Blog Author : Kirsten Triller

  • Repetition, Repetition

    Graduated cylinders, field notebook, and buckets set up against a tree pot
    "Let's Do This." Let's collect leachates from 72 trees.

    Repetition is an action of many diverse functions, highly dependent on person and context for its specific purpose. I remember my high school choir director teaching us repetition’s function for the musical, lyrical context: he would ask, “Why is something repeated?” Then, with a little more assertion and gusto, “WHY is something repeated?” Then, face reddened and voice projected with the strength of lower abdominal muscles refined after 30+ years of proper singing, “WHY IS SOMETHING REPEATED?” After a pause, he’d answer his own question: “To give EMPHASIS.” Of course.


    Yes, in the context of musical dynamics, poetic description, public speaking or rhetoric of other sorts, repetition does very well in bring an idea to light, giving it added attention and consideration.


    But science doesn’t use repetition for this purpose. As with music, poetry, or rhetoric, repetition does play an essential role in the success of the study, but in science, repetition’s necessity is not based on its ability to add emphasis to an experiment, but, quite practically, to help ensure the experiment’s reliability.


    When I refer to repetition in my project, this is what I mean:


    • 4 soil amendments: biochar, biosolids, biochar + biosolids, and none

    • 3 soil types: lots of sand, lots of silt, and a mix between the two

    • 2 soil coverings: turf grass and woodchip mulch

    • 4 X 3 X 2 = 24 varieties

    • 24 varieties X 3 repetitions = 72 potted trees

    • Therefore, each task is repeated 72 times...


    To measure the effect on nutrient leaching from a variety of soils, I get to spend some quality time with a plot of 72 trees. Seventy-two. Consequently, when I do any task regarding my trees, no matter the complexity of the task, I repeat it seventy-two times. To any office or factory worker, this number may seem insignificant, but I expect that for many others, like myself, it is not often that we repeat a task seventy-two times in daily living. I put two shoes each morning, fill up one car with gas, and wash three sets of dishes at the end of the day. Given my current lifestyle, I simply did not know what to expect out of 72.


    I’m often at fault of overestimating my efficiency, but, like I mentioned in my last post, I am here to learn! Let me tell you what I’ve realized so far in completing tasks 72 times over:



    Expectation: 1 hour?

    Actual: approx. 2.5 hours

    Hose spraying a pot with a small tree planted in it.
    115 seconds X 72 trees = 138 minutes


    Measuring soil respiration (aka carbon dioxide levels coming out of the ground---a measurement of microbe activity).

    Expectation: 4 hours?

    Actual: approx. 6 hours

    LI-COR soil respiration machine in place in one tree pot
    5 minutes X 72 trees = 360 minutes


    Collecting and measuring leachate (water drainage from each pot).

    Expectation: 2 hours?

    Actual: 3 hours with a helper; 4 hours by myself. (Yay volunteers!)

    Birds-eye view of two graduated cylinders and a bucket of water vials
    3 minutes X 72 trees = 216 minutes


    Filtering all leachates.

    Expectation: 2 hours?

    Actual: approx. 3.5 hours


    A long line of filtering contraptions arranged on a lab table
    3 minutes X 72 trees = 216 minutes


    Separating out 10 mL of each leachate for phosphate analysis (i.e. aliquoting).

    Expectation: 1 hour?

    Actual: approx. 2.5 hours

    Birds-eye view of a 100 uL micropipette, held by a gloved hand
    2 minutes X 72 trees = 144 minutes


    In short, my expectations have usually been a bit too idealistic for the number of samples I’m working with, and things generally take much longer when repeating them 72 times over.


    So why 72? Why the repetition? Why the extended time and “tedium”?


    Imagine conducting a door-to-door neighborhood survey.  You want to know if your neighbors are happy with where they live! Do they feel safe? Respected? Known? Is it a good place to raise kids? Have pets? Host block parties? You don’t have time to stop by all 500 homes (it’s a big neighborhood!), but you don’t want biased or skewed answers. You’re going for a true representation of the overall perception here, so you decide to choose the homes randomly that you’ll pay your visits to. Great start! But how many homes should you stop by? Three? Six? Fifty? If you stop by only three or six, what happens if you randomly select cranky Mr. McGregor, the neighborhood Scrooge? (In all fairness, he has had a very difficult life, but he does tend towards extreme, abrasive negativity now-a-days.) On a satisfaction scale of 1 to 5 (5 being “extremely satisfied”), he chooses “1” all the way down the list without much consideration. Even if the other two or five responses are generally positive, the total response will still be tugged towards the negative end. Are these responses fairly representative of the entire neighborhood? Maybe, but we can’t be sure. We need a quite a bit more input in order to balance out Mr. McGregor’s unusual pessimism. Let’s say 50 homes will do! (Unless, of course, you want to make Mr. McGregor some cookies before you interview him, which may normalize the results and bring smiles all around.)


