage to the soil can be reduced to a minimum through consequent planning of skidding tracks and by paying due attention to the prevailing humidity of the soil at the time when vehicles are used. Thanks to the connection established between the character of the ruts and soil functionality, the classification of rut types provides a practically relevant and objective instrument for effective physical soil protection.