Joel and Lindsay love plants. You can tell by the way they delicately pull back the leaves and carefully stroke the stems when they are trying to identify one, or by the way they excitedly hold up an unusual plant that they find, telling you what it is as though it were a treasure of infinite worth. Of all the interns working at Cedar Creek Natural History Area, they are the two best and most enthusiastic botanists, which is why they were chosen to work on two experiments that had been untouched for a while.

These experiments were started all the way back in the early ‘90s by the University of Minnesota’s Dr. David Tilman. Out in the field of an oak savanna, which naturally contains some of the greatest diversity of plant species at Cedar Creek, he planted the seeds of various numbers of plant species for the first experiment. For the second he planted various species of seedlings not already growing in the area. Then he stepped back to wait and watch what would happen. Essentially, he wanted to see whether the plots were saturated with species or whether even more new species could grow there if only you added them.

Both experiments had been checked up on at least once since their beginnings, but now the time had come to sample them both once again.
When the public learns about science experiments they generally hear about the results. “Data collection” on the other hand is an illusive process, surrounded by an aura of mystery, and different for every experiment. So, I was very excited to be allowed to tag along with Joel and Lindsay, to see the preparation and procedure that would go into this step of the scientific process.

I listened as Dr. Tilman met with the two young botanists and gave them the rundown of what he needed from them. He explained how he had set up the experiments and why. The answer would help researchers to know whether or not the plants growing in the plots were using up all the resources available. What Lindsay and Joel needed to do was record the names of all of the species they could find growing in each plot, how many individuals there were of each species, and what percent of the plot each species covered. How exactly they wanted to do this was their decision, but their methods had to be well documented and practical so that in the future others could follow the exact same procedure.

Before he let them go, Dr. Tilman reminded Lindsay and Joel not to record anything because they thought it was the result Dr. Tilman wanted, but only to record what they actually observed. “I’m just really interested in finding out what has happened out there,” he told them. The speech was a little cheesy, and probably superfluous, and everyone knew it. But, it focused on a concept that is at the heart of scientific research and reminded us all of how surprisingly easy it is to let your preconceptions unconsciously bias what you see.
Now it was time for Joel and Lindsay to lay out their plans, and I quickly discovered that even a straightforward task requires significant thinking ahead and good judgment calls.

Lindsay and Joel’s very first decision was easy enough: they chose to begin with the smaller of the two experiments (the seedling one) because it had fewer plots to get through and would prepare them for the other, larger experiment. However, these plots were a sprawling 4X4 meters - a lot of area to cover all at once when scouring for plants. So, they also decided to divide each plot into four smaller plots. This meant they needed a 2X2 meter frame to bring out to the plots, otherwise it would be pretty hard to judge where exactly they were supposed to be counting species at a given time.

We took a trip out to the dusty, attic-smelling tool shed. After poking around there and in the damp woods behind we managed to turn up four 2 meter long pieces of PVC piping. But try as we might, we couldn’t find any plastic corners with which to put the pipes together. A trip to the hardware store was in order.

The hardware store produced not only plastic corners, but also some blindingly bright fluorescent pink string, and an excellent new plan. We would pound stakes in at the corners of the plots and at the halfway mark along each side and then wrap the string around the stakes, dividing the plot into the desired smaller size and removing the burden of carrying a huge plastic frame. This change may not seem like a big deal, but Lindsay and Joel were excited by how much easier it would make things and a little proud of themselves for thinking outside the box…or outside the plastic frame, rather.

The field where the experiments were begun	The pink string worked wonders for dividing plots.

The next big innovation was the move to divide the percents of area that the plants covered into ranges and to give the ranges letters. So, a plant that covered less than 1% of a plot would receive an A, 1-5% a B, and so on. We also made cardboard squares that were 1, 5, and 10% of 2 square meters, to help with visualization. This turned out to be embarrassingly difficult, since it had been a while since any of the three of us had used much arithmetic. But after some hand waving, flustered looks, erasing and rewriting we managed to calculate the correct numbers and make the squares.

