Planning Habitat for Very Long-Distance Connectivity under Climate Change

Post provided by JENNY HODGSON

Climate change and habitat fragmentation are interacting threats: it is likely that many species cannot reach newly suitable areas at the cool edge of their range because there is not enough habitat, in the right places, to support range expansion over multiple generations. Conservation efforts are already underway to restore large areas of habitat, and to improve the “connectivity” within networks of habitat. However, there are multiple ways of measuring connectivity and few of them address the scale of shifts that are likely to be needed under climate change. This could be a problem if it leads to inefficient conservation prioritisation.

The Conductance Metric

How conductance generally depends on the amount of habitat in the landscape. Squares show the conductance of landscapes with a random selection of cells chosen to be habitat. The red line is based only on the 100% point and the expectation that conductance is proportional to amount of habitat squared.

How conductance generally depends on the amount of habitat in the landscape. Squares show the conductance of landscapes with a random selection of cells chosen to be habitat. The red line is based only on the 100% point and the expectation that conductance is proportional to amount of habitat squared.

We first developed the conductance metric in 2012 and we found that it is correlated to the speed with which a species can spread through a landscape, from a specified source location to a specified target. A key difference between this and most other connectivity metrics is that it incorporates both reproduction within habitat patches and dispersal between habitat patches, over multiple generations (further explanation here). Sometimes there could be many very well-connected patches in a network, and yet no easy way for a species to cross the landscape from end to end. This could be a problem for the species’ survival, if staying within its current regions of occupancy is unsustainable, for example if it is being pushed northwards by climate change. Continue reading

Space-time continuum and conservation planning: Helping Species Adapt to Climate Change

Post provided by Diogo André Alagador

The world’s most threatened felid (Iberian lynx) is endemic in a region predicted to be severely impacted by climate change: the Iberian Peninsula. ©lynxexsitu.es

The world’s most threatened felid (Iberian lynx) is from a region predicted to be severely impacted by climate change: the Iberian Peninsula. ©lynxexsitu.es

Climate change is driving many species to alter their geographic distributions. The ranges of some species contract, expand or shift as individuals track favorable climate conditions. In some cases, threatened species are moving out of protected areas. These trends are expected to intensify in the coming years.

To increase conservation effectiveness within protected areas in the future, researchers at the Research Center on Biodiversity and Genetic Resources at the University of Évora and the Department of Mathematics of the Faculty of Sciences and Technology from the NOVA University in Lisbon, Portugal, have come up with a set of modelling tools to optimize the scheduling of conservation area allocation as the climate changes. These take into account restrictions of conservation area expansion derived from the prevailing socio-economic activities. “The objective is to select the best dispersal corridors for each species considering a budget restriction or competition with other socioeconomic activities” said Diogo Alagador. “These selections are complex and non-trivial as they incorporate decisions on the spatial and temporal trends of large sets of species.”

The concept of a spatio-temporal corridor for a species in an environmental heterogeneous region.

The concept of a spatio-temporal corridor for a species in an environmental heterogeneous region.

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