Tag Archives: platte river prairies

Watching a Wetland Breathe

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It’s amazing what you can see when you compress time.

Back in October, I posted some early results from a timelapse photography project at our Niobrara Valley Preserve.  That project is helping document the recovery of the property from a wildfire and to see other changes that our eyes would otherwise miss.  We’re hoping to learn just as much from a similar, though smaller, timelapse project along a restored wetland/stream complex in the Platte River Prairies. Last week, I got my hands on the images from that project and have been looking through them to see what we can learn.

So far, one of the most fascinating things I’ve seen comes from a series of images from July 2012 – right after the camera was installed.  As I scanned through the photos, I realized that one little wetland pool kept changing size.  Its water level (exposed groundwater) was going up and down, making the pool bigger and smaller.  Looking more closely, I realized that it was happening in a regular daily pattern.  I’ve put a selection of images from a three day timeframe into a slideshow below.  If you let your cursor hover over the slideshow window, you can click the arrows to move through the images more quickly.  Watch the water level in the pool in the center of the photo – it starts out full in the morning, empties as the day goes along, and then is full again the next morning.  This same pattern repeated itself over and over throughout the summer.

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I shared what I was seeing with John Heaston, The Nature Conservancy’s Platte River Program Director (in Cozad, Nebraska), who said the pattern is a great illustration of the effects of evapotranspiration – the process through which water moves from the surface of the earth to the atmosphere.  Evapotranspiration is a combination of direct evaporation of exposed water and plant transpiration – the movement of water out of a plant’s stomata (pores in their leaves).

Plants try to regulate how much water they lose through their stomata by opening and closing those pores, but transpiration is also strongly affected by light, heat, humidity, and wind.  During hot, dry and windy days, plants pull a lot of water in through their roots and then lose it into the atmosphere as they try to cool themselves.  In dry soils,  plants may shut their stomata altogether during the hottest part of the day in order to conserve moisture.  In wetlands, however, plants have abundant water, so they can continue transpiration through the heat of the afternoon.  Add that high rate of transpiration to the evaporation of standing water during those same sunny afternoons, and you have evapotranspiration in high gear.

What’s exciting to me about these timelapse images is the opportunity to watch evapotranspiration happen.  The plants in the wetland are pulling so much water from the ground during the day, the local level of groundwater drops by at least a few inches.  During the night, transpiration slows dramatically, and that groundwater level recovers.  Interestingly, the stream to the left of the little pool doesn’t appear to change during the day.  While it doesn’t appear to have a strong flow, there is presumably enough water coming from upstream to negate any losses from plant transpiration, so the level of water stays stable through the day.

Watching the repeating pattern of dropping and rising water levels in a wetland is fascinating.  It’s as if we’re watching the earth breathe – which, in some ways, we are.  It’s also a great example of the power of timelapse photography.  By condensing time, we can see patterns we would otherwise miss.

To see more examples of timelapse photography, check out the Platte Basin Timelapse Project’s website.  They have one of their cameras on this same wetland (separate from the one that produced the images shown above) and you can see a couple years’ worth of images in a few minutes.

The other interesting aspect of both sets of timelapse imagery from this wetland is that 2012 was the driest year on record for this area.  Most streams, rivers, and wetlands went dry last summer, including most of the stream that runs through our property.  However, throughout the entire summer, the wetlands and stream in the stretch shown by these cameras maintained a fairly steady water level.  It’s one of the reasons we’ve spent so much effort trying to restore the site – we feel like we need to take full advantage of the unique resource there.  We’re not sure why the groundwater is so strong in that particular place, but in dry years, the fish, birds, invertebrates, and plants sure appreciate it.  So do we.

Thanks to John Heaston and Tala Awada for technical help with this post.  Any errors are mine, not theirs.  In addition, thanks to Michael Forsberg and Jeff Dale of Moonshell Media for partnering with us on the set-up of the timelapse project(s), and to Steven Speicher for his help and advice.

