Watching Wetland Water Levels – Timelapse Photography

It’s timelapse photography time again…  I downloaded more photos from the cameras at our restored wetland in the Platte River Prairies a couple weeks ago, and have been looking through the images for stories.  One theme that stood out in this batch was the variability of the water level in the wetland through time.

This wetland is directly connected to the water table, but is also supplied by a groundwater-fed stream that brings both rainwater and groundwater from about 25 miles west of us.  Platte River flows and irrigation pumping both influence the water table here in the Platte Valley, as does evapotranspiration by plants – and other factors.  It’s a complicated series of events and processes.  However, in general, we expect the water table to be relatively high in the spring and to decline as summer progresses.  I looked at photos from early June and early July (below) and that pattern of summer decline is apparent this year.

June 8, 2014

June 8, 2014.  A panoramic image created by merging photos from two adjacent timelapse cameras.

July 8, 2014

July 8, 2014.  You can click on each photo to see a larger/sharper version of it.

Seeing the pattern of water level rise and fall through weeks and months is interesting, and timelapse photography allows us to watch that pattern pretty easily.  However, it’s also interesting to look at shorter-duration patterns.  I shared one example of that back in December, with a series of images showing daily water level drops due to evapotranspiration.  Today, I’m sharing a second example of short-term water level changes – this time, it’s due to water coming downstream after a rain event.

In the early morning of June 21, 2014, a big storm system moved through our area, dumping between 2 and 4 inches of rain.  The map below shows the precipitation amounts from that storm.

This photo from http://water.weather.gov/precip/ shows rain amounts for our area on June 21.  The black arrow indicates the location of our wetland.

This image from the National Weather Service (http://water.weather.gov/precip/) shows rain amounts for our area on June 21. The black arrow indicates the location of our wetland.

Rainwater from the storm swelled the stream that flows into our wetland, but also created runoff flow throughout the watershed.  The Youtube video below shows the water level changes in our wetland through the day on June 21, 2014, starting at 7am and ending at 8pm.  The changing light conditions from image to image make it a little difficult to see, so you may have watch it several times to get the full effect.  The foreground, the green peninsula on the left, and the little island just left of center are all good landmarks to help see the water level change.

There’s nothing earth-shattering about stream or wetland water levels rising and falling after a big rain event.  On the other hand, it’s not often we get the opportunity to actually see it happen.  Timelapse photography gives us the opportunity to compress time and see natural processes from a different perspective.  For me, at least, that opportunity helps me better understand and appreciate the variability of the earth we live on.

As always, thanks to Moonshell Media for their help with this timelapse photography project.  If you’re interested in exploring timelapse photography for conservation purposes, you can contact them at 402 817 4313 or info@moonshellmedia.com.

The Density of Ants in Prairies

About five years ago there was a major rainstorm in early May that dropped 12 inches on our Platte River Prairies within 24 hours, and flooded most of our sites for several days.  I wasn’t too worried about most of the prairies (they’re floodplain prairies, after all, and should be used to flooding) but I was concerned about the influx of purple loosestrife from the out-of-bank river and about the fate of a few young prairie restoration seedings. A the same time, I was hoping the big rain would help end the drought we’d been in for more than five years (it didn’t).

As the prairies dried out, I started checking them to see how things looked. I was walking through a 5-year –old prairie seeding looking at the prairie plants, which were looking very good, when I suddenly noticed the ant hills. Everywhere I looked, there were ant hills. I couldn’t take a step without trampling one. I had a quick illogical thought that we’d been invaded by fire ants. Once my brain kicked back into gear, I realized that I was likely seeing the simultaneous rebuilding/repair of all the ant tunnels that had been in place prior to the big rain.

Ant hills in a 5-year-old prairie seeding about 2 weeks after flooding.

Ants are extremely important to prairies as predators and earth movers (and fill other roles as well) and I knew that they were really abundant, but until I saw the density of hills after that flood I didn’t really have a good idea HOW abundant they could be. After all, the hills are the tip of the iceberg, and only indicate the presence of numerous and extensive tunnels beneath the surface.  Before writing this post, I contacted James Trager (Missouri Botanical Garden) to see what he could tell me about the phenomenon I’d observed.

James said he thought most the hills were probably made by Lasius neoniger, the “cornfield ant”, which is a very abundant species common to prairies with sandy soil. He also said ants can survive floods by finding refuge in air pockets within their underground nests. That’s something I hadn’t thought about either – all the invertebrates living belowground have to be able to survive saturated soils, especially in floodplain prairies.

I thought about using these photos and story as the basis for a larger post on prairie ants, but decided that it would be redundant.  James has already written an excellent and succinct synthesis of the fascinating world of prairie ants.  Rather than trying to steal his ideas and re-write them, I’ll simply give you the link to his.  If you haven’t read his introduction to prairie ants, it’s well worth the few minutes it’ll take you to read it.

A wider view of the same site. This density of ant hills appeared to exist across the entire 80 acre prairie.

It’s an amazing world, isn’t it?