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42 CLIMATE CHANGE ALBERTAS BIODIVERSITY Identifying Climate Refugia Climaterefugiaareareaswithaclimate currentlysuitableforaspeciesandexpected toretainsuitabilityinthefuture. Species distributionmodelingforborealsongbirds suggeststhattheMartenPelicanandSwann Hillsarelikelytobeimportantclimate refugiaforalargenumberofspecies. Climate refugia are those areas of current species distribution that are expected to retain climatic habitat suitable for the species in the future. Such areas can be important for species conservation since they mitigate the need for adaptation and dispersal and can provide species with additional time to respond to environmental changes. Of the 84 Alberta songbird species modeled by Diana Stralberg and Erin Bayne 2013 42 were expected to see a decline in area of refugia by the end of the century and nine species were expected to retain less than 1 of their original range in refugia. Boreal songbirds rely on more than suitable climate however limitations to forest growth and succession will also impact the potential future distributions of suitable habitat for these species. Diana Stralberg and colleagues in revision extended the refugia concept to evaluate modified refugia or those that track both suitable climate and forest age over time. Boreal forest stands are expected to become younger as natural disturbances such as fire increase in frequency and intensity and forestry activity continues. Considerable young forest will become available and bird species that depend on that forest type like Mourning Warbler can be expected to change distribu- tions rapidly as the climate changes. However sufficient suitable habitat to maintain large populations of old forest specialists like Black- throated Green Warbler will become available only after a lag time of many decades as the forest matures. Conservation planning for boreal songbirds must therefore consider maintaining both stable habitat for those species that are unable to easily shift their distributions and newly suitable habitat for species that are able to occupy new areas. Taking into account constraints placed by forest age conservation areas expected to protect the greatest propor- tion of boreal birds over time are concentrated at higher elevations. By including habitat considerations into the interpretation of species distribution models this modified refugia approach represents a significant refinement in predicting areas that will be of the greatest conservation significance in a changing climate. Boreal-wide results have been summarized for Alberta by Diana Stralberg and colleagues 2014 to suggest that the provinces hill and mountain systems are conservation priorities Fig. 10. The Marten Pelican and Swan Hills in central Alberta are particularly important because they are expected to retain their current upland mixedwood and white spruce forests until the end of the century in the absence of land use change or natural disturbances like fire.