Lessons from a Yellow Tub

Last Friday night, I went to our family prairie for a last check of fence and water before cattle came in on Saturday. Shortly after the sun dropped below the horizon, I was preparing to head back home when I noticed an old yellow mineral tub that had been sitting upside down at the bottom of a small draw. I’d seen it many times before but had left it there, thinking maybe our lessee (owner of the cattle) would salvage it. This time, I figured I’d waited long enough and just picked it up. That’s when I realized how long it must have been sitting there.

The yellow tub and the results of the accidental experiment it created. For scale, the tub is 16 inches deep.

When I lifted the plastic tub and saw the mass of yellow-green grass beneath it, a rapid fire series of thoughts passed through my brain. As I processed all those thoughts, I realized there were a number of interesting ecological observations and conclusions that could be made from the situation. In other words, that empty livestock mineral feeding tub, emptied, blown by the wind, and then abandoned, had accidentally become an educational tool. Here are some of the lessons that I believe we can draw from the yellow tub of the prairie.

Let’s start with a little context. We’re managing our prairie with the ‘Open Gate Rotational Grazing System’ I described in a post a couple years ago. The prairie is split into four main pastures and a couple smaller units. Last year, the pasture containing the yellow tub was grazed intensively for most of the season, resulting in most plants being repeatedly cropped short. This year, it will rest all season, as well as most of next year.

Also, the tub landed in the former location of a big tree the cows used to cluster around for shade until I recently cut it down. That shade and consistent disturbance pushed the plant community toward brome/bluegrass dominance. As a result, most of the yellow-green grasses appear to be Kentucky bluegrass, with a little smooth brome mixed in.

A first observation is that the bluegrass and brome under the tub must have gotten an early start on the season because the tub acted as a kind of hot house this spring, providing much warmer temperatures inside the tub than out. That allowed those grasses to start growing well before most of their neighbors. Apparently, the tub was translucent enough to allow those plants to photosynthesize too, though based on the color of the grasses, they wouldn’t have minded a little more light (more on that below).

However, the disparity in height between the grasses inside and outside the tub seems too great to be explained only by warmer temperatures this spring. Instead, I believe two other factors influenced the height of those in-tub grasses. First, that tub was probably sitting there long enough to protect those grasses from last year’s grazing. The grasses outside the tub have barely managed to grown a few inches tall this spring. Those inside were touching the top (bottom?) of the tub, which is about 16 inches deep. That’s really tall for Kentucky bluegrass, even with an early start.

The impact of grazing on the grasses around the outside of the tub can be seen by looking at the other three pastures across the prairie. For example, in the pasture that didn’t get grazed at all last year, the brome is about 10 inches tall right now. Bluegrass is a little shorter, averaging around 6-8 inches. That’s way taller than the grasses in the ‘tub pasture’, which are showing stress from being repeatedly grazed last year. That grazing affected the size of their root mass and energy reserves, from which it will take them a full year or more to recover. Inside the tub, the grasses were unaffected by that grazing (just low light), so they had more energy for growth this year.

The second reason the grasses inside the tub were so small is due to a term I learned from my wife over the weekend: etiolation. Those of you who follow me on Instagram might have just caught that ‘etiolation’ is the second term I’ve learned from Kim in the last week or so. The other was ‘guttation’, which is when water droplets come out of plant leaves overnight because of a build-up of water pressure as roots continue acquiring water while transpiration has shut down.

Early morning droplets on a spiderwort leaf last week. I remarked to Kim that the drops were on spiderwort plants, but not on the other plants in the garden. That’s when she taught me about etiolation.

I digress. Etiolation, it turns out, is the name for the phenomenon that occurs when plants grow under insufficient light. Those plants are a pale color (sometimes nearly white under extreme circumstances) and tend to grow extra long and skinny in an apparent desperate attempt to reach better light. You’ve probably seen this before – I have an example in our basement right now where a bindweed plant is trying to grow from between the bricks. Anyway, I think the combination of etiolation, early warm temperatures, and grazing exclosure were probably responsible for the crazy difference in height between the grasses inside and outside of the yellow tub.

The bindweed growing in our basement. We already have enough of it to deal with in the garden – we don’t really need more. And yet, I can’t bring myself to yank it out either… It’s trying SO HARD!

