Uncovering lines of evidence hidden in complex problems: using conceptual models to inform ecosystem-based management of the Missouri River cottonwoods

Unintended consequences arising from the damming and regulation of large multi-state river systems have generated complex socioecological conflicts that must now be addressed to facilitate ecosystem-based management in a holistic, sustainable, and resilient fashion. In these situations, the involvement of numerous stakeholders with disparate and often conflicting values, mindsets, and agendas generate a dynamic decision-making environment riddled with critical knowledge gaps, teeming with uncertainty, and driven by high stakes negotiations perpetuated by a sense of institutional urgency to embrace quick fixes. The system complexity calls for a transparent and prescriptive approach grounded in creative problem solving, transformative design, and collaborative adaptive management. Here, a spiral-based approach to ecosystem modeling is presented emphasizing system conceptualization while encouraging reflection, active learning, and hypothesis-driven monitoring. A case study on the Missouri River focuses on the development of a conceptual model for the cottonwood forest community lining the banks of this highly regulated river system. Between 2006 and 2010, eighty local stakeholders were engaged in six, week-long interactive workshops to integrate their existing knowledge of the cottonwood ecosystems and to synthesize this information into critical drivers, stressors, and valued ecosystem components using conceptual diagramming and tabular crosswalks. The final product has exposed clear lines of evidence tying essential ecosystem responses to measureable endpoints that are now being used to establish performance measures for both alternative comparisons and adaptive management thresholds that will trigger future management responses.