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ŠUMARSKI LIST 11-12/2021 str. 77     <-- 77 -->        PDF

Copernicus across Europe’s Regions showcases, among many others, 11 user stories that describe how public administrations across Europe are using Copernicus data and information to address their challenges regarding forest issues (NEREUS, ESA and EC, 2018). Cole et al. (2018) analysing CLC changes in period 2006-2012 in the UK, found that the over 54% of changes were related to coniferous clear cutting (conversion of coniferous forest to transitional woodland /shrub).
Regarding forest, the two primary status layers Dominant Leaf Type (DLT) and Tree Cover Density (TCD) at 10 m spatial resolution are derived from multi-temporal Sentinel-2 satellite data from the European Space Agency (ESA) and provide information about leaf type (broadleaved/coniferous) and the proportional tree cover at pixel level (TCD in %). The HRL Forest 2018 product portfolio already comprises a Forest Type (FTY) product. Apart from mapping the current status, it is possible to monitor change, which can be a result of manifold influences, e.g. related to climate or forestry. This is enabled by the 3 year update cycle of the HRLs which allows to not only map the loss of tree cover but also the gains (CLMS, 2020).
Some of the existing Earth Observation based products, however, require verification and tuning to meet the user requirements. For example, it was estimated that the satellite based Copernicus HRL-tree cover density layer has an overestimation error up to 7.5% (Mirończuk and Hościło 2017; Hościło et al, 2016).
For proper management of any area, and particularly protected ones, it is essential to include as much relevant data as possible from different sectors (e.g. natural science, demography, administration, forestry, agriculture, etc.). Very often, those data have different formats, precision, resolution, origin, etc. A geographic information system (GIS) enables successful integration of such diverse data into a harmonized database containing all data in compatible format (Marić-Limari et al, 2017).
A Digital Elevation Model (EU DEMv1.1.) with a resolution of 25 m and the FTY 2018 layer with a resolution of 10 m have been used to view the spatial distribution of forest types by altitude zones. By using the GIS tool Raster Calculator, the areas under broad-leaved and coniferous forests have been calculated by altitude zones. Considering the altitude range from 0 to 2367 m, four altitude zones of 0-500 m (39.47% of the B&H territory), 500-100 m (35.53%), 1000-1500 m (21.9%) and over 1500 m (3.1%) have been taken into account. According to Stjepanović (2019), among the main species of forest in the zone with an altitude of less than 500 m, the most common ones are sessile oak forests, covering about 95% of the area, in the hilly zone (500-1000 m) there are beech forests with 47% of the area, and in the mountain zone (1000-1500 m) there are beech and spruce forests with 71% of the area.
CLC Changes data for the B&H territory have been extracted by using the GIS software and changes in the form of polygons for all three periods have been visualized. The data have been exported to Microsoft Excel and classified by type of change. The individual sum of areas of all land cover types and changes by periods have been calculated by using the Sort & Filter and Subtotal Sum tools. Through the processing of this data, we get a spatial and temporal insight into all the processes that take place in the field.
The total area under forests in B&H in 2018 was 30498.57 km2 or 59.55% of the territory, which is a decrease by 2.94%. in comparison with 2012. Broad-leaved forests decreased by 0.39% and coniferous forests by 2.55%. Among the forest types in 2018, broad-leaved forests account for 80.98%, while coniferous forests account for 19.02%. In comparison with 2012, when broad-leaved forest covered 77.78% and coniferous forest 22.22% (Table 1), this is a significant change.
Distinguishing forest area losses (i.e. conversion to non-forest land uses or deforestation) from tree cover losses, which may be temporary (i.e. natural disturbances, sustainable forestry) or which may eventually lead to forest area loss (i.e. unsustainable logging, altered successional pathways), is critically important for two reasons. Firstly, the impacts of permanent loss in forest area on biodiversity, ecosystem functioning, and resource use opportunities are fundamentally