Former floodplains in many European countries increasingly suffer from serious floods due to intensified human activity. These floods have caused safety and ecological problems as well as they have resulted in economic losses in agricultural used watersheds. In this context, the influence of the management practice of forest transformation in forested areas on soil hydraulic properties is presented and discussed as a means of preventing such disasters at a reasonable cost and during a foreseeable period. Investigations were carried out in northeastern Germany on forest stands differing in tree populations and stand structure. It was found that infiltration capacity and hydraulic conductivity K exhibit overall low values nevertheless the tree species. This finding appears to be related to water repellency, the predominating texture, and a poor macroporosity. During the different stages of forest transformation, the type and amount of soil organic matter and humus in the litter layer change, leading to a decrease of the water capacity of the litter layer and the uppermost part of the mineral soil. Furthermore, these changes affect soil properties connected with water repellency. It is concluded that for the approximate duration of one century the practice of forest transformation does not contribute to flood prevention through enhanced infiltration capacity or water retention.
Forest transformation: Scots pine (Pinus sylvestris) stands in North–East Germany recently are converted in a large scale (800,000 ha within the next 25–30 years) to mixed forests consisting of Scots pine and European beech (Fagus sylvatica), which com- plies with ecosystem changes as well as of forest structures and functions Into a pure Scots pine stand with a mean tree age of 40 years, an understorey of beech trees is incorporated within this stand by forestry management, resulting in stands with mixed tree populations....mixed tree popu- lation stands are represented by P76/B34 (young mixed stand) and P114/B57 (older mixed stand). The hypothet- ical final stage is represented by stand B91, where 91- year-old European beech is stocking in first generation after pure Scots pine management.
|Climate change impacts||Effect of Nbs on CCI||Effect measures|
|Freshwater flooding||Mixed results||Water capacities (m3/ha) of the upper nine cm (F and H layer and Ah/ AE) of the forest floor|
forest area of Kahlenberg (52°52 0 N, 13°53 0 E), approx. 50 km NE of Berlin