Habitat fragmentation

Habitat separation, division or even Habitat Habitat cleavage or habitat fragmentation, is an environmental process of change that has a significant impact on evolution and biodiversity. It involves a splitting of the habitat of animal or plant species, with the result that a genetic exchange between the resulting partial habitats is prevented. Habitat separation is partly caused by geological or climatic processes such grave breaches or glaciations, on the other hand by human activities such as deforestation and transportation infrastructure construction. In the first case one also speaks of geographic isolation. These processes, which take place over a long period of time, regarded as an important factor in speciation. The, also known as landscape fragmentation, much more rapid changes caused by human influences other hand, are seen as the cause for the extinction of many species.

Effects

A Habitat separation is usually associated with the following effects that have an impact on biodiversity:

• Smaller habitat area: Reduce the population sizes in the sub- habitats inevitably, in extreme cases, the minimum size of stable populations is exceeded, resulting in long-term extinction of the population. Also negative is the impact of genetic erosion, reducing the gene pool.
• Higher proportion of border areas: Optimal living conditions have kinds usually only at a certain distance from the edge of their habitat, depending on their action space. That are " more valuable " inner regions disproportionately reduced by habitat separation may disappear completely.
• Habitat destruction: In the area of the dividing line, there is a direct habitat destruction, often particularly valuable centrally located areas.

Consequences for species conservation

Conservationists are well aware of the negative impact that human-induced habitat separation already at relatively low land use on biodiversity, so that often counter-measures are sought.

One way in advance of the planning is the shift from intervention to areas far away from the edge of particularly valuable core zones. This, at least one of the resulting partial habitat is still preserved in largely intact. The same goal of maintaining large contiguous habitats is achieved through the establishment of compensation areas and their corresponding design (eg unsealing, abandonment, afforestation ).

Other measures to overcome existing divisions, is the creation of a biotope network by means of bridging elements between sub- habitats. These include so-called " stepping stones ", smaller habitats that can accommodate a stable population itself, but they move from one habitat to another permit. The same function linear network elements such as hedgerows or field margins. Especially for bridging traffic routes and green bridges are applied occasionally. Although these measures do not create new core zones, but will affect the population dying due to genetic impoverishment contrary.

All measures must, however, to be successful, be adapted to the existing inventory of species, and have the requirements of the species most affected by the habitat separation in mind.