Photo of the Week – November 5, 2015

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.

October 1, 2011

October 1, 2011

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.

July 25, 2012

July 25, 2012

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.

TNC Niobrara Valley Preserve, Nebraska.

October 23, 2015

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.

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About Chris Helzer

Chris Helzer is the Director of Science for The Nature Conservancy in Nebraska. His main role is to evaluate and capture lessons from the Conservancy’s land management and restoration work and then share those lessons with other landowners – both private and public. In addition, Chris works to raise awareness about the importance of prairies and their conservation through his writing, photography, and presentations to various groups. Chris is also the author of "The Ecology and Management of Prairies in the Central United States", published by the University of Iowa Press. He lives in Aurora, Nebraska with his wife Kim and their children.
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6 Responses to Photo of the Week – November 5, 2015

  1. Dan Tarpley says:

    Chris: I have been watching this blog since the fire. I am very interested on the recovery after the burn and especially the time lapse photos. The fire killed almost all our pines on the TNT across the river. I think the burn was much more intense there. Continue your work I enjoy the blog and more so when discussing the fire recovery.

    W Dan Tarpley President HRR Enterprises Inc. Sent from my iPhone

  2. James McGee says:

    I think the reason the pine woodland suffered catastrophically from the wild fire in 2012 was because it had not been burned in such a long period of time. I think of frequent low intensity fires as being like exercise for the forest. If the forest gets ‘exercise’ before the big race then it will do well. If it does not get enough practice for the big race then it will die. A forest does not have the option of dropping out of the race and trying again later.
    The result of the forest receiving frequent fire is branches and trees are more widely spaced which reduces the chance of crown fires that are so devastating. Also, trees better adapted to fire dominate. A good example from savanna is burr oaks compared with red oaks.

  3. Julie Bain says:

    Hi Chris, In the southwest, where I come from, it is gospel and science that ponderosa pine trees are well-adapted to fire when exposed to it frequently (every 5 to 15 years). Trees having only ten percent of their crowns intact mostly survive, as observed in the small trees. When an entire stand dies, such as across the river, it is usually because the trees haven’t been exposed to the fire that thins them out and the fire is a crown fire rather than a ground fire. It seems more correct to say that ponderosa pine is not well-adapted to fire as managed by people over the last 100 years. Let me know if I am missing something. Thanks as always for a great read and the eye candy. Julie

    • Cody Wienk says:

      I would agree with Julie. Ponderosa pine are fairly well adapted to fire, but to surface fire and not crown fire. Seedlings and saplings are more sensitive to surface fire, but that helps keep the stands thinned out so stand density and ladder fuels don’t build up to the level that leads to crown fire.

  4. K Corman says:

    Hi Chris, I would agree with Julie’s comment. Ponderosa pine are well adapt to fire with thick bark, open crowns, and buds hidden within moist needles. However, the fire they are adapted is low-intensity and high-frequency which produces much more open stands and more variation in age of trees. Historic fire return internals I have heard for ponderosa in the Black Hills are every 5-35 years depending on location and site characteristics.
    Also, I notice some pruning of the lower limbs on the large pine in the picture (another adaption to fire). It looks like this started before the 2012 wildfire. Was the foreground part of any prescribed fires before the wildfire?

  5. Chris Helzer says:

    Great comments. I was sloppy with my writing about pondo pines and their fire sensitivity. What I meant was that YOUNG trees are vulnerable to fire. As several of you have rightly pointed out, mature trees are nicely adapted to low intensity fires, and those fires can be critical for maintaining healthy woodlands. Thanks for catching my error – I’ll fix it in the post.

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