You would have to have been living in a bubble to be unaware of the fires that swept across over 20 Kansas Counties and Oklahoma, Colorado, and Texas this past week. And these are in addition to the major grass fires from last spring. Media has reported the devastation and the why – howling winds that changed direction, low humidity, and a great deal of fuel due to last summer’s rains. But what exactly is the connection between fire and the prairie.
If you live in Kansas, you are familiar with the yearly ritual of ranchers burning the prairie in the Flint Hills. They due this to eliminate plant residue and rejuvenate this year’s grass growth. In our area, pastures are burned, though not as frequently, for similar reason and to keep undesirable plants away. However, prairie and fire have been linked for thousands of years.
Many think that the prairie, grassland, is grassland due to a lack of rainfall and heat. While less moisture certainly can play a major role, it isn’t the determining factor. If that were the case, much of the traditional Corn Belt would have been forest, not grass. This would be the case for much of Kansas east of I-135. The driving ecological factor that determined grassland vs. forest is fire. Periodic fires, typically the result of lightning kept tree growth at bay. And grasslands can be found far north of here. So why are these fires so serious?
• In the past periodic grazing by herds like the American Bison helped keep growth down. Before European settlement in North American an estimated 60,000,000 roamed the prairie. They were constantly on the move. We now have fenced off the prairie, many thousands of acres are in the Conservation Reserve Program, and we don’t burn as much for a variety of reasons. That leads to the next point.
• Where we have quit burning, native and invasive shrub and tree species have been allowed to flourish. Some such as Eastern Red Cedar are extremely flammable, even when green. And without grazing and periodic controlled burns, fuel is allowed to accumulate. Before we settled here, these types of fires occurred, however, there weren’t structures and permanent settlements in the way. Which leads to the last point.
• In Western Kansas much of the damage was to farmsteads and operations. In other parts it was to family homes of people wanting to live in or close to the country. These areas are prairie with a mixture of grasses, trees, and shrubs. Much of the land hadn’t seen a controlled burn in ages and the cleared area around the houses was insufficient to help protect the homes. And with the excessive winds, it may not have mattered how large the cleared area was.
One last thing of interest, the humidities this past week were incredibly low with some dew points below zero degrees Fahrenheit while the air temperature was around sixty. That meant the air would have had to cool from 60 to below zero before the air would have been saturated which is incredibly rare, even in Kansas.