As I was looking at some of my recent photos from our Niobrara Valley Preserve, I realized that I have a series of photos from approximately the same vantage point that illustrates the site’s recovery from the major wildfire back in 2012. If you’ve followed this blog for several years, you’re probably aware that we have a significant timelapse project going on at the Niobrara Valley Preserve that is documenting that recovery as well. Those images will provide a very comprehensive look at change over time, but those cameras weren’t installed until after the fire. The three photos below are interesting because they represent shots taken before, immediately after the fire, and a few years later.
The above photo was taken in the fall before the big 2012 wildfire. The big pine tree on the right is a good landmark to watch as you compare this photo to the next two. The following photo was taken just a few days after the wildfire.
The last photo (below) was taken just a few weeks ago. The grass and other vegetation has clearly recovered nicely from the fire. That’s not really a surprise to any of us who are familiar with grassland fires. Even a very hot summer fire in the midst of severe drought is not typically fatal to most prairie plants. In fact, the drought was harder on prairie plants than the fire was, but even so, those plant species are well adapted to both.
More interesting than the recovery of grasses and wildflowers is the recovery of woody plants. The two small pine trees on the left side of the image look happy and healthy, despite the fact that young ponderosa pines tend to be vulnerable to fire. If you look closely at the image taken immediately after the fire, you can see both of those trees. The one on the right, especially, had the majority of its needles burned by the fire, but both appear to have come out of that stressful period just fine. Why were those two trees able to survive (along with the big tree) here when just across the river, almost every single pine on the south-facing slope died? Most likely, there are multiple reasons, including slope, fire intensity, and the fact that these trees were surrounded mostly by grasses instead of lots of other pine trees (and eastern red cedars). The point of showing these photos isn’t to answer these kinds of questions as much as it is to stimulate them.
It’s also interesting to note that most of the oaks and other big deciduous trees seem to have survived. That is the case across most of the Preserve, although many of the bur oak trees that were growing close to pine and eastern red cedar trees were top-killed by the fire and are now regrowing from the base. A few oaks and other deciduous trees (especially cottonwoods) did die from the fire, but most didn’t.
I’m hoping to put together some timelapse sequences this winter that will help tell the story of recovery from multiple locations across the Preserve. For the most part, those stories will show that the natural communities along the Niobrara River are well-adapted to major disturbances such as the drought and fire that occurred in 2012. The big exception is the pine woodland that was nearly completely wiped out across big swaths of the landscape. The density of pine and cedar trees led to fire intensity that caused 100% mortality in many stands, and while those areas will recover, they will be grassland and/or shrubland for a very long time, and their long-range future as pine woodlands is far from assured.
Aside from those pine woodlands, however, the natural communities across the Preserve did what natural communities usually do in response to fire, drought, and other major events – they continued to thrive.