Modeling a map of the conservation status of the FFH openland habitat types of the Natura 2000 area Ennstaler Alpen/Gesäuse National Park Gesäuse

This report documents the method of modelling a map of the conservation status of the Offenland-FFH habitat types (FFH-LRT) in the Natura 2000 area Ennstaler Alpen/Gesäuse & Nationalpark Gesäuse. The conservation status map available so far (only digital; Report: Zimmermann 2018) only represents the conservation status (EHZ) of the forest-FFH habitat types (including bushes), but also discusses the procedure for all other habitat types. Our project is essentially the GIS technical implementation of the proposed modelling approaches. The definition of the habitat types of FFH follows the FFH habitat type map (Zimmermann 2017a). As handled in Zimmermann 2018, we adhere to the indicators from Ellmauer 2005 and derive them from an existing data base. For example, qualitative information on vegetation, such as the degree of shielding or the influence of pasture from the Habitalp aerial image interpretation can be obtained. Other indicators, such as impairment, were derived from the road network and the climbing routes. Altitude data and calculated elevation levels and slope inclinations are generated from an Airborne Laser Scanning (ALS)-based terrain model (DGM). Unlike the forest map version, the modelling of the conservation states is implemented with the Graphical Modeller in QGIS. For the calculation, various processing tools are created in a graphical model and at the end deliver a layer with single-surface conservation states. The approach of determining a conservation status for each individual area via individual indicators is maintained. The graphical models, with all calculation and combination logics, are comprehensibly available in digital and editable form. Already in the first version of the conservation status map, the Habitalp aerial image interpretation was identified as a significant source of error. In the present case, this concerns in particular the assessment of the vegetation structure, because the correct determination of the coverage proportions of trees, shrubs, herb and dwarf shrubs is not always guaranteed or is not in the necessary sharpness; this is due to the fact that the open land polygons of the FFH habitat type map often come from terrestrial mapping, e.g. biotope mapping, and usually represent only parts of Habitalp polygons whose coverage percentages often do not match those of the subareas. Finally, according to the scheme indicated in Ellmauer 2005, a total conservation status for the Natura 2000 area and the National Park is declared separately by habitat type.