Špela Planinšek Slovenian Forestry Institute

Transcription

1 A model for valuing and allocating forest sites providing a hydrological role Adapting Forest Management..., Koli, Finland 2009 Špela Planinšek Slovenian Forestry Institute

2 PROBLEMATIC OF TERMS Function and service combined Hydrological role = hydrological service Not yet addopted: REGULATING SERVICES (de Groot, 2003, 2007) environmental > ecosystem services

3 Trends in classification of ecosystem services

4 SLOVENI A Slovenia is the land of forests sustainable use nature-based management multiple-use of forests Forest area: ha (GFRA( 2005) SFS data (200( 2005) Europe: Finland 73,9 % Sweden 66,9 % Slovenia 62,8 %

5 Forest & water relationship - map reveals areas with the different ranks of hidrological function. - according to the current legislation (Karst regions, water catchments) - large area! - we tried to optimise this large area.

6 Objective of the research to develop a spatial model, determining the discrepancies between the demands for hydrological role and the capacities of stands to provide it. in this research we didn t address forests merely as water consumers but also as a natural filter, a water reservoir and as the crucial factor significantly influencing water runoff. Adapting Forest Management..., Koli, Finland 2009

7 Contribution of forests to water cycle Forests basically perform two ecosystem sub-services / roles: they protect surface and ground waters and waterbeds, they protect the existing forest soils and prevent from water erosion. Contribution of foresters to water cycle maintenance and improvement of forest structures and stands to assure better protection against floods, landslides, erosion and an increase of water-retention capacity of soils. underestimated and scientifically & practically less known task

8 Study area description 1786 hectares a high proportion of forest (83%); beech, spruce, fir, scots pine, other broadleaves elevation range m folowing green water paradigm pixel size 12,5x12,5m

9 External ecological and internal stand factors influencing forest hydrologic role Value Terrain slope EXTERNAL - ECOLOGICAL FACTORS Soil - erodibility and ground porosity INTERNAL STAND FACTORS Stand structure Stand density Forest preservation low erodibility, normal porosity uneven-aged forests, forest shrubs high, normal preserved medium erodibility, normal porosity mature stands, pole stands low changed and above high erodibility, low porosity young stands, rejuvenated old stands gaps, interrupted highly changed matrix modelling decision support GIS model, criteria based on published studies, forestry researches and forestry practices, involves and uses general data/ways to provide useful result for forest practice without nutrient studies, precipitation measures... evaluated using a scale from 1 to 3 (1 - ''the best'', 3 - ''the worst condition''). Slovenian Forestry Institute

10 Matrix model (Cross-sectional analysis) After evaluating basic data layers with Idrisi program, the results were combined for further analysis a a * m k a l a m 1 2 an 1 a m 3 4 an 2 a m 6 9 a 3 n

11 1 2 ROLE CONCLUSION Diagram showing merged data layers used in the model Slovenian Forestry Institute

12 needs Hydrological needs on the basis of ecological factors Cross-sectional analysis of external factors: terrain slope and soil types Slovenian Forestry Institute

13 capacity Forest capacity for maintaining hydrologic role Cross-sectional analysis of forest stand factors: stand structure, stand density and preservation of forests Slovenian Forestry Institute

14 Summarrized results for managed (multiple-use) forests Value EXTERNAL - ECOLOGICAL FACTORS (% area) INTERNAL STAND FACTORS (% area) JOINT MAP (% area) 1 good condition 2 acceptable condition 3 bad condition The state of protection forests is rather alarming with only 20% of the area in good condition, 46% in acceptable and a third of areas in bad condition, meaning that the forest fails to perform its hydrologic role problem is the realisation of silviculture measures. Slovenian Forestry Institute

15 Conclusions = this model presents: Good foundation for silvicultural planning enabling to sustain existing conditions and improving forest hydrological role. Critical areas should be prioritised to silvicultural measures. Each spatial unit (pixel) carries five different types of data enabling detailed analysis of factors influencing hydrological needs and forest capability to satisfy these needs. Practical recommendations for forest management a handbook with forest management guidelines for enhancing the hydrological role - to improve practices in forestry and other activities related to environment. Slovenian Forestry Institute

16 Precautionary forest - management actions Forest roads, logging trails! Silviculture: % of forest cover, tree species composition, vertical & horizontal forest structure, frequency, intensity and technique of felling. Silviculture development of water retention areas, brooks and floodplains, wetland and peat swamps. Soil structure NEW: nature-based management of water retention basins

17 EXAMPLE: Forest stand structure In the area of water basin, a dynamic balance of trees in various development phases should be maintained. First regeneration cuttings should be less intense to secure a large share of young fir and beech trees. Regeneration should be performed in longer time periods without multiple interventions. Slovenian Forestry Institute

18 In dense stands of coniferous trees, cores of deciduous trees should be planned. Unstable and over-mature trees should be removed since they may cause erosion. Pioneer stage (willows, shrubs and grey alders) should be maintained and promoted in areas near the trenches and sliding areas (inclined to landslides and torrential floods). The composition of different tree species should be maintained. Tree species with strong root systems (i.e. dwarf pine, scots pine, larch, sycamore maple, fir) are more suitable for extreme sites (with steep incline, high altitude). Contact and more information: Slovenian Forestry Institute

19 Thanks to my coleagues: Anže Japelj and Andreja Ferreira from SFI Thank you for your attention Adapting Forest Management..., Koli, Finland 2009