Flow & landform dependencies & potential adaptations for recovery of riparian cottonwood trees

Year: 2023
Presenter/s: Michael Burke
Symposium Session: 2023 - 10 Charismatic Megaflora: Cottonwoods Restoration
Topics covered: cottonwoods, flow augmentation, idaho, montana, mountain west, and riparian


Riparian cottonwoods play an essential role in the ecology of riparian ecosystems in western rivers. Yet their recruitment, establishment, and succession are susceptible to a variety of factors which have led to declines in many river systems. In particular, land use changes and river regulation have resulted in substantial impacts. Using the case study of the Kootenai River in north Idaho and western Montana, this presentation will first review quantitative methods developed to apply the concepts of the cottonwood recruitment box model (CRBM) in assessment of impacts resulting from river regulation. We will then review adaptations integrated into restoration planning, implementation, and adaptive management to foster recovery of cottonwood forests along this great river. Adaptations include 1) shifts in the regulated flow regime towards more normative, natural flow patterns, 2) use of tools and observations to recognize the most viable locations within the altered riparian landscape for passive recruitment, 3) strategic adaptations of floodplain areas formed by historical river processes to the realities of the contemporary regulated regime, and 4) adaptive management strategies such as proactive ‘disturbance’ techniques to reset potential recruitment sites plagued by invasive species colonization.