German Federal Agency for Nature Conservation (BfN)

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Ecological Networks

Background

Development of extensive grassland areas in a section of the Bayerischer Wald

The mounting utilization pressures placed upon landscapes by the construction of roads and settlements, in combination with the intensification of farming and forestry, is leading to the loss of valuable habitats. These are not only declining in overall area, but are also being fragmented into isolated patches which, due to their small size, are increasingly exposed to 'edge effects', i.e. disturbances from the surrounding areas. The remaining habitat islands are too small for many species; their isolation hampers the exchange of individuals among the areas. This is causing genetic impoverishment of populations and is jeopardizing their survival over the long term.

A further important aspect is that in both the natural landscape and traditional cultural landscapes many habitat types have characteristic spatial interconnections and functional interdependencies. Many species depend upon such habitat complexes to meet all their requirements. Besides the important interconnections, these ecological matrixes at the overall landscape level are being lost due to the fragmentation of habitats into isolated parts embedded within increasingly 'hostile' surroundings caused by the intensification of land use.


landscape "Elbe"

This is why the present protected area system, which is led by 'availability' and often concentrates upon protecting these usually small isolated habitats, can only conserve some 30-40% of native species in viable populations. To permit the survival of a substantial proportion of native fauna and flora, it is therefore essential to create suitable conditions for species outside of protected areas too, in landscapes used predominantly for farming and forestry. This includes creating the preconditions for species to disperse and migrate.


Objective

aerial photo woodland

The goal of habitat networking is accordingly - in addition to sustaining natural and semi-natural habitat - to preserve, restore and develop functioning ecological interconnections in landscapes. The habitat requirements of native species are at the centre of such efforts. The purpose of habitat network systems is to ensure genetic exchange among populations, animal migrations as well as natural dispersal and re-colonization processes.


Legal bases and political perspectives

The habitat network approach is enshrined in the German Federal Nature Conservation Act since 2002. In the latest law amendment (2009) this is regulated in articles 20 and 21. These articles prescribe the development of a habitat network system covering at least 10% of the territory of Germany. Thus the coherence of the Natura 2000 system shall be improved. Only some of the categories of protected areas will regularly meet the criteria for habitat network areas. This will make it necessary to secure and, where appropriate, develop additional areas. However, the spatial setting which needs to be considered from a conservation perspective to implement the habitat network concept is much wider.

The habitat network concept is further underpinned by the European Union Water Framework Directive, which will contribute to improving the state of waters, including dependent terrestrial ecosystems, and their interconnection.

There is overall a need for innovative approaches in order to ensure the sustainable use of the cultural landscape. These include - besides "alternative area protection concepts"which are also supported in model projects by the German Federal Agency for Nature Conservation (BfN) - notably a reorientation of agricultural and forest policy, including a regionalization and substantive redirection of grant policies.


Conceptual design

When drawing up habitat network concepts, it is crucial to give consideration to landscape characteristics and development potentials.

Concepts need to be designed for different spatial levels. Broad-scale concepts must be taken into consideration in concepts crafted at a smaller spatial scale, and implemented in an increasingly concrete manner for specific locations from level to level:

(inter)nationalbroad-scale corridors, giving consideration to species with very large spatial requirements and migratory species
regionalregional corridors, providing conductivity within landscape units and physiographic units
localhabitat complexes, networking individual habitats

Implementation

To develop spatially concrete habitat network systems, there is a need to elaborate and apply selection criteria that are valid across the whole country. Key quality criteria for assessing the suitability of sites as components of a habitat network system include spatial location, size, representativeness and habitat assemblage. They also include the current state and development potential of sites as well as their ecological function.

A habitat network system comprises a number of different components:

  • Core areas secure stable, permanent habitat for native species. These comprise remnants of natural or semi-natural areas, surrounded by buffer and development areas which prevent negative impacts from intensively used landscapes upon the core areas. Buffer and development areas can have conservation value in themselves, or may have the potential to develop towards semi-natural habitat.
  • Connectivity elements are areas which ensure or facilitate genetic exchange among the populations of animals and plants in the core areas, as well as migration, dispersal and re-colonization processes. These can be 'stepping stones' or corridors.
  • The surrounding landscape matrix needs to be made less hostile to organisms and thus provide greater conductivity. This can be achieved by setting minimum quality requirements upon land uses. Such requirements are frequently met by broad-scale extensification.

The ecological network at national level

map of nationally significant areas for the ecological network
map of nationally significant areas for the ecological network
map of national and internationally significant ecological axes
map of national and internationally significant ecological axes

A conceptual plan for the trans-regional ecological network in Germany was compiled on the basis of several R&D projects for the Federal Agency for Nature Conservation (Fuchs et. al. 2010). An important basis for this work consisted of habitat maps provided by the Länder and known locations of target species for the trans-regional ecological network. This information was used to identify networks of ecological functional spaces for dry land, wetland and woodland habitat complexes. These were then used in turn to identify and compile maps of nationally significant areas for the ecological network and national and internationally significant ecological axes.

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International importance of the ecological network

map of corridors of European importance in Germany
map of corridors of European importance in Germany

Key international ecological corridors such as the large river systems with their floodplains (e.g. the Rhine, the Oder and the Elbe), hill and mountain ranges with geographically extensive forest ecosystems (as in the Bavarian Forest National Park) and near-natural zones in lightly populated or border areas (such as the Green Belt) require a coordinated approach at international level if they are to be effectively protected and allowed to develop. This includes integrating connecting points with internationally significant ecological corridors that Germany shares with neighbouring states (Finck et al. 2005 – see Publications).

At a workshop initiated by BfN for this purpose in November 2004, 23 experts from Germany’s neighbours and from the German Länder that share borders with them identified 94 trans-border core areas and ecological corridors (in German). The international connecting points with ecological network plans in neighbouring states were updated and a map of ecological corridors of European and international importance for Germany was compiled as part of an R&D project on ecological corridors in a European context in 2010.

BfN activities in this field dovetail with Council of Europe efforts to establish a Pan-European Ecological Network (PEEN) under the framework of the Pan-European Biological and Landscape Diversity Strategy (PEBLDS). They also contribute towards the ‘Green Infrastructure for Europe’ promoted by the European Commission.

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In addition to developing conservation concepts, including the elaboration of selection criteria for habitat network areas, the BfN is also engaged in carrying out model testing and development projects and large scale nature conservation projects to establish habitat networks.

Contact

For further information please contact:
Karin Ullrich
Peter Finck

FG II 2.1

Last Change: 23/07/2019

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