Separation of previously connected natural habitats due anthropogenic land use changes is one of the most important drivers behind biodiversity loss.
Constructions of for instance roads can separate natural habitats and isolate local populations. This makes them vulnerable to disturbances and can ultimately lead to regional extinctions of species.
Different species are affected differently, depending on the manner in which a landscape is fragmented. But common to all species is that at a certain level of fragmentation, which is specific to locations and species, the negative effects of fragmentation accelerate rapidly.
Network modelling as a tool
A recent Licentiate thesis by centre researcher Arvid Bergsten demonstrates the importance of developing management strategies that supports crucial landscape connectivity.
The study highlights strategies that can help avoid the negative impacts of landscape and habitat fragmentation, and can lead to an ecologically sound governance of landscapes.
Bergsten has investigated how urban planning deal with the assessment and management of landscape connectivity. Through the use of analytical tools like network modelling, Bergsten showed how landscape management can be improved by measuring the regional importance of patches.
"In network modelling a landscape is viewed as a network of habitat patches. The survival of a species depends partly on its possibilities to move between patches. Network models make it possible to examine the landscape's ecology in relation to land use activities," says Bergsten.
This, in combination with experience of the local landscape can give rise to management practices where the dispersal of species across landscapes are considered.
So far the incorporation of such theories into management and planning has been slow.
Social context matters
The outcome of local assessments is in part determined by how the ecological knowledge is packaged and presented. The position of the analyst in the social network can also influence the outcome.
"For an assessment method to be helpful in planning practice, empirical and conceptual knowledge of landscape ecology need to be adapted to the social context of the actors who apply or communicate this knowledge," says Bergsten.
In his study, urban planners were given a network software to use in their planning. The software illustrates the habitat network and makes it possible to quantify the importance of patches.
This helped the planning process, making it easier to visualise both ecological theory and the consequences of land use planning. Because of its illustrative nature, the software could provide strong arguments in negotiations between actors.
Successfully integrating ecology and planning
Bergsten believes there is a need for more pedagogic tools in landscape management and urban planning.
"I encourage a decentralised knowledge production in the science-policy interface, supported by ecological evidence and tools as well as by social learning and experience", he says. He also argues that scientists need to learn more about the role of the local planners and the constraints they face.
Source: Bergsten A. 2012. Fragmented landscapes - Assessment and communication of landscape connectivity in human-dominated landscapes. Licentiate in Philosophy Thesis 2012:2. Natural resource management. ISSN 1401-4106.