Paul Rogers - The many faces of quaking aspen: Biogeography meets resilience management
Managers and scientists alike commonly practice quaking aspen (Populus tremuloides Michx.) management with a 'one-size-fits-all approach' based a simple successional model: aspen as the "pioneer" species is overtaken by locally dominant confers as time increases post-disturbance. We now know that aspen reacts to disturbance, at various scales, along multiple pathways. How might this realization affect a more informed management/restoration approach? We examine a variety of aspen types as ecological systems; not exclusively seral dynamics and single species management. The framework presented here distinguishes three first-order “functional types” with a total of seven embedded second-order “subtypes”: Seral (boreal, montane), Stable (parkland, Colorado Plateau, elevation/aspect limited, terrain isolated), and Mixed Seral-Stable (riparian). This presentation draws from a larger review paper on aspen functional types to describe unique disturbance processes in varied geographic settings. Important features of these distinctions include physiological and climate conditions, stand structures and dynamics, and disturbance types and periodicity. The talk will briefly look at confounding factors—such as past management, ungulate herbivory, and climate futures—that impact the functionality of aspen disturbance regimes. Finally, the discussion will explore appropriate short- and long-term management considerations for each of the aspen sub-types. The quaking aspen framework lends itself to future management and research courses that seek to emulate ecological processes rather than alter or control them. There is potential for applying a functional approach to other vegetation types (e.g., ponderosa pine, sagebrush, short-grass prairie) whose wide geographic ranges engender diverse adaptations, as well as management responses.