    So we conclude that 50 homes is best---or, to bring the analogy back around, 72 pots of trees. The numerous trees balance out, in this case, the few trees that have nature either unusually for or against them. (Cookies won’t help in this situation, unfortunately.)

    I want to know if my trees are happy with where they live. Are their soils allowing them enough nutrients? Enough water? Do they have an excess of nutrients so that the chemicals go to waste, drain out through the soil, and harm surrounding water quality? To discover reliable trends between a tree and its soil, I need to investigate many repeats, and take that extra time to do so. For the sake of having meaningful results about happy trees with resultant clean water, I am learning to not mind, and maybe even enjoy, repetition. :)

    Kirsten smiling while holding a ruler next to new twig growth
    Smiling still comes easy after measuring 720 twig growths. (10 twigs per tree!)


  • Three Lessons Over Three Weeks

    A long row of medium-sized trees planted in pots, raised on cinder blocks with a milk jug connected at the bottom
    My beloved plot of 72 elm trees

    Dear readers,


    My name is Kirsten Marion Triller, and this is my fourth week as an Undergraduate Research Fellow with Bryant Scharenbroch as my mentor. (I started two weeks earlier than the other three fellows since I have to be back up at school on August 8th!) The past three weeks have been a whirlwind, but I’ll get to that shortly...


    To start, let me give you a brief overview of the world-viewpoint from which I stand. :) I am a biology major at a small liberal arts school in the Twin Cities, MN, the University of Northwestern--St. Paul. Next year I will finish off my bachelor’s degree, along with an Environmental Science minor, a Science & Theology minor, and a Bible minor. Afterwards, I would love to continue on to graduate school, and I am considering the possibility of environmental consulting as a long-term career. I guess we shall see! Science, to me, is an exciting way to get to know my Creator more deeply and understand how He’s ordered this world, and I’m happy to pursue any career with an ecological focus.


    My family lives just over the border in Wisconsin, and we also have many ties to Chicagoland, so this summer at the Arboretum was like coming home for me! I’m a midwest girl through and through, and I don’t think I would last too long in a place without trees. I love to enjoy life and its many blessings: people, music (my family has a deep love of musicals), and yes, nature. I am so happy to spend my summer in an expansive tree garden with 16 miles of “hiking”, 9 miles of biking, and beautiful scenes like this:


    Landscape picture overlooking a hill with many trees
    Frost Hill is a great lookout spot! And an excellent place for thinking...


    Young lady smiling in a prairie
    I want to be able to identify more plants in this prairie by the end of summer!

    Landscape picture with hill, lake, and purple crabapple trees
    I pulled off to the side of the road to snap this one :)



    I view creation as a giant puzzle, and I get a thrill discovering how the pieces fit together! I believe that we’ve, as humans, been given minds inclined to question, explore, and understand, and it gives me great joy to exercise that gift here.


    I haven’t been in a full-time research position before; the most experience I’ve had was a semester of studying nestboxes and their winter inhabitants (doing DNA extraction to identify the species leaving behind their feathers, hairs, etc.)---a job requiring only 4-5 hours a week. But I’ve taken my general biology, plant science, and natural resource management courses, and I’ve had a summer of practice in fieldwork (working in natural restoration sites as an Ecological Restoration Intern in Glenview, IL), and I’ve been long looking forward to an opportunity where I get to devote a good amount of attention towards research.


    These past three weeks have already taught me much.


    Firstly, the amount of effort it takes to scientifically learn anything astounds me. My research goal for the summer seemed simple enough (at least the premise): study how different soil amendments influence nutrient leaching (i.e. the drainaway from soils that can seep into other water systems, leading to possible water quality issues and health concerns). My hypothesis was pretty short, so I was curious if each day would actually fill up with tasks to do for my research, or if I’d end up with an abundance of time to lend my hand to another’s project.


