Toward a general measure of landscape connectivity for climate change

Jennifer CostanzaCurtis Belyea, James Watling, Ron Sutherland, Nick Haddad

Biological Conservation 142 (2009) 14-32

Increasing connectivity consistently ranks as the most popular strategy for climate change

2009, Biological Conservation

Big, bold plans for landscape connectivity are emerging

Theobald et al. 2012 Conserv.Lett.WA Connected Landscapes Project

Courtesy of Ron SutherlandFrom the Wildlands Network

Connectivity planning in the Southeast

Black bear (Ursus americanus)

Rafinesque’s big-eared bat(Corynorhinus rafinesquii)

Timber rattlesnake(Crotalus horridus)

Approach: connectivity for multiple species

Research questions

•Where are the most and least threatened connections for each species?

•Do species vary in the climate change threat to their connectivity?

Alternative resistance surfaces

Niche model Empirical (literature)

Red High resistance

Blue Low resistance

Expert opinion (surveys)

Black bear

Mapping connectivity

Resistance surface Habitat nodes Connections

Linkage Mapper software: least-cost paths between nodes

Future threat is change in suitability

Black bearpercent change in suitabilityrecent to 2050, A2 scenario

Red Decrease

Blue Increase

Red Large decrease

Orange Moderate decrease

Blue Increase

Black bearniche resistance, Linkage Mapper

Change in habitat suitability

BatSnake Bear

Changes in suitability by ecoregion

Red = largest decreaseBlue = increase

Which links connect to important nodes?

Change in Integral Index of Connectivity for nodes(Pascual-Hortal and Saura 2006)

Dark blue = 10% most importantnodes

Black bear

Where are the important links that are most and least threatened?

BatSnake BearRed = 10% most threatBlue = 10% least threat

Summary

• We mapped climate change threat to habitat connections for three species in the Southeast

• On average, suitability decreased within mapped connections, and species were similar in average amount of climate change threat

• The geography of climate change threat varied by species

• We are doing parallel work to examine effects of future land use change on connections