Angelo Coast Range Reserve

16 Jul, 01 PM - 06 Aug, 11 AM

Fluvial Controls on Tree Uprooting and its Effect on Riparian Tree Survival Fluvial processes create patterns in the riparian plant populations and distributions, by affecting seed dispersal, germination, establishment and survival from flooding (Cunnings, 2014, 2016). The dynamics of the riparian habitat mosaic is, therefore, fundamentally affected by the feedbacks between the vegetation and fluvial processes. The mechanisms underlying this dynamics between rivers and riparian vegetation have been investigated for the white alder (Alnus rhombifolia) along the south fork of the Eel River (California, USA) (Cunnings, 2014, 2016; Jablkowski, in progress). The Eel Rivers hydrological regime is one of fall and winter precipitation (storms) and consequently several increasing and decreasing hydrographs. Spring and summers are dry with river flow decreasing to base-flow. The dispersal of white-alder seeds can be described by an advection and dispersion model with coupled eddy compartments that explains the location (in eddies after riffles - a geomorphic constraint) and timing (after the last descending hydrograph in late winter) of where seeds are deposited (Cunnings, 2014, 2016). After the seed is dispersed, germination is determined by: the stage height (persistence from being washed away), the temperature that determines the amount of time required for germination and the matric water potential as the threshold for germination. Overall, the fastest germination times occurred near the end of the dispersal period. The spring and summer hydrological regime alder seedlings can grow at most observed matric water potentials, so survival depends on growing enough of a root system to survive the fall storm flows (Jabikowski, in progress). The present research investigates the next period of the alder survival. The following the first summer after germination survival will mainly depend on the ability of the tree to avoid being uprooted by floods. A mechanistic model for tree uprooting will use thirty individuals of riparian White-alder of varied sizes to simulate the overturning force of floods causing the trees to deflect around the rotation axis and the center of mass of the tree to moves over the hinge point of the roots and the weight of the tree to contribute to the uprooting moments. The uprooting moments are resisted by the tree anchorage moment and weight (at small deflection angles). If the uprooting moment exceeds the resistive moments of the tree, the tree will deflect further and finally uproot. The uprooting forces and the trees resistance will determine by a tree winching which measures the uprooting and resistive forces.

Visit #46615 @Angelo Coast Range Reserve

Approved

Under Project # 20935 | Research

Eel River Alder Study: hydrological and geomorphic definitions of riparian tree population dynamics.

faculty - University of Calgary

Reservation Members(s)

Group of 1 Other Jul 30 - 31, 2016 (2 days)
Cas Porto Jul 16 - Aug 6, 2016 (22 days)
Patrick Jablkowski Jul 16 - Aug 6, 2016 (22 days)
Sarah Kroeker Jul 16 - Aug 6, 2016 (22 days)

Reserve Resources(s) | Create Invoice

Wilderness Lodge 3 Jul 16 - Aug 6, 2016
Wilderness Lodge 1 Jul 30 - 31, 2016
Network 3 Jul 16 - Aug 6, 2016