The parts

Habitat networks can help to make habitats more resilient and assist species survival in a fragmented landscape and a changing climate.

Habitat networks can be divided into different components:

• core areas - these areas are often referred to as habitat 'patches'.  They are areas which provide high quality habitat for the particular species or group of species under consideration.
• the matrix - this is all the outer land that surrounds the core areas, which may be being used for urban development, agriculture or any other land use.
• movement routes - these are areas which allow plants and animals to move from one area to another.  

See below for more detail.  See also 'the connections' page for how these parts fit together.

Core areas

These areas are often referred to as habitat 'patches'. They are areas which provide high quality habitat for the particular species or group of species under consideration. These areas may be large enough to support a limited population of the species, but are unlikely, by themselves, to be large enough for guaranteed species survival. For example, a single catastrophic event such as a fire or the introduction of a new predator could wipe out the entire population within a core area.

In many cases the core area will be land which is managed specifically for nature conservation, for example a site designated as a Site of Special Scientific Interest.

For some species, the core area may be land which is managed as green space within an urban setting. Whilst these areas are often well protected and managed, their long-term security can be increased if they are connected to other similar habitat patches. For example, if a population of a particular species is wiped out in a well-connected core area, other individuals of that species will be able to move into the area and if climate change forces species to shift their range, these connections may assist in the move to a more suitable core area.

Matrix

This is all the outer land that surrounds the core areas, which may be being used for urban development, agriculture or any other land use.

For an animal or plant to move from one core area to another, they will need to pass through this outer land or matrix. Some land-uses will discourage individuals from passing through - for example, a badger is unlikely to travel through an urban centre, and pedestrian might not be able to travel across a motorway. Other land-uses may be more conducive to travel - that same badger might travel through an area of livestock farmland and a pedestrian might be able to cross the motorway via a foot-bridge or underpass.

So different land uses can vary in the extent to which they are 'permeable' to different species. The permeability of the outer land will affect how easily a species can move through an area. This means that, in some cases, we don't need to create large areas of new habitat to create a network, we just need to make the surrounding land easier to pass through (more permeable), perhaps by altering the way it's managed. That can also have social and economic benefits, perhaps by enabling more people to use an area for recreation, or increasing the attractiveness of an area and encouraging economic growth.

Movement routes

These are areas which allow plants and animals to move from one area to another. They can be linear patches of habitat, like a corridor, or more often a connecting area of variable shape. They might even be a series of 'stepping stones' of habitat patches, which species can use to 'jump' from one area to another, or be a particularly permeable part of the matrix, which plants and animals can move through more easily