Resilience of Alaska’s boreal forest Terry Chapin Bonanza Creek LTER

Alaska’s big transformations ~12000 yr BP: climate warmed, first people arrive, megafaunal extinction, loss of steppe tundra 8000 yr BP: arrival of Athabascan-like people 6000 yr BP: Shift to black spruce system

Alaska’s big transformations ~12000 yr BP: climate warmed, first people arrive, megafaunal extinction, loss of steppe tundra 8000 yr BP: arrival of Athabascan-like people 6000 yr BP: Shift to black spruce system fur trading brought cash economy; culture challenged by missionaries; Euroamerican diseases decimated indigenous populations 1950 compulsory education, sedentization into permanent villages with costly infrastructure

Carpenter 2003 Identifying and managing critical transitions

Chapin et al. 2010

Drivers of change Climatic changes –Effects on ecosystems –Effects on disturbance regime Potential land-use changes Climate-disturbance interactions Socioeconomic changes –Rising disparities of power and economics –Resource development

March-June Average Temperature (C°) Alaska: Rupp

Current Soil temperature at 1 m

Landscape drying

Kenai bark beetle outbreak

Area burned in W. North America has doubled in last 40 years

Close connection between ecology and culture If we change ecology, what happens to culture? Mimi Chapin

Sources of vulnerability (Amplifying [positive] feedbacks) Thermokarst Feedbacks to the climate system –Carbon loss (wildfire) –Methane emissions (thermokarst) –Albedo (shorter snow season) Rural poverty –Rising energy costs –Urban migration

Chapin et al. 2005

Sources of Resilience (Stabilizing [negative] feedbacks) Permafrost-organic matter interactions Species-biogeochemistry-fire interactions Predator-prey cycles Landscape reorganization Fire-vegetation-climate albedo feedbacks Subsistence sharing networks Responsive political institutions (a need) Community-univ. partnerships (in progress)

Johnstone et al. 2010

Lloyd and Fastie Forests are expanding

Scheffer et al Evidence of potential thresholds

Scheffer et al. 2013

Enhancing resilience Protect wetlands Manage landscape connectivity –Foster landscape reorganization Manage predator-prey cycles –Avoid predator pits, prey population booms Foster cultural integrity and subsistence Increase institutional responsiveness Foster local innovation and experimentation

Opportunities for transformation (Assess tradeoffs!!) Wood harvest to reduce fire risk, promote habitat conversion, and reduce diesel use Manage proactively for inevitable ecosystem transformations (e.g., grassland expansion) Foster diverse patterns of landscape reorganization Integrate local management of multiple subsistence resources