Monday, August 2, 2010: 3:40 PM
330, David L Lawrence Convention Center
Background/Question/Methods
In British Columbia, Canada, the massive mountain pine beetle (Dendroctonus ponderosae) outbreak resulting from interactions of historic climate variability, anthropogenic changes in forest disturbance regimes, and a warming climate has generated broad public awareness that seemingly resilient natural systems can undergo catastrophic shifts that expose underlying social-ecological vulnerabilities. In response, British Columbia has undertaken a comprehensive program of climate change adaptation research (the Future Forest Ecosystems Initiative) involving down-scaled climate projections, ecosystem and tree species modeling, social-ecological vulnerability assessments, rural community planning exercises, and forest and range policy review. The research program uses linked multi-scale ecological models to project climate change impacts. The foundation of most of these modeling exercises is a linear climate envelope-based approach to species and ecosystem change. This study uses a complementary agent-based modeling approach whereby plant:soil feedbacks underlie ecosystem resilience to climate change and interact non-linearly with changes in environmental resources and disturbance regimes. A first-generation “toy” model was prepared and tested across a range of hypothetical climate and disturbance regime scenarios. Second-generation models are being developed for three landscapes of west-central British Columbia subject to multiple stresses: (1) aspen – scrub steppe ecotone; (2) lodgepole pine plateau landscape, and (3) montane whitebark pine woodlands. Data from a network of ecological monitoring plots and the provincial biogeoclimatic ecosystem classification and disturbance databases are used to parameterize the models.
Results/Conclusions:
A key prediction of the toy model is that negative plant-soil feedbacks result in homogenized, disorganized landscapes in response to rapid cumulative change, whereas positive feedbacks create islands of resistance to change. This finding is (tentatively) supported by the field studies. Unsurprisingly, the agent-based model is more likely to project threshold-type ecosystem responses to climate change than the climate envelope approach. It will take several years for the second-generation models to be satisfactorily parameterized using empirical data acceptable to resource professionals and the sceptical public. By that time, however, the Future Forest Ecosystem Initiative will have terminated. Two conclusions are inavoidable: (1) preliminary social-ecological adaptation exercises must focus on preparing resource professionals and the public for uncertainty rather than on scaled-down predictions; (2) theoretical modeling tools may help professionals and the public understand non-linearity but are unlikely be accepted unless communicated in terms of their real-world experience.
In British Columbia, Canada, the massive mountain pine beetle (Dendroctonus ponderosae) outbreak resulting from interactions of historic climate variability, anthropogenic changes in forest disturbance regimes, and a warming climate has generated broad public awareness that seemingly resilient natural systems can undergo catastrophic shifts that expose underlying social-ecological vulnerabilities. In response, British Columbia has undertaken a comprehensive program of climate change adaptation research (the Future Forest Ecosystems Initiative) involving down-scaled climate projections, ecosystem and tree species modeling, social-ecological vulnerability assessments, rural community planning exercises, and forest and range policy review. The research program uses linked multi-scale ecological models to project climate change impacts. The foundation of most of these modeling exercises is a linear climate envelope-based approach to species and ecosystem change. This study uses a complementary agent-based modeling approach whereby plant:soil feedbacks underlie ecosystem resilience to climate change and interact non-linearly with changes in environmental resources and disturbance regimes. A first-generation “toy” model was prepared and tested across a range of hypothetical climate and disturbance regime scenarios. Second-generation models are being developed for three landscapes of west-central British Columbia subject to multiple stresses: (1) aspen – scrub steppe ecotone; (2) lodgepole pine plateau landscape, and (3) montane whitebark pine woodlands. Data from a network of ecological monitoring plots and the provincial biogeoclimatic ecosystem classification and disturbance databases are used to parameterize the models.
Results/Conclusions:
A key prediction of the toy model is that negative plant-soil feedbacks result in homogenized, disorganized landscapes in response to rapid cumulative change, whereas positive feedbacks create islands of resistance to change. This finding is (tentatively) supported by the field studies. Unsurprisingly, the agent-based model is more likely to project threshold-type ecosystem responses to climate change than the climate envelope approach. It will take several years for the second-generation models to be satisfactorily parameterized using empirical data acceptable to resource professionals and the sceptical public. By that time, however, the Future Forest Ecosystem Initiative will have terminated. Two conclusions are inavoidable: (1) preliminary social-ecological adaptation exercises must focus on preparing resource professionals and the public for uncertainty rather than on scaled-down predictions; (2) theoretical modeling tools may help professionals and the public understand non-linearity but are unlikely be accepted unless communicated in terms of their real-world experience.