    However, the days fill up astonishingly quickly, and it didn’t take me long to realize that.


    To simply determine if and how biosolids (an organic mulch, “soil amendement #1”) have contributed to greater nutrient leaching than biochar (another organic mulch, “soil amendment #2”), an approximate 400 hours (8 hours x 5 days x 10 weeks) will be devoted to my plot of 72 potted elm trees (see below), first familiarizing myself with the wealth of knowledge that already exists in scientific literature on the matter, then jumping into data collection and data analysis for: collecting leachate (the leached-out water sample containing various concentrations of nutrients; a 2-3 hour job with two people); filtering the leachate (I expect about 4 hours for a complete set of samples); other preparations for nutrient analysis (2-3 hours); and actually doing the analysis (a 2 day job at least). All this, each time after it rains. When it’s not raining, I’ll be measuring a whole slew of other factors, from tree growth, to leaf area, to soil respiration, to chlorophyll abundance, to spending hours problem solving---trying to minimize leaking from the tree pots, except into their water collecting jugs. (I’ve been told that most of research is time spent trying to figure out what went wrong, and how to fix it!)


    A soil respiration machine is positioned at one tree in a line of 45
    Testing soil respiration rates at one of our 72 trees


    Needless to say, my summer days are definitely spoken for. But, though it seems that research is a slow, meticulous process, I love it! And I have such a greater appreciation for the scientific community, where we can all share the few results from our singularly small projects, and together, collectively, learn something big. I feel already a part of this worldwide, time-transcendent team, and I’ve still yet to finish my bachelor’s degree. :)


    And, goodness, have I been learning the value of teamwork in this research endeavor. Even in the early steps of my project, the reality of the complications with research has struck. Tree pots leak where they shouldn’t, and it takes an abundance of work and wisdom to make them functional again--much more work and wisdom than I can muster by myself. I am so grateful for a team of coworkers, smarter than I, who are so willing to offer help and advice for a project not their own! I am so grateful for a team of volunteers who will come out into the blistering sun with me to find the leaks and fix up the pots! Take a look at the “MacGyver-esque” do-hingy we made from a 10 mL pipette tip to flush out any clogs from the pots’ tubing:


    Young lady holding a hose with an attachment
    Our state of the art tube-blaster!

    ...Additionally, I would like to give a quick shout-out to unofficial teams, particularly the one formed among us research fellows last Tuesday night when I locked my key in my car! This was the second time I’ve been a part of a “MacGyver-esque” team last week, and yes, I do know who MacGyver is. My parents taught me well. We nearly opened up my car door with a shoelace and hanger, until after an hour of patient, hopeful endurance, we succumbed to defeat, called the police, and a lovely policewoman opened up my trunk for us to climb through. Yay team!


    Four young ladies standing outside of a locked car
    We're locked out of my car, but still having fun :)

    I’ve also been learning that teamwork isn’t the only value that people can provide, but simple company refreshes the soul. In my being here two weeks prior to the official start of the program, I lived by myself in an onsite house. In short, I believe I would have gone crazy if I had to spend another week in this solitude. Yes, you may attribute this attitude to my being a college student and accustomed to tight living quarters and being surrounded constantly, on all sides, by a variety of people... but I truly think it better to have a roommate than to live alone. At least for me. While I was fine on my own---I ate well and slept well, going to bed and arising earlier than I ever had before (5:30 am doesn’t easily happen during the school year...)---once the other fellows arrived, my excitement and motivation for my project immediately augmented, like an old battery jump-started. Although I wasn’t able to continue with my short-lived “early to bed, early to rise” habit, in just this past week, these other three research fellows have reenergized me, giving me a new eagerness to learn, discuss, and grow. “As iron sharpens iron, so one person sharpens another.” I’ll take the “sharpening” over an early sleep schedule.


    So there you have it, three life lessons learned in three weeks! I expect many more lessons to come, and much more growth in these areas as well---learning eager endurance for extensive research projects, a gratitude and participation in teamwork of all shapes and sizes, and a simple enjoyment and appreciation of company. No, this summer at the Arboretum will not be an easy walk in the woods, but that’s good! A bit of pressure produces precious stones, and I am here to learn.