Assessment and mapping the dynamics of soil properties in selected forest stands from the region of Central Balkan National Park in the context of ecosystem services

Forests set natural conditions and embody a repository of biological diversity that represents a myriad of ecosystem services for human well-being. The spatial patterns and the forest ecosystems’ dynamics over time make the forests of particular environmental significance for the provision of ecosystem services. The terrestrial biodiversity and the sustainable management strategies' demand for mapping and assessment of the dynamics for the condition of forest ecosystems by drawing attention to the soil properties. In order to take on that task, the data series obtained by the International Co-operative Programme on Assessment and Monitoring of Air Pollution Effects on Forests (ICP Forests) for the period 1986–2016 were found as appropriate quantitative indicators that convey information about the ecosystem’s capacity to provide certain regulating ecosystem services. The ICP Forests Level I sites, located in the Central Balkan region, provide consistent information, which is collected on a regular basis about observed forest stands. The primary focus of the present research is to conduct a biophysical assessment of the forest ecosystems and to define their overall condition regarding two time series – the periods 1992/1993 and 2015. This study attempts to introduce an innovative approach and aims at linking the existing ICP Forests network dataset with the ecosystem services concept and the identified spatial units from the CORINE Land Cover (CLC) polygons for the territory of Central Balkan National Park. On this basis and through the implementation of GIS techniques, the dynamics of soil properties in selected forest ecosystems was analysed with regard to their capacity to supply relevant ecosystems services, which were assessed and mapped. The biophysical data provides robust information on the ecosystem services and the results show the variations in the capacity of different forest sub-types to provide ecosystem services within a well-defined land cover unit. Additionally, the research work intended to review the generated outcomes with reference to the DPSIR (driver-pressure-state-impact-response) method by giving feedback on the changes in the terrestrial ecosystems in the last 25 years. Further application of the mapping approach in assisting the communication in the decision- making process is also discussed.