Photo of the Week – March 31, 2016

Many of you remember previous posts about the wildfire that swept across the Niobrara Valley back in July 2012.  About half of The Nature Conservancy’s Niobrara Valley Preserve burned during that event.  Through some funding from the Nebraska Environmental Trust Fund and assistance from Moonshell Media, we set up an array of timelapse cameras to document the recovery of our site from that fire.

I’ve spent much of this week looking through many thousands of images from those cameras.  The cameras (when they are working properly) take one photo each daylight hour.  Between April 2013 and today, that is approximately 14 billion images – or so it seems through my weary and bloodshot eyes.  As I’ve been poring through these photos, looking for stories they can tell us, one thing that keeps my fire stoked (so to speak) is the periodic discovery of dramatic light and/or scenes captured by the automated cameras.  Today, I’m sharing a selection of those accidental masterpieces taken by one particular camera that was set up to peer downstream from near the top of the bluff north of the Niobrara River.

April 2013, just before the first growing season following the wildfire. The ground was still bare and punctuated by the skeletons of ponderosa pine and eastern red cedar trees killed by the fire.

April 2013, just before the first growing season following the wildfire. The ground was still bare and punctuated by the skeletons of ponderosa pine and eastern red cedar trees killed by the fire.

When we set up this camera, my hope was to watch the re-greening of the hills beneath the dead ponderosa pine and eastern red cedar trees and maybe catch a nice sunrise or two.  Both objectives were achieved, along with some other really gorgeous photographs – some of which happened only because the camera malfunctioned.

October 2015. This image caps off the third growing season of recovery from the wildfire. Bare slopes formerly underneath an overgrown canopy of pine and cedar trees

October 2015. This image caps off the third growing season of recovery from the wildfire. Bare slopes have grown a covering of grasses, shrubs, and other plants.  Many of the plants seen here are annuals, yet to be replaced by perennials, but those are slowly spreading on the slopes as well.  A number of yucca, sumac, and other shrubby plants have regrown from their bases and we are waiting to see how that transition continues.

August 2015. A beautiful foggy morning.

August 2015. A beautiful foggy morning.

May 2013. This photo wasn't supposed to have been taken because the camera was only meant to shoot during daylight hours. However, the controller somehow decided to take this photo at 9:13pm and it is a beautiful one.

May 2013. This photo wasn’t supposed to have been taken because the camera was only meant to shoot during daylight hours. However, the controller somehow decided to take this photo at 9:13pm and it is a beautiful one.

November 2015. A serene photo taken in the middle of a snowstorm.

November 2015. A serene photo taken in the middle of a snowstorm.

December 2013. This is one of the few sunrise photos we got that had much color in the sky.

December 2013. This is one of the few sunrise photos we got that had much color in the sky.

August 2014. Annual sunflowers dominate the foreground of the image, as they and other annual plants cover the hills in the background.

August 2014. Annual sunflowers dominate the foreground of the image, and they and other annual (and some perennial) plants cover the hills in the background.

August 2014. A foggy morning with the same sunflowers seen in the previous photo.

August 2014. A foggy morning with the same sunflowers seen in the previous photo., but taken a week earlier.

June 2015. Flowering stalks help highlight the abundance of yucca on a cloudy summer evening.

June 2015. Flowering stalks help highlight the abundance of yucca on a cloudy summer evening.

January 2014. A hazy sunrise on a cold winter morning.

January 2014. A hazy sunrise on a cold winter morning.

March 2014. Fog, frost, and a sunrise through silhouettes of trees make this my favorite photo of the three years of timelapse images fromthis camera.

March 2014. Fog, frost, and a sunrise through silhouettes of trees make this my favorite photo of the three years of timelapse images from this camera.

So, there you go.  A beautiful series of images that also show what happens following a wildfire.  Ecological processes don’t stop after a fire, they just shift into a different gear.  We have done nothing to aid or enhance the recovery of the woodland at this site.  To this point, we’ve just been watching for signs of trouble – invasive plants that might take advantage of the situation, serious soil erosion issues, etc.  There hasn’t yet been any reason to step in and act.  Plants and animals are thriving on the slopes shown in these photos, though the composition of those communities has changed pretty dramatically – and continues to change.

Ecological resilience is about the ability of natural systems to absorb shock and keep functioning.  The pine woodland is gone from these hills, and it will probably take many decades to show up again because they are pretty far away from unburned pine woodland that could provide seed.  In the meantime, we will do our job as land stewards and try to facilitate the most biological diversity we can, using the primary tools available to us – prescribed fire and grazing to manipulate plant competition and habitat structure, and spot-treatment (as needed) with herbicides to control invasives.

We hope to keep these timelapse cameras going for at least several more years.  Hopefully, that will help us continue documenting the amazing resilience of nature, and the specific stories playing out at the Niobrara Valley Preserve.  If nothing else, we should be at least get some more beautiful, if accidental, photographs to enjoy.

