The Pacific Northwest didn't have a bison population like the plains. I think looking into the difference between elk and bison eating behavior might help guide the riparian zone pasturing strategy here.
With the vegetation covering the ground, you have less runoff, less heat evaporation and transpiration happens through the plants, the ground springs replenish, the aquifers below recharge as well. With lower ground temperatures, the ambiant temperatures are lower and the plants have a larger growing time as well as dew in the mornings to remoisturize the ground.
