PARENT SESSION
Tuesday, August 8, 8:00-11:30 am
Symposium 6 - The detection of catastrophic thresholds: perspectives, definitions, and methods
Steamboat, Mezzanine Level, Cook Convention Center
Organized by: RA Washington-Allen (washingtonra@mac.com) and L Salo

This symposium is focused on the conception, definition, and detection of ecological thresholds or regime shifts, particularly on the operational use of catastrophe theory, time scale calculus, self-organization, scaling laws, and other aspects of complex systems science in natural resource management.

Cross scale structure, thresholds, and the generation of novelty in discontinuous complex systems.

Allen, Craig^*,1, ¹ USGS Nebraska Cooperative Fish & Wildlife Research Unit, Lincoln, NE

ABSTRACT- Adaptive cycles and self-organization occur at discrete scales within complex systems. Changes in scale domains are characterized by thresholds, reflecting abrupt changes in pattern and structure with changes in scale. The existence of these thresholds has several important implications. First, it suggests that variables within systems are distributed discontinuously. Second, it suggests that interactions and processes, such as community-level interactions for animals, are compartmentalized by scale. Third, theory and empirical analyses suggest that thresholds generate novelty and innovation as a result of the variable dynamics observed at these transitions. Heightened variability at the species, population and community level has been observed at scale breaks as indicated by phenomena such as invasion, extinction, nomadism and migration, reflecting both heightened variability and increased opportunities for innovation. Invasions and extinctions represent turnover in animal community composition, and migration and nomadism are annual or unpredictable periodic turnover, and are novel solutions to resource variation in space and time. Continuously creating novel solutions to current or potential challenges insures a maximization of energy/resource use within a system without reorganizing the system, and allows a system to be dynamic in its internal structure, connectivity and relationship with other systems, and promotes adaptation. Here I offer a conceptual framework that explores the relationship between thresholds and innovation and novelty in complex systems. Understanding the sources of variability and novelty may help us better understand and manage complex systems such as ecosystems.

Key words: Novelty, Cross-scale structure, Complexity