Now, to really figure this out, I could get 6 or 8 identical yellow tubs and scatter them around the prairie for replication. I could put half of the tubs in areas of recent grazing and the other half where plants are recovered from grazing. If I let them sit between now and next May and then measure grass heights I should have enough statistical power to determine the relative contributions of the ‘hothouse effect’, etiolation, and grazing exclusion toward what I saw under the tub this year.

(Don’t hold your breath. I think I’ll stick with my current observations and educated guesses on this one.)

Look at how much that abandoned tub taught us! Isn’t it a good thing I waited so long to pick it up? Maybe that’s the real lesson here. I wonder what educational value I can find from the clutter in my garage. Most of that has been around much longer than the tub…

Photos of the Week – April 30, 2020

This week, one of my favorite organizations turned 40 years old. Prairie Plains Resource Institute came to being through the vision of Bill and Jan Whitney. The two of them, along with a group of friends, had a big vision and the courage and persistence to make it a reality. The result is a terrific non-profit conservation organization that is focused on protecting local prairies, conservation education, and prairie restoration.

Gjerloff Prairie (formerly known as Griffith Prairie) after a prescribed fire. Gjerloff is a great example of a diverse and beautiful mixed-grass loess soil prairie. Even more importantly, it’s a very short drive from my house!

Most of the high quality prairie restoration work happening in Nebraska can be traced back to the pioneering work of Bill Whitney. That absolutely includes the restoration work I’ve done. One of the most fortunate aspects of my career is that I got to spend a lot of time learning from Bill during my first several years as a professional. Several years ago, Prairie Plains passed the 10,000 acre mark for their restoration program. That’s not too bad for an effort that started with a coffee can full of seed and a dream.

The conservation education work done by Prairie Plains has also been very influential around the state, but has especially been valuable for the hundreds of local kids (including mine) who have gone through the SOAR summer program, as well as many others. Jan, Bill, and a large group of staff and dedicated volunteers have set a very high standard that others tried to emulate. All the kids that have interacted with Prairie Plains have come away with not just a better understanding of nature, but a better understanding and connection to the history and culture of the landscape they are growing up in.

Perhaps most important, however, are the local community prairie preserves established and managed by Prairie Plains Resource Institute. Especially in east-central Nebraska, there are high quality prairies that exist today only because Prairie Plains stepped in to save them. Even better, they make those prairies available to those of us who live nearby. This part of the state is heavily dominated by row crop agriculture. It’s a productive use of the land, but it’s also important to retain the remnants of prairie we still have, both for the ecological value of those sites and for our own recreation, connection to place, and emotional health. I’m beyond grateful to have the good fortune of living very near several Prairie Plains prairies.

In that vein, today’s post highlights some of my favorite photos that have come from prairies owned and managed by Prairie Plains Resource Institute. I have many thousands of images taken from those sites, including all the images from my recent Square Meter Photography Project, which was located at Lincoln Creek Prairie, right here in Aurora. I hope you enjoy this small selection of what Prairie Plains Resource Institute has helped conserve. If you’re not aware of the organization, please check out their new website to learn more. Bill and Jan recently retired from the organization, but their new director and the incredible staff are continuing to sustain the very important mission and activities of the organization.

Grasshopper on milkweed in autumn. Lincoln Creek Prairie.
Fringed puccoon at Gjerloff Prairie.
Digger bee in the morning. Lincoln Creek Prairie.
Prairie dandelion seeds. Gjerloff Prairie.
Variegated meadowhawk dragonfly. Gjerloff Prairie.
Chinese praying mantis eating a tachnid fly. Lincoln Creek Prairie.
Goatsbeard seed and hoary vervain. Lincoln Creek Prairie.
Bee fly. Lincoln Creek Prairie.
Blue sage bee. Lincoln Creek Prairie.
Dragonfly and sunrise. Lincoln Creek Prairie.
Big bluestem flowers. Lincoln Creek Prairie.
Inchworm. Lincoln Creek Prairie.
Carolina anemone. Gjerloff Prairie.
Hover fly. Lincoln Creek Prairie.
Indiangrass and sunrise. Lincoln Creek Prairie.
Hover fly and New England aster. Lincoln Creek Prairie.