I Otter Be Happy But I’m Not

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Last month, I got a call from a neighbor who lives next to one of our Platte River Prairies.  I was a little nervous when I picked up the phone because I never know how a neighbor call will go.  Sometimes they’re just calling to shoot the breeze or see how much rain we got.  But other times, they’re calling to let us know that one of “our” hunters shot a deer on the wrong side of a fence or that the cows from our pasture are eating their corn.  This time, it was even worse.  He was calling to tell me he’d just seen a river otter.

I should have been excited to hear about a sighting of one of those cute, playful animals right next to our property, especially because they are considered an at-risk species in Nebraska.  I should have been gratified that our neighbor was excited enough to call me and celebrate it.  Well, I wasn’t.

I don’t have anything against river otters.  In fact, I think they’re great.  But I’ve never seen one in the wild in Nebraska, let alone on one of our properties.  Not one.  Not that I care, of course.

This restored wetland hosts numerous otters, as testified to by scat, tracks, and occasional dead fish. See any otters in this picture? Me neither.

This restored wetland hosts numerous otters, as testified to by scat, tracks, and occasional dead fish. See any otters in this picture? Me neither.  The Nature Conservancy’s Platte River Prairies, Nebraska.

My failure to see an otter comes despite the fact that we own and manage a wetland that has some of the highest otter use in Nebraska.  Several years ago, we even housed a research technician on our property who was trapping and implanting radio transmitters in otters.  The researchers chose our site because of all the otter scat and tracks they found there.  I’ve seen the scat.  I’ve seen the tracks.  I’ve even seen piles of dead fish scattered around holes in the ice where otters have been fishing during the winter.  What I haven’t seen?  One single stupid otter.

This fuzzy little jumping spider is very cute, and I photographed it at the wetland where the otters often hang out. But it's not an otter.

This fuzzy little jumping spider was very cute, and I photographed it at the wetland where the otters often hang out. But it’s not an otter.

I spend a lot of time on our properties.  I mean a lot.  And the stream/wetland habitat where the otters hang out is also one of my favorite places to hang out.  We should be buddies!  The otters and I should be waving at each other every day on the way to work, exchanging pleasantries like good neighbors and friends do.  Instead, they’re avoiding me like the plague.

This tiny soft-shelled turtle is very cute, and also lives at the otter wetland. However, it is not an otter either.

This tiny soft-shelled turtle is very cute, and lives at the wetland with the otters. It is, however, not an otter.

Quite a few of the technicians that have worked for me over the years have seen otters.  Even some of our volunteers have seen otters.  Now the neighbor right next door has seen one too.  The researcher tracked the otters up and down the river, and located their signal on our wetland countless times.  He even showed me video clips of entire otter families tripping along the bank of the river and playing cute otter games in the water.  I went out with him to check his traps, figuring it’d be a good way to see an otter.  When I went out, he caught beavers, raccoons, and a skunk.  Not that it’s a big deal either way.

Kent Fricke caught lots of otters and implanted radio transmitters in them. When I went out with him to check traps, he just caught other animals like this big beaver.

Kent Fricke caught lots of otters and implanted radio transmitters in them. When I went out with him to check traps, all he caught was other animals like this big beaver.

I get to see other animals on our properties, and they don’t seem to mind me watching them.  Notwithstanding my rocky relationship with prairie dogs (see my earlier post and a follow up to it), I’ve had pretty good luck with most kinds of creatures, including fairly reclusive ones such as Franklin’s ground squirrels, smooth green snakes, woodcock, and whooping cranes.  Often, animals even pose pretty nicely for me while I photograph them.  SO WHY DON’T OTTERS LIKE ME?

Maybe I’m trying too hard.  Maybe if I stay away from their favorite wetland for a while, they’ll stop hiding from me every time I show up (the little dirtbags).  Maybe I’ll spend more time with other animals for a while – animals that are just as cute as otters, but that have more generous dispositions.  Maybe if I do all those things, I’ll eventually get to see a real life otter on one of our properties.  Someday.

Not that I care.