As fall approaches, plants move nutrients from their tops into their roots to store through the winter. This banking system is especially important for tallgrass species, which sprout later in the spring than their shortgrass competition. Since the early sprouters can draw first on nutrients stored in the soil, the nutrients stored by the plants themselves may be the only resource left for the tallgrass. But if cattle mow the grass stalks all summer, little green material is left to fill the nutrient reservoirs before winter, and the tallgrass will be at a disadvantage next spring. The city grazes cows on some of its prairie plots to mimic the action of the bison.
Tests show that grazing in winter and spring is most effective.
However, summer-long grazing, especially with this year's dry conditions, meant hungry cattle took a heavy toll on the South Boulder Creek tallgrass tract. We ll have to wait and see if it recovers in the spring. He believes that a combination of prescribed burning and winter grazing would best serve Boulder s tallgrass prairie parcels. But this site won t stay here without some attention to management. Seastedt also hopes the new department will seek expert scientific counsel on managing Colorado s rarest ecosystem.