The ‘not so slow’ days of winter at the KBS LTER

By: Sarah L. Hanks, KBS LTER Outreach Team

Many folks tend to think that winter is a time of rest and recuperation for farmers and agricultural researchers and professionals. The KBS LTER team would suggest that this could not be further from the truth. Just because there is snow falling and the ground is frozen does not mean that there is time to relax. After talking with Stacey VanderWulp, LTER Project Manager, and Kevin Kahmark, LTER Research Assistant, I found out just how busy things are around the KBS LTER during these cold months.

Hundreds of plant samples are collected, by hand and machine, throughout the end of the growing season and these samples must be processed and analyzed. Every plot in the LTER and GLBRC experiments are sampled, everything from corn, soybean, wheat, cover crops, old fields, poplar trees and native prairie plants. Processing these samples keeps technicians constantly busy in the winter season: they weigh, grind, archive and pack the plant material into tins for carbon and nitrogen analysis. This analysis tracks where these nutrients go in the ecosystem. As Stacey explained, “When you harvest a crop, you want to know how much carbon and nitrogen you are removing from the field. With cover crops, what nutrients are going into the soil?”

While many samples have been collected in the fall and are processed in the dormant period there still some samples being collected throughout the winter. Greenhouse gas samples are collected monthly at the LTER and GLBRC sites using the standard chamber method. According to Kevin, this process takes a lot more effort because of the winter conditions. While other LTER sites around the country sample greenhouse gases in the winter, KBS measures more intensely than most because of the automated system that is also used and takes samples every day. Winter in Michigan is also a great time to try and see how new technologies such as the automated system withstand cold weather.

While the trees are dormant, measurements are taken for DBH (diameter breast height) in the deciduous and coniferous forests. Technicians bundle up and spread out in 6 different plots (approximately 1 hectare each) to take these DBH measurements from over 1250 trees. This is a winter task because the trees are not actively growing, it’s easier to get around the trees without the thick understory, and there is limited time for this during the growing season.

Preparing for the upcoming growing season is no small task, either. Kevin spends time with graduate students and postdocs to review and update the last season’s protocols and experimental design to help them plan out experiments. At the same time researchers and faculty members are starting to submit their plans and field request to Stacey. She must start looking at the logistics of assigning fields for these experiments. Innovation and new technologies are developed and tested during the winter as well. Kevin is currently testing how a structural change to the rainout shelters will hold up to the winter conditions. By replacing the PVC piping structure with a sturdier steel frame he will observe if this is a worthwhile improvement to make on all of these shelters.

He is also testing a mobile (QCL) Quantum Cascade Laser. This measures nitrous oxide, methane and water vapor in static chambers. Kevin is planning to use the QCL technology this growing season to compare QCL analytical outcomes with the current methods that are being used to measure greenhouse gases.

There are a number of other important tasks that are carried out in this “off season”: installing weather stations at new experiment sites, quality control and quality assurance on past gas chromatograph analysis (hundreds of thousands of data points), catching up on data entry from the previous growing season and sending sub samples to main campus in East Lansing for additional analysis just to name a few. Stacey and Kevin are just two of the many researchers, technicians and staff members who keep the wheels on this LTER program during the not so slow days of winter.