The mysterious underground
Sharing my experiences researching belowground ecology and pursuing a career in science
My name is Kelsey Patrick. I'm a recent graduate from Aurora University and currently working as a Research Aide in the Root Biology Lab at The Morton Arboretum. All posts and views shared here are my own.
Why study roots?
For the health of our planet and all the life it supports, connecting and learning about the environment is important (and exciting)! Scientists and the public are working harder than ever to strengthen that connection by addressing issues such as climate change, deforestation, loss of biodiversity, and more. Plants, as the backbone of ecosystems, are a common focus of this work, but much of the story involving environmental processes remains an underground mystery.
Roots perform vital ecosystem functions by regulating water and nutrient cycles. The smallest roots in a plant’s root system (known as “fine” roots) control water and nutrient uptake, as well as how much water that plant puts back into the soil and atmosphere. Who knew the rain falling on our heads could be coming from a leaky root? A similar story can be told regarding root influence on ecosystem nutrient cycling. Carbon and nitrogen fluctuations in the soil and atmosphere are largely driven by roots. To uncover how roots grow, interact, and influence the world around us, the Root Biology lab at The Morton Arboretum uses the following tools:
Using this tool, we can see how roots grow and die over time. Plastic tubes are placed in permanent locations within designated forestry plots around the arboretum, allowing us to scan the same area at 4 different depths.
Sap flow meters
This tool uses temperature change to track sap movement up the tree. We can measure when water uptake and flow fluctuates depending on tree species, season, temperature, and precipitation.
Beginning this past spring, we have started taking respiration measurements in some of the forestry plots. The chamber seen in the picture above is placed on a column on top of the soil. This allows us to measure the CO2 emissions of roots, mycorrhizal fungi, and soil microbes, which in turn tells us about the metabolic activity of each of these biological systems.
Did you know that the trunk of a tree expands and contracts everyday? With the help of dendrometers, we can track these daily changes in tree diameter as well as the growth over longer periods of time.
By tracking leaf greenness throughout the season in the forestry plots with cameras, we can see how species differ in leaf emergence timing. The Root Lab has been matching this leaf data with minirhizotron scans for three years now to compare when leaf growth and root growth occurs.
To study the responses of tree roots to waterlogging, my primary project will track root growth, death, tissue stress levels, and photosynthesis rates of four different tree species before and after a 2-week waterlogging period. Find out more about this project below.
Trees in many regions, especially urban settings, experience frequent flooding events. During and after heavy rainfall, the soil can become saturated with water (i.e. waterlogged). This leads to low oxygen levels in the soil. Roots need oxygen to “breathe,” just like us. So you can imagine that these conditions present many problems to trees. Metabolism, growth, water flow, and filtration of toxic compounds are just a few of the main plant functions impacted by waterlogged soils.
Each pot has four clear acetate windows that will allow us to monitor and track root growth.
A serious discussion among scientists! Pictured here: Dr. Luke McCormack, myself, and Isabella Vergara
Using a root-lab invention coined the “rhizo-pot” we will be able to view the root systems of two maple species and two magnolia species through clear windows. In addition to tracing the roots, we will also be taking images, photosynthesis measurements, and running tissue analysis to get an idea of what is going on inside of the tree. How does root response influence tree survival and recovery from flooding events? Do roots have specific strategies to deal with flooding? Uncovering the answers to the above questions is critical to understanding what is going on belowground. In the coming years, flooding events are projected to increase in frequency and magnitude in many regions (Christensen et al. 2007). We can begin to address this issue before we are in too deep!