CONTROLLING A
HOW FIRE CAN BE HELPFUL
hen the oak leaves fall at the end of October, Landscape Ecology Manager Leslie Berns knows it’s time for our controlled burn program to begin. “We sometimes start burning grasslands before that,” said Leslie, who manages the program, which restores around 3,000 acres of grassland and woodland each year. “But then again, grasslands dry out at the same time oak leaves are coming down, since all these species evolved together with fire.”
Controlled burns are prescribed to recycle nutrients into the soil, remove thatch from previous growing seasons, and top-kill invasive woody plants. It’s like pressing a reset button. Because wind and weather conditions for a controlled burn are so specific, the program may only get 25 suitable days per year. “The vegetation has to be dry, so we’re talking about dormant season,” Leslie said. “There can be no snow on the ground and
temperatures must be above freezing. You have to have some wind, but not too much wind.” Another factor is relative humidity. “Often the relative humidity may be too high, generally more than 50 percent,” said Restoration Ecologist Ken Klick. “The fire doesn’t get going, or it’s spotty.” While crews conduct controlled burns only in spring and fall, Leslie prepares for them every month of the year. Plans and permits are organized well ahead of a burn day.