Tree Volt
By Gabriel Lee
Intermediate Category (Grades 9-10)
Study | Environment
Tree Volt is an investigation on the correlation between Soil Potential Difference (SPD) and Microbial Life Densities (MLD) near trees, done in effort of creating a harmless yet accessible method of determining and foreseeing a tree’s health. I wanted to do this because of how fascinating trees are to me, they are vital to life in general; from the wood and shelter for microbes they provide, to the oxygen they produce. Many of the modern day methods of determining a tree’s health are visual, which may be ineffective because by the time there is visible deterioration, it is often too late. Another common method is sampling the living tree’s tissue, which can be fatal, since a hole will be left in the tree’s life giving cambium, leaving it prone to fungal and bacterial infections. I wanted to make a method that would not put the tree at risk, nor be dependant on less accessible lab equipment.
After some preliminary research, I developed procedures to gather data on my two variables, SPD, and MLD. I chose these two since I believed that together, they could be a strong indication of a trees health. The SPD test measures ion gradients from the tree. I believed that the more active the tree, the more ions it would absorb and hence the larger electric potential imprint. I measured SPD by using 35m of wiring, conductive probes, alligator clips, and a multi-metre. I collected data by anchoring a probe 10 cm away from the base of the tree and probing once every meter, checking and recording the Voltage in mV, for 30 m radiating away from the tree.
MLD is measured because it is known that trees live in symbiotic relationships with a variety of microbes, since MLD is a variable heavily affected by root activity, I believed that by measuring the densities of microbes around a tree, I could determine how active it was. I did this by sampling soil with a clean probe, since it was a more laborious task, I sampled every other meter, starting at the 1m mark. I brought the samples home to control the amount, dilute in 10 ml of water, mix, and let settle for 5 minutes so the heavy particulates would not be as present during the viewing. I found this next part of the test very interesting and rewarding for it took a while to develop and it allowed me to see moving microbes that would otherwise be challenging to quantify. Then, I took samples of the mix, and placed it under a microscope, took multiple images, put the images into Photoshop and used a really useful tool called the “Difference Layer Mode” which allows me to see the difference between very similar images, this way I could visualize the displacement of microbes between shots. After the image was processed, I took a histogram and used the white pixel count to represent the quantity of active microbes.
By visualizing and analyzing the patterns and correlation of the two variables in the form of graphs, seeing their peaks in activity, where they are, and by how much the peaks are apart. I believe that I can paint a good picture of the future and current well being of a tree. I think that this project can be a bright beginning in a new field of environmental sciences.
