Yellowstone. Glacier. Mount Rainier. North Cascades.
These iconic national parks represent some of the largest protected areas in western North America. But without connectivity to the surrounding landscapes, they act as isolated islands for the many species of conservation concern that live in them.
Newmark, W.D., Halley, J.M., Beier, P., Cushman, S.A., McNeally, P.B. and Soulé, M.E. 2023. Enhanced regional connectivity between western North American national parks will increase persistence of mammal species diversity. Scientific Reports 13: 474.
As global conservation efforts grow to protect large regions of the planet, more information is needed to understand how we can better connect these regions to create large-scale networks. These networks are becoming increasingly important to realize, as climate change and anthropogenic barriers continue to make movement and dispersal difficult for many species.
While we know that large-scale landscape conservation strategies can work, too few studies have looked at connectivity at the mid- to large-scale and at the community level. A new analysis takes a look at mammal communities at two hypothetical networks in western North America – a Yellowstone-Glacier network and a Mount Rainier-North Cascades network – and asks: what is the value in connecting them?
The analysis is based on relaxation theory, which addresses the delay in species extinction and the phenomenon that declining populations will eventually go extinct in fragmented or degraded habitats. This novel approach is general and can be applied broadly to many regions and taxa (although at the expense of reduced precision), and can be useful for assessing the value of regional connectivity.
In this case, the analysis shows that enhancing connectivity between the national park assemblages would greatly increase species persistence: by an average factor of 4.3, or almost 700 generations, within the Yellowstone-Glacier protected area network, and by an average factor of 4.3, or over 300 generations, in the Mount Rainier-North Cascades protected area network. The added linkages would not only support greater movement and dispersal for species, but also increase average population size by enlarging the amount of area under protection in the region.
This level of connectivity would be challenging, but several techniques could help – an increase in wildlife crossings, planned housing development away from critical linkages, and coordinated management efforts across administrative boundaries. These connections will only become more important as habitat fragmentation continues and climate change creates the need for many species to shift ranges. Putting a number to the value of large-scale, connected networks takes them one step closer to becoming a reality.
Related Posts
Aquatic-terrestrial connectivity sustains communities
Extensive surveys across the United States show that aquatic insect richness strongly shapes bird communities, underscoring the deep ecological connections between freshwater and terrestrial ecosystems.
How well do range shifts mitigate climate change for North American birds?
A continent-wide analysis of more than 400 North American bird species reveals that while many are shifting ranges northward, these movements only partly reduce their exposure to rapidly rising temperatures.
New guidance for transboundary conservation
A new publication from the partners of the Staying Connected Initiative synthesizes recent insights on connectivity conservation across eastern Canada, the northeastern United States, and many Indigenous territories.
