The majority of endangered open land habitat types (LRT) according to Annex I of the Habitats Directive (FFH-RL) are dependent on extensive agricultural use. First and foremost, the various forms of use-dependent dry grassland (e.g. LRT 6210 (*), 6240 *), lowland hay meadows (LRT 6510), species-rich wet grassland (e.g. LRT 6410, 6440) and montane mountain meadows ( LRT 6230 *, 6520) as well as naturally small-scale special locations such as inland salt stations (LRT 1340 *) or heavy metal lawns (LRT 6130), which are also at least periodically dependent on maintenance interventions. These habitats are usually rich in species (flora, fauna), but at the same time also have a high proportion of endangered species. Reasons for their endangerment are, on the one hand, intensification of use at more productive locations, but currently mainly abandonment of use at marginal yield locations.
For larger contiguous areas with open land LRT, concepts have recently been developed for Saxony-Anhalt that can guarantee the preservation of open land in the long term. Examples are the extensive grazing projects with robust mega-herbivores in the area of areas formerly used by the military in the Oranienbaumer Heide and in the “Dead Valleys”.
Endangered open-land habitat types and the habitats of rare plant and animal species are nowadays often extremely small. In many cases, these are relics of formerly large occurrences that are only present as islands as splinter or residual areas (e.g. dry grass splinters in the middle of bushes).
A large part of these splinter / residual areas, which are very valuable in terms of nature conservation, are located in Natura 2000 areas. Nevertheless, many of these areas have been fallow for several decades or have only recently been taken out of use for socio-economic reasons. Often, specific surface characteristics make it difficult to manage the marginal yield locations (e.g. terrain relief, high groundwater level, isolated location, lack of initial maintenance).
Nevertheless, these small areas often still have very species-rich remnants of open-air habitat types and populations of rare plant and animal species. For these fragments / residual areas, which are very valuable in terms of nature conservation, new approaches to solutions with regard to use and financing must be developed in a timely manner. Since the biodiversity in the open country is concentrated on these small areas, the solution of the "splinter / residual area problem" is of central importance for the preservation of biodiversity in Saxony-Anhalt.
In 2015, a preliminary study regarding the evaluation of existing data material was carried out against the background of the "splinter / residual area problem". For these evaluations, the habitat type cadastre of the state of Saxony-Anhalt (short LRT cadastre) was used, which took into account 20,683 open land areas with a total area size of 34,569 hectares to be considered in the project period. The majority of these open land areas (87%) are located within FFH areas. These are predominantly very small: 87% of the areas have an area size of ≤ 3 ha, 69% were only ≤ 1 ha in size. In particular, the typical dry grassland and lean grassland biotope mosaics (a total of twelve different habitat types, mainly type 6210 (*)), but also the grassland type habitat types in medium-sized locations (type 6510, 6520) are subject to the "splinter remaining area problem" due to the small area of many occurrences. . Another highlight is the LRT 6130 (heavy metal lawn), which only occurs in very small areas.
For the selection of species-rich splinter / residual areas on the basis of the LRT cadastre, a query scheme was developed that takes into account all relevant parameters from the available data (e.g. area size, degree of isolation, number of species, occurrence of endangered plant species) and various possible combinations of these parameters . On the basis of the available data, it seems to make sense to limit the selection of splinter areas to areas ≤ 3 ha. The currently favored combination of selection parameters results in an area backdrop of at least 1,000-2,000 ha with species-rich splinter / residual areas for Saxony-Anhalt, whereby it should be noted that the LRT cadastre covered only 30% of the state's area during the project period. In addition, depending on the priorities set when selecting the selection parameters for splintered areas, both the size of the area backdrop as a whole and that of individual areas can differ.
On the basis of the experience gained and the figures determined, a large number of topics that need to be deepened must be dealt with in further investigations. This applies in particular to the regionalized plausibility check of the available data.
A comprehensive processing of the topic is planned as part of a follow-up project, for which numerous coordination discussions have already taken place and cooperation agreements have been made. Initially, in three model regions (districts Börde, Harz, Wittenberg) on the basis of existing data material (e.g. LRT cadastre, management planning) in close cooperation with the regional authorities (LAU, UNB) and experts (e.g. Botanischer Verein Sachsen-Anhalt) an area pool of species-rich splinter / residual areas can be determined and evaluated. In addition, selected care projects are to be initiated and implemented on priority care areas in the model regions. On the basis of the determined area pool and the research of current costs for landscape maintenance and initial installation measures for the different biotope types, as well as the examination of further financing instruments and partners, solutions for species-rich maintenance areas in Saxony-Anhalt are to be presented. Thus, in the medium term, maintenance is to be guaranteed at least on selected priority areas.
Management: Prof. Dr. habil. Sabine Tischew
Researchers: Dr. Daniel Elias, Dipl.-Ing. (FH) Gerd Jünger
funded by: Ministerium für Landwirtschaft und Umwelt Sachsen-Anhalt (project duration: 17.10.-31.12.2015).