Continuing Wildfire Recovery at the Niobrara Valley Preserve

When I was at the Niobrara Valley Preserve a couple weeks ago, I spent some time exploring the area north of the river where the 2012 wildfire ripped through oak savanna and ponderosa pine woodland.  As discussed in earlier posts, the density of trees, especially eastern redcedar, fueled a fire that killed nearly every pine and cedar in the 3000 acres of Preserve land on the north side of the river.  Most oaks and other decidous trees were topkilled, but many resprouted within a few weeks of the fire.  I have been following the regrowth and recovery of this part of the Preserve with great interest, and trying to help the Preserve staff as they think about how to manage the area in the future.

Here is a series of photos from an uphill hike I took on September 18.  The photos are roughly in order of elevation, starting at the river road (just above the floodplain) and proceeding upslope to the ridgetop at the north edge of the valley.

Hemp and marestail

On the first slopes above the river road, hemp (Cannabis) and marestail (Conyza) dominate the understory of a woodland that now consists mainly of skeletons of eastern redcedar and oak trees.  Most of the oaks have resprouts from their bases, however, and a few still have live branches up high.

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Marestail and cedar skeletons

The abundance of marestail (a native pioneering species) is especially interesting to me because it’s the same species that usually dominates two-year-old prairie plantings.  This is the role it plays in ecosystems, and it plays it well.  It’s difficult to see very much below the marestail, but when I looked closely, I found scattered grasses, sedges, and wildflowers – a good sign of future recovery.

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ragweed

As I walked higher and got into the prairie-covered slopes, ragweed (Ambrosia) replaced marestail as the visually dominant plant in the formerly shaded areas beneath cedar trees.  The ragweed is playing the same role as the marestail – quickly filling in the open space until a more permanent plant community establishes.  That community should move in pretty quickly in cases like that shown in this photo, in which a cedar tree is surrounded by prairie.

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prairie

Higher up the slope, large areas of prairie had not been encroached upon by cedars, and recovery after the fire was just as predicted – quick and easy.  The vegetation was still a little thin, but that was more of an aftereffect of the 2012 drought than of the fire.  In this image you can see the scattered cedars further downslope (such as the one featured in the previous photo).

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Oaks

Almost every bur oak tree I saw was vigorously resprouting from the base.  Those numerous stems should thin themselves down to three or four major trunks over the next decade or so.  Some of the branches were already 6-8 feet high, so recovery is proceeding quickly.  These oaks were growing along the edge of one of many steep draws scattered along the north side of the river.  As I was wading through 3-4 foot tall marestail, I couldn’t help but wonder if that dense growth and the presence of mountain lions in the area explained the near absence of deer browsing on the oak sprouts (Ecology of Fear).   I don’t know if the deer felt it, but I sure had moments of discomfort, knowing that if a lion was hiding in the weeds nearby, the steep slopes and thick vegetation would make escape nearly impossible.  It made my hike a little more exciting, but I didn’t stay down in those draws very long…

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Sedges

I was surprised and pleased to see numerous examples of large sedge patches growing under the marestail forest, especially on the steeper portions of draws.  I don’t remember seeing many sedges last year, so either I missed them or they are expanding rapidly.  Either way, they will sure help stabilize those slopes as other plants move in to join them, and they’ll also help carry fire when we restart fire management of the area.

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Pine woodland

High on the slopes, where ponderosa pine and eastern redcedar had dominated just a few years ago, the scenery was every bit as spectacular as it had been before the fire – just different.  Marestail was abundant here too, but there was quite a bit of grass and wildflower cover as well, and several shrub species were flourishing, including smooth and skunkbush sumac, chokecherry, snowberry and others.  Despite the density of scorched tree trunks, the overall feel of the slopes was not one of death and destruction, but rather of abundant life.

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Ridge top

Even the very steep erodible slopes at the very edge of the ridge top were full of previously established perennial wildflowers and shrubs, as well as colonizing annuals.

I came down the slope after my walk with a great feeling of optimism.  My greatest worries about this area of the preserve had been that

1) Invasive plants would fill the slopes before the native vegetation could recover, and we’d be faced with the difficult challenge of attacking those invasives in difficult terrain.

2) Numerous eastern redcedar trees would colonize the slopes before there was enough vegetation to carry prescribed fires to knock those cedars back.

3) Soil erosion would be so severe that the seed bank needed to reestablish the native plant community would wash down the slope, along with the topsoil those plants needed to grow.

None of those three have occurred – or at least to the extent I feared they might.  There has been some erosion, but much less than I anticipated, and it doesn’t seem to be affecting vegetation recovery much.  I haven’t seen any truly invasive plants yet – which doesn’t mean they aren’t there, but they sure aren’t roaring in.  Finally, the recovery of the vegetation has been fast enough that we should be able to start running prescribed fires up the slopes within the next few years.  I didn’t see any little cedar trees on my walk, and while I’m sure there are a few around, the abundance is much less than I feared, and our ability to use prescribed fire should make it fairly easy to control them, except on the steepest slopes.

Most of all, the beauty of the Niobrara Valley has survived the wildfire.  The pines are gone from some parts of the valley, but are still doing well in other areas nearby, including other parts of the Niobrara Valley Preserve.  Whether or not (or when) they’ll return to the site of the 2012 fire is still an open question.  Regardless, there is abundant life on the slopes north of the river.  Just because those slopes will be dominated by different species than before doesn’t change the scenic or ecological value of the site.  It’s still one of my favorite places on earth.