Fire, Ticks, and No Significance: Oh My!
Okay so two weeks ago I went on a little adventure, but instead of going to Puerto Rico or China, I found myself out in the forests. This was my first time venturing out to the forests/prairies, specifically one known as the Conard Environmental Research Area (CERA). My classmates went there a few weeks before to watch some birds in the cold, but luckily sadly I wasn’t able to go because I got pretty sick a few days before. When we arrived at CERA I knew that we were going to go out and count some plants, but I definitely underestimated the experiment. When we first arrived, I found myself a bit overwhelmed as the details of the experiment were explained to us.
“Poison Ivy.
Ticks
Outside.”
Those were the words that got my blood pumping, but before I could really respond my classmates and I shuffled into another room to be trained in plant physiology. Then in less than 20 minutes from arriving, my fellow Grinnellians and I become very error prone botanists. As we walked into the forest to collect data, the further in we got, the more I realized I was not living my best life. Forests and me? Yeah, not a good pair. I just never had a need to walk into a place filled with a lot of dirt, insects, and potential danger.
But I’ll save all of that for another post. Anyways, when my group and I arrived at our assigned plot, we took 16 random samples of 1 meter squared areas and observed how many different plant species were there (Biology Department, 2018). Now let me tell you, trying to tell apart two different blades of grass along with a lot of other similar looking plants (looking at you Ranunculus abortivus and Viola adunca) can be so tiring. Once we finished I was so happy to return to a building that I didn’t even mind doing the data analysis. Each group (18 in total) then determined the richness, diversity, and richness per meter squared of their plots using their sample data.
Pause.
This is just a quick update on what each of those variables meant.
Richness:
The number of different plant species in a plot
Evenness: The abundance of those various plant species in a plot not considering species richness
Diversity: The abundance of all the different plant species in a plot that considers the species richness
Now before I continue, I just want to mention one quick thing. At first you may have thought
“Come on Steffie, why were you so dramatic about going outside?”
But after this you’ll understand. So as I was sitting in my seat, waiting to go back to school, I felt something tickle my neck a bit. Instinctively, I reached up and grabbed whatever was there, thinking it was just a piece of lint. But the next thing I know I see a little black thing with legs between my fingers and before I could even think I screamed and tossed the little bugger away. And what were the repercussions of my amazing survival skills? The whole class staring at me.
Yeah, I was not living my best life yet again.
Despite that one traumatic experience, I trudged onward and began focusing on the important things. The data. The purpose of my trek into the wilderness was to see if controlled burns would actually increase the species richness of the entire plot, richness per meter squared, plot diversity, and plot evenness of the burnt plots. We believed such a difference would occur because in oak forests, such a change was observed in the past and although this experiment focused upon the herbaceous and shrub plant community on the ground we thought a similar trend would be seen (Kruger and Reich, 1997).
But guess what...
No difference was found.
And this was after I ran four two sample t-tests comparing the unburnt plots to the burnt plots. Now let me tell you, there’s nothing sadder than seeing a p-value greater than 0.05 when you’re really hoping that there is a significant difference, especially after using Minitab. Although previous research has found that certain herbaceous plants did manage to grow better after a fire treatment, those plants were not observed in our plots (Hutchinson et. al, 2005). After this massive disappointment I took some time to breathe and began to consider potential reasons why we saw such a lack of effect with the fire and I have come up with three reasons:
The seeds of some plant species at CERA are basically immune to fire. I say this primarily because the plants at CERA may have hardier seeds that allowed them to withstand the annual fire treatments than predicted.
How I imagine some of the seeds may have reacted to the fire.
Iowa’s lovely and absolutely annoying strong winds may have carried some seeds from the unburnt plots over to the burnt plots. Thus reintroducing plants into the burnt plots to increase plot richness, diversity, etc.
The plant species there at CERA are naturally strong competitors. This increased competitive ability in the plants may have made it so that when new plants sprouted in both plots, evenness between the two plots became similar because none of the plants were able to outcompete the rest to create a skew of appearance in the proportions.
The Rock -- a human version of these CERA plants.
So now, you may be thinking
“Steffie, would you do this again?”
Quick answer --
No.
But it has nothing to do the lack of significance found, it honestly has everything to do with the idea of venturing out into the wilderness and potentially encountering a tick again.
#NotMyMood
However, I still would 110% support anyone who would continue on with this research. This is because although no significance may have been found in our data, this may not be the truth for all existing herbaceous and shrub plant communities. Instead I believe that we should persevere and continue on with our research. For future similar experiments at CERA, I suggest that a physical barrier be put up between the burnt and unburnt plots. This may be helpful because it would make it harder for wind to carry the seeds from the unburnt plots to the burnt ones. Maybe then we’d see a significant difference between the two plots.
Who knows?
But hey, if you’re interested in this, comment and I’ll help you plan an experiment in your own community!
Let’s burn some plants!
References Listed Below
