DIGITALNA ARHIVA ŠUMARSKOG LISTA
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| ŠUMARSKI LIST 13/2011 str. 150 <-- 150 --> PDF |
I. Pilaš, Š. Planinšek: OBNOVAVODNOG REŽIMANIZINSKIH ŠUMAKAO POTPORAPOTRAJNOM ... Šumarski list – Posebni broj (2011), 138-148 species such as the common oak (Quercus roburL.), field ash (Fraxinus excelsior Vahl.), common hornbeam (Carpinus betulus L.) and softwood species such as black alder (Alnus glutinosa(L.) Geartn.), poplars (Populussp.) and willows (Salixsp.). For the biological diversity of lowland forests and attached wetlands is strongly important specific combination of hydrology and soils. The development of these forests in history was determined by regular seasonal alternations of groundwater tables (hydro period) and periodic flooding. This paper presents the possibilities for the re-establishment of the water regime of lowland forests as one option to reduce the impact of climate change in the future. To reduce negative impacts of anthropogenic alternations in the groundwater regime from the past and to attenuate slow down future very possible prolongation of droughts and water scarcity in the lowlands, various forest managerial and engineering practices could be considered. Basically, there are potentially two main contrasted measures of soil water balance manipulation: drainage of soils (through drainage ditches and channels) which contribute to decreasing the groundwater tables and forest management i.e. (tendering and thinning) which contribute to increased soil water content and increase in the groundwater level. Through these water table management practices, the amount of soil water required for the survival of lowland forests could be maintained to some degree to attenuate the negative hydrologic trends and natural hazards such as droughts. The comprehensive methodological review of activities that must precede such reconstruction activities are presented. As the initial segment all the major components of floodplain ecosystems – the morphology of the terrain, hydrography, soils stratigraphy, vegetation and anthropogenic influences – should be assessed. As a next step methodological options towards how to obtain the knowledge of the natural water regime prior anthropogenic hydrotechnical activities which caused the creation of the ecosystem in its current form are presented. For this purpose the morphology of hydromorphic soils i.e. relict indicators of natural water regime in lowland habitats are assessed. The next step includes the spatial determination of critical areas or hot spots, threatened by excessive falls in the groundwater level on which specific measures can be applied to return to natural water regime conditions (i.e. water retention in dry riverbeds). Key words:Lowland forests, water regime, groundwater, relict indicators, soil morphology, hydro-technical measures |