Protecting surface water resources through silvicultural methods

Abstract

Water was considered an inexhaustible natural resource until reality has proven its reverse. Climatic changes increase the pressure on surface runoff and groundwater, amplifying regional differences. As such, the necessity to adapt to climatic changes implies applying certain biologic/silvicultural works for protecting water resources. Water is strongly connected with forests so that forests fulfil an exceptional hydrological purpose. In this paper we presents some types of silvotechnical works realized in the past for improving degraded lands from Vrancea area, as well as the results of investigations concerning the efficiency of this kind of works in protecting water resources. The investigations were realized in Caciu-Barsesti torrential watershed, an affluent of Putna River (pilot area in CAMARO-D project) situated in the Curvature Subcarpathians. The investigations have targeted forest ecosystem installed on degraded lands mainly comprised of Scots pine and European black pine, as well as the management/consolidation technologies used for eroded lands and their effects in reducing soil and leakage erosions. Forest ecosystems realized through the afforestation of degraded land have an important role in retaining, filtering water and in regulating the course of surface waters, as well as in reducing soil erosion and transporting alluvium. All these roles have an effect in protecting water resources, in maintaining their quality and ensuring a permanent water flux. Amongst the most important effects exerted by forest plantations from degraded lands we mention: reducing soil erosion, improving pedostational conditions, and regulating surface and depth leakages. In comparison with unafforested lands, degraded afforested lands present surface leakages of 4 up to 10 times lower as well as a much more reduced specific erosion (0.06 t.ha-1year-1, in comparison with 50-300 t.ha-1year-1).