Sward
The cohesive vegetation of the ground with grasses and herbs is referred to as turf , which is firmly held together by the closed vegetation and the roots .
The word came from Low German in the written language. Related terms are grass or lawn cover , also heather scar , in the southern German and Austrian language area Wasen , on alpine pastures the sheep drift .
Sward and erosion
The natural turf offers a high level of resistance to weathering and erosion of the rock , which can be many times higher than that of bare ground. Some centimeters lower the actual begins soil life in the form of millipedes , earthworms besides bacteria and a rich ground flora. Where this is partially missing, or where the mechanical cohesion is impaired by high humidity or heavy rain , the turf can tear off. On steep slopes , plaiks (uncultivated areas) or landslides can arise, whereas in flysch mountains , soil flow is slower (solifluction).
The stability of a natural sward can be transplanted using agriculturally produced turf tiles (up to approx. 8 cm thick) or turf (1.5–2.5 cm thick) and used both in the garden and on the sports field , as well as for securing bare slopes or in the Mountains to prevent landslides . In recent years, rolled turf has become increasingly popular over sowing, as the sward of the rolled turf stabilizes the occupied area immediately after laying and prevents water and wind erosion. During the vegetation period, turf / turf grows together with the ground in 10–14 days; the maximum root penetration depth is reached after three months, depending on the type of grass.
The grazing usually contributes to the consolidation, except on very steep terrain and when the soil is wet. The management of alpine pastures therefore not only has agricultural aspects, but also serves environmental protection (prevention of natural hazards ) and tourism through landscape maintenance .
Soil life and voids
Shallow cavities often form under the grass , which are reinforced by the freezing of stones, by ants or by tree roots. They can also erode flat rock due to their acidity and other biological-chemical weathering or widen existing fissures . Also, soil organisms , various mosses and the mycelium of fungi help solidify the other hand the latter the turf.
The geodesist often struggles to find overgrown surveying points under the sod, which increases in height by up to a few centimeters every year due to the gravel on the roadside . The tried and tested antidote are precise "topographies" ( point descriptions ) with restricted dimensions to buildings or prominent trees.
Individual evidence
- ↑ Sward. In: Jacob Grimm , Wilhelm Grimm (Hrsg.): German dictionary . tape 8 : Glibber – Gräzist - (IV, 1st section, part 5). S. Hirzel, Leipzig 1958 ( woerterbuchnetz.de ).