Past Ecosystem Processes and Human-Environment Interactions

The theme for the 10^th International Paleolimnology Symposium is borrowed directly from the IGBP-PAGES¹ program known as Focus 5, which deals with the broader dimensions of human impacts on the Earth’s ecosystems. Because the vast majority of our global ecosystems have a significant history of human impact, viable strategies for their preservation, conservation, or sustainable management require an understanding of long-term responses to climate and human activities.

Key Questions

• Past and present human impacts on global ecosystems
• Interaction of human impacts with climate change
• Sensitivity and resilience of ecosystem to climatic and anthropogenic stresses
• Sustainable management strategies for the future

Learning from the Past

• Define background or pre-impact conditions
• Determine trajectories and rates of change
• Quantify natural variability
• Determine threshold conditions for change

Applying to the Future

• Develop and test predictive models

Topic Areas

As a historical science, paleolimnology has advanced in its ability to decipher ever more detailed, robust, and quantitative information from a complex and fragmentary sedimentary record. The topic areas for this conference will emphasize those areas where the science has made greatest progress and holds greatest potential to address the pressing problems of global ecosystem change.

Geography, spatial scales, and rates of change (Coaxing history to perform experiments)

• Extreme events, threshold responses, abrupt transitions
• Landscape position and large vs. small lakes
• Multiple and regional lake studies
• Impacts at different spatial scales: local to global
• Extreme environments; arid regions, the tropics, Arctic areas, high elevations

Processes, models, and complexities of the sediment record (Making better sense of the past)

• Groundwater/climate/lake interactions
• Diagenesis, taphonomy, and microbial influences
• Testing and calibration of proxies through monitoring and experiments
• Temperature and its complex linkages to sediment records
• Paleo records and mechanistic models of lake/catchment processes
• Spatial patterns of sediment accumulation – multi-core records and models

Ecological impacts, drivers, and environmental applications (Addressing applied and real problems)

• Long-range atmospheric pollution (heavy metals, organic contaminants, acid deposition)
• Climate change and interactions with other human impacts
• Water-use and engineering projects
• Nutrient (N & P) enrichment from domestic and agricultural sources
• Accelerated infill from catchment soil erosion
• Ecological disruptions from species introductions and invasions
• Natural process and internal ecosystem dynamics
• Past human responses to climate and environmental change

¹International Geosphere-Biosphere Programme (IGBP); Core Project Past Global Changes (PAGES)