Climate Change and the Loss of Whitebark Pine Ecosystem Resilience in British Columbia
Description
An ecosystem’s resilience depends on its vulnerability to pulse disturbance events and its capacity to reorganize following these disturbances. Whitebark pine ecosystems in British Columbia are in serious trouble, on both counts, due to global climate change, exotic blister rust infections, and possibly fire exclusion policies of the past. Warming climates have caused mountain pine beetle outbreaks to expand throughout much of the range of whitebark pine, into areas where beetles were previously unable to persist. Due to their age, at least 35% of whitebark pine forests in British Columbia have been highly vulnerable to expanding beetle outbreaks. Among old stands sampled in both the northern and southern parts of whitebark pine’s range, 60-100% of trees were killed by beetles between 2005 and 2008. In some very rare cases, trees resisted beetle infestations. The capacity for whitebark pine ecosystems to reorganize after beetle or fire disturbance in British Columbia is becoming increasingly difficult. Losses of mature trees from the recent beetle outbreak and blister rust infections are substantially reducing seed sources. Young trees already established in open post-fire stands, on dry sites and timberline habitats are frequently killed by blister rust. Together, beetle outbreaks and blister rust are accelerating ecological succession and reducing the abundance of whitebark pine ecosystems in British Columbia’s landscapes. Using various model projection techniques, this study of ecosystem resilience showed that climate change will continue to make whitebark pine ecosystems increasingly vulnerable to beetle outbreaks and substantially reduce the ability of whitebark pine to regenerate by 2080. The future for whitebark pine ecosystems looks grim. The province of British Columbia has taken various steps to promote the conservation of whitebark pine ecosystems. They will be outlined in this presentation.
Climate Change and the Loss of Whitebark Pine Ecosystem Resilience in British Columbia
An ecosystem’s resilience depends on its vulnerability to pulse disturbance events and its capacity to reorganize following these disturbances. Whitebark pine ecosystems in British Columbia are in serious trouble, on both counts, due to global climate change, exotic blister rust infections, and possibly fire exclusion policies of the past. Warming climates have caused mountain pine beetle outbreaks to expand throughout much of the range of whitebark pine, into areas where beetles were previously unable to persist. Due to their age, at least 35% of whitebark pine forests in British Columbia have been highly vulnerable to expanding beetle outbreaks. Among old stands sampled in both the northern and southern parts of whitebark pine’s range, 60-100% of trees were killed by beetles between 2005 and 2008. In some very rare cases, trees resisted beetle infestations. The capacity for whitebark pine ecosystems to reorganize after beetle or fire disturbance in British Columbia is becoming increasingly difficult. Losses of mature trees from the recent beetle outbreak and blister rust infections are substantially reducing seed sources. Young trees already established in open post-fire stands, on dry sites and timberline habitats are frequently killed by blister rust. Together, beetle outbreaks and blister rust are accelerating ecological succession and reducing the abundance of whitebark pine ecosystems in British Columbia’s landscapes. Using various model projection techniques, this study of ecosystem resilience showed that climate change will continue to make whitebark pine ecosystems increasingly vulnerable to beetle outbreaks and substantially reduce the ability of whitebark pine to regenerate by 2080. The future for whitebark pine ecosystems looks grim. The province of British Columbia has taken various steps to promote the conservation of whitebark pine ecosystems. They will be outlined in this presentation.
https://digitalcommons.usu.edu/nafecology/sessions/whitebark/11