Sustainable management of Slovenian floodplain forests at landscape level

Forests cover 57% (11500 km(2)) of Slovenia and have primarily been preserved in higher and steeper locations less suitable for agriculture, where their protection significance has been even higher. Floodplain forests on the other hand have been under severe pressure since times of the first settlement and they have been severely affected by heavy cutting of pedunculate oak and extensive regulation of watercourses over the past hundred years. In the last decades land consolidation and drainage of fields to increase crop productivity or to reclaim wetlands for cultivation have decreased structural diversity in land use. As a consequence, vitality and natural regeneration of those forests have decreased where pedunculate oak in particular is showing most severe decline. A spatial model was used to assess the depth of the interior environment of forests and forest patches and to determine the agricultural landscapes, which have lost self-organising and regenerative properties. By using the spatial model and historical data we obtained from the forest areas and according to the data from the 18(th) century military reaps, we can conclude the forest areas to represent the cores of the primary floodplain forests in Slovenia. In the light of further preservation of key-tree species an experiment was carried out in two bigger pedunculate-oak forest patches where critical groundwater level for efficient regeneration was defined. Not only did water regime change, but also emissions, management errors from the past and consequences of a changed water table may also play an important role in future management perspective of Slovenian floodplain forests.