PARENT SESSION
Poster Session 39: Late Breaking and Newsworthy Posters
Friday, August 12, 8:30 AM - 10:30 AM, Exhibit Hall 220 A-E, Level 2, Palais des congrès de Montréal

Developing a dynamic model to predict the recruitment and survival of Salix nigra in response to flooding.

Ahn, Changwoo^*,1, Moser, Kurt¹, ¹ George Mason University, Fairfax, VA

ABSTRACT- Black willow is a woody species competitive with moist-soil plants, an important food source for migratory birds in the Illinois River floodplain. Since flooding regimes favorable to moist-soil plants may also be conducive to establishment of the flood-tolerant black willow, it is important to identify flooding regimes which might discourage woody species to maximize annual moist-soil plant production. Predictive models can be used to evaluate management options. The model presented describes the physiological responses of black willow to flooding regime, predicting black willow recruitment and early survival for a 1m² floodplain patch over a simulation period of the first three years. The model responds to daily water depth, flooding depth and duration, length of growing season, and timing of seed dispersal. The model was tested for seed germination and seedling growth of the tree in the elevation ranges that were observed as historic tree lines from aerial photos at three locations along the river. Simulations showed the establishment of the tree population at treeline elevations tested, and also revealed variability of seedling survival as affected by flooding regime, especially during the growing season. The survival/recruitment was sensitive to capillary water depth, and that seed dispersal timing had effects on population size and distribution. More alternative scenario-based runs and rigorous testing should be conducted to further improve the model

Key words: Black willow model, Illinois floodplain river, moist-soil plants, flooding regime