Biotope mapping Gesäuse — Part report mapping area Johnsbach incl. Humlechnergraben

The biotope mapping was carried out on a scale of 1:2,000 from a minimum biotope size of 100 m with a minimum biotope width of 5 m. As mapping units, the biotopes were according to the “Red List of Endangered Biotope Types of Austria” (ESSL et al. 2002, 2004 & in Vorb.; Traxler et al. 2005) used. The images were documented in a survey sheet based on the biotope mapping Salzburg (NOWOTNY & Hinterstoisser 1994) and managed in an MS Access database. Biotopes that could be assigned to an endangered biotope type and/or habitat type according to the Habitats Directive (FFH-LRT according to Directive 92/43/EEC) were additionally documented with a list of species. Furthermore, the biotopes were digitally separated from colour orthophotos. The extensive terrain surveys took place in 2006. The taxonomy depends on FISCHER et al. 2005, the syntaxonomy according to WILLNER & Grabherr 2007, Grabherr & MUCINA 1993 and MUCINA, Grabherr & Wallnöfer 1993, supplemented by WILLNER 2001. Ellmauer was used to address the FFH habitats in 2005. In the Johnsbach UG, 520 biotopes were mapped, which were detected on 909 individual areas (increased number of individual areas due to vegetation mosaic on dolomite rocks). Biotopes, which are only partially within the UG, have been mapped out flat. As a result, the entire mapping area increased from 153.7 ha to 226.5 ha by 72.8 ha or just less than half the area. The area sizes of the individual biotopes range from 12 m (field wood) to just under 5 ha (Snowheide-Rotföhrenwald on the northern slopes of the Hellichten Stein to the Humlechnergraben). Due to the adjoining of four further investigation areas (Gseng, Kaderalblschüttgraben, Langgries, Enns) there are overlaps with these UGs in the area statistics. For example, the mouth of the Johnsbach is also described in the sub-report “Enns”, since a functional separation of these estuaries (or in the three other cases of the corresponding side trenches to the Johnsbach) is not possible.