Suppressed memories may be a good thing

This week heralded the beginning of the harvest of permanent prairie plots to get biomass data. Fortunately your memory of previous harvest seasons and how much work it entails dims, and you get newbie graduate students who know no better. Only 1/4th of a square meter is harvested but it can be a pretty impressive amount of vegetation in a community where the herbaceous vegetation reaches 2.5 meters in height and so dense it impedes your movement through it. While others were snipping TPP was marking out the portions to harvest and after just 1.5 hrs my hands and arms were covered in little scrapes, punctures, and abrasions such is the nature of prairie vegetation this time of year: hard, dry, sharp-ended and sharp-edged, like little hack saws. Unfortunately TPP's high mileage back was sore, so attention turned to sorting the bags of vegetation into piles back in the lab: grasses, forbs, various legumes, any exotic species, and a hemiparasitic plant. This is a really "fun" activity and much harder visually than you might imagine, but not so hard on the body. Harvesting is half done, and the sorting just barely started. Pile on the lower left is silky bush clover (Lespedeza cuneata), an invasive Asian legume. The 2nd image shows a thicket of this legume where it has all but replaced the prairie vegetation (except for the big grasses). It's so thick you have trouble walking through it, and it's essentially impossible to get rid of. Even if you nuked it with herbicide a sizable seed bank remains. Sad.

TALL grass prairie vegetation

One obvious aspect of field research is that you cannot apply treatments or gather data if you cannot find your permanent plots. Now least you think TPP is careless or an amateur, several precautions were taken this spring, and in prior springs, to mark and map the 100 or so meter square plots out there on our research prairie. There is a permanent spike in the SE corner and smaller markers in the other corners, and in the late spring a 30" piece of white pvc pipe is pushed in over the spike.  Then in early summer 4-6' bamboo poles are placed within the pvc pipe with a bit of gaudy flagging on the top in those areas where the prairie vegetation is known to grow the tallest. TPP's September assessment is that tall grass prairie had a very good year; the vegetation is thick and tall, and even the bamboo poles are all but invisible. The tallest vegetation reaches 8-9 feet tall and it's solid up to 5-6 feet tall, so dense that TPP had difficulty even pushing through it. Armed with maps and familiarity and experience, it only took us 5 hours to find most of the plots and remark them so samples could be easily collected next week. It was exhausting work and at times my colleague was totally out of sight even though only a handful of meters away. These plants are all herbaceous perennials so all of that above ground biomass grows annually, and in this case on some very poor, low nutrient soil. Still you would have to experience such vegetation to truly appreciate just how amazing the prairie is this time of year.  And in case you wonder, very few short students have been lost in the course of our research.