Bugs, land reclamation and soil: the final frontiers
PhD student Stephanie Chute-Ibsen is trying to find a better way to monitor land that has been damaged by industry, and they think soil invertebrates hold the key
By Riley Tjosvold
Some say that space is the final frontier, but for Stephanie Chute-Ibsen (pronouns: they/them), the most mysterious part of the universe is right under our feet.
A PhD student in land reclamation and remediation, Chute-Ibsen has been fascinated by hidden worlds since childhood, when they remember begging their parents for a microscope so they could take a deeper look at the secrets hiding within leaves and soil in their backyard.
Their current research project marries their love of soil with their keen interest in bugs and their desire to see damaged ecosystems returned to good health. Bugs, specifically soil invertebrates such as spiders, beetles, mites, worms and insects, says Chute-Ibsen, play a key role in reclaiming land that has been damaged by extractive industries.
Chute-Ibsen is hunting for the right bugs, ones whose presence in an ecosystem can tell us whether land has been successfully reclaimed after it is mined for resources, damaged by flooding or fires, or degraded by some forms of agriculture.
I talked to Chute-Ibsen about their research, soil invertebrates, and the challenges of doing land reclamation.
Can you tell us about your research?
I’m looking at the way we monitor success in land reclamation. If you’re going to build a pipeline, or mine coal or oil sands in Canada, legally you have to go back in and return that land to some kind of equivalent land capability. How we determine that equivalent land capability has been met is through monitoring, typically of vegetation and soil, and comparing the reclaimed land to an off-site reference. As long as companies are hitting those major soil and vegetation thresholds, the reclamation site is deemed successful, they receive a certificate, and can walk away.
But reports and studies are saying that those indicators may not be telling us what we thought they were telling us. A lot of sites that were certifiably reclaimed, when we’ve gone back, they’ve failed those standards. Right now the way we measure soil doesn’t tell us anything about function, and it doesn’t tell us anything about resiliency. In the wake of climate change, we need to be that much more confident that the reclamation work we’re doing will stand the test of time
The good news is that when we look at what makes a good indicator of ecosystem health, soil invertebrates beat everything else hands down.
Why are soil invertebrates such a good indicator of reclamation success?
The research about what makes a good indicator says that it has to be sensitive, it has to respond to changes quickly, and it has to be present over wide geographical areas. Soil invertebrates are incredibly sensitive to management practices. If you apply a pesticide or fertilizer, they will respond. If the soil is too dry, they will respond, either by dying or leaving the area. They are also found everywhere, whereas birds or other vertebrates are only found in some areas of the province or Canada.
But compared to everything else, what makes soil invertebrates so good is that they produce a ton of offspring, grow quickly, and don’t live long. An oribatid mite, for example, usually lives for one year. If you planted trees, you can come back in five years and they are still little saplings, while in the soil there have been five generations of mites. If there were harsh environmental conditions, we will be able to see them in the abundance of the mites and their community composition.
What role do soil invertebrates play in ecosystems?
They are ecosystem engineers. They are especially important in reclaimed systems, where we struggle with things like soil compaction because of the heavy machinery we use to put the soil back. They break down all the organic matter, they bring all the nutrients in, they help soil retain water, they help with the soil formation by introducing soil pores, the small spaces between soil particles. They’re critical to soil health.
When might we start to see soil invertebrate monitoring become commonplace in land reclamation?
After years of counting and assessing, we’ve narrowed down two soil invertebrates that show the most promise as a land reclamation success indicator: Oribatid mites and Collembolans (springtails). Now I have to make a case for whether they are providing value above and beyond what the soil and vegetation is telling us. Finally, we have to use these results to put together a toolkit for industry partners and ask them if they want to try something new.
Including invertebrates in monitoring will cost more, and it will very likely increase the timelines for companies to get certificates showing the land has been reclaimed. So are companies going to be happy about that? No. But we have a responsibility to be stewards of this land. If it means extending timelines a little more, but it allows us to be more confident in the systems we’re creating, I think that’s important.
How successful have we been at doing land reclamation in Canada so far?
We used to treat our soil like dirt. In agriculture, we would plow until the cows came home. When we started doing land reclamation in the early sixties, reclamation was: if it’s green, it’s good.
Now we’ve changed the way we treat soil; we’ve changed the way it gets salvaged, stored and used in the sites. We have amazing research in Alberta on the use of different amendments like peat mineral mix, manure, sewage sludge and biochar in soil reclamation to help jumpstart soil fertility and the nutrition status of reclaimed sites. We are even finding ways to repurpose materials that were intended for the landfill into soil building materials.
In my opinion, soil is a non-renewable resource. It takes tens of thousands of years to form this beautiful agricultural soil we have here in the western Prairie provinces. Now we’re realizing we need to take its health more seriously. It’s time for us to step it up once again, and monitoring soil invertebrates is one way we can do that. We have to take this next step.