Now Lindsay went and found lists of the plant species growing in the area where the experiments were. Though some people might say it could bias the results to have a list of species - since this might prompt you to look more specifically for those - we figured that it would probably be more helpful than detrimental as long as Joel and Lindsay kept in mind that they would most certainly have to tack on extra species as they found them. With lists in hand, the two with a botanical inclination got to have the fun of reviewing plant species they weren’t already familiar with – looking in books, at pressed samples, and out in the field – while I was relegated to making a spreadsheet.

I had just finished coaxing the computer to produce a very nice chart with species names (including a bunch of blank spaces for extras), a column for percent cover, and a column for number of individuals, when Joel and Lindsay burst in with a long list of extra species they had already found that they thought should be added. They had also come up with a plan for dealing with gopher mounds.

There are a lot of gophers at Cedar Creek, and as they construct networks of tunnels they often kick up piles of dirt right in the middle of experiments. This freshly exposed soil creates a different environment from the undisturbed earth and may make a difference in whether or not new plants can grow in a plot, so their presence had to be noted. Joel and Lindsay decided that if a plot had a gopher mound, they would record what percent of the plot the mound took up, what plant species were growing on the mound, and the number of individuals of each species. New boxes went up on the spreadsheet. We also added spaces for recording how much of each plot was exposed bare ground and how much was covered with litter – dead leaves, stems, and other plant parts – because these too were factors that could possibly affect whether new plants could move into the area.

A fresh gopher mound	An experimental plot, full of many species

We had finished a full day’s work doing nothing but preparing.

However, none of this prepared us for the weather that came the first few days of sampling. My mother has always told me “there’s no such thing as bad weather, only bad clothing,” but to need to wear a sweater, a polar fleece, and a wind-breaker in August, and still to be shivering seems somehow unfair. On the plus side, the chill certainly provided an effective defense against the mosquitoes and deer flies.

Lindsay and Joel hid their heads in their hoods and pulled their arms inside their jackets to keep warm as they looked for plants, stooping and peering into the plots like shorebirds searching for prey. Under their trained eyes what would look to most people like a mass of undifferentiated flora became an array of individuals. They paid assiduous attention to detail, checking and rechecking portions of the plots, squinting closely under leaves and grasses or scanning broadly from above. They worked together on each plot helping to jog one another’s memories and confirming each other’s findings.

Searching through the plants	Lindsay and Joel consult about a plant name

A flagged unknown	As innocuous as it looks, this hole is full of bees!

It kept things interesting, scooting around a bee nest that happened to be smack in the middle of the path around the plot from which Joel and Lindsay were trying to gather data. Somehow we always managed to forget the nest was there, step on it, and then be forced to scurry away covering our heads. Finally the plot was finished, and we moved on, but not without a casualty – at the last moment Lindsay was stung on the hand.
After this we continued without disruption, except for the occasional plot where everyone had to watch out for Rhus radicans individuals – poison ivy, that is. Sometimes they paused to tell plant stories or to warm up in the truck, but otherwise Joel and Lindsay worked with great determination. It took about four days to finish the first experiment, by the end of which the weather was finally beginning to feel like summer again.

As I write Joel and Lindsay are still working on the second experiment, whose ground cover is even thicker and more varied than that of the first. My job as recorder has been taken over by programmed Palm Pilots (I feel only a very little bit devalued), and estimating the percent cover of each species is apparently a bit more complicated. Other than that, however, it is pretty much the same drill as the first experiment: hard work in the face of the elements and every so often something quite unexpected.

Perhaps someday the results from these experiments will be published as a paper in a scientific journal. In the materials and methods section it will most likely say something like “percent cover was visually estimated for each species and the number of individuals in each plot was recorded.” It won’t mention fluorescent string, cardboard squares, or ground bees, but at least some of us will know that they were there.

Consulting a pocket field guide, just to